Wiring to eliminate reverse

[MPS1982]

Originally Posted by crash test dummy

15 AH... that's really low

Any estimate for how long it might last?

thats a johnnieb question
my guess you need 58AH for one hour of run time at 25 amps
so maybe 15 min ???
help johnnie

[Clemsoncartguy]

Seems like a lot of work for a 15 minute ride or whatever?

[Clemsoncartguy]

Originally Posted by crash test dummy

thats a johnnieb question
my guess you need 58AH for one hour of run time at 25 amps
so maybe 15 min ???
help johnnie

Ha. I just read this after I posted what I did and it took me to the last page of this post!

[MPS1982]

Originally Posted by Clemsoncartguy

Seems like a lot of work for a 15 minute ride or whatever?

It's just a project to keep busy. I don't want to go spend hundreds of dollars on batteries. I picked all these up for a good price and figured whatever they can do will be fine. I'll be disappointed with 15 min, but at the end of the day, it's just for fun.

[Helirich]

Pretty cool. I worked at a company that had a small foundry many years ago. We did use sand casting, but had perminate molds that had to be packed in halves. I helped sometimes. It was interesting and rewording work, but it was a lot of work.

As far as machining, I can't see "no machining" on that part, but I have no experience with that kind of casting. We did make shinny parts, but not accurate enough to press bearings in. I'm thinking you will need to have a outside lip to tuck in to the motor and a bearing race accurate in the center.

The only reason we cast anything was because some of the parts would have cost to much to cut from billet. Example, it would require a 50 lb. billet to make a 7 lb. part. The rest would be a pile of chips. In your case, you could make that part with very little waste on a lathe.

I'm not trying to stop you. On the contrary, you've really got my interest. Please take lots of pics. This is a project I might take up. When I was a kid, some guy in my naighberhood made an electric mini bike. He used a 12V starter. I think he had to put bearings in it. (Instead of bushings) he had one big car battery. I don't know what he used for a controller. (Maybe it didn't have one)

[MPS1982]

Originally Posted by Helirich

Pretty cool. I worked at a company that had a small foundry many years ago. We did use sand casting, but had perminate molds that had to be packed in halves. I helped sometimes. It was interesting and rewording work, but it was a lot of work.

As far as machining, I can't see "no machining" on that part, but I have no experience with that kind of casting. We did make shinny parts, but not accurate enough to press bearings in. I'm thinking you will need to have a outside lip to tuck in to the motor and a bearing race accurate in the center.

The only reason we cast anything was because some of the parts would have cost to much to cut from billet. Example, it would require a 50 lb. billet to make a 7 lb. part. The rest would be a pile of chips. In your case, you could make that part with very little waste on a lathe.

I'm not trying to stop you. On the contrary, you've really got my interest. Please take lots of pics. This is a project I might take up. When I was a kid, some guy in my naighberhood made an electric mini bike. He used a 12V starter. I think he had to put bearings in it. (Instead of bushings) he had one big car battery. I don't know what he used for a controller. (Maybe it didn't have one)

If I had a lathe, I'd be on my way but I don't really have a good space for that kind of machinery. Also, I think a block of aluminum that size would be rather expensive, no? If you get bored, look up YouTube videos of people casting with aluminum. The detail they are getting leads me to believe that with the right procedure, I can get machine-free parts. The bearing will only have a light interference fit, and will be held in place with a retaining ring. In theory.

[INWO]

Originally Posted by MPS1982

Here's what I've come up with to run a shaft out of the open end of the motor. Currently this is a plastic 3d printed part but I have plans to make a mold of it and cast it in aluminum.

What is the reason for using a golf cart motor, if you need a shaft?

[MPS1982]

Originally Posted by INWO

What is the reason for using a golf cart motor, if you need a shaft?

Well, I bought the motor before I knew what I was going to do with it because I'm a sucker for anything involving lasers, magnets, or motors and I stumbled upon it for a price I couldn't resist. And now that I have it, I need to do something dangerous with it. It's a problem I have.

That said, if I could find a reasonably priced, nice powerful dc motor with an output shaft, I'd probably consider it.

[JohnnieB]

Originally Posted by MPS1982

I must say, you are doing a fine job following along here! I failed to mention my motor side sprocket is 20t and friction drive sprocket is 16t. I designed around the assumption that I'd be able to get the motor up to 3K rpm. I should be right about 25MPH if I hit 3200.

Any tips on where to find a used series motor for cheap? I have a tight budget for this build and a new motor pretty much folds this one up.

Oh and by the way, the size of the rear wheel is irrelevant in this drive set up. The friction driver surface speed will match ground speed regardless of wheel size. I could have a 3" wheel and I'd have the same speed and acceleration characteristics. But I want the huge wheels so it's a smooth ride (saves me the trouble of coming up with a suspension). Plus, it looks more ludicrous. Wheels are from a Suzuki gsxr

Oops, the fact it is a friction drive on the tire's circumference managed to dodge around the few functioning brain cells I have left.

So you effectively have a 2" tire height and a 0.8:1 final drive ratio, which will give you 23.8 MPH at 3200 motor RPM (25 MPH is 3361 RPM)

As for finding an inexpensive series motor, try posting a WTB in the but/sell parts forum here: http://www.buggiesgonewild.com/golf-carts-parts/


In addition to a smoother ride, the tall tires have a lower impact angle on the bumps and might reduce the drag a little.