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Discussion Starter · #1 ·
Hi everyone,

I recently purchased a set of love joy couplings before realizing that it wouldn't work out because it was too small for the Warp9 motor I'm using. Here are some pictures to show what I'm talking about:
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The motor shaft is too long for the coupling so it sticks out (shown in first image) so when I put the second part of the coupling on, it doesn't sit all the way on properly leaving space in the middle (shown in second image). If I lift the bottom up, then it fits properly but it's elevated from the motor (shown in third image). If I put a key in and used the hex screw to jam the key in place, would that keep the coupling safely elevated and connected or is that not reliable?

My other option is buying a whole new lovejoy coupling that is larger. I've been looking on eBay and I can't seem to find the right one though. The Warp9 motor shaft is about 30mm tall so the coupling needs to be at least that tall. And the coupling can be 95mm in diameter maximum because that's the size of the small circle platform that it's sitting on. Please let me know if you have any links to lovejoy couplings that I can buy or if there's any way I can make what I have work.

Thanks,
Sifa
 

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How about a bushing under the coupling ? I assume there is a shoulder on that shaft, so whatever you put in there should be seated against the shoulder. It seems like you've got enough engagement on the key, you just need to make sure the coupler doesn't shift towards the motor during operation. So basically you need a spacer. ID is known, OD can roughly match such of the coupler, and so the only thing you need to figure out is how much thickness you need for it.
 

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Why the heck are you using a Lovejoy coupler? Im assuming you are putting this in an on road vehicle. No, Don't. Get a proper coupler that will hold up to the torque the Warp9 can dish out. You will destroy that Lovejoy and it won't be joy any longer.
 

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Why the heck are you using a Lovejoy coupler? Im assuming you are putting this in an on road vehicle. No, Don't. Get a proper coupler that will hold up to the torque the Warp9 can dish out. You will destroy that Lovejoy and it won't be joy any longer.
What are you connecting this coupling to? We need to know to come up with a better coupling.
 

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I recently purchased a set of love joy couplings before realizing that it wouldn't work out because it was too small for the Warp9 motor I'm using. Here are some pictures to show what I'm talking about:
View attachment 127364 View attachment 127363 View attachment 127362
The motor shaft is too long for the coupling so it sticks out (shown in first image) so when I put the second part of the coupling on, it doesn't sit all the way on properly leaving space in the middle (shown in second image). If I lift the bottom up, then it fits properly but it's elevated from the motor (shown in third image). If I put a key in and used the hex screw to jam the key in place, would that keep the coupling safely elevated and connected or is that not reliable?
Why are you insisting that the motor side of the coupling sits against motor case? Of course it can't touch the case because it would rub; the coupling is mounted on and located by the shaft, locked in place by the set screw, not the motor case or any step in the shaft diameter.

Here's a collection of support information from Lovejoy, which might help with understanding of how these couplings are used:
Product Resources – Installation Instructions, Videos, Catalogs
You appear to be using a keyed and set-screw equipped type L coupling, so the guide would be Jaw Couplings L-Line (L, AL, SS, C, H) Installation Guide (plus the accompanying video). As the guide explains, the face of the hub is normally aligned with the end of the shaft, and the exact positions along the shafts of the hubs are adjusted to give the correct space for the spider.
 

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Discussion Starter · #6 ·
After much research, I have come up with a better solution to the problem that I am facing. I will be using an L150 lovejoy coupler with a bore size diameter of 1.125 inches.
Why the heck are you using a Lovejoy coupler? Im assuming you are putting this in an on road vehicle. No, Don't. Get a proper coupler that will hold up to the torque the Warp9 can dish out. You will destroy that Lovejoy and it won't be joy any longer.
I chose to use a Lovejoy coupling because I'm following Rich Rebuild's Mini Cooper conversion where he also used an L150 lovejoy coupling and while I know that this conversion was pretty quick and dirty, it worked and was road worthy which is good enough for me. Also, according to the spec sheet below, an L150 coupler (which is larger than the L100 I am using currently) will be able to hold up to the torque of the Warp9. Here is the spec sheet for the L150 lovejoy coupler:
Rectangle Font Line Parallel Screenshot
Font Rectangle Number Screenshot Parallel

**Small note: the SOX(NBR) is the spider piece that will be going in between the two lovejoy couplers and the torque rating is somewhat dependent on that.
So according to the L150's torque rating of 1,240 in-lbs, I believe that it will be able to handle the Warp9's torque rating of 840 lbs-in. Please let me know if you think otherwise.

