Electric downhill/freeride bike

[Byte]

Just beautiful!

[GITech]

Very NICE!

[Ratking]

Hello guys,

Been doing a bit more work, still waiting for a lathe, but did some welding with a mig this time. Unfortunate, it got too hot, even when I tack-welded the cover. So the cover did bulge and I don't like that. It takes away the look of a serious build. Thats why I have decided to cut out the bad part of sheet-metal and make a cover in carbon fiber on both side. It's not just for looks, but also weight saving. The frame is already bullet proof, and I don't think there will be any structural weakness from me doing that.

Here's some pictures from the short time I had.

[Whiplash]

For sheet metal, a stitch weld is better suited. Set your gas flow higher than normal, use a bigger nozzle on the gun, and just use a series of quick tacks in a grow all the way down and it helps to pre heat the part a bit with a propane torch to spread the heat over the surface before welding to help minimize warping.

[Ratking]

For sheet metal, a stitch weld is better suited. Set your gas flow higher than normal, use a bigger nozzle on the gun, and just use a series of quick tacks in a grow all the way down and it helps to pre heat the part a bit with a propane torch to spread the heat over the surface before welding to help minimize warping.

Thanks, will try that next time. I guess there is no way to make the warping go away? There is so much to know about metal, its an art really. Sometime the best way to learn is by learning by my own mistakes.

[Ratking]

Hello guys,

Been doing some work in the lathe, but my phone decsided to delete all the pictures that i took, so I only got pictures of the finished parts.
I will weld them to the frame today.

The frame is almost finished, I just need to check the alignment of the jackshaft and crank before I weld them togheter.

[Ratking]

Hello guys,

Been doing a little more work, although there is alot more to go.
I had to take of some material on the parts I made and started to modify the torque limiter. I think I will try to make it a bit lighter, all the parts adds up quite a bit of weight. I will just spam the tread with progress pictures, if anyone have a question just ask.

[Ratking]

Hello guys,

I've been having some great progress with the build, and I think the frame is finished and ready for paint.
I think the best aproach is to wait with paint to everything is tested, so I don't get any unpleasant surprises when painted.

The motors are close together, I hope the losses aren't to big.

[recumpence]

Freaking awesome!

[Byte]

+1 Awesome! Can't wait to see the result of 2 Turnigys, never done on this forum before I think. (Only dual astros)

[waxman123]

Just Beatiful!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[etard]

Great work man, I can't wait to see how this thing performs, very close to a superlight motorcycle!

[Ratking]

Thanks for the kind words, I really enjoy this build.
I am a student, and its hard to focus on school when I get new ideas.
One thing I have to draw is a new torque limiter with a one way bearing and sprocket. I need a compact unit that is narrower than 40mm.
I will have to make everything very thin to fit.
First my plan was to use the rear cassette one the bike, but I think Matts approach with using the rear brake mount is much better, so I will try to make it fit.
The one way bearing with ID of 30mm can take 110 Nm, that should be enough for me.

[TopCat]

The more pictures I see, the more I fall in love with this build. Nice work Can't wait to see a walk around video of it before it burns some rubber

Regards
Tom

[Ratking]

Thanks Topcat, it gives me motivation to keep building

I mocked up the sprockets and chain to see if it cleared the chain as I hoped, unfortunately I had to buy a wider bottom bracket, so I hope that is covered.

I was not pleased with the torque limiter, so I made a new one in Inventor incorporating one way bearing that I also bought today. The specs says that it holds 110Nm, hope that true, I am only going to hit it with 60Nm by my calculations.

Since I don't have the skills to draw a sprocket properly and I cant find the sprocket generator in Inventor, the sprockets will show as a blank disk.

PS. The rust on the sprocket came with it when I bought it.

[E-racer]

Since I don't have the skills to draw a sprocket properly and I cant find the sprocket generator in Inventor, the sprockets will show as a blank disk.

looking good man!

In an open assembly follow this guide:


Select a plane or planar face:


Specify your setup (gear teeth):


Drag your sprockets into approximate locations (it will auto step to even chain length increments):


click ok, ok to create components:


Now constrain them wherever you want ( you wont be able to change the length between sprocket axis due to the set chain length you created earlier). They are all individual parts so you can sketch on them to fully detail them. When your done you should have something like this:

[Ratking]

Thank you, i did not know that you had to be in the assembly to get the design meny, thats where that was.
I will try to make a sprocket and chain today. interesting to see that you use Inventor also. Self-learned?

[E-racer]

Yea im self taught in Inventor I've been using autodesk stuff since 10th grade. I took engr graphics 1 and 2 in my undergrad but that was using solidworks and it was incredibly basic/waste of my time. I have some experience with CFD from our formula SAE restrictor design. I'm learning how to use the FEA features slowly.

[Ratking]

Yea im self taught in Inventor I've been using autodesk stuff since 10th grade. I took engr graphics 1 and 2 in my undergrad but that was using solidworks and it was incredibly basic/waste of my time. I have some experience with CFD from our formula SAE restrictor design. I'm learning how to use the FEA features slowly.

Ouch, I feel like a noob when I see what you can make in Inventor, I'm just able t open the program and make some circles and squares.

I was able to make some progress, although I'm not quite where I want to be. There are some minor issues that I need to address. One of them is where I can shoe horn the torque limiter in. I really have problems with having a tight and god design and including all the features that should be included in the bike.

[E-racer]

CAD is the key to elegant pakaging of componets in a confined space.

[Ratking]

Got my capasitivie discharge welder with scr working last night, and wow, this one is strong. Got four 1F car stereo capasitors in parralell and using Jeremys electrical design, altough I will change some details today. I started out with 12v and pressed the two probes against a steel plate, and kaboom, lightnings and shock. It was like a gunshot, so I started out with 6v after that( thats what I should have done in the first place). The welds got better and better until I got to 10v, then its starts to burst trough the original makita tabs that is a bit thinner than mine, I got 0.25mm nickkel plates. I have to say, this is one cheap way to weld batteries, I cant wait to make the packs in any shape I want.

[Craigh85]

Hi Ratking your builds looking great. Quick question on your nickel sheet for tabbing the cells together, I recently got a load of copper sheet approx 0.5mm thick to join my cells, is nickel a better material to use? My spot welder is based around a microwave oven transformer.

[Ratking]

Hi Ratking your builds looking great. Quick question on your nickel sheet for tabbing the cells together, I recently got a load of copper sheet approx 0.5mm thick to join my cells, is nickel a better material to use? My spot welder is based around a microwave oven transformer.

Thanks

As far as I know, nickel have four times higher resistance than copper, but is easily spot welded and will not corrode as fast as copper. The problem with copper is that it's very hard to weld, I know that several guys here tried it and they did not get any good results. I remember they tried different electrodes, but they all got stuck. I don't think that a cheap crude spot welder is up for the task, but I may be wrong.

[Craigh85]

dohh, ahh well could mabe just solder the copper then. nickel doesnt seem that easy to come by here unfortunately need to investigate further. Thanks for the advice , all the best . Craig

[Ratking]

dohh, ahh well could mabe just solder the copper then. nickel doesnt seem that easy to come by here unfortunately need to investigate further. Thanks for the advice , all the best . Craig

There are some sellers at ebay that have a good amount of different sheets of nickel, but quite expensive.
I did try to weld 02 mm copper, and it did work, but not a good as nickel did. You might want to try to get it to work, it would be a lot better than nickel, thats for sure.