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7.5.8: mobi`trailer

summary

. since 2000 I've been gathering notes for making
some sort of human-powered mobile office
. by 2005 I was set on driving it with the Dahon folding bike
. it wasn't until 2006 that I decided to base the design
on a Harbor Freight Tools` mini.trailer kit
. seen pictured is that trailer connected to the Dahon`folding bike
. the trailer kit comes with suspension springs,
but since my vehicle is going no faster than 20mph,
just having pneumatic tires should provide plenty of cusion .

7.5.8: mobi`trailer

00.5.20: project"mobile

mobile` mission

. project"mobile has the primary goal of not being bound to my current situation by unreadiness;
the idea of mobility was encouraged by the portability of today's computing,
and the chance at a million sq.ft pine-panelled office space
--. this is the same day I made that nutty wooden scooter to help with getting to the bus`stop from employer`s .

00.5.21: layered mobility

. a bike trailer would be unpacked to set up waterworks and a
cot.tent (a cot that has a built-in tent)
that could be taken to shady spots while the trailer was left by the roadside.

5.10.23: hand trucks

$99.00 Appliance Hand Truck" Milwaukee 700 Lb. Capacity Model HDA700

5.12.03: trailer ideas

. consider the lowes trailer $500; you could build quite a structure on that;
and rent parking space to keep it like a storage;
. keep your lockbox, and make it part of the trailer structure
. look for bike | motorbike parts online,
and see if there's a way to convert a ten-speed into something with a much lower gear ratio,
( small dia. back wheel, large back chain ring, small front chain ring ) .

5.12.13:
. checked out the details of the
lowes`s trailer (4x6G item#145557, $498, 2000lb, gross vehicle wt rated, 4:80 x 12 6-ply tires )
. expanded metal mesh floor
-- the mesh you see on the display (like fencing but stamped instead of woven )
. he showed me where they were stored out back,
and said they were in kit form, and that I would have to put the kit together myself,
but they would help me
--. all I expect is that they produce the parts, make themselves available for suggestions,
and let me build the thing in their back parking lot ( where the trailer` bodies are stored );
I need a tire iron, a torque wrench, a socket set,
and some way to bolt the thing onto my bike
. I should do it early in the day
when the roads are dry, and have a map for staying on small roads
. first I need to find some place to park it close to home,
while I finish the construction
. before that, I may want to use it for hauling stuff
to storage, dump, charity, etc .
5.12.19
. nix lowes`trailer -- there are cheaper trailers
. an even better idea -- if it flies with officials --
is to use a pair of dollies alongside a bike

5.12.16:

Utility Trailer with 48in. x 40in. Bed
. Complete road-ready kit with fenders! You add plywood. See below for additional product information.
-- approved lighting, high-speed wheels and tires, and slipper springs.
Sale Price $169.99 + 70 shipping 120.0 lbs
    * Tire: 4.80-8 tubeless, 4 bolt demountable

4-Hole Standard Rim Tire Assembly
Sale Price $21.99,     * Tire Dimensions: 4.80 x 8in.     * Load Range: B     * Capacity: 590 Lbs.     * Tire O.D.: 16.5in.
    * Bolt Hole Pattern: 4 hole on 4in. bolt circle    * Center Opening: 2 1/2in. diameter

5.12.25: www.utilitytrailerkit.com

. consider plans for calling local tractor dealership for trailer service
. I wanted to get a small trailer through www.northerntool.com
but then,
while collecting the info about northerntool to make the contact,
I discovered www.utilitytrailerkit.com,
and have renewed my hope of getting good service through the mail .
7.5.16:
--. if moving around, it helps to get service from on-line,
but I was thinking my need for utility(mini)-trailer service
wasn't met by local business .
5.12.26:
www.utilitytrailerkit.com has no small trailers -- but they might have parts ...

6.3.6: purchase the Harbor Freight` $130 minitrailer

ph: (509) 922- 2495

5.12.15: trike#in-line -- trailer, bike have alligned rear.axles

5.12.14: bike integration:

. as mom was worried how I would get the trailer attached to my bike,
I rediscovered a fleeting idea of setting the hitch`cup on my seat post
-- after removing the seat;
and, looking around for how to keep the hitch on the post,
I noticed that the bike is constructed so that the rope will easily stay in place;
...
however, how will the rope stay on the the hitch`bar?
could use 2 hose fittings to hold down then ends of a handle, and the wind the rope through the handle .

5.12.15: mis"trike design is literally scraping!

. the previous design -- a bike bolted rigidly to trailer -- was fatally weak;
because, it wears out the parts
by not having a pivot point between every pair of axles !
. a friendly critic had asked
"( would it be side-by-side? or tandem? how would it work to bolt them together? )
. it had the front edge of the trailer frame bonded near the rear of the bike frame,
which was dragging the bike`back tire sideways when turning;
the only way my trike would run smoothly is when the bike`s rear wheel axle was the same as the trailer`s axle;
ie, when a cart has 4wheels that are all non-turning, then to turn the cart,
you have to drag the wheels a bit instead of rolling them,
which trashes energy just to stress the spokes and wear out the tires
. the way my trike design could be least wasteful
is to use a bike with small tires, and embed the bike
so that the back tire is nearly touching the axle of the trailer

. the most economical solution was hit apon a few days ago:
remove the bike`seat, and use the seat post as the ball to set the trailer`s coupler on .
...
but that approach is too unstable .

