PM45 - Moving the head height crank to the front.

Does anyone have a torque wrench that can check how much torque is needed to lift the head?

The lowest my wrench goes is 40 ft-lb/55Nm.

Gary

With how tight I have my gibs currently adjusted (any tighter causes the head to skip when lowering), I get about 8 ft-lbs with my Snap-On digital to get it moving. But this was just a quick & dirty method of measuring so YMMV. I'll see if I have something handy to take a reading directly on the shaft to eliminate the error of the Z handle.

But for now, the highest reading I got was 9.2 ft-lbs to break the tension to get it moving. Max continous movement was roughly around 5-6 ft-lbs. 5ft-lbs is the lowest reading on this wrench. With my clicker type torque wrench with a min reading of 10ft-lbs, the head moved before reaching the 10ft-lbs setting.


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With how tight I have my gibs currently adjusted (any tighter causes the head to skip when lowering), I get about 8 ft-lbs with my Snap-On digital to get it moving. But this was just a quick & dirty method of measuring so YMMV. I'll see if I have something handy to take a reading directly on the shaft to eliminate the error of the Z handle.

But for now, the highest reading I got was 9.2 ft-lbs to break the tension to get it moving. Max continous movement was roughly around 5-6 ft-lbs. 5ft-lbs is the lowest reading on this wrench. With my clicker type torque wrench with a min reading of 10ft-lbs, the head moved before reaching the 10ft-lbs setting.

Very cool tool! But that's not the way to measure it. You would need to do some math to come up with the correct number. Kind of like you would using a crows foot.

I make this out of some 1" CRS I had laying around. I could have tapped the end and screwed in a hex head bolt real tight, but I just used my indexer to the cut the hex.

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But my clicker wouldn't go low enough. I can't justify buying a torque wrench just for this.

Gary

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Very cool tool! But that's not the way to measure it. You would need to do some math to come up with the correct number. Kind of like you would using a crows foot.

I make this out of some 1" CRS I had laying around. I could have tapped the end and screwed in a hex head bolt real tight, but I just used my indexer to the cut the hex.

Yeah I know, that's why I mentioned that in my post. I figured since you know the length of the handle you could just do the math. ;)

You got me curious so when I got home I made a proper adapter. Funny cause using a hex head is exactly what I did since it was easier & I didn't feel like seting up the super spacer.

So here you go, I'll save you math..... I get about 6-7 ft-lbs consistently turning it. If I pull real slow it takes about 11 ft-lbs to break the tension to start movement. I forgot to test lowering the head before I put the handle back on but I didn't think it was necessary anyway. Since I have the adapter now it's easy to take more measurements if you need them.


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What? None of you guys has an in/lb torque wrench? Need to borrow mine, Gary, or is this academic?
 
I've got an in-oz torque wrench and think I used it once. -Not planning on testing the PM 45 crank though... About a year ago, I set out to motorize mine and did a quick test by rigging-up a bar of some sort, held it horizontal and put gym weights on it until it moved. Don't remember the exact dimensions of the bar but it came out to around 10-11ft-lb because I jotted the number down with a marker on the column. My plan was to find a gear motor with at least 25ft-lb but I couldn't find one at the RPM and price-point I was comfortable with. -Never did get around to making something.


I gave somebody down there a "Thanks" for testing with a torque wrench because, it pretty-much validated my prior test.

Ray

What? None of you guys has an in/lb torque wrench? Need to borrow mine, Gary, or is this academic?
 
Yeah I know, that's why I mentioned that in my post. I figured since you know the length of the handle you could just do the math. ;)

You got me curious so when I got home I made a proper adapter. Funny cause using a hex head is exactly what I did since it was easier & I didn't feel like seting up the super spacer.

So here you go, I'll save you math..... I get about 6-7 ft-lbs consistently turning it. If I pull real slow it takes about 11 ft-lbs to break the tension to start movement. I forgot to test lowering the head before I put the handle back on but I didn't think it was necessary anyway. Since I have the adapter now it's easy to take more measurements if you need them.

Thanks Will,

Now I just need to find a reversible AC gear motor with over 168 in.-lb (double your reading) of torque at 60+ RPM. All this at a decent price.

After using the front crank for a while I find that it's so much better. It's great even without a motor.

Gary
 
Thanks Will,

Now I just need to find a reversible AC gear motor with over 168 in.-lb (double your reading) of torque at 60+ RPM. All this at a decent price.

After using the front crank for a while I find that it's so much better. It's great even without a motor.

Gary

Your welcome Gary, anytime.
 
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