trike pusher trailer - ideas

B

bobc

10 kW
Joined
Jan 20, 2011
Messages
993
Location
Knutsford England
A colleague has a recumbent trike & we've been talking about electrifying it:
here are a few ideas it would be interesting to hear the collective reaction to...
I reckon a single wheel pusher trailer -
1) 2x 28Ah SLA deep discharge batteries to give traction & range
2) single wheel trailer with batteries each side of wheel about 2" up from road
3) for trailer coupling use a steering column UJ with a QR skewer in the pinch bolt
4) only electrical connection to trailer is 3 pin twist grip throttle
5) $15 outrunner + $10 ESC + veroboard control board - bish bash bosh
it leaves his trike completely standard when he's not using the trailer.

BTW he likes his new trike - only problem is that it freaks out horses!!!! weird
horse = a ton of neuroses with a child on top
 
Thanks SM - quite a few around then! Interesting to see how others have done things.
I really like this idea so I've started building already - I'm going to make one to go on my Raleigh 20 folder. Unfortunately I'm away from home next week so all I've done today is bend the connecting tube (which goes round the bike wheel) and weld on the connecting UJ (hooke joint). I'm going for space for 4 20Ah 12V SLAs (SEC MRT range), a single 16" wheel & UK legal performance. I expect I'll usually run it with just 2 batteries, all 4 would run for hours....
This is the bike - the only difference to it will be a twist grip throttle & a small coupling bracket over the back brake.
folder.jpg

here is the coupling UJ and curved stem for the trailer. The coupling bracket on the bike will have the splined shaft welded onto a small plate.
trailercoupling.jpg

I'm away next week - I'll post progress as it happens!
Bob
 
Looks like a beautiful area for cruising BC.
Did a bit of design work on the old trailer; should be able to knock this together easy enough, mostly 20mm box with some flat and angle, the CAD gets the frame weight as 4.5kg, the batteries are 6 or 7kg each. There's a small "cargo" area in front of the wheel & it should be easy enough to chop about if I have to change things. The bat's will be held by draught excluder foam and some velcro straps & I'll knock up some guards for the greasy bits ;^)
trail.jpg
 
Based on some thoughts I've had (and comments from others) about doing something similar
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=21060&start=0
and an experiment with someone else riding the back and pedalling hard (whcih I apparently never posted to that thread?--fixed), I recommend not going with the over-the-wheel-to-seatpost type hookup, as it could decrease traction on your rear wheel, causing some funky performance when either turning sharply or when trying to use the bike's pedals to help the motor.

Depending on the weight of the bike and rider it may not matter, but if you have problems you might instead want to try going with the BOB trailer type of hitch. The pics by Olaf-lampe in the thread I linked above are of such a hitch.
 
Thanks Amberwolf, I hadn't thought of that - I was using the opposite logic thet if the trailer were pushing I'd wnat extra traction on the trailer wheel!
I put some slopey bars on the side of the trailer so it will ride up a kerb rather than stopping dead!
 
Seems like trailers are having a bit of a surge here. I"m also building one. I've ordered an extrawheel and will be putting a hub motor on it along with low mounted DeWalt batteries. I'm not sure if there will be enough weight on it, so I'd like to see how yours handles with the SLA's
 
"Seems like trailers are having a bit of a surge here" - weird how these things happen, I was thinking a bit more about Amberwolf's experience - his post is interesting in that his coupling is near identical to mine, but his trailer did have an infinitely heavier "motor" mounted much higher up and with significant fore-aft weight shift. I'm going for neutral weigh balance & I was more worried about the trailer wheel slipping (hence the force vector thing) - if the trailer's pushing I shouldn't need to pedal hard..... AW's trailer also has the hitch very high (big wheel and hitch a long way up from that). The fact that his hitch worked OK with a person pedalling on the trailer gives me a slightly warmer feeling about the stability of mine - time will tell!
It'll take me a few weeks to finish, I'll try to make a start on the frame this weekend & start buying bits.
Took me a while to suss what a BOB hitch was - it actually puts the side to side pivot much further back (behind the wheel) making effectively a much shorter trailer and actually amplifying turning transients: it wouldn't surprise me if any reported "twitchyness" might not be helped by this - I can certainly see the merit in having the pivot over the rear wheel contact patch!
 