5.12.23: trailer kit plans @ www.re-cycle.org/trailer

. if you have a spare bike, and 2 spare forks (as I do),
then with the addition of angle iron,
you can make a trailer that uses the forks to hold the tires
5.12.24:
. this didn't seem like the strongest design,
but it got me realizing that I have 2 forks,
and I do have an easy way to add stock wheels to a homemade trailer

6.11.6: in-line #long.wheelbase

. a prev'ly mentioned way to reuse a std bike and trailer
is to keep the bike`s rear inline with the trailer`s wheels
. a revision that could keep that idea alive
is to increase the wheelbase by separating the
front and back parts of the bike,
to mount the bike front on the trailer`boom;
and also to think of the trailer`axle as movable:
put that as far back as possible
-- depending of course how much heavy stuff there is,
since you still want to keep the load balanced .

trailer-trike

2006.01.15: trailer-trike good for procumbent hand-pedaling

. I was worried about being able to pedal with a knee injury;
but my co.self/med/[left knee tear]-logger just noticed
that any recumbent trike could easily be refitted
for procumbent hand-pedaling
. now I'm definitely more interested in converting the dahon into a trike front
. notice that, for steering stability,
the fork tube is reclined several degrees,
so that when you ride hands-free, it still goes straight .

6.6.14: trailer-bike connection

. reviewing trailer instr's,
I got an idea that I must have had before,
but I guess that last time I wasn't sure if I'd get
possession of junk bed`s frame;
according to the mgt that just left,
I should leave it in the hall way and see if anyone wants the whole thing;
and strangely they took only the parts I couldn't use;
so now I have these 2 long beams
. the trailer comes with one tongue,
but with these frame girders I can have 2 tongues,
one on either side of the bike
... the first idea was that I can connect it near the pedals
but making it swivel there
makes it more unstable than being a little behind the stationary wheel

. the 2 forks still have to come together at one point that pivots;
but now the design has more options about
how that point connects to the trailer
..
. another option that is available
-- due to the low speed of the trailer within the hpv context --
is nixing the suspension bows, or springs,
and securing the axle directly to the frame,
so that
it would be possible to saw the axle enough to
put the bike`s stationary wheel in line with the trailer wheels,
which would then allow
the solid and more secure design of a trike
instead of a bike pivoting a trailer

. the odd part about this
is that it creates a bit less living space,
because,
although there are low-profile bikes
that could allow the floor to be built over them;
--
. there is still the problem
that either the wheel base is very short,
or the design is complicated by the need for separate bike pieces;
however,
the folding bike already comes that way!

. it could be modular so that the car part
formed a foundation on which the house part would be quick-bolted .

6.10.3: center of trailer mass issues

. while weight behind the trailer wheel increases sway,
. weight that is concentrated around the trailer wheel
will tend to increase the trailer`s rotational forces
when just one trailer wheel is snagged
. this won't matter much when the trailer is hitched to a pair of wheels,
but being hitched to the bike directly
could throw the bike to one side when hitting a pot.hole .

6.10.23: trike# culti

. the plan for a trailer trike is nearly crystalized;
the only missing pieces are details of unclear significance
. tilt up so the seat tube is pointing backwards
(see B&W)
. keep the whole frame of dahon intact,
except remove the detachable folding front
because when attaching the boom it will provide twist-strength
. the boom is the gym`seat`s support beam, .. or the axle?
in any case,
the piece forming the connection between the dahon and trailer
is a hub&axle like the ones on the trailer
. that is exactly the joint that is on the culti
culti with study lines overlayed

6.10.24: mobi#lite/culti simulation:

re:
"(

. tho' the culti`s back wheels stay on the ground during a turn,
both the rider and the front wheel lean into curve;
. in order to simulate that with the bike&dolly,
the rack needs handlebars, and seat needs to pivot for rider`lean .

)
--. that is incorrect;
it's best to think of culti as proof that the trailer.trike would work
. the folding bike`s rear is tilted up,
and a seat bar is bonded to it
. the trailer is then hinged under the seat
just like a trailer hub is hinged to axle;
in fact,
the best seat bar may be a trailer axle!
. the trick to steering then is
(1) as the seat`bar pivots from side to side,
it is both banking and slightly turning
(you increase the turning aspect by
making the bar-wheel connection very high and then
sloping steeper to meet the trailer .
(2) having handlebars connected to the trailer
can provide the way for rider to control the amount of pedalwheel lean .

. the picture of culti shown above (and here)
has been rotated so that the centerlines of the
bike`s rear front hub are on the same horizontal,
which should show you the exact degree of boom recline
assuming the wheels are the same size .
the angle has a
0.28 vert(joint, boom intersects front hub vert)
and 2.8 horz (joint, front hub center),
so the recline is negative (approx 190 degrees)

. culti has the pedals well ahead of the front wheel,
so the seat stand can still fit on the boom
(otherwise they'd have had to make the boom longer
or built long seat post to get from boom to
a seat that is well behind the trailer-cycle joint

staying upright

. is it possible to arrange it so the trailer tends to go straight?
or is it the nature of that steering system
that when lean gives also directional change
then the bike flops to the side unless held up? .
todo:
. is there any word online about suggestions for improving the culti?
...
. to stay upright, the lean should lift the rider`s weight;
one solution is to put the axle on the trailer`boom,
and then bolt the hub onto the upper part of the rider`s back support
. this could be done by modifying the gym
which is like a recliner balanced on a beam;
when fully reclined your head nearly hits a vertical
that is part of a benchpress
. this could be reused by reusing the seat beam as the cycle`boom
and then the hub attaches to the vertical,
while the recliner is scooted back towards the vertical .

. the culti solution is to put a cargo bay under the boom,
so that leaning causes the cargo`s weight to be lifted
and thus countered by gravity .

