Pedal Car by Dan

[dandeangeli]

Greetings to All

New to the site. but I want to start my own thread to show progress, share failures and successes, gain some modicum of wisdom.

I taught myself how to weld to create an electric assist vehicle that I could ride in all weather. It has become a kind of obsession, for a while it had four wheels now back to three, and in the interim I created an exoskeleton that I hope to eventually enclose before next winter.

I will post pictures below of its various interations.

Here are some lessons I have learned.

• Mid drive systems (bafang in my case) really performs badly on a long chain. Therefor I want to put one, possibly two hub drive motors in the rear.
• welding takes time to learn
• steering with ackerman geometry very important
• more lessons at a video my friend Owen made at (paste into browser to see)
• still not sure how I can install suspension in the rear but I looking for suggestions.

Ok here are some images.

 

[DaLanMan]

I dribbled a thought in Amberwolfs thread, Suggestion on dealing with rear suspension.

I have never tried a long chain/mid drive.. I am working a different angle on the one I am building.

The image labeled "jackshaft setup" Is where I applied power in my design (I am building a trike modifying an existing Schwinn. I got a motor and drive kit (motor from Vevor) and at the coupling point added a chain at a 26degree rise angle facing rearwards, going to the motor which is sitting on a cross body plate behind the transit shaft.

I tried at first for the obvious, connected motor to sprocket on rear axle. Found out, when the person handling the controls is your 12 y/o son, your first power test results in a fantastic wheelie, and you having to dodge the incoming front wheel because lil man did not thing to let go.. luckily that resulted in loss of power (running off ground station, no batteries on board.) I do not suggest this technique unless you have profoundly good bladder control. That said, I ran afoul of the drive speed issue. The first test was with what I had laying about, to see if it would move the bike. It did great at a 1.1 to 1 gear ratio it was very quick and had not tork. I discussed this at length with smarter than I am folks, and it quickly became.. how do I get that gear ratio in the space I have. Answer.. move the motor. easier to put it on the hub with gear space available.

I am also considering going to a belt drive, because it will add a little more give to the initial acceleration, trading belt life for damping force.

Fwiw: Love the concepts, and the color. Now you don't happen to have a tilt front steering concept do ya ::grins::

 

[The Toecutter]

You definitely need some sort of suspension on that thing. Nice work!

 

[DaLanMan]

I have ridden in a go-cart ish item (it was a 1 driver 4 kid seat build) and it had no suspension besides the sidewalls.

I think my kidneys are still mad at me about that.

 

[offGridDownUnder]

it had four wheels now back to three

Of possible interest is my stoke-monkey motor in my trike (see signature for thread). I started with a GMAC, now have a Shengyi SX, and I've just ordered a Grin All-Axle v3 rear to install. I designed for the Grin motor before it became available, and I'm happy with the Shengyi (much quieter than the GMAC), but now that Grin has officially stated their motor qualifies as a 250w (legal requirement in Australia and I know it's powerful enough with my reduction ratio), I have enough reason to use that.

If the suspension axis coincides with the motor axle, you can otherwise do as you like for the suspension, but as I'm using a Gates belt, the coincidence would need to be very good. Another approach would be having the motor and rear wheel on the same moving frame member.

 

[dandeangeli]

If the suspension axis coincides with the motor axle, you can otherwise do as you like for the suspension, but as I'm using a Gates belt, the coincidence would need to be very good. Another approach would be having the motor and rear wheel on the same moving frame member

Hi OffGrid

Please send pics if you can of what "do as you like" might look like

thanks Dan

 

[dandeangeli]

A friend has offered me use of this old Sun trike frame for my project. I could go back to four wheels, but how to add suspension?

 

[offGridDownUnder]

Please send pics if you can of what "do as you like" might look like

Sorry, I have nothing specific to offer. My point is that if you have one rear wheel, then you can make suspension by pivoting how the arm connects the wheel to the body of the trike. Add a spring and a damper.
As to examples, there are many bicycles with suspension, with various linkage schemes and designed weights. Pick one you like and use two of the shocks to accommodate the extra weight?

 

[fill]

This came to mind, though its a design that would still require some clobbering up for really wet weather..

 

[DaLanMan]

I am *not* the expert on construction. I do have a trash pit of a memory, every useless fact I ever saw I seemingly memorised.

To the point of that, I caught a discussion at a car show about a guy that had both a 3 and a 4 wheel custom chassis for the project car he was working on. I honestly did not necessarily follow all the conversation, but in short there is evidently a bit of a challenge when doing 4 wheel suspension on a drive axle that I believe it was Chevy on the Corvette had overcome with a split axle, and all other carse just suffer for it. It is not a big issue unless (like this guy was doing) you are building an off road vehicle/cross country racing vehicle then solid axles become a nasty problem.

Myu answer afer running one Baja as a 2nd seat.. was to never do that again. I was unaware of the damage your cranium would take when you stuff a 6'4 body into a Baja buggy built in a garage.

 

[dandeangeli]

Thanks for the feedback. I now see my error. If you compare my project car with a commercially made suspension, you can see how when there is force exerted by a bump, my front shock will depress, but also the shock itself will act like a pivot forcing the vehicle to sink down. Same in the rear where the shock swings laterally, and barely gets depressed. In the second and third photo you can see how forces on the shock come near perpendicular to the motion of compression and offer the proper resistance. My plan is to reconfigure my shocks accordingly. Dan

 

[dandeangeli]

somekind of reorientation with a pivot arm is needed now...as shown

 

[dandeangeli]

As with most of my errors they seem so obvious when I see the problem clearly

 

[dandeangeli]

This came to mind, though its a design that would still require some clobbering up for really wet weather..

Yes I have been following this guy, he did the whole project in plywood...

 

[dandeangeli]

Thanks all for the feedback. I have a plan in mind now that may work.

 

[dandeangeli]

Hello All

i have been advised to go with a two motor system by Justin of Grin. He does an impressive data driven presentation for why this makes sense for heavy, long distance or unusual setups. Check it out here

For my project I want to keep the Bafang mid drive and add a hub motor in the rear. The drive train problems I have had seem to be from the length of the chain and the three idlers I use plus a garden hose (!) to guide the chain from the mid drive location back to the rear wheel. My hope is that a second hub drive will lighten the strain on that chain. (First Diagram) I have even considered scrapping the derailleur system and replacing it with an Envilio (formerly Novinci) internal hub as was used on the now bereft ELF. Second diagram and picture)

My questions to the forum:

Has anyone used an Internal gearing hub in combination with a mid drive or hub motor?

Anyone out there wish to share your dual motor story for a Tadpole trike setup like mine?

thanks Dan

 

[dandeangeli]

Updated photo of new shock placement and direction of travel.