Newbie

[jrotoole]

My 3 year old Grandson has Autism, who love trains. I' m planning on building a Thomas the train (wood body) on rubber wheels with 1-1/4" square pipe frame, with 2 ea my1020 800w 36 volts motors. I have searched the internet for about 2 weeks without finding exactly a plan or information needed to proceed to the next steps.'
1. I plan on the frame to be about 6-7 feet long. 2 seater holding my Son-in-law 155# and Grandson 45#.
2. 2 motors 800w 36 volts, buy from whom?
3. Want it to go about 10-15 mph max.
4. Spocket type needed?
5. Tie batteries in Serials?
6. Chain size
7. source for drive shaft
8. Battery types and qty
9. controller model?
As you can see many questions, please help me create this project for the my grandson, look forward to all your replies
sincerely
Ron

 

[dcastillo]

sounds like a fun project, there is lots on info on this site and explanations that will help, I unfortunately cant help much as I am working on my first project as well....
Its a 2 seater gokart im making for my 4yr old daughter to drive my 6yr old son around whos also autistic. He has no desire to drive, but loves to ride along
best of luck

 

[itsid]

Ron
Sounds like a plan!

1. I'd recheck the length you need about 4ft for the adult legs and seat alone, and since Thomas is a rather slim train, you will not have much room left for batteries.
That is if it's not a ride-on train you intend to build.

2. They show up on ebay every once in a while, being cheaper than in most of the (web-)stores around (namely for just under USD100 new).
or you can go here
http://www.monsterscooterparts.com/36vo800wamow.html
or here
http://www.motopartscenter.com/36v-800w-united-starter-motor-for-electric-scooter-p-851.html

3. that's okay, maybe you want a jackshaft to reduce the ratio even further, in any case since it's an electric motor you can always limit the rpm without any issues.

4. chainsize is #25 so that's what you need as a sprocket.

5. Yes, 3 12V batteries in series to give you the 36V you need, and packs of that in parallel to get more 'fuel in the tank' for a longer driving experience.
(I think you should be okay with 3 x 12V @ 55Ah for about 45-50mins of driving)

6. Again (as in point 4) the my1020 comes with a #25 sprocket (see first link) that's the chaintype

7. *shrugs* depends, if you want a differential check Northern Tool, a live axle can be found in any kart shop (or also at northern tool)
http://www.northerntool.com/shop/tools/product_35768_35768
http://www.northerntool.com/shop/tools/product_21285_21285

8. multiples of 3 (3,6,9...) if you buy 12V batteries, see point 5. I think you should be okay with 55Ah

9. that's a bit of a problem you need a controller that provides around 50Amps @36V all the time, (~20 per motor plus a backup )
I'm sure we'll find something for you that doesn't cost a fortune

'sid

 

[jrotoole]

Good Information

Sid,
Thank you for all the good links and information.

Since I'm still in the planning stages, I will increase length of footprint overall a few more feet.

With regards to the sprocket, using a chainsize of #25,
How many teeth should the sprocket have? with my desired speed of 10 to 15 mph.

Last question: Estimating total weight with people on board at about 400-500#, Do you think I will achieve mph.
Look forward to your responses, have a great day
Ron

 

[itsid]

You're welcome Ron,
I think two more feet should be sufficient, but to be sure sou should measure your gradson up to his waist and ask your son-in-law to measure his height to the waist,
then get the measurements for all the bigger parts like motors, batteries etc.
just to have an educated guess about what goes where and how much room it'll take.

Personally I'd go for a Kid sits inside Thomas and Parent sits on Thomas layout I guess, but that's up to you.

For the tooth count, the motor is rated at 3100 rpm, assuming your wheel diameter is 11" you should use a 72 T sprocket (OD < 6") on the axle with that ratio (6.54:1) you would have a top speed of 15mph
You can play with different sprocket tooth counts here:
http://www.diygokarts.com/speed-calculator.html
in case you have other wheels in mind for example.

1600W in total is good enough to get it moving slowly on pavement yes, but uphill will be a different story, 500lbs is quite a task.

I think you might even need a second controller to make sure the motors are at the same rpm, if they're not exactly the same one will heat up quite badly.
I can't tell how good they are, so if you purchase two, ask the supplier to send two of the exact same batch.
Maybe one motor is an easier approach, given it has enough power of course.

Take into consideration, that you under no conditions want your grandson to touch any battery or motor terminals, neither be in an arms length of moving parts.
but given the weight you assumed, I guess you already have

'sid

 

[OzFab]

I think you might even need a second controller to make sure the motors are at the same rpm, if they're not exactly the same one will heat up quite badly.

Which begs the question, why two motors instead of one larger motor? (or did I miss something)

 

[jrotoole]

Motor

Mr. Sid,
Mr. Fabroman

My original thinking came from "buggies for fun" a UK website, their plan for a 1500 watt (2 motor) go kart, and I was going to use that plan as a basis for my design.

This morning I found www.electric-go-kart.co.uk with a free plan, that seems to better suit what I want to do. It appears to be a much heavier design only using a 500 watt motor.

I would definitely like to use only 1 motor, but what voltage/wattage/make/model?

Also both sites referenced 4QD controllers and they seem to be very expensive based upon my web surfing. Any recommendations?
If you guys have a chance to review the electric-go-kart site, you will see the kart with wide seat for 2. I'm going to keep the design for the seats to the back and from the front panel, modify to look like Thomas the train setup.
Thanks for all your help
Ron
I appreciate all input, this is sure a learning curve, but responses have help me greatly.

 

[dcastillo]

Im no expert, but I ordered one of these based on a recommendation from this forum
http://kellycontroller.com/kds48200200a24v-48v-mini-brushed-controller-p-395.html
I believe it can do a continuous 48V at 80amps, which is almost 4000Watts,
its over kill for my initial plans, but I eventually want to get two 1000W motors, one per rear wheel and control them from the single controller, I dont want to buy another controller when that time comes...
If you search that site you can find lots of controllers at different power ratings...
some advice, always over spec your controller to be on the safe side...