Welding a geared hub motor clutch.

[slaphappygamer]

I’m no good at welding. I’ve never done it. I don’t have any of the equipment. I’d like to have my clutch welded to not freewheel and have regen. Instead of welding, could a welding compound be used?

Something like a SteelStick?

This looks like it would withstand the heat. Just not sure about the torque. Using unitconverters.net, 4000 psi is 27579029.173 NM (squared). This seems strong enough.

I feel like this would work except if the compound starts to breakdown. Maybe there are better options?

I have a Shengyi DGW22 rear hub motor.

 

[hillslayer@]

It's starting to look like the back and forth torque on axles break's them. Break pads don't cost enough to mess around with Regen .

 

[gromike]

Regen, if done right, is a great tool to have.

 

[slaphappygamer]

I was also considering opposing forces as well. Definitely don’t want to break anything.

More than saving on brake pads. I have a lot of hills on my 4 mile commute. Literally uphill both ways. I think it’ll serve me well

 

[amberwolf]

I suspect DP420 (like Doctorbass used to use to glue torque plates on frames with) would work.

Whatever you use you'll need to thoroughly degrease and clean all of the clutch parts involved.

If it's possible you can also roughen up all of the surfaces that need to be bonded to each other to ensure better epoxy bonding to them.

You may also want to replace the clutch springs with solid metal pieces that tightly fit between the rollers and the ramps to force them to stay engaged as an additional measure, if it's possible.

 

[slaphappygamer]

That DP420 looks like what I would need. Pretty expensive stuff though. I found a replacement clutch on Aliexpress. This clutch has been pretty hard to find so I might just buy one anyway. I might check with a friend of mine. He has welding things.

 

[slaphappygamer]

Regen, if done right, is a great tool to have.

Yes. I’m excited to do this last bit to gain regen. I was debating this method or wait to see what comes of Freegen but, the governed speed on downhill seems like a feature I would want. So I think this is a better method to gain regen, for my case.

 

[amberwolf]

Keep in mind that regen heats up motor, phase wires, controller, and potentially the BMS FETs (depends on the BMS design).

Using regen to regulate speed on downhill could overheat one or all of those, especially in a smaller geared hubmotor that has a long exit path for heat.

Regen is usually less efficient than driving the motor, depends on how the controller is designed and setup to do it. So the heat generated in regen is usually greater than just driving it, so you can overheat things with regen that don't overheat in traction.

So....you might want to add a thermal sensor while you're in there if you don't already have one, and keep an IR temperature monitoring gun with you for the initial testing so you can scan all the involved parts to see what happens.

 

[slaphappygamer]

Yes, I have a temp sensor and info from another user that have successfully installed a temp sensor, on the same motor. I just need to get off my butt and open the motor already……next weekend….maybe. I’d like to get the sensor in first, then regen another time. I kind of want to see a “before and after” regen mod temps.

 

[glennb]

Sorry, nothing to contribute to welding clutches, just wondering why you want to go slower down hills. Maybe just me, but I consider going top speed down hills the fun reward for the effort of climbing them.

 

[E-HP]

I’m no good at welding. I’ve never done it. I don’t have any of the equipment. I’d like to have my clutch welded to not freewheel and have regen. Instead of welding, could a welding compound be used?

I always look at DIY projects as an opportunity to acquire more tools. I watch a lot of those product review videos on YouTube, and saw this one and started trying to think of stuff that needs welding. Looking for a job for the tool, instead of the other way around lol.

 

[slaphappygamer]

Sorry, nothing to contribute to welding clutches, just wondering why you want to go slower down hills. Maybe just me, but I consider going top speed down hills the fun reward for the effort of climbing them.

I have to consider other drivers. The street I ride on has lots of side streets and driveways. It’s safer, for me, to not be barreling downhill. Some of the driveways and streets are blind. The faster I go, is less time other vehicles have to respond to me.

My co-worker is a road biker. He regularly complains about how he “almost got hit”. Well, I know he rides fast. He also doesn’t like to wait or stop. We commute the same route and I’ve never had a close call on that commute. Yes, he rides faster than me on my ebike. He is also a “local celebrity” in the bike community, since he has been biking for almost 40 years. So he’s got that attitude. Lol


Not that I want to go slower on downhills, I would like take advantage of getting some extra juice on my descents. Also, setting up regen is another thing I can tinker with.

 

[slaphappygamer]

I always look at DIY projects as an opportunity to acquire more tools. I watch a lot of those product review videos on YouTube, and saw this one and started trying to think of stuff that needs welding. Looking for a job for the tool, instead of the other way around lol.

Cheap is great. If it’s cheap AND works well, that is better. I have been looking at cheap stock welders as well. I might just get a new tool. I also dive drop in before a purchase. YouTube is great for that. Imagine me, decades ago, thinking “I hope this works” when there was no YouTube. With video reviews, you’ll know pretty fast and without losing money. Well, I have a birthday coming up, maybe I’ll put this new toy on my list. Lol

 

[Barncat]

I'd need to see the actual assembly in question, but this sounds like an idea I'd avoid.

Welded parts must be scrupulously clean, you are possibly talking dissimilar metals that cannot be joined, enormous heat is sunk into adjacent parts, and even if successful you then have cogging torque as drag whenever you're not on the throttle. Will look for a pic if you take motor apart...

 

[E-HP]

I'd need to see the actual assembly in question, but this sounds like an idea I'd avoid.

Welded parts must be scrupulously clean, you are possibly talking dissimilar metals that cannot be joined, enormous heat is sunk into adjacent parts, and even if successful you then have cogging torque as drag whenever you're not on the throttle. Will look for a pic if you take motor apart...

Grin has a decent instructional video

 

[slaphappygamer]

Grin has a decent instructional video

I was always bad at doing my homework in school, but I've been trying to make up for that in my adult life. haha. I've watched this video many times and also found this thread that includes photos of the same motor that I have. I was going to use the same method. I see the O ring and the plastic wafer that I'll need to remove. I should also apply new grease while I'm at it. This motor sounds and runs fine. I've got about 3-4k miles on it.

 

[Barncat]

Ok, watched the video, so it's already been done. I've done a lot of TIG, and am surprised that significant grease and oil didn't get sucked into the weld puddles in their example. And the cogging torque looks quite low, so have at it then if so desired. I would caution that tack welds can break, so it's a fine line here between strength and not damaging adjacent parts.

 

[slaphappygamer]

Now that I got that temp sensor in and working, Im going to monitor temps throughout the week. Monday high is 75F and Friday high will be 58F. Will be a good week to see the temp ranges. I'll note my findings in my build thread.

My buddy came by to help with the snap ring. I had the pliers and could separate the ring, but couldnt get it up off the shaft. Anyway, I showed him the clutch. He has done welding and has been a handyman for over a decade. He said it would be a piece of cake. Not sure why I didn't ask him in the first place. Ill bring it to him and buy him lunch.