Video on coupling for a leaf motor from damian
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Jacobsmess
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Video on coupling for a leaf motor from damian
Do I remember rightly in that there was a video about this from Damian? I cannot seem to find it now but I remember he used a few particular tricks for a DIY coupling and making an adapter plate. He also recommended a particular type of pipe but I can't seem to find it anywhere... Anyone got any ideas?
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Bratitude
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Re: Video on coupling for a leaf motor from damian
Jacobsmess wrote: ↑Sun Jun 11, 2023 7:40 pm Do I remember rightly in that there was a video about this from Damian? I cannot seem to find it now but I remember he used a few particular tricks for a DIY coupling and making an adapter plate. He also recommended a particular type of pipe but I can't seem to find it anywhere... Anyone got any ideas?
i have write ups on the subject: https://bratindustries.net/how-to-mate- ... r-coupler/
and have couplers available for the leaf motor, https://bratindustries.net/product/niss ... coupler-2/
solturbolove has some good videos on making a gearbox adapter
https://bratindustries.net/ leaf motor couplers, adapter plates, custom drive train components
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Jacobsmess
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MattsAwesomeStuff
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Re: Video on coupling for a leaf motor from damian
I'm a little skeptical of Damien's methods here, as Damien has regularly shredded transmissions (5? 6?). His workaround seems to be to use the Diesel version of the transmissions, which are heavier duty. But I wonder if he's going through transmissions so quickly because of misalignment.
He addresses this a bit at the end of the video, some strong naysaying going on that you have to align the transmission within 0.004" accurate (about a sheet of paper), and, that transfer punches are nowhere near accurate enough, bolts aren't nearly accurate enough, you need the dowel pins to center it, etc. This is true, that is OEM spec, and, misalignment of the concentricity of the shaft will soon (or eventually) ruin transmissions. You cannot rely on the center of the transmission input, as it can move 5-10mm in any direction, as it's supposed to be supported by the pilot bearing in the engine. That's not within 2 orders of magnitude accurate enough.
Also, basically no one has a lathe and mill capable of doing this at home, and if they did, they probably don't need advice from Damien how to machine, so, it's a bit of a catch-22 advice-wise. He's shown a solution that is a solution, but isn't a solution to anyone who'd need the solution.
In a video Damien made many years ago, he cut a hole in the side of the bell housing and put a dial test indicator onto the shaft to measure runout. I'm not sure even that would suffice, but it'll pick up vibration and misalignment a lot better than just finger pressure and hope will. (He's actually made many videos on this over the years, for various vehicles). I think you lightly clamp the two together, and then bump one with a rubber mallet to slowly adjust it truer and truer, then clamp tight, doublecheck, and then drill your dowel holes and bolt holes using the existing holes as your template without taking anything apart.
13 years ago, part 3:
10 years ago:
9 years ago:
8 years ago:
...
I can't actually find the one I'm thinking of. But I'm almost certain there was one in there that he put the dial indicator through the hole he cut in the bell housing.
If someone digs it up, post away. I've gone through a few hours of footage now trying to find it.
He addresses this a bit at the end of the video, some strong naysaying going on that you have to align the transmission within 0.004" accurate (about a sheet of paper), and, that transfer punches are nowhere near accurate enough, bolts aren't nearly accurate enough, you need the dowel pins to center it, etc. This is true, that is OEM spec, and, misalignment of the concentricity of the shaft will soon (or eventually) ruin transmissions. You cannot rely on the center of the transmission input, as it can move 5-10mm in any direction, as it's supposed to be supported by the pilot bearing in the engine. That's not within 2 orders of magnitude accurate enough.
Also, basically no one has a lathe and mill capable of doing this at home, and if they did, they probably don't need advice from Damien how to machine, so, it's a bit of a catch-22 advice-wise. He's shown a solution that is a solution, but isn't a solution to anyone who'd need the solution.
In a video Damien made many years ago, he cut a hole in the side of the bell housing and put a dial test indicator onto the shaft to measure runout. I'm not sure even that would suffice, but it'll pick up vibration and misalignment a lot better than just finger pressure and hope will. (He's actually made many videos on this over the years, for various vehicles). I think you lightly clamp the two together, and then bump one with a rubber mallet to slowly adjust it truer and truer, then clamp tight, doublecheck, and then drill your dowel holes and bolt holes using the existing holes as your template without taking anything apart.
13 years ago, part 3:
10 years ago:
9 years ago:
8 years ago:
...
I can't actually find the one I'm thinking of. But I'm almost certain there was one in there that he put the dial indicator through the hole he cut in the bell housing.
If someone digs it up, post away. I've gone through a few hours of footage now trying to find it.
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Bratitude
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Re: Video on coupling for a leaf motor from damian
if anything hes blown the gear boxes from the fact that some of the bmw boxs are weak to begin with and not up to snuff for the electric torque. im sure diamine gets up to some naughty fun...these are RWD cars after all.
the method of vertically stacking, running the motor intill to help settle everything works pretty darn good for those making adapters by hand. if your looking for a better finish your going the cnc rout anyway
the method of vertically stacking, running the motor intill to help settle everything works pretty darn good for those making adapters by hand. if your looking for a better finish your going the cnc rout anyway
https://bratindustries.net/ leaf motor couplers, adapter plates, custom drive train components
Re: Video on coupling for a leaf motor from damian
Its always difficult with these things. The basic BMW Getrag box fitted to the 320i is rated to 250nm for instance so its very possible they're being overtorqued. However its also not that uncommon in the automotive tuning scene to crank up engine power/torque beyond the oem ratings, and a lot of the time the gearbox is fine. (some models are worse than others ofcourse) OEM's dont (usually) like running things on the ragged edge.
An anecdote from another sphere, Landrover R380 boxes live quite happily behind a 4.6L V8, but can fail behind a tuned TD5 making similar torque. The theory in the landrover circles is that the torque pulsation from the diesel having less cylinders hits the box harder, where as the V8 sees more, smaller pulses and the box doesnt see the same extremes.
Taking that further, one could surmise that nice smooth electric torque should be even better on the transmission than a combustion engine. They also dont have to deal with someone smashing the clutch out with the engine spinning at high RPM's in an EV.
This is ofcourse the problem with these modifications. We simply cant know the failure cause. It might be the torque, it might be the misalignment. It might be a bit of both mixed together. You'd have to do detailed analysis on the box (ideally multiple boxes!) to see what actually failed, and thats typically beyond the home gamer.
It will also depend a lot on the design of the gearbox. Some boxes have a very poorly supported input shaft, relying heavily on the pilot bearing to ensure the bearing and gear alignment is perfect. Other boxes have a much better support for the input, and it may well be those live much longer with things are done in a less accurate manner. I've seen FWD boxes with no pilot bushing whatsoever. The input is part of the main shaft and extremely well supported internally and they simply dont need it.
It really depends on your outlook, theres something to be said for just getting it together and working well enough. Buy a spare box and stick it on the shelf if they're cheap enough. If the failures become an issue, it can be revisited. Others might want a more expensive "one-and-done" fix, doing their utmost to get it right first time.
An anecdote from another sphere, Landrover R380 boxes live quite happily behind a 4.6L V8, but can fail behind a tuned TD5 making similar torque. The theory in the landrover circles is that the torque pulsation from the diesel having less cylinders hits the box harder, where as the V8 sees more, smaller pulses and the box doesnt see the same extremes.
Taking that further, one could surmise that nice smooth electric torque should be even better on the transmission than a combustion engine. They also dont have to deal with someone smashing the clutch out with the engine spinning at high RPM's in an EV.
This is ofcourse the problem with these modifications. We simply cant know the failure cause. It might be the torque, it might be the misalignment. It might be a bit of both mixed together. You'd have to do detailed analysis on the box (ideally multiple boxes!) to see what actually failed, and thats typically beyond the home gamer.
It will also depend a lot on the design of the gearbox. Some boxes have a very poorly supported input shaft, relying heavily on the pilot bearing to ensure the bearing and gear alignment is perfect. Other boxes have a much better support for the input, and it may well be those live much longer with things are done in a less accurate manner. I've seen FWD boxes with no pilot bushing whatsoever. The input is part of the main shaft and extremely well supported internally and they simply dont need it.
It really depends on your outlook, theres something to be said for just getting it together and working well enough. Buy a spare box and stick it on the shelf if they're cheap enough. If the failures become an issue, it can be revisited. Others might want a more expensive "one-and-done" fix, doing their utmost to get it right first time.