A-C Special (cyclekart)

[Todd]

Another question, if you don't mind. Did you fab the louvered side panels, or are they ready-made off of something else?

Those were from a 31 Model A hood that was laying around the shop.

 

[smallfoot]

Hey Todd, did you use a TAV with the forward motion? If so, which one?

 

[Neto]

Hey Todd, did you use a TAV with the forward motion? If so, which one?

I have a couple of old Snapper riding mowers - would the drive system off of that work, or would that add too much weight? (I'm talking about the type that has a flat disk against which a drive wheel rests, and can be moved toward the outside of the spinning disk to increase the speed, and across to the opposite side for reverse.)

 

[Neto]

Those were from a 31 Model A hood that was laying around the shop.

I was afraid of that - hoping that it was off of some appliance or something easier (& cheaper) to come up with. I have a lead on the sheet metal & gasoline tank from a Farmall C, and just thinking through how to complete the necessary sheet metal.

 

[Todd]

Hey Todd, did you use a TAV with the forward motion? If so, which one?

I used a clone Comet torque a verter.

 

[Todd]

I have a couple of old Snapper riding mowers - would the drive system off of that work, or would that add too much weight? (I'm talking about the type that has a flat disk against which a drive wheel rests, and can be moved toward the outside of the spinning disk to increase the speed, and across to the opposite side for reverse.)

Not sure that would work the best.

I was afraid of that - hoping that it was off of some appliance or something easier (& cheaper) to come up with. I have a lead on the sheet metal & gasoline tank from a Farmall C, and just thinking through how to complete the necessary sheet metal.

Some of the tractor pullers used a polished aluminum side panel to fill that area. Was a nice clean look.

 

[Neto]

Thanks, Todd.
re: Snapper drive system:

Not sure that would work the best.

I'll have to tear the Snapper down to see if it's workable. One potential problem is that it is only around 24" track width. If it can't be widened, then it won't work for sure, because it needs to be at least 36", right?

re: side panel ideas:

Some of the tractor pullers used a polished aluminum side panel to fill that area. Was a nice clean look.

I think I would either make something out of steel (and be forced to paint the whole thing), or possibly could use the lower body trim (plastic) off of a Chrysler minivan I scrapped several years ago.

Another question: Is the steel in your gasoline tank a lot thicker gauge than the sheet metal parts? (On the Farmall M one, the gas tank is made of a heavy gauge steel, and seems to weigh as much as the hood & grill shell put together.)
(I hope you don't mind the questions, if so, just ignore it. I don't want to be a pest.)

Basic mock up. Did you shorten your hood, or is this tractor just longer? (The hood section is 38 3/8" long.)

 

[Todd]

38" is the rear track width on the Stevenson type chassis.
The gas tank was thicker material than the other body tin. I cut my hood and moved the cut off to the rear, (you can see that in earlier pics) then molded in connector links.
I like your mock up. The brother in law says we should make a red one for him.

 

[bob w]

Todd, that cyclecart is so ding dang cool. Excellent job building it.

 

[smallfoot]

Hey Todd, help a brother out please! I've been trying to review this thread for info on your build in hopes of bringing my project along. For some reason, now none of the pix are showing up on the first page where your list of parts was. Could ya write the list out again??? I've deleted board cookies and signed out and signed back in to no avail on changing the pix back to working...
Thanks buddy!

 

[Neto]

If you attempt to load the pictures in a new tab, a message from PhotoBucket appears saying that they are down for maintenance. Other threads seem to be the same.

 

[Neto]

Todd, another question, if you don't mind. (I can't get this whole deal out of my mind....)

I've been reading on the cycleKart site a good bit, and I'm trying to understand the gearing ratios used with the CVTs. From what I see there, they get roughly 3:1 at the low end, up to a bit over 1:1 at the high end.

Then, they also talk about the gear reduction at the sprockets (chain), most running around 6:1 up to around 4.5:1. Does this sound right?

OK, now my question is, what is the final ratio at the axle? Assuming they use 6:1 reduction at the chain, and the CVT gives them 3:1 through 1:1, is the final ratio at the axle 18:1 at the low end, and up to 6:1 at the top end?

