# Made a new pulley speed label for my PM935 this morning.



## Ken226 (Aug 16, 2021)

When I had the head apart installing the tach sensor and 3 phase motor,  all of the handling ended up damaging the spindle speeds decal label.    I removed the decal because it was barely useable.

This morning I didn't have anything else to do,  so I made a new label out of some 1/8" aluminum plate.

I cut out the shape on my band-saw, milled it square, then bent in on a press brake.

The coating is cerakote cobalt,  and I engraved it with a diamond drag tool.

I used the existing holes from the stock switch to mount it.


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## Ken226 (Aug 16, 2021)

Bummer.  I already see a screwup.   It should say motor on the left side, and spindle on the right.  I got that backwards.


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## Aukai (Aug 16, 2021)

I like how it came out.


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## extropic (Aug 16, 2021)

Ken226 said:


> Bummer.  I already see a screwup.   It should say motor on the left side, and spindle on the right.  I got that backwards.



It looks very good. 

Backwards? It depends which side of the machine you're on when changing speed.

If you re-do it, hinge the face so it swings back against the side of the head. YMMV

PS: I think I saw a speck of dirt on your machine . . . . . Never mind. It's on my monitor.


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## Ken226 (Aug 16, 2021)

extropic said:


> It looks very good.
> 
> Backwards? It depends which side of the machine you're on when changing speed.
> 
> ...




I made another one today and made a cnc program correcting the engraving error.  I'll run the engraving tomorrow and put it in.

Yea, I fully admit to being OCD about some things.  As evident by remaking the chart over a minor typo. 

Cleaning and maintaining my equipment is another thing tend to go too far on.  I've got little shop-vac attachments that let me get into all the little nooks and crannies.  

Everything gets wiped down with mineral spirits after use,  and kept nice and pretty. If/when I kick the bucket,  potential buyers shouldn't have much to nit-pick when the wife sells it all.

The scratches all over my lathes stand bugged my so much, I paid $$$ to have it stripped and powder coated.   My brand of OCD is an expensive one as well.


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## Ken226 (Aug 17, 2021)

I finished up version 2.0.   corrected my mistake and added a little more fluff.

No hinge for folding though.  I didn't have anything suitable handy, and didn't wanna postpone to order parts.





Here's a pic just for you @extropic 
See, there are a few chips in there.  But they won't be there long.


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## extropic (Aug 17, 2021)

Lets see if I can tickle your OCD a little.
I don't know your machine but because you reference hz, I'll assume it's 3 phase powered by a VFD.

On the plaque, the center column RPM (Nominal RPM?) indicates @*65*hz. Why not *60*hz?

When I read "Minimum" and "Maximum" I want to know "at what frequency?". I would replace min and max with XXhz. Or, XXhz MIN. and XXXhz MAX.  YMMV

The nomenclature at the bottom is too cryptic for me to decipher. I'm curious, if you want to explain.


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## Ken226 (Aug 17, 2021)

extropic said:


> Lets see if I can tickle your OCD a little.
> I don't know your machine but because you reference hz, I'll assume it's 3 phase powered by a VFD.
> 
> On the plaque, the center column RPM (Nominal RPM?) indicates @*65*hz. Why not *60*hz?
> ...



Basically, for the middle column I used the RPM from the stock PM label.   I set the corresponding pulley/belt arrangement,  turned on the spindle and adjusted the potentiometer to the get my tachometer to the RPM indicated on the stock decal,  then took the frequency indicated on the front of the VFD.  Rounded of course.    When set to the factory speeds,  they were all oddly alot closer to 65hz than 60hz.

For the min and max,  I just turned the POT all the way up, and all the way down recording the speeds from my tach.   

I could have,  and perhaps maybe should have engraved  the frequencies at min/max speeds.  But,  I guess since I set the upper and lower limits of the VFD to 30hz and 80hz,  figured I'd know those frequencies anyway. 

Either way, I'm not making a 3rd one. 

I found another project for the day.

I made a copy of the Or3gun marine spacer tube for my shotgun.  Just need to go test it out.







The info at the bottom is for calculating the spindle speed in back-gear.

The tach pickup magnet is on the pulley,  so doesn't read accurately in back gear. Those are formulas for getting the correct spindle speed in back gear.

The RPM displayed on the tach multiplied times 0.121 = the actual spindle speed.    For example, in back-gear,  2500 on the tach = 302.5 rpm.

Or,   to set a specific spindle speed in back gear,   you can multiply the speed you desire times 8.26,  then dial the tach to that value.

For example,   If I want a back-gear speed of 122 rpm,   I would multiply 122 x 8.26, which = 1007.72.   so I would set the tach to 1008 rpm.


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## hman (Aug 17, 2021)

That's a VERY nice looking and useful label!  Now here's a suggestion for your next "OCD" task:

I've always disliked the fact that spindle rotation is reversed on a mill when "back gear" is engaged.  So I added a microswitch to the head, which senses the position of the clutch arm.  The microswitch reverses the sense of the forward/reverse VFD control.  That way, you're ALWAYS going forward when you set the control to forward.  Details (for my PM835S) are in this post:








						Converting a knee mill to 3phase/VFD
					

I've recently bought a Precision Matthews PM-835S.  Advertised as a "small" knee mill, it's still amazingly massive - and TALL.  I've had to build a platform to stand on (re-using some of the the 2x4s and OSB the mill was crated with), just to be able to reach some of the controls and levers...




					www.hobby-machinist.com


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## Mike23 (Aug 17, 2021)

Ken226 said:


> I finished up version 2.0.   corrected my mistake and added a little more fluff.
> 
> No hinge for folding though.  I didn't have anything suitable handy, and didn't wanna postpone to order parts.
> 
> ...


That is some amazing work. I wish I had those skills.  Mike


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## Ken226 (Aug 17, 2021)

hman said:


> That's a VERY nice looking and useful label!  Now here's a suggestion for your next "OCD" task:
> 
> I've always disliked the fact that spindle rotation is reversed on a mill when "back gear" is engaged.  So I added a microswitch to the head, which senses the position of the clutch arm.  The microswitch reverses the sense of the forward/reverse VFD control.  That way, you're ALWAYS going forward when you set the control to forward.  Details (for my PM835S) are in this post:
> 
> ...



Thats some outside the box thinking.  I like it.  That's definitely going on my to-do  list.


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## extropic (Aug 17, 2021)

You explained all very well. Thank you.
It all makes sense when viewing from your perspective (knowledge).

One more clarification please. "LOW" range on the plaque = back gear, correct?


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## Ken226 (Aug 17, 2021)

extropic said:


> You explained all very well. Thank you.
> It all makes sense when viewing from your perspective (knowledge).
> 
> One more clarification please. "LOW" range on the plaque = back gear, correct?



Yes, exactly.  Not sure if it's technically correct or not, but it's what popped into my head when I was drawing it in CAD.

I used the same CNC drag tool/cerakote to built my lathe and mill control panels.  Not as nice as some, but it produced results that I'm happy with.  A coworker gave me a sheet of 2' x 4' x .125" 6061 aluminum sheet.  I used most all of it making DRO scale brackets, control panels,  and little data plates.


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## Aukai (Aug 17, 2021)

I'm just stuck with a label maker


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## Ken226 (Aug 17, 2021)

Aukai said:


> I'm just stuck with a label maker



A label maker works just fine.  All the equipment I built before I got the CNC mill  is set up with decal labels.   The same cerakote oven I built from an old cabinet smoker, and baked those control panels in,  has stick on labels. 10 years after building it,  the same label decals are working like a champ.  Nothing wrong with that!


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