bobc said:
Took me a while to suss what a BOB hitch was - it actually puts the side to side pivot much further back (behind the wheel) making effectively a much shorter trailer and actually amplifying turning transients: it wouldn't surprise me if any reported "twitchyness" might not be helped by this - I can certainly see the merit in having the pivot over the rear wheel contact patch!
Click to expand...
Bobc:

Here is the video that I made in 2009 of Jack's push trailer, which he made the Bob trailer adapter plate. If you wish to contact him directly to get his experience, just pm me with your email address, He doesn't come on the forum.
http://www.youtube.com/watch?v=zjZ2tLOF_PQ
 
bobc,
what kind of a trike does your friend have?
 
it's a red one ;^)
It's a tadpole, foldable - I can't remember the make, I'll ask him on Monday. I think it set him back between 1 & 2 grand.
 
Hello....Here's my E-Bob, 406 crystalyte (250-500W)laced into a 16" wheel, EZEE Lithium Ion 36V 9.6ah batt. and a 25a infineon controller mounted on the trailer deck. Coupled with my Catrike Trail, this is one sweet ride, and I'm still be able to park the trailer and ride the trike light.......OH YA!!
 

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updates: I got a brace of goodies from the laser cutters today, that's a sprocket to bolt to a freewheel, a clamp plate for same, dropouts, trailer hitch plate (all 3mm) and some side plates in 1.5mm.
Img_0040.jpg

I started making the hall effect throttle to RC-ESC circuit on stripboard. I'll post a schematic and better pictures on here when it's going. It will work with a BEC or non-BEC ESC and will have an input from the cellog or brake switch to cut the power to the motor. I've had a bit of interest in this so maybe it can go in the circuits/schematics sticky when its done (I had a quick look and couldn't see one already in there....)
Img_0039.jpg

I should make a bit more progress tomorrow, I ordered gears, hubs, motor bearings etc. etc last week so starting to come together.
 
Did a lot today: bought the materials, made the frame, made the trailer hitch for the bike and fitted it. I'll paint all these bits tomorrow with rustproof primer.
Here's thge trailer hitch on the bike:
trailerhitchjpg.jpg

And this is the complete frame
traframejpg.jpg

I still have to make the wheel, & gearing system, the motor hasn't come yet from HK. I'll weld on the dropouts when I have done the wheel.
Good days work!
PS what you see there (minus the friday hammer) weighs 6kg
 
actiopn bent recumbents in the U.s.[google it] have a single wheel trailer for $195.00 that is made for a tadpoloe trike :mrgreen:
 
that's a days work & about £30 in material - add a wheel & mudguard & factor stuff I've not counted (i.e. had lying around) - it would have been cheaper to spend $195 .... but that's not why we play with these things is it ;^)
Oh yeah - that flag on the back - I'm starting to think that's an important bit of the kit... do we think?
 
i have two flags on 5' poles on my tadpole.... still been hit once and at least two near misses....would not ride without them... 10x 15 pennants./.. you are right building IS the fun...when it works,start improving?? :mrgreen:





''
 
Done some more on this:
I got some gears in 0.8Module size from HPC but I managed to mangle the steel one in the lathe while trying to taper ream it, so I've bought some more in 1mod size. I'll be more careful next time (REALLY annoying - I had all but finished the damn thing when zzzzip - it spun in the chuck & mangled the gear teeth...) I'm trying to do a "collet chuck" type arrangement to grip the 5mm shaft.
Idid my usual trick of buying a cheap disc brake hub & machining a freewheel thread onto it. This time I put the sprocket inside the teeth on the freewheel & clamped through the teeth from a clamp plate on the outside - all laser cut bits - another laser cut sprocket there bevelled by mr angry grinder - this really IS the way to make custom sprockets...
bigsproconfreewheeljpg.jpg

I have everything for the trailer except what's coming from the far east - I think the chinese new year is to blame - spokes, motor & LCD DPM all "in transit"
Here is the throttle on the bike - which is now complete. (BTW who noticed the "snowflake" spoke lacing on the front wheel of the bike above? it's actually quite hard to see it...)
hallthrottleonbikejpg.jpg