 

[Todd]

Hmmm, I just bought the recommended axle sprocket and used the gear that was on the CVT. It feels wicked fast to me.

 

[smallfoot]

Your final drive ratio would come from the ratio of the last two pulleys going to the shaft driving the wheels. 10 tooth on one and 60 on the other will give you about 6/1. The cool thing about the torque converters is that expanding belt pulley that changes diameter as the motor speeds up changing the whole deal from there on out. It allows you some breaking control with engine speed. We're having a ball with my kart and the grownups are in just as much as the kids. According to calculators, mine will do 31 mph. I firmly believe that....it's hauling buggy tho for kids going thru the woods out here...
All I can say is try one. Simple to build. Respectable fun for peanuts too. Go to the kart sites and follow directions if ya get stumped...nothing to it!

Lots of info here: http://www.bmikarts.com/Racing-Karts-and-Parts_c_778.html

 

[Neto]

Your final drive ratio would come from the ratio of the last two pulleys going to the shaft driving the wheels. 10 tooth on one and 60 on the other will give you about 6/1. The cool thing about the torque converters is that expanding belt pulley that changes diameter as the motor speeds up changing the whole deal from there on out. It allows you some breaking control with engine speed. We're having a ball with my kart and the grownups are in just as much as the kids. According to calculators, mine will do 31 mph. I firmly believe that....it's hauling buggy tho for kids going thru the woods out here...
All I can say is try one. Simple to build. Respectable fun for peanuts too. Go to the kart sites and follow directions if ya get stumped...nothing to it!

Lots of info here: http://www.bmikarts.com/Racing-Karts-and-Parts_c_778.html

OK. I think I understand now. You sort of ignore the variable ration at the CVT, or you might say assume it is running full out (at 1:1) to arrive at the final ratio of 6:1 with the gears you mention. Is this correct? So then the low end ratio (at just above idle, or where you begin to get forward motion) is around 18:1. Or am I still messed up? (Here's how I'm figuring this. I've read that the CVT's low range is around 3:1. So 3 X 6 = 18.)
The reason I'm trying to get a handle on this, is because I'm thinking of using a differential with a variable speed mechanism out of a Snapper riding mower as a jack shaft. From my figures, the stock ratio is about 37.8:1 in high gear. But I can easily drop that to 3.3:1 by leaving out part of the mechanism. That's about where the normal cycle cart's CVT is in the low range, so then my final gears (each wheel separate, from the jack shaft to the wheels) would need to be sort of reversed, like maybe 1:1.8, to get a final ratio of 6:1. (You can probably tell I'm still having trouble wrapping my head around this. Please don't laugh just yet.)

 

[Neto]

...
The reason I'm trying to get a handle on this, is because I'm thinking of using a differential with a variable speed mechanism out of a Snapper riding mower as a jack shaft. From my figures, the stock ratio is about 37.8:1 in high gear. But I can easily drop that to 3.3:1 by leaving out part of the mechanism. That's about where the normal cycle cart's CVT is in the low range, so then my final gears (each wheel separate, from the jack shaft to the wheels) would need to be sort of reversed, like maybe 1:1.8, to get a final ratio of 6:1. (You can probably tell I'm still having trouble wrapping my head around this. Please don't laugh just yet.)

I realize now that I reversed the way ratios should be represented in that last one. (I had 1:1.8, but the final figure should always be 1, for the rotation at axle. Correct?) I need to get some pictures of how this Snapper diff. is set up, and did take a few, but need more to hopefully have it make sense. But work is getting in the way of this.

 

[Neto]

Hey Todd, I don't know if you are still watching this thread of yours, but if so, I was wondering if you ever weighed the sheet metal from the Allis Chalmers you used. I recently got a scale, and weighed the cowl & hood from the FarmAll M I have, and just those two pieces come to around 43 lbs. I knew it was heavy stuff, but didn't expect that much.

 

[Todd]

I never did weigh it. Just went for the cool factor.