. instead of varying the amount of cargo in front, vs in back,
you could still use that idea
by making the hub connection variable above or even below the seat

. a nice feature of the culti way is that it stays put when you get out,
and the steering is more lightweight:

. when the culti is steered, the handles are stubs by your side
but since your body is arc'ing during the lean toward the stubs
then it gets easier as you get farther into the lean,
but in my way#1 of steering,
the rider has to find some way to arc upward during a lean
so you either need a complicated chain&gear system,
or you need the handles to be longhorns that rise high
where you can do pullups and crunches to make the turn
. that's just about what people do when driving a car
so it's not too bad, but not as light

6.10.26: gym`pivot

. the gym`base can hook directly to gym`pivot;
so it does provide a long axle with a hole parallel to the axle`length
. the`gym pivot`s forking arm does not have to stay forked:
it can be used cut into the 2 arms, and 2x2 connector
then the 2 arms can be reconnected to that connector in some other way
. although the bike`steering`axle is heavier than the gym`pivot`axle
the bearings are not nearly as strong .

6.10.26: trailer`frame`s nut&bolt arrangement

. another change I made was making the nuts easy to inspect:
they had some being hidden inside the rafters,
though the way I do it,
an inspector would need access to the floor as well as the under side .

6.10.26: trailer`tire installation

. the seal is a little chewed on, but otherwise it goes quick
after now having some experience and a grease gun .

6.10.26: springless-axle design

. inventory the foldingbike, and rack my brains thinking of
how to redesign the trailer without the springs (they weight more than a bike does)
-- and there are two of them!
. I get one design, only to change my mind about the spec's,
which was fortunate because it was not until much later
that I had the commonsense idea to make every link in the new system
functionally like the DOT-certified one:
either 4 chewy nuts, or a plain nut with a cotter pin .
. I was having trouble finding a way to dig all 4 bolts into the frame
and some plans simply without,
but the only time their plan uses only one bolt
is when that bolt uses a cotter pin .
... . still looking for the perfect way to bolt-on the axle without the springs .

6.10.31: safety considerations

. when excluding the springs from the design,
notice that the springs were anchored to the main beams on the side,
not the crossbeams,
because many more bolts have to loosen
before a for a catastrophic release of the axle can occur .
6.11.6:
. the side frame is cross-section shaped like a u on it`s side like a c;
if 2 holes are drilled near the bottom,
then 2 u-bolts can be held by a 1'' band that is the bottom of the frame;
place an axle`end between these 2 bolts
then the axle can be pressed to the bottom of the frame
by screwing a 4-hole plate onto the pair of u-bolts
6.11.12:
. if the kit changes, so that there are no naturally well-placed holes
for directly connecting the axle to the frame
and you still don't want to connect using the kit`s springs
then one way -- without drilling new holes --
might be :
having one u-bolt chaining the other .. [I eventually drilled new holes] .

6.11.12: todo"axle allignment

... noticed the axle is not perfectly straight;
which means that while moving, the trailer will be slightly rotated
. the problem can be solved through varying-width shims
between axle and the u-bolts that keep the axle sandwiched by
a plate and the trailer`frame .

bike.connect# modular

5.12.15: mobi#lite tows trailer

. the most modular solution is to buy the trailer transporter
(turns a trailer into a wagon that can be manually pulled)
and modify that to be pulled by a bike

. the most economical solution was hit apon a few days ago:
remove the bike`seat,
and use the seat post as the ball to set the trailer`s coupler on .

6.11.17: trailer-trike constructor

. the modular way is having a part that can be bolted onto a normal bike
so that the result can quickly be attached to a normal trailer
. this does not consider how a useful unicycle could be integrated with the part;
it simply notes that if you want a single-point object (such as a unicycle)
to hold up a trailer,
it has to have not only the ball going up into the trailer`socket,
but also an arm reaching under the boom
and then ending in a fork pointing upwards
. finally that fork has to be bolted around the boom

todo:

. the holy grail of trailer-trike design is finding a cheap way
to transform a bike into a unicycle that attaches to such a part

. see that a bike rear is a triangle (top.fork, bot.fork, seat.tube)
and that you want the bot.fork vertical,
while the top.fork is slanted forward to fight deceleration forces
. the easiest way seems to be a turning-table tech,
where you bolt a panel to have it extending the seat.tube
into a horizontal plane
...
. the easiest way is to nix the requirement of having a stock trailer,
and use the sawyer`steering
that puts the axle on a turning table for steering via a trailer`wheel rotation

. use a bending boom`ext!
that bolts onto both of the bike forks
-- this is a very strong design!,
and is much easier and safer than modifying the axle dynamics .

. replace the std boom socket module
with something that uses a wheel spindle & hub
to form a joint in the near-hor`plane
. this joint is then connected to the bike`back.forks
ok!

. see the spindle going through where the ball would go;
this is connected to the hub,
which has 4 holes on which is connected
(336, a wheel hub in the std way;
and then bolted to this is) the trailer`fork
that is then bolted onto the bike`back.forks ...

... at an angle that rotates the bike backward just eno' to
have the driver postured as on the safety bike
. now the bike`front.forks are still far from vert.planed
and so they can still be trailer-cabled
in a simple way that nevertheless changes the trailer-bike angle
. this is an important design because it
uses a stock bike, and trailer
(the current design requires a dahon and many odd parts)
. stock bikes should be much easier to pick up at a 2nd hand store
and constructing a hor.pivoting boom`ext
should be much easier to engineer than steerable trailer wheels

. if the spindle is tilted slightly back,
then any turn has to lift the trailer
and should thus make it easier to keep the trailer-trike headed straight .

