LightningRods mid drive kit
- Thread starter spinningmagnets
- Start date
oh, i didn't mean in great detail, cause like i said i'd never understand the details, was something along lines of
1. replace motor shaft with pulley: 2-3 hrs.
2. heat treat jack shaft: 1 hr
3. paint parts : 30 mins
like a cooking recipe. probably he has a list like it taped somewhere between the mountain of parts
1. replace motor shaft with pulley: 2-3 hrs.
2. heat treat jack shaft: 1 hr
3. paint parts : 30 mins
like a cooking recipe. probably he has a list like it taped somewhere between the mountain of parts
spinningmagnets
100 TW
Takes a long time when you make one kit start to finish, then better when you make several kits at the same time, then a dozen kits at once, then 20, etc...it will evolve. Here's a pic of my wife:
Yea that's part of the reason I don't want to get married, I hate to think of all the fights I would have for throwing all that money on ecospeed kits,controllers, parts ,never getting license I feel guilty just thinking about it, never "growing up"
Then again I capture portals from another dimension in my spare time (go smurfs!) So I'm long gone in terms of responsible aduLtd.
Then again I capture portals from another dimension in my spare time (go smurfs!) So I'm long gone in terms of responsible aduLtd.
Wishes
1 kW
emaayan said:Yea that's part of the reason I don't want to get married, I hate to think of all the fights I would have for throwing all that money on ecospeed kits,controllers, parts ,never getting license I feel guilty just thinking about it, never "growing up"
Then again I capture portals from another dimension in my spare time (go smurfs!) So I'm long gone in terms of responsible aduLtd.
ROFL emaayan.
Don't you guys know the Wife trick? We have a saying in the RC world, "When I die, please don't let my Wife sell my hobby collection for the amount I told her I paid" Everything cost $25 or $50
Wishes
Mike,
I'm back on the project and am having trouble adjusting the tension on the belt and chain. After tensioning everything and tightening as much as I can, the chain keeps getting loose. I'm running a test where I run the motor at full speed and then slam on the brake. That always causes the whole contraption to skew to the side and slacken the chain. This test is designed to simulate the loads that I will put on the bike going up the steep SF hills.
As far as I can tell, the weak link seems to be in the lower sheet adjustment. The carriage bolts are really skinny and are having a hard time holding on when I run the above test. In fact, I've already snapped one of the bolts from over tightening, even though I didn't put that much torque on it.
It looks like the lower sheet is skewing on the secondary side. Given that the nut for the carriage bolts is 3-1/2 inches away, on the other side, there really isn't anything holding the chain side still.
Any advice? Is anyone else seeing this problem? I'm sure my original GNG setup was doing this also, but with the GNG idle wheel, I guess I never noticed
Jim
I'm back on the project and am having trouble adjusting the tension on the belt and chain. After tensioning everything and tightening as much as I can, the chain keeps getting loose. I'm running a test where I run the motor at full speed and then slam on the brake. That always causes the whole contraption to skew to the side and slacken the chain. This test is designed to simulate the loads that I will put on the bike going up the steep SF hills.
As far as I can tell, the weak link seems to be in the lower sheet adjustment. The carriage bolts are really skinny and are having a hard time holding on when I run the above test. In fact, I've already snapped one of the bolts from over tightening, even though I didn't put that much torque on it.
It looks like the lower sheet is skewing on the secondary side. Given that the nut for the carriage bolts is 3-1/2 inches away, on the other side, there really isn't anything holding the chain side still.
Any advice? Is anyone else seeing this problem? I'm sure my original GNG setup was doing this also, but with the GNG idle wheel, I guess I never noticed
Jim
speedmd
10 MW
You need to anchor the top support better to the down tube. That will fix it.
LightningRods
1 MW
spinningmagnets said:
What most women don't realize is that there always has to be "another woman". If that other woman is a car, or a motorcycle or an electric bike, she's lucky.
I have 40 motor shafts out of the cases and ready to go to the machine shop. I've been given a lead time of about a week. Let's keep our fingers crossed that this is a week in some time dimension that we're familiar with. I've found that a laser shop 'week' equals about four Earth weeks.
I agree that a better upper frame clamp is needed. At this point I'm using the GNG hose clamp method which I've never liked. I'm working on custom solutions for several customers specific bikes. What's difficult is a universal clamp that will fit all of the different sizes and profiles of front downtubes out there. I could easily offer several sizes of straight, round tube clamps. But for tapering tubes, curving tubes, trapezoid rectangles, I'm not sure what to do. I'm open to suggestions.
KMB
10 mW
http://www.lawsonproducts.com/image...aust-Clamp/largeImage/DV_WebLarge_P_25028.jpg
Mike....would something like this work? Increase of clamping area and force? They actually form to different shapes.
Mike....would something like this work? Increase of clamping area and force? They actually form to different shapes.
LightningRods
1 MW
More surface area would make it better than a hose clamp. We need something to resist the twisting forces caused by the secondary chain pulling on the right side of the upper sheets. Users can add their own torque arms but again that leaves more engineering and fabricating than many people want to deal with.
I've been reading about some two part epoxy putty that can be formed right on the bike. I could provide the metal parts that attach to the upper bracket and surround the formed epoxy block. A piece of sheet plastic could be inserted on both sides of the frame while the putty is setting up so that it forms a split block to grab the frame.
I'll do some drawings if I can find a minute.
I've been reading about some two part epoxy putty that can be formed right on the bike. I could provide the metal parts that attach to the upper bracket and surround the formed epoxy block. A piece of sheet plastic could be inserted on both sides of the frame while the putty is setting up so that it forms a split block to grab the frame.
I'll do some drawings if I can find a minute.
You can get much better quality strap clamps like hose clamps, my neighbour gave me some, cut to length, made of 1.2mm thick stainless. Made for industrial ac gear, so super strong.
Still cam-screw tightened. Works great on mine.
For those willing to drill into their frame, another option is to use a rivnut (scrivet?, they have a few names).
Still cam-screw tightened. Works great on mine.
For those willing to drill into their frame, another option is to use a rivnut (scrivet?, they have a few names).
speedmd
10 MW
I attached photo of my prototype mount that was extremely effective at stopping the twist in the upper motor assembly. Pardon the temporary clamp / screw setup as it was a quick test to see how/if it would work. The down tube nests into the aluminum block that I matched cutout diameter to the down tube diameter and only slight strap clamp pressure is required to hold it rock solid. I have cleaned it up since but no new photos, hopefully you get the idea from the old shot.
LightningRods
1 MW
A huge improvement! A broader base and much more contact with the frame tube are high on my priority list for this bracket. Thanks for sharing your mods.
Cryptic
10 W
LightningRods said:
Don't know if it would be strong enough - would Polymorph (polycaprolactone) be of use to fashion the equivalent of speedmd's ali block?
speedmd
10 MW
I think UHMW or HMW Poly (ultra high molecular weight polyethylene) would work fine. 13mm / 1/2in sheet that they use for cutting boards should hold up as long as your not trying to anchor the strap to it with just a few screw threads. As a spacer, it should do fine. Mike, it can be cut easy with low watt laser to fit different tube diameters or even leave it somewhat more of a vee block with a bit of padding to accommodate a broader range of tube diameters. Poly-carbonate is terrible around oils and greases and its creep strength (fractures over time with mild screw pressures) is very poor. You can make one easy with a hack saw/ drill and half round coarse file.
MitchJi
10 MW
Hi,
What about non-round downtubes?
What about non-round downtubes?
speedmd
10 MW
MitchJi said:
You can match any tube shape you need to match. Just file away.
Once it is nested and the block is locked between the plates, you will not need much clamp to hold it from moving side to side from significant chain loads. It was fine on mine running more than 3kw. Much better than stock GNG at 50v with the stock 20 amp controller.
The force that we need to counteract is shown by the green vector in the picture. It would seem to me that some kind of stiffener acting in the opposite direction is what's needed. Clamping to the down tube seems like it wouldn't help much, as the jackshaft is still free to rotate (purple vector).
The lower sheet and upper sheet form 2 sides of a triangle. It would make sense to close the triangle with a bar or bracket along the top. It would have to be adjustable of course, given that the other 2 sides are adjustable.
Possible solutions might be a straight piece that clamps to the seat post. Or a curved piece that connects to the bottom bracket at the lower sheet. But, that would have to be rigidly attached to the lower sheet so that it can't rotate back against the chain.
LightningRods
1 MW
You're agreeing with what has already been said. We need to resist the twisting forces caused by the secondary chain.
