# Ideas for Quill Stop for PM932/940 mills with power downfeed



## 9t8z28 (Aug 12, 2020)

I am wanting to make a dedicated quill stop for my PM932M-PDF mill and was wondering if anyone has already done so.  I see that darkzero has made one for his PM45 PDF mill but I want to try and keep the stop inline with the quill.  There is already a hole in the bottom of the headstock directly in-line with the quill and another hole directly below in the quill collar which is for the non PDF models.  I was thinking of something similar to what is found on a Bridgeport.  I already have a 1/2-20 threaded rod, a Morton quick-adjust quill stop and a clamp style quill stop for a Bridgeport so I figure I will try and use these parts.  I am wanting to know if anyone else has made one and if you can post pics of it it would be greatly appreciated or post your thoughts or ideas.  I also see that Stefan Gotteswinter has made a quill stop for his RF45 mill but I don't think I want go this route.  If I did though, he did mention that it did tighten up the quill a bit.  What are your thoughts?  
I am aware that the handwheel graduated depth collar can be used as a depth stop but I have heard that it is not recommended to be used this way.  
Here is a link to Stefan's quill stop


			rf45 mill depth stop - Google Search


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## darkzero (Aug 12, 2020)




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## Dan_S (Aug 12, 2020)

You might find this interesting.





I'm probably going to do something very similar when i install the dro in my 940-PDF.


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## 9t8z28 (Aug 12, 2020)

Yes I mentioned Stefan’s quill stop.   He states that it removed some of the twist from the quill but even so I’m not sure I want to go this route although I can see a dial indicator being more accurate than the threaded rod but then again I have a factory equipped quill DRO.   





Dan_S said:


> You might find this interesting.
> 
> 
> 
> ...


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## darkzero (Aug 12, 2020)

He's since changed it, no more dial indicator.


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## darkzero (Aug 12, 2020)

9t8z28 said:


> I can see a dial indicator being more accurate than the threaded rod



Stefan's stop is quick & easy to use it looks like. I made mine before that video was released, I based mine of using a Morton quick release for a BP. I liked the threaded rod idea for fine adjustment & on the fly, it has been very handy for me for things like countersinking multiple holes.

Also with the threaded rod, although I'm using the Morton, I also use one of those quick clamps too. I use it for when I want to prevent the quill from retracting all the way. Comes in handy for me saving time for certain repetitive operations.

My PM45 did not come with a factory quill DRO. Since I already mounted my Mitu in the front I decided to put my stop off to the side like a DP. Plus I didn't want to cut a slot in my face plate & didn't want the whole assy to stick out forward much, that was the idea anyway. I didn't like the bar I made that connects to the stop, thought it would get in the way a lot but it really hasn't much for me. I've learned to live with it plus I use it to attach other things to now.


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## 9t8z28 (Aug 12, 2020)

Very nice darkzero.  What does the knurled set screw function as?  . C





darkzero said:


> Stefan's stop is quick & easy to use it looks like. I made mine before that video was released, I based mine of using a Morton quick release for a BP. I liked the threaded rod idea for fine adjustment & on the fly, it has been very handy for me for things like countersinking multiple holes.
> 
> Also with the threaded rod, although I'm using the Morton, I also use one of those quick clamps too. I use it for when I want to prevent the quill from retracting all the way. Comes in handy for me saving time for certain repetitive operations.
> 
> ...


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## darkzero (Aug 12, 2020)

9t8z28 said:


> Very nice darkzero.  What does the knurled set screw function as?  . C



That was my simple "plan b" solution to "plan a" that didn't work out quite as I hoped. Post 20

I'm thinking about adding another hole further outward for a chip shield. Low on my project list though.