In this image that highlights the specs of the of the Warp9 motor, I've also highlighted the Warp9's RPM of 5,500 because the L150 apparently has a max RPM or 5,000. Here is the spec sheet:
Rectangle Font Line Parallel Number

So is this difference in max RPM's a problem or not? Someone please let me know.
What are you connecting this coupling to? We need to know to come up with a better coupling.
I will be using a 2006 Mini Cooper S Manual transmission shown below.
Tire Wheel Automotive tire Motor vehicle Automotive lighting

Why are you insisting that the motor side of the coupling sits against motor case? Of course it can't touch the case because it would rub; the coupling is mounted on and located by the shaft, locked in place by the set screw, not the motor case or any step in the shaft diameter.
Yes, I just realized that. In looking at Rich Rebuild's Mini Cooper conversion, I thought that the coupling was sitting on the motor base, but now I know that the coupling will need to sit up from the motor.

So...what does everyone think that using the L150 lovejoy coupling will work? Any more feedback is appreciated.
Rectangle Font Line Parallel Screenshot
Font Rectangle Number Screenshot Parallel
Rectangle Font Line Parallel Number
Tire Wheel Automotive tire Motor vehicle Automotive lighting
 

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After much research, I have come up with a better solution to the problem that I am facing. I will be using an L150 lovejoy coupler with a bore size diameter of 1.125 inches. I chose to use a Lovejoy coupling because I'm following Rich Rebuild's Mini Cooper conversion where he also used an L150 lovejoy coupling and while I know that this conversion was pretty quick and dirty, it worked and was road worthy which is good enough for me. Also, according to the spec sheet below, an L150 coupler (which is larger than the L100 I am using currently) will be able to hold up to the torque of the Warp9. Here is the spec sheet for the L150 lovejoy coupler: View attachment 127375 View attachment 127376 **Small note: the SOX(NBR) is the spider piece that will be going in between the two lovejoy couplers and the torque rating is somewhat dependent on that. So according to the L150's torque rating of 1,240 in-lbs, I believe that it will be able to handle the Warp9's torque rating of 840 lbs-in. Please let me know if you think otherwise. In this image that highlights the specs of the of the Warp9 motor, I've also highlighted the Warp9's RPM of 5,500 because the L150 apparently has a max RPM or 5,000. Here is the spec sheet: View attachment 127377 So is this difference in max RPM's a problem or not? Someone please let me know. I will be using a 2006 Mini Cooper S Manual transmission shown below. View attachment 127378 Yes, I just realized that. In looking at Rich Rebuild's Mini Cooper conversion, I thought that the coupling was sitting on the motor base, but now I know that the coupling will need to sit up from the motor. So...what does everyone think that using the L150 lovejoy coupling will work? Any more feedback is appreciated. View attachment 127375 View attachment 127376 View attachment 127377 View attachment 127378
After much research, I have come up with a better solution to the problem that I am facing. I will be using an L150 lovejoy coupler with a bore size diameter of 1.125 inches. I chose to use a Lovejoy coupling because I'm following Rich Rebuild's Mini Cooper conversion where he also used an L150 lovejoy coupling and while I know that this conversion was pretty quick and dirty, it worked and was road worthy which is good enough for me. Also, according to the spec sheet below, an L150 coupler (which is larger than the L100 I am using currently) will be able to hold up to the torque of the Warp9. Here is the spec sheet for the L150 lovejoy coupler: View attachment 127375 View attachment 127376 **Small note: the SOX(NBR) is the spider piece that will be going in between the two lovejoy couplers and the torque rating is somewhat dependent on that. So according to the L150's torque rating of 1,240 in-lbs, I believe that it will be able to handle the Warp9's torque rating of 840 lbs-in. Please let me know if you think otherwise. In this image that highlights the specs of the of the Warp9 motor, I've also highlighted the Warp9's RPM of 5,500 because the L150 apparently has a max RPM or 5,000. Here is the spec sheet: View attachment 127377 So is this difference in max RPM's a problem or not? Someone please let me know. I will be using a 2006 Mini Cooper S Manual transmission shown below. View attachment 127378 Yes, I just realized that. In looking at Rich Rebuild's Mini Cooper conversion, I thought that the coupling was sitting on the motor base, but now I know that the coupling will need to sit up from the motor. So...what does everyone think that using the L150 lovejoy coupling will work? Any more feedback is appreciated. View attachment 127375 View attachment 127376 View attachment 127377 View attachment 127378
 

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Motor torque output is basically proportional to current. The combination of 72 volts and 335 amps is enough electrical power for the 32 horsepower listed, but that combination of voltage, current, and power won't occur at either 5,500 RPM (that will be maximum speed) or 70 lb-ft (that will the maximum torque, at a lower speed); the 32 HP is a rated power for some condition that they think can be sustained, and perhaps the 70 lb-ft is for another sustainable condition, but the peak torque and power are both higher. The performance data for the WarP 9 at 72 volts shows 100 lb-ft (1200 lb-in) at 500 amps. That puts the Lovejoy L150 right on the edge for a WarP 9, and of course with more voltage and a controller able to handle more current both torque and power can be higher.
 

