# PM45 Mill Auto-Feed



## Ray C (May 27, 2013)

All,

In another thread, I mentioned the PM45 auto downfeed feature.  Someone asked if I could explain it so, here you go...

The side of the mill has two additional selector switches.  One is just on/off for the auto feed.  The other is the inches per revolution of feed rate. 





Once they are set to your needs, you rotate and adjust the depth collar (index finger) and lock it with the screw tab (thumb).  The collar is marked in 1/8" increments but it's infinite and has no set detent positions.  You can see at the web of my hand, another little knob.  That will be explained later.




The handle crank has two positions.  In the straight position, the quill is manually operated like any normal quill.



When you push the handles away from the head, the autodrive kicks in.  It slowly rotates it under power just as though you were operating it.  When it reaches the set depth, the handles pop back to the straight position and the quill returns.  At any time while in auto feed mode, you can push the handle toward the head and disengage power feed.




Couple notes... you'll notice I've removed the bottom handle grip on the crank.  It kept getting in the way.  Also, if you look at the second picture from the top -the one of the depth collar, you'll see another knob just behind the web of my hand.  That knob can be screwed-down to prevent from accidentally engaging the down-feed by accidentally pushing outward on the handle.


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## GaryK (May 27, 2013)

Very cool Ray. I didn't get the PF option.

Can you set a downward travel limit while in manual mode? Kind of like a depth stop on a drill press?

Is there a way to do a manual down fine feed?

Gary


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## Ray C (May 27, 2013)

No, it doesn't have a built-in stop like you see on drill presses.  Probably a good thing as if you had a manual stop set and also set the power feed for greater travel, something would have to give -and that power downfeed has serious torque!  I think I know what would win.

On the front, there's a small crank wheel for manual fine feed.  It has calibration lines but like many other fine-feeds, the calibration lines are a rough approximation.  The fine-feed crank works smoothly though and if you have a caliper-like DRO attached (which I do) it's very easy to set down to half-thou.  The quill can also be locked in any position.

It's a very nice mill...  A workhorse that can sprint and do fine work too.

Ray




GaryK said:


> Very cool Ray. I didn't get the PF option.
> 
> Can you set a downward travel limit while in manual mode? Kind of like a depth stop on a drill press?
> 
> ...


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## itsme_Bernie (May 27, 2013)

Hey Ray!

That was me.. Thanks for the demo!  That does help me, as I am trying to find a way to retrofit my machine..  Thanks man!

Bernie


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## Ray C (May 27, 2013)

No problem.  I think it will be challenging to design something like this into an existing mill.  Impossible?  Nothing is impossible.  Tricky -heck yeah!


Ray




itsme_Bernie said:


> Hey Ray!
> 
> That was me.. Thanks for the demo!  That does help me, as I am trying to find a way to retrofit my machine..  Thanks man!
> 
> Bernie


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## richl (May 27, 2013)

Hey Bernie

There is also a nice video of the PDF being used on the PM site. Go to the bottom of the page:
http://www.machinetoolonline.com/PM45MMill.html


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## GaryK (May 28, 2013)

Ray C said:


> No, it doesn't have a built-in stop like you see on drill presses.  Probably a good thing as if you had a manual stop set and also set the power feed for greater travel, something would have to give -and that power downfeed has serious torque!  I think I know what would win.
> 
> Ray



Thanks ray.

I was just wondering if maybe it was like a Bridgeport that stops the feed when it hits the stop.

I really like to ability to set the depth, like for drilling to a certain depth or counter sinking a bunch of holes.

Gary


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## Ray C (May 28, 2013)

It was a lifesaver on the turret plate. All the counter-sinks and hole chamfers came out even.  Do realize though this probably does not have repeatable accuracy tighter than say a few thou because it's purely a mechanical disengage driven by a very clever mechanism with a couple simple non-precision gears.

It takes a little practice and getting used to for drilling and in the beginning, I must admit to snapping a couple smaller drill bits.  You get the hang of it after a while and watching the chips and curls is the best indicator if things are going right.  Sound too... Need to hear if the cut sounds good.

It's an absolute dream for boring!  Finish comes out great.



Ray



GaryK said:


> Thanks ray.
> 
> I was just wondering if maybe it was like a Bridgeport that stops the feed when it hits the stop.
> 
> ...


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## itsme_Bernie (May 28, 2013)

richl said:


> Hey Bernie
> 
> There is also a nice video of the PDF being used on the PM site. Go to the bottom of the page:
> http://www.machinetoolonline.com/PM45MMill.html



Thanks Rich!  Great video- Matt did a great job there!


Bernie


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## darkzero (May 31, 2013)

Great post Ray.




GaryK said:


> Can you set a downward travel limit while in manual mode? Kind of like a depth stop on a drill press?
> 
> Gary





Ray C said:


> No, it doesn't have a built-in stop like you see on drill presses. Probably a good thing as if you had a manual stop set and also set the power feed for greater travel, something would have to give -and that power downfeed has serious torque! I think I know what would win.
> 
> Ray




Actually there is a way & I do it all the time without any issues, very useful & no risk of damaging anything as in the case Ray mentioned. In manual mode the depth collar can be used as a depth stop. I figured this out when chatting with Matt when I first got my mill as mine did not auto disengage with power feed. Turns out the stop pin that disengages the handle was sheared off but of course Matt quickly sent me a replacement so I didn't have to make one. Matt told me the depth collar was only used for power feed. Since I had mine apart to replace the stop pin, I know there are pins on the depth collar & one of them can be used as a depth stop. 

So in manual mode, lower the quill to the desired depth, with the depth collar lock loose, rotate the depth collar counter clockwise until it stops which should be past the 0 mark. Then lock the depth collar. You now have a depth stop. Just remember the pin in the depth collar that is acting like a depth stop is like 3-4mmØ or so, I forget. So when you get to your depth, don't go pulling on the quill handle with all you weight & there is no reason to do anyway.

This of course does not work in fine feed mode because the depth collar will act the same way as in power feed mode & will disengage the fine feed if you reach 0 on the depth collar. With that said, when using fine feed, be sure to set the depth collar so that you don't disengage while working with the depth you need.

I can post pics if anyone wants.


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## woodrowm (Jun 3, 2013)

Good morning - Pictures would be great.

Thanks,
Woodrow


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## jgedde (Jun 3, 2013)

Ray C said:


> All,
> 
> In another thread, I mentioned the PM45 auto downfeed feature. Someone asked if I could explain it so, here you go...
> 
> ...



Ray,

I have the same mill.  I discovered that the feed rate dial is calibrated in mm rather than inches.  So, the three values correspond to (IIRC) 0.004 in/rev, 0.007 in/rev, and 0.010 in/rev.

Be careful with the downfeed.  There is a slipper clutchn inside, but it doesn't really work all that well.  All hell breaks loose if the spindle feed hangs up.  Don't ask me how I know...

John


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## bartives (Mar 22, 2015)

This is fantastic.  I did not understand how the power down feed worked.  I will definately use this on my next project to mill pocket to depth!  Thanks everyone for the great information.


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## darkzero (Mar 22, 2015)

bartives said:


> to mill pocket to depth!



I wouldn't recommend the power down feed for that. It can't be trusted for accurate depths & it won't disengage that consistently (repeat to depth) either.


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## bartives (Mar 22, 2015)

I understand, but I will practice on some scrap so I can rough the pocket out quicker and then follow with some finishing passes to depth.


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