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## 9t8z28 (Aug 16, 2020)

I’ve got the cover off and have been doing some playing around with different setups.  It appears as though there will not be enough travel for the 1/2”-20 threaded rod and quick release.  I have been also mocking up a similar setup to what Stefan did except using a 1/2” diameter linear shaft with a bronze bushing.  The hole in the headstock is 20MM Which is 2MM larger than the hole in Stefan’s headstock.  Also the bore is rough and size is inconsistent.    I’d like to go 20MM but there will be clearance issues again at the top of the travel.  I’m also thinking what would be the best method to mount the shaft to the quill collar.  I want to clean out the pocket like you did and make a steel insert to go in there and maybe press the shaft into it.  What do you think about pressing it in or threading it?  Which will be stiffer and most likely to remain parallel to the quill travel?


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## CrossSlide (Aug 22, 2020)

@9t8z28 I have PM932M and I'm looking to do the same thing.

What's the progress or your final solution?


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## 9t8z28 (Aug 23, 2020)

I have been doing more brainstorming while scouring the internet looking for alternatives and materials to use and going through my materials on hand to see if I can make this stop with what I have. I have pretty much ditched the idea of using the 1/2-20 threaded rod in-line with the quill because I do not see there being enough vertical travel.  I want there to be a solid flat surface for the quill stop but that will take up more of the already limited travel.  
What I don't like about the PDF heads is that the hole for the quill depth stop is very close to the edge of the casting although I am finding the location and size of this hole vary depending on when it was built and the name on the machine.  For instance Stefan's Optimum branded mill which was built many years ago has a smaller 16MM bore located deeper into the head and there is a boss that protrudes below the base of the head casting.   The same goes for the slotted hole on my quill ring.  The slot is cut close to the edge of the face and this leaves little material for strength so I will be adding a steel insert (basically the same design as darkzero's) that sits in the pocket of the quill ring after I machine the rough casting.  
I am pretty much set on building a quill stop very much like Stefan's and I think I am also going to add a dial indicator as well.  My though is that although I already have a digital readout to assist in monitoring the depth of the quill it wont work with the depth stop as accurately.  I have thought about ditching the Z-axis scale for the head height and cutting down the scale and putting it on the depth stop.  I feel that the Z-axis scale will get very little use but somehow I think I will regret it so this option alone has slowed down my progress because I am trying to figure the pro's and con's of this option.   
What I am in the process of doing right now is cleaning up the rough casting inside the head where I would I am going to be making a positive stop for the adjustable stop.  I want to keep it as short as possible and there are tall flashings that need to be removed.  I will keep this updated with my future progress.  


CrossSlide said:


> @9t8z28 I have PM932M and I'm looking to do the same thing.
> 
> What's the progress or your final solution?


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## 9t8z28 (Aug 23, 2020)

Ok here is what I got accomplished tonight
I ground and filed down the rough flashing of the headstock.  I also milled out the pocket in the quill ring using a 1/4” 4 flute EM with a .030” radius.  I removed about .045” off the sides and about .070” deep to clean it up.  Lastly I mocked up the the 1/2” shaft and took a photo with the quill retracted and extended.  I decided that a dial indicator will not work because there is just not enough room and the more I think about it having a quill dro and dial indicator is overkill.  I can check my depth with the quill dro and if I make an adjustable stop I can still use gauge blocks if I really wanted to.  Here are some photos.


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## 9t8z28 (Aug 24, 2020)

Darkzero  I don’t know how I missed it, I must’ve been so excited to see the thread you started on mods to your PM45 mill that I totally missed that your mill doesnt have the powerbox on the left side of the head.   I wouldn’t be able to use your style quill depth stop if I wanted to


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## darkzero (Aug 24, 2020)

Yeah the PM45 did not come with a power head (Z) so my control box is very basic, just the spindle fwd/rev switch & a switch for the coolant pump. My PM45 did not come with a factory quill DRO either so mine did not come with a quill bracket. Luckily & thankfully when I asked Matt to purchase a quill bracket he sent one to me for free. The last of the PM45s did come with a quill DRO but still no power Z.