. instead of cabling the steering to the trailer`s outer corners,
do it in a chainring design
which requires that a ring be around the pivot with it`s plane
in the same plane as that of the the steering`chain? .
6.11.28:
. the most likely problem is that there are plenty of holes but they aren't spaced correctly
or the correctly spaced pair is not in the desired location
. in that case,
perhaps just one u-bolt can suffice?

6.10.31: bike.connect# bust

pivot# spindle-boom.connect

.. felt confident about a bike boom connection,
but apon doc'ing the details,
it was the other connections in that design
that were the main headaches
while I was mulling that idea,
I noticed that the flanged spindle might fit in the
hollowness of the trailer`boom ... with angle irons;

pivot# fixed-boom

. the culti design might be varied
by having the boom fixed, while the driver`s chair
is on a cylinder that rotates around the boom,
so that the driver can still lean with the drive wheel
. the way to imagine a fixed-boom turn is that
the more vertical the steering column is
the more a steering turn is actually
turning the vehicle and not just the lean;
but the more horizontal the steering column
the more the driver can lean with the turn
rather than rotate around the drivewheel
trying to stay aligned with the pedals
6.11.1: and thereby worsening the centrifigal throw

pivot# linear.drive

. another major fork idea that is more simple
by separating the steering`design from drive`s,
is the use of cables and linear motion,
like cable-weight macines provide
the cables can twist around on pulley systems
to follow the turning wheel like a car`s universal joint .

pivot# dual-posture

. a 4th idea specific to workbikes,
is having a completely separate drive system for very slow situations
like hills and corners
like getting out of recumbent mode, and riding the wheel like a
normal bike so turning the driver with wheel is trivial
since the driver is standing about a seattube
that is not moving through space as it rotates .

6.11.5: bike.connect# culti

6.10.30
. finding ways that the gym`parts can work:
from the gym pivot the rear bench leg provides a 45degree-angle,
and then a good connection for a 4x4 beam;
meanwhile, the gym`bench`s 45-degree angle
may help firmly bolt it to the dahon
. however,
since this morning, I've gotten a new interest
in a variation of the
bike`steering`pivot design:
. the dahon is tilted back, as in the culti design,
but then riding on the seat tube,
and u-bolted to the dahon`toptube,
is the forks of the tourbike
. I still haven't seen a safe way to connect the trailer boom
to the tourbike`steering`pivot-toptube frame .

6.11.5:
. rotate the bike backward on it`s back wheel until the seat`tube is pointing at the trailer frame;
replace the seat`post with a giant bolt,
and insert the bolt into a set of bearings strapped to the trailer`front`crossbeam
just as an axle`spindle gets fitted to a wheel`hub .

(7.5.8:
I'm guessing this is was what I meant then;
I was totally confused by it earlier,
thinking it was part of 6.11.5`bike.connect# culti.sawyer )

7.1.24: shim

. see what size rubber shim will fit between dahon`end and boom:
the best way to fill that slim space would be epoxy .

sci" culti`s steering design

. panic about being sure how to make culti work?
make the design adjustably angled

. you can see again what you need
from identifying what culti and classic chopped bike steering
has in common:
culti with pivot angle analyzed

after the steering pivot,
there is an upward bend in the steering column;
it is this bend that translates rotations of the steering
into changing the sideways direction of the wheel
. the gym`pivot needs to have it`s forks cut to stubs
and at an angle,
so when the fork bridge is bolted back on to them
that angle is the vital upward bend

6.11.6:
. to connect culti`boom to the angle,
reuse the 4x4 bracket that was forming the gym`[4x4 y-joint]
; also, the slotted angle iron is reusable
and there are 2 4x4 joints
that can be used in various ways and in combination with
the trailer`boom
. the trailer`boom can strengthen the pivot-trailer spine
. the angled 4x4 joint can be bolted onto the 4x4 it was cut from
and the end will point down at the pivot-trailer spine
providing yet more bounce-strength .
. the gym`bench`beam includes a joint for leg ext
which has 2 plates for that joint`s forks;
this is the same beam used as the culti`boom,
and the plates can possibly stay in place,
and be reused to strengthen the pivot-boom connection .

6.11.7: tech" pivot near axle

. just as the culti has the driver seat
immediately in front of the wheels,
mobi could:
. instead of having the pivot at the front,
the boom would be so long that
even though the driver`s seat was still in front of the trailer,
the pivot would be clear back at the axle
. then when a quick stop came down hard,
the trailer front would bottom out on the boom,
instead of putting the brunt soley on the pivot;
which means that during a crash,
most of the down force is applied in the center
where it has much less leverage,
and is less likely to damage-twist the boom .
6.11.8:
--. just a day later, the culti`design was given up entirely,
in favor of the sawyer`style (yaw-centric pivot
and cable-driven steering of back wheels) .
7.4.23: that is:
. the culti-style of steering (with z-axis pivot),
was replaced with the sawyer`style (y-axis pivot)

6.11.9: sawyer# gym`pivot

. pictured is a mid-project experimental version
where the dahon would be used as supine recumbent,
and the steering pivot would come from a lifting bench
that had a built-in spotter mechanism
v0.1` pivot

6.11.22 bike.connect# culti.sawyer

6.11.5:
. this would be a bike where the part of the frame behind the steering
has turned into a trailer
while the handlebars have turned into the driver`seat
. the pedaling is done by replacing the front wheel with the back wheel
(with the rear bike frame still attached)
and reclined to give driver`posture same angle as the safetybike'84
(with a 45deg seat.tube)
. with a conventional bike, rather than the dahon,
the trailer is then fused to the bike`s top and bottom tubes

. this arrangment is acceptably strong only if
braking and acceleration are done by the rear wheels,
and there are no pot.holes (good luck) .

6.11.22: sawyer# dahon`pivot

glossary

. dahon`head == dahon`steering`bearing asm (left)
. dahon`tail == dahon`steering`top.tube (right)

. the gym`4x4 Y-joint can be sawed to fit that,
and the same bolts that hold it together
can sandwich a 4x4 beam along with the part

. the gym`U-strap can fit very strongly
to resist forces that would tear the head off:

the simplest boom is just a 2x2 with the dahon` inside it,
and using that strap to hold it there .
. the trailer`front.crossbeam goes on top of the dahon`head
and then the dahon`tail sits on the lip of the
another trailer`crossbeam
. the forces tend to pull the dahon`head off from the bottom,
so that's where the strap should go .

6.11.26: dahon-connect with gym`strap

. use 2nd gym strap for connecting
front handle bar to seat`post .

12.7: gym`pivot

. is it possible to have the current design
ie, with both forks on the rear wheel
but then instead of bearing the front fork`trunk
with the dahon`tube it came with,
use a stronger tube-bearing set, such as the gym`s?
yes, it is possible,
but the gym hinge would not be stronger than
the trailer`boom & gym`strap with epoxy .

6.11.28: testing

. the twisting forces are primarily during fast stops,
where
the pivot`top is being twisted forward
u the `bottom backwards
. this is where that chewey marine epoxy would come in handy

tipping problem resolved

6.11.28:
. looking at the dahon prototype again,
to see how stable the rider remains during a turn,
I'm reminded this is a simple design
with not too many options or var's to wonder about
-- only how far back you let the rider lean
. in any case,
the 3 points of landing are stationary,
so unlike the other design,
a turn is not insanely-likely to dump the trike over!
6.12.7:
. notice there is still some problem with the safety bike recumbent style
putting too much rider weight on wrong side during turn,
but the amount of recumbency is variable,
and the rider can just lean forward during a turn
to have the same effect as leaning into a turn;
so, that particular issue is indep' of other disign problems
as long as the recumbency remains variable .

28: mis"driver placement

. in a right-handed road system,
the right-handed turn can be very sharp,
so in this design, and in the usa,
the driver might want to be shifted slightly to the right of center
so that while the steering pivots to the right,
and the driver`s mass swings to the left
there will be less chance of tipping over
12.7:
. keep the driver in the center,
since this allows turns > 90degrees in either direction
to provide a reverse drive .

6.11.29: dahon`top.tube in trailer`boom# naive

. the position of the top.tube is upside down
because it is L__ -shaped that way (the vert being the bearing set)
and this will be the strongest during a hard stop,
because:
. the bottom of the bearing is pushed back,
and will be stopped by the top.tube
. the top will be thrown forward,
and is naturally weak but in this system,
the gym`strap will be lasso.ing it,
and that strap will be bolted to very thick metal in the boom
like so:
. the boom`end can be curve-carved to hug the roundness of dahon`bearing set;
and, using just the right depth of carving
will also bring the gym strap in-line with
the bolt holes provided for the boom`head (holds the towing vehicle`s towing ball)
. use short bolts on each side
vs one clear-through bolt,
and then it will have the perfect fit,
being loose when first nutting,
and then pulling tighter on the strap as the nut-tightening is completing
. the L__ -shaped top.tube needs to have something sitting on top,
so that as the boom pushes down on it,
it does not push the strap down to the middle where it's not being put to good use
. the top.tube is conecting with the boom
by being hacksaw-slotted to fit without cutting the boom
. the boom is essentially a square tube
except that it many places, a cut-away would look like a downward facing C
. top.tube will be providing push only indirectly,
because it is being slotted so that the boom`s rounded edge is nearly riding the dahon`bearing casing,
and thereby providing stabilization .

. that version assumes that the rotational forces are insignificant;
unfortunately, that would only be true on a bike, not a trike,
where you are no longer balancing

6.11.29: dahon`top.tube in trailer`boom# trike-aware

. in the trike-aware version that has strength against
torque forces that are due to rider leaning against trike`s wide-apart tires
instead of balancing like on a bike,
-- considering that the top.tube may be much stronger as a tube than as a slot,
just as an egg can take much more hand-squeezing when not cracked

. the gym`U-strap will be pull the dahon tight against the trailer`boom;
it`s 1'' of siding is going to resist rotational forces?
.[12.7: yes,
with epoxy at the strap, and with the tail-end cut to exactly fit boom
so as to retain as much of the original structure as possible
and thereby keep it as strong as it was designed to be . ]-12.7

. the trailer boom must be facing down?
the trailer boom can be cut in half,
and the halves used to form something thats shaped more like the top.tube?
[12.7:
. keep in mind the need to keep it simple,
in case of hell, and the need to start from scratch on the road
. the important thing is that
during a hard brake,
when the dahon`steering.column is bonded to the boom,
there is top of it jolted forward,
and bottom pushed back
. now,
while the strap provides a gently wide interface for the top
there is still a problem on the bottom
because
the rearward force is being stopped only by the edge of boom tube
coming down in the middle of the column,
which is likely to dent it,
since at that point it's not backed by the bearings;
1412:
.. other parts of this design have already solved this,
as it was decided to cut away any part of the boom necessary in order to
avoid cutting the top.tube,
and, if the butt of the top.tube has a firm bonding to the boom,
then rearward forces will translate to the top.tube where the interface is very gentle . ]-12.7

12.7: dahon`top.tube in trailer`boom/impl

. saw up the dahon;
find out as I'm going along, all the options I hadn't noticed before:

option#1

. the top.tube`s butt can be locked in place by a cross.band on the boom`s underside;
but,
to have some shelf to do that, I need to

remove the first cross.band,
and then form the top.tube to fit in the resulting C-shape:

. the sides are shaved to be the same width (when the C-shape is pointing downward)
and then slit on either side to make room for the bottom lips
(the lips of the C-shape)

option#2

. not sure how to nail after that without drilling it,
but something in addition to the 2bolts, gym`U-band, and epoxy
seems advisable .

mis"tunnel vision

. making cuts that are just going to be tossed by other cuts .
6.12.12:
. come time to actually do the bonding with the assist of epoxy,
I'm concerned about not being able to make it plumb,
so that the fork.tube is vert
. my first response is iterative:
if not plumb then can re-angle the entire boom w washers .

make boom hug with varying width:
. need to take a wedge out of boom
so it looks like a pair of tweezers,
and then the bolting will make the tweezers
grasp the dahon`top.tube in a plumb way .

modular use of epoxy

. apply the epoxy, it comes in dbl-barrel syringe but that didn't work,
the clear stuff had a big air bubble in it,
and they came out at uneven rates;
but fortu'ly, I needed the whole thing
. for now I'm just doing the most important part of the epoxy job,
and the part that is most modular;
ie, suppose the trailer gets messed up, and I want to reuse the dahon?
then I want to attach the trailer`boom only by bolts,
and want to spend all this chewy (and expensive) epoxy
on making the dahon more boltable;
hence, then only thing being epoxied to the dahon
is the gym`U-strap around dahon`s steering.tube and top.tube
. the U-strap is holding these 2 tubes together
while also providing 2 reinforced holes for bolting .

clean up epoxy

. loosen bolt used as pin to hold part in place,
razor a drop off the floor
. flatten dribbles on the product .

12.19: 2nd hole

. drill 2nd hole into dahon`top.tube for connecting with boom .

sci" boom-trailer.connect

6.12.8: horiz'ly angled

. with the trailer`frame setting on top of v0.2.0 shot#1

the inner.box (short side facing forward)
then
the axle can be mounted under the inner.box,
and shortened to make wheels close to inner.box
. the box`walls are tall eno' to raise the frame above the wheels
but low eno' to keep frame level when the dahon is underneath it .

. this design was attractive at first
because the trailer`boom could be attached in the standard way to the frame;
but later, I started thinking of revisions after it seemed obvious that a tilted boom
would give the bike-trailer connection a stronger, triangular shape .

6.12.10: rearward placement of axle/crossbeam reusable

. if keeping the axle in the rear rather than middle
then axle doubles as a crossbeam,
so the rear crossbeam can be reused elsewhere

6.12.12: indep steering and lean control

. the plumb should be designed variable instead of fixed since roads are often slanted
ie, but that is dangerous for this scrappy design;
best to just design as is,
... but
if you did have advanced engineering skills,
then could make power steering mechanism like a joy stick on airplane
that would do both turn and lean
. it could be placed like the culti`s handlebars,
and the action would be
rotation would rotate the front wheel, just like a normal bike,
but then pulling up or pushing down would affect the lean
. to make one from a culti,
straighten it`s pivot, so it has only lean and no steering,
and then make each handhold on the handle bar rotatable,
and that rotation gets gear-chained to the steering pivot
..
. but the front wheel doesn't have a steering pivot
because that's where the pedaling is being applied
so either
the steering rotations are affecting the rear wheels -- sawyer`s style --
or
you have to back up a bit,
when you where straightening the lean pivot to have no turn:
now,
you need to make that angle adjustable by wrist rotations,
which I can see no elegant mechanical solution for
-- it would need a hydraulic line, like brakes have
the culti way would be the normal state,
and then if you wanted lean without steering,
your wrist rotations would cable-down to straighten the culti`boom
.
. to make one from the dahon trailer is easy
but operating this could be a strain:
just as the driver is steering by holding onto the walls,
so also this wall grasping controls lean
. the boom -- on which the driver`s seat is affixed --
is on a pair of hinges for lean,
and the driver`s cockpit is affixed to the {trailer`frame, axle} .

. come time to actually do the bonding with the assist of epoxy,
I'm concerned about not being able to make it plumb,
so that the fork.tube is vert
. my first response is iterative:
if not plumb then can re-angle the entire boom w washers .

6.12.19: angled boom`connect

tech:

trailer`spring`connects can be rolled into a square .

. in order find a lower anchor point for the boom`end,
connect boom to axle somehow ... using spring`connects .
. spring-connect blocks useful for rise in middle of boom
to surround and stabilize use of long bolts to form a rise .
. decide to use all 4 spring connects to form blocks
that put space between boom and it`s intended anchor point .

7.3.21: todo"boom`angle is still off

. the frame is still not level, and it`s front rides so high that
the driver`s butt bottoms-out on the gym`arm during a pot.hole;
so,
it would be worthwhile finding a way to lower the trailer`front
ie, raising the boom-connect`front;
eg, by shimming it with a gym block and using a longer bolt
. the lower, the better;
so a hard stop will present less of a stress on the pivot
7.5.17:
. actually, what helps keep enertia off the pivot
depends on which brake is used:

front.brake:

. the trailer`s center of mass should be below the trailer-boom`connect.point .

back.brake:

. the trailer`s center of mass should be well behind or under the axle,
so that as the trailer rotates toward the front, the trailer`weight is working against gravity .

7.3.21: todo"consider use of cheaper connector

. review rear boom connection for smarter design;
why wouldn't a gym`block work there too, like planned for the front? .

6.11.28: reverse drive

6.11.28: reverse#dahon`hyper.turning [obs]

. can this design allow a reverse?
it should try to work that in if possible;
ie,
imagine the driver is turning and does a 180
instead of the usual 0.. 45
in this design that would turn the transmission 180 too .

. since the most strength should be dedicated to quick straight stops,
the mobi has a boom at the 180,
so this design can allow a left or right reverse turn,
but not a straight reverse
. it may seem like an annoyance having to do more than a 180
just to change from left to right while in reverse,
but this feature is just for emergencies
28.1420:
. the discouragement is that
turning driver is cramped (need pedals in min'position )
and it reduces design options in connecting pivot

severely complicates steering

. now having to think about sawyer`chained steering;
but that too is trouble because unlike the sawyer,
my model requires a reclined seat
for both balancing over the pivot, and for ergonomics .
12.21:
. forget it: the angled boom is a good idea and should stay,
but is obviating my plans for doing a reverse by going forward on a hyper.turn
. this makes steering easier though, since I have many more options
knowing that no hyper.turns are needed;
eg, steering can simply be a handles on a bar across the cabin`front .

6.11.30: use 2nd bike [obs]

. use a bike on other end
. when you walk to that end the trailer tips on that side
to put that bike in contact with traction .
... and when that bike is not being used for reversing,
it`s the generator?
reuse the 2nd bike as the generator .

6.11.28: reverse#2nd set of pedals

. how can there be a 2nd set of pedals that work in reverse but disconnectable? .
. mobi can use the sting-ray` kick brakes
to connect the large sprocket to the 2nd set of pedals?

6.11.28: reverse#powerchair

. another way to handle reverse is just having a way to move trailer wheels individ'ly:
this is the way that powerchairs move very nimbly;
they have a motor to each main.rear wheel,
29:
and if the chair has an intelligent controller
all steering can be done with a balancing of left and right acceleration

7.2.24: reverse# manual/ external brake control

. the primary requirement for a manual reverse
is having a brake control that is located
where both the driver and the reverse.drive pusher can reach it
. it should consider both inclined cases
where gravity is pushing the car either backwards or forwards
. falling backwards,
the brake is near where you want it, by the front wheel
which the other hand is on for steering
. falling forwards,
you are might not be able to manually push the mobi uphill,
so your only hope alone is to steer it to one side instead of reverse,
or if there is a tree nearby,
to ratchet or pulley the craft uphill by cable .

6.12.8: trailer# internalized wheels

design#1

. cut the axle to shorten it,
combine the axle pieces by interlocking the concaves (the axle is a U-beam)
now using the same trailer`frame,
the wheels are on the inside of the frame
. now for support of the axle,
reuse the rear cross.beam by cutting it in half,
and placing these pieces parallel with the boom,
and connecting them between the other 2 cross.beams
at points where the axle can rest on them

problems

. a problem with this is that you have to
remove the entire axle just to change a tire!

design#2

. like design#1 but instead of reusing the cross.beam#rear,
use pieces of the boom for supporting the axle
. this would be compatable with the current trike design,
as no boom is really needed,
esp'ly if the braking power were moved primarily to the trailer`tires
. attaching the boom is not expensive because
it can be bolted through hacksawed slots
rather than drill`holes .

v1.0 (2006.12.19: angled boom connect)

. in order find a lower anchor point for the boom`end,
connect boom to axle somehow
... using trailer`spring`connects
that can be rolled into a square to form blocks
that put space between boom
and it`s intended anchor point .

7.1.11: steering

. checking gym`handle`size, I found it's tall eno' to connect direct to boom
but needs an odd angle fitting
. thepivot makes joiint angle adjustable
. the gym`arm connects by a u-beam,
and if the arms were removed from this beam,
then it could be bolted to gym`handle (inverted from the usual way):
which then gives the handlebar 2 fins that can be cut in a way
that provides the needed angle .

. saw the gym`arm in half and re-bolt to make it shorter,
then attach this dbl-barreled arm
with the 2 bolts being used by the boom .
. don't replace short bolts on boom with long bolts to fit handlebars,
because that boom-bolting needs to be very tight .

todo.mobi`steering: [19: todo: if possible not doc'd]
. the steering can be jupiter like how was that possible ? any angle ? .

7.1.12:
. the part of the gym that helped attach the pivot`vert to the boom
might also attach the handlebars to the boom .
7.1.13
. if the L-irons extend from lockbox to near pivot,
then the handlebars have more secure place ?
even better would be securing to lockbox .

mobi# trailer-trike v1.1 (foundation transport)

7.1.15: lockbox`positioning

. I had the idea to minimize cutting the lockbox by sending the boom through the lockbox,
but it's difficult to install the boom that way,
so the lockbox needs to be cut so that it can be laid on top of
the pre-built trailer-trike frame
. the cut needs to scoot it forward eno' to make room for the inner box to sit on the end,
with centerline on end`crossbeam, so there is balance .

7.1.20: minimal trike complete

. this is the operational trike without the a cabin, bathroom, or driver shell
. the gym`arm is connected by hinges that allow it to be rotated back
for easier entry or for changing the angle of the handlebars
. the white box on the trailer`frame is the shell of an
antique General Motors`Frigidaire
that serves as both a base for the handlebars, and a lockable trunk .

7.1.26: cabin`bolting/carriage.bolting:

. all the bolts attaching the cabin to the trailer`frame can be carriaged:
they are going into the hollows of beams,
and if the beams are soap-washed then the carriage.bolts can be held in
place with sealing tape .
7.3.2: mis:
. if the carriage bolts are fit by epoxy then they don't need sealing tape,
else the only way to ensure good tightening is using a large bolt,
and the making the hole match with a square file .

7.3.21: boom`angle:

. the frame is still not level,
and it rides so high that the driver`s butt bottoms-out on the gym`arm during a pot.hole;
so it would be worthwhile finding a way to lower the trailer`front
by raising the boom`front;
eg, by shimming with gym block and using a longer bolt
. the lower, the better;
because, more of the weight should be toward the 3rd wheel (call that the front),
so a hard stop will present less of a stress on the pivot if
the mass up front is low as possible .

. if there are changes to boom and cross-struts are used,
then these should be anchored to the trailer`frame rather than the cabin
because cabin materials gen'ly won't have the needed strength .

7.4.22: axle as crossbeam

7.4.23:
. for the axle`s z-axis placement to be modular,
the fender-brake mechanism would have to be anchored to the axle rather than the trailer`frame .

. the axle could be used as a crossbeam,
and it could also be drilled to become the anchor point for the trailer`boom
. it would be positioned low, so the hardware being used for that now could be freed for other uses
(the 4 U-brackets that were meant to anchor the kit`s springs to the trailer`frame) .

. by making the axle replace the trailer`frame`s middle crossbeam,
the holes that are left behind can be used for U-bolts
sand this can be done with only one u-bolt on each side,
so the u-bolt washers and 2 u-bolts can be reused elsewhere,
such as attaching the boom
. the u-bolts don't have to fit both of the holes left by the crossbeam:
one hole could be a hacksaw'd slot,
or the axle could be placed at any point on the z-axis,
by hacksawing a hole for the entire axle to sink half-way into the side.beam;
this would allow the u-bolts to reach the top ledge of the side.beam
on the other hand,
if the axle were not sunk into the side.beam,
then it`s z-axis location could be changed to match load balancing trends .

7.5.5:
. with the crossbeam missing,
the lockbox needs a shim to rest on the axle,
and it needs to be slid back 3" so it can rest on the rear`crossbeam
because the lock box should be cross-supported at 2 places within it`s body area
rather than it`s flimsey foot.space area

. moving the lockbox back,
would allow more space for the seat,
so it didn't bottom-out on the handlebars during bumps
. the seat could also be reclined,
but that would require removal one of the front cantilever brakes .
7.5.5:
. moving the boom forward for the same effect might be more expensive,
since that would could change the bolting arrangement,
which in most designs will want to stay with the bolt.holes provided by the kit .

7.4.22: boom`suspension

. if the heavy spring (recycled from an office chair)
were incorporated into the boom`s front connection,
so that the boom would bounce when the front hit a pot.hole,
then the the boom-dahon connection would be less likely to fracture

. it would need something to keep it from tilting sideways,
and the gym arm might provide that sort of support -- needed anyway --
although it's still a risky design change that could stall the project
and isn't needed if the speed is kept down .
. another problem with the gym`arm
is that one of the welds was dirty and snapped,
which means the whole job is suspect, and can't be trusted for heavy work .

7.5.5: pos

. that [crossbeam removal] modification
has a low priority,
because of the [necessity vs time] constraint,
and so,
the location of the axle should not depend on it
. however, it was attempting to fix some problems that still stand,
including:
( make the boom more resistant to swaying
, increase boom angle -- if shim'd then also needs side-cabling
, lower the lockbox from the seat -- same as increase boom ankle
, add boom suspension
) .

7.5.7: bumper

. the lockbox`foot area has a crossbar that was cut to allow
placement of the lockbox onto the trailer`frame
with the boom pre-installed and in the way .
. the remaining crossbar can provide anchor points for a wooden replacement

. lockbox is predrilled with screw holes for wood,
wood or composite shelving is applied to form a pan whose lip reaches up beyond the boom
. a door is hinged at the boom line to fold down and throw stuff that needs ventilation
(the bathroom is well vented,
but the lockbox`foot area additionally provides a fireblock from the main cabin,
whereas the bathroom is separated by a hidiously burnable plastic .

. if rear-ended, the wood and innerbox will crumple,
while the L-irons remain resistant;
if the L-irons are not capped with something strong,
they will inflict much more damage
since they are bypassing the car`s bumper system
. the L-irons don't extend out to the bumper`s plane,
so the bumper should be connected to something that will stay with the L-irons,
and thereby keep the bumper attached to, and padding, the L-iron .
. therefore,
the bumper should be bolted to side beams that are hollow and fit around the L-irons,

. including some springy or compressable material inside the tubing,
might also help my side of the collision .

. some good tubing for this job would be the gym`arm:
if sawed in half, it forms 2 L-structures:
where
one arm of that structure is a square tube,
and the other arm is U-iron (welded onto the square tubing by the gym`kit)
. the pair of U-irons have bolt.holes for a crossbeam that connects the 2 L-structures
to form a solid foundation for any other bumper materials .

summary:
. going from front to back:
lockbox is bolted to inner box and L-irons that support innerbox;
bumper is tubed around L-irons, and bolted onto innerbox .

corrections:
. that will mean the current wooden frame will need to be modified
so that it exposes area around the L-irons for the tubing to fit .

. after finding that small tubing would not fit over the L-irons,
and not wanting to make any modifications to the L-irons
because iron is very hard,
I discovered instead that since the vehicle of concern
would have a bumper that remains solid sideways,
all mobi needs is one strong beam up the center
that keeps a bumper from moving forward without also moving
the trailer -- and the L-irons .
. a large beam already has the needed hole
for connecting to the trailer`frame

. this center beam can be sawed to length,
and drilled for bolting with another large beam to form a T .

. the L-irons are so low to the ground, that they likely won't do any damage on impact;
however, a bumper could reduce fender-bender damage on mobi`s cabin;