I spent £110 on ebay last night - bought 2x 20W PV arrays - yes, they're going on the trailer to charge the batteries.... There's no financial incentive to do this, it just means that (in theory) I'll never have to mess about with battery chargers - park the bike in the sun & at the end of the working day it's full up already to take me home.... It's going to be interesting seeeing how that works! I therefore want to make a maximum power point tracking battery charger for them - I have a plan using an AVR micro & a synchronous current mode buck converter chip; the converter chip is set to o/p 14V but the AVR will mess with it's current limit (having multiplied PV V and PV I) & using a hill climbing optimisation algorithm - I reckon it should work (first post doc job I did was a micro controlled maximum power point controller for a solar power station - back in 1984 - I don't think solar cells have changed much since then....). MAybe later - 1st iteration will have a series or shunt linear regulator getting very hot!
With luck, the next update will be at the very least mobile, & hopefully electric!!! I'll try to be objective about how well it works ;^)
 
Made more stuff: these are the 1module gears for the primary reduction. The small spur, I've tapered the hole in it, and threaded the boss 12mmx1.0. I'll weld a 2mm flat on one end of the nut so it pushes the tapered brass collet into the spur to grip the motor shaft. The larger delrin gear, I've bolted onto an aluminium hub, the same bolts will force a tapered thing in to grip the shaft in a similar way.
I finally got my spokes & discovered I'd managed to buy a rim with the wrong number of spoke holes - should get the right rim in a day or so. My batteries have arrived too.
cogbitsjpg.jpg
 
Starting to come together; here is a picture of the status quo - wheel together, jackshaft on & chain drive in place, all running nicely.
I have to make a small bracket out of 3mm steel plate for the motor. I am waiting for another ESC to come, it turns out that my old one will not work at 12V - it cuts out with low voltage cutout at 12.75V It is actually becoming increasingly apparent that the beep codes on the thing adhere to no protocol decribed either in the supplied data or on the web (I spent some time trying to find the right instructions!) Anyway, I spent another £6 & bought one that WILL do 12V. I also have to buy a power transistor to make a shunt reg for the PV arrays, and rig up some kind of box for the control electronics & to keep road filth off the gears.
I went for a small bike ride with the trailer unpowered (& with no batteries) & you really can't tell it's there - I guess that will change when there's a few kg of battery on there.
wheelchainandshaftjpg.jpg
 
Just got mine running today. I have had issues with 36V controller LVC's as well since the batteries I'm using are only 33V. I finally solved it with a 24-60V controller. You are running just 12V total? Does your sprocket have a freewheel?

My trailer weighs in at 38 lbs, with 30 of it on the wheel. Normal riding is so smooth that you can ignore the trailer even without power. Bumps and hills are where the weight is apparent. That and trying to maneuver the thing when it is not on the bike. It is an unruly beast when not attached to anything.

5507695884_092af08c04_z.jpg
 
I'll get mine going just as soon as the ESC arrives from hobbyking - yes I'm running 12V & the sprocket is on a freewheel (picture above). I can't wait to see how it goes - there is a lot that might go wrong - the plastic gear, the tiny motor - will it push me up the hill near work without melting/smoking? I ran it with too many volts on a bench power supply & the motor+ gears made quite a racket; but I need to adjust the mesh of the gears, it's too tight at the moment. Just as soon as it's mobile I'll get a vid on utube. My trailer weighs just a litttle more with the lead acids, but lighter motor option. That slowboat from china seems to be taking an age....
 
Update:
I got the thing going the other week, but because the motor kV was a lot bigger than I designed for, it was geared for 24mph and not 15mph - so the motor & controller were being forced to "try too hard" & consequently overheated. I redesigned one of the sprockets to bring the speed & torque requirement down & am now waiting for the laser cutters.
On road behaviour - seems fine - no drama just a push in the rear. Noise from the gears is loud - something will have to be done!
Oh yeah - to stop it bouncing I had to reduce tyre pressure in the trailer wheel to < 30psi
 
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