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## 9t8z28 (Aug 30, 2020)

Update:  I started the quill rod lock (made from 1” diam 01) to make sure it would fit with the quill rod retracted. Then I ordered a 1” long Oilite bronze bushing and 1/2” hardened and ground linear shaft with the last 2” of length tempered back soft.  I then made the sleeve that will go into the base of the head and house the bushing.  I used 1.625” diam 4140 PH.  Next is to make the bracket that will hold the linear shaft to the quill ring.  Anybody have any ideas on how to attach the quill rod to the bracket?  I want to make sure its a solid joint.  I though about threading it or press fit?  
here are some photos of progress..









the bushing still needs to be pressed into the housing


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## 9t8z28 (Jan 15, 2021)

I can't believe it's been since August since I started this project.  Sorry for the delay!  Quite a bit has changed since I last posted and I didn't realize that I had previously posted the same info.  For some reason the forum wasn't showing me all of my posts.  Oh well.  Hopefully I do not confuse anyone.  Sometimes I question my ideas and change things up before I turn my thoughts into metal.   Other than breaking my toe and constantly fixing and maintaining my cars and trucks, I have no excuse for being lazy during this pandemic! 

I'm basically done fabbing the quill stop other than cutting a vertical slot in the front cover and adding a boxed shield behind the quill rod to keep swarf from entering the PDF gearbox and lastly remounting the DRO. 
I was originally going to use a 1/2-20 threaded rod and a Morton quick quill stop but I soon found that there wasn't going to be enough room if I wanted to keep the 5"+ of quill travel, hence why I decided to go with a 1/2" linear shaft and make my own depth stop.

The first thing I did was remove the factory cast iron quill ring and clean up the pocket on the underside.  I used a 1/4" end mill and took out only enough material to give me a nice flat/square pocket to work with that would also be perpendicular to the bore of the quill ring. 










Next, I made the quill shaft clamp and quill shaft headstock sleeve.  I used 01 tool steel for both parts since I figured they would both be in repeated contact with each other and therefore would definitely need to be heat treated.

Offset Boring of the quill shaft clamp




The parted quill shaft clamp. 





Offset turning and boring of the quill shaft headstock sleeve





Test fitting the oilite bearing










Checking the fit and alignment









Continued in Next Post..........


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## 9t8z28 (Jan 15, 2021)

Next step was making the steel block to fit tightly in the quill ring.  I used 01 again, (I have a ton of it so might as well use it) but i did not see a need to heat treat it.  
	

		
			
		

		
	






I then bored to a half thou under 1/2" for the quill rod and  drilled/tapped holes for mounting the block to the quill ring.

After some more test fitting and brainstorming I got around to slotting the quill lock and drilled and tapped for 6MM thread.  Sorry no pics. Next was surface grinding the  quill shaft clamp and quill shaft headstock sleeve.  I did a quick job of getting them flat and really saw no need for a spectacular surface finish.






The last step was fitting the finished parts to the mill.  I had to do some minor fitting to assure the quill rod traversed parallel to the quill.  The fit of the quill rod and bearing was a tight fit so I had to get it under half a thou or else it would bind and restrict the quill from retracting all the way.  Also instead of pressing the quill shaft headstock sleeve into the head of the mill decided to enlarge the hole and glue it in.  I considered using JB Weld to glue it in but I wanted something that I was sure would stand up to oils, vibration, and impact.  After speaking with McMaster-Carr I decided on an epoxy called Scotch Weld which is specifically designed for bonding steel together.  It was expensive but worth it.  It has a thick consistency which would not run when applied to a vertical surface and set within 10 minutes.

(Notes for below pic)
Take notice to the quill rod.  If it needed to be any longer it would not have cleared the casting.  The factory hole in the headstock for the PM-932 (non PDF models) is centered in the base for a threaded rod depth stop.  The components of a sliding depth stop need to be planned and measured accurately or interference would be inevitable. 
ALSO Notice the paper towel jammed in the corner of the headstock.  Apparently my mill seeps gear oil  and I didn't want it soaking into the uncured epoxy. 




















Conclusion:  I am glad I took my time making sure everything fit inside of the headstock because when the quill stop setup is in the retracted position I literally have .020"to .040" of clearance from the top of the rod and lock to the headstock casting.  Besides being able to set precise depths without using the wonky powerfeed depth stop, I can already tell that the quill assembly while unlocked is tighter and has less tