Building an EV motorcycle. Batteries: Need opinions.

[TurnNBurn]

Originally Posted by mechman600

Probably not a big deal being on the unloaded side of the chain. Ryland's suggestion is good. Even a simple plastic guide would be good enough on the unloaded side, the same as most motorcycles use along the top of the swing arm to guide the chain during decel.

Nice build!

I don't know if I would feel comfortable with the chain sawing away at the plastic and then the swing arm. I'd be paranoid it would cut through. I don't think the picture does it justice, but it's not a little rubbing. It's actually resting a lot on that arm. It doesn't look good.

Thanks for the compliments. I'll have to get the higher res copies up soon. They have better lighting.

[mechman600]

I just took this photo. My bike has 50K miles on it and the rubber/plasticky chain guides (top and bottom) are like new.

[TurnNBurn]

Originally Posted by mechman600

I just took this photo. My bike has 50K miles on it and the rubber/plasticky chain guides (top and bottom) are like new.

Hmmm. in my head here at work I remember mine being uncomfortably relaxed with too much slack. I'll have to check again when I get home and reconsider. I could also test it for a while and see how comfortable I am with a custom chain guide.

I plan to get some lead acid batteries (two) and break it in while I wire up everything. I'll see how the guides hold up then. If I need to re-position the motor mount I can do that easily.

The original bike and chain also had a rubber guard that I mutilated getting off, but this chain now is dropping way too low from what I remember. But like I said, I'll have to double check it when I get home.

[Ryland]

Placing the motor in such a way that nothing rubs is ideal, but plastic cutting board is amazing stuff and you can cut it on the table saw, same with roller skate wheels, chuck them in the drill press and turn a notch in them for the chain or just use them as they are.

[mechman600]

Originally Posted by TurnNBurn

I plan to get some lead acid batteries (two) and break it in while I wire up everything.

Make sure they are wired in parallel. 24V is too much for unloaded motor and may cause your fancy new motor to fling bits all over the place.

[Daox]

He has a permanent magnet motor, he'll be fine. Its not series wound.

[TurnNBurn]

Originally Posted by mechman600

Make sure they are wired in parallel. 24V is too much for unloaded motor and may cause your fancy new motor to fling bits all over the place.

Yeah, I'm a bit confused. how would 24v be too much for this motor?

[mechman600]

24V to an unloaded series wound motor would likely cause it to over rev. Like Daox said, you should be fine. I forgot PM motors are different.

[TurnNBurn]

I just re-assessed the chain slack situation and there's no way I'm going to just patch it up with a chain guard. The motor has to be moved. So I'm going to head to Lowes and get a bar of aluminum so I can make a bracket to mount it about 1.5" higher.

-edit-
progress will be halted until I am healed. I may have torn a muscle in my arm while putting that rear wheel back on the bike.

[TurnNBurn]

Okay, everything is healed and I've started working on the bike again. Since the 12"x12" plate of aluminum had enough scrap metal leftover from cutting out the mounting plate, I was able to use my angle grinder and cut out some spare bracket pieces. I was able to get a 1" wide piece by about 10" long and I'm going to use this to raise the motor about 2 inches higher. This should be the perfect height. I'm in the process of drilling the holes now, but I need to stop by lowes to get some bolts for the new bracket. I'll post progress pics of the bracket modifications and pictures of the motor lifted.

After this, the chain gets connected and I think I'm done except for mounting and wiring the controller. After the controller and wiring is in place, I'm going to get 2 lead acid batteries (only using lead acid for a temporary dry run) and we'll see this bike on the road.

-edit-

Mounting plate has been raised, the bracket is done and it seems to look good. Top of the chain is no longer rubbing but the lower half looks iffy. I won't know about the lower part of the chain rubbing until I have the chain set to the proper length and the master link is in place.

-edit-

Went to work on the chain to adjust it to length and I guess I'm going to buy a stand for the rear wheel. That'll make life a lot easier. So until payday I can't get the stand and until I get the stand I can't adjust the chain. Without adjusting the chain I won't know if it's still rubbing.