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Discussion Starter · #11 ·
Motor torque output is basically proportional to current. The combination of 72 volts and 335 amps is enough electrical power for the 32 horsepower listed, but that combination of voltage, current, and power won't occur at either 5,500 RPM (that will be maximum speed) or 70 lb-ft (that will the maximum torque, at a lower speed); the 32 HP is a rated power for some condition that they think can be sustained, and perhaps the 70 lb-ft is for another sustainable condition, but the peak torque and power are both higher. The performance data for the WarP 9 at 72 volts shows 100 lb-ft (1200 lb-in) at 500 amps. That puts the Lovejoy L150 right on the edge for a WarP 9, and of course with more voltage and a controller able to handle more current both torque and power can be higher.
Thanks this is very helpful. I have a 500A semiconductor fuse so even if I hit 500A, the fuse will blow, cutting off all power. Considering this and the fact that my system will be running on 88V nominal (96V peak), I think I'll be safe using the L150 lovejoy coupling. Do you agree?
 

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I have a 500A semiconductor fuse so even if I hit 500A, the fuse will blow, cutting off all power. Considering this and the fact that my system will be running on 88V nominal (96V peak), I think I'll be safe using the L150 lovejoy coupling. Do you agree?
It's on the edge of torque capacity, and speed would need to be limited... but the data says yes.
 

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Im thinking you will eventually not be joyous when the Lovejoy coupler dies. As a matter of practicality I think you should not cut corners when building an EV. You don't need to break the bank but you do want your parts to hold up and don't underestimate the the torque these motors dish out. For a stationary motor powering some belt driven device at low rpm the Lovejoy is perfect but for an on the road vehicle it is not practical. For a quick test of something maybe but for daily driving, I do not recommend under any condition for a DIY EV build. It is not the first time seeing someone wanting to use them. I even thought about but that was a rather fleeting thought. 500 amps or 2000 amps the motor dishes out lots of torque in ft lbs not in pounds.
 

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Discussion Starter · #15 ·
Im thinking you will eventually not be joyous when the Lovejoy coupler dies. As a matter of practicality I think you should not cut corners when building an EV. You don't need to break the bank but you do want your parts to hold up and don't underestimate the the torque these motors dish out. For a stationary motor powering some belt driven device at low rpm the Lovejoy is perfect but for an on the road vehicle it is not practical. For a quick test of something maybe but for daily driving, I do not recommend under any condition for a DIY EV build. It is not the first time seeing someone wanting to use them. I even thought about but that was a rather fleeting thought. 500 amps or 2000 amps the motor dishes out lots of torque in ft lbs not in pounds.
Ok, so I would not like my coupler to die but it seems like in this case everything works out fine. I'm using a Zilla controller and I'm setting the motor max amps to 450A (starting out at 300A max) so my amps will be relatively low. My max voltage is 96 which is also pretty low. The L150 coupling is also able to handle the max torque of the Warp9. So with all of these considerations, I don't really understand why it won't work. It seems near perfect to me. What do you think? Also do you have any other suggestions for couplings?
 

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I guess you are fully set on the Lovejoy so I can no longer persuade you to see. Experience is a good teacher. I await seeing your project on the road. I await your responses to your choices a year from now.
 

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Discussion Starter · #17 ·
I guess you are fully set on the Lovejoy so I can no longer persuade you to see. Experience is a good teacher. I await seeing your project on the road. I await your responses to your choices a year from now.
I am not fully set to Lovejoy. As I'm making this tough and important decision, I find it helpful to weigh the pros and cons based on facts so that I can make a better, more informed decision. I listed the facts that I have above in my previous post (mainly pros), but if you felt that something was off or that there was something that I was missing, please let me know because that would be a valuable part of my decision. I don't know about you but I would not like to have my EV fail after a lengthy conversion so I am willing to make changes if those changes are for the better, so please let me know why the Lovejoy won't work for my conversion and I'll take that into consideration.
 

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The teeth of the love joy, 3 per side is a weak point as well as the rubber center. Constant stop and go will eventually cause the center rubber piece to be slowly crushed and as the gap increases the degradation happens faster. The teeth of the Lovejoy are also a shape that can fail due to fatigue of the edges. They are not designed for constant stop and go hard torque situations. They are designed for light duty or for constant speed and use. So a motor that is always moving without high torque applications constantly beating it to death will last much longer. I think you might be underestimating the power of the torque from these motors. Im sure some Lovejoy couplers might work but using the original vehicles means to couple things together with a clutch or auto trans is best. The solid couplers are best. I chose to use my VW's clutch and pressure plate. I'll be putting in two induction motors for a 167 hp and 173 ft/lb torque at the motor but much more at the wheel. I want to be sure it all holds together. My flywheel will have two clutch discs and a floater plate for the clutch so a stock pressure plate will suffice for the pressure and double the surface area of the clutch disk. 144v and up to 1000 amps combined.

I don't know any who actually had any long term success with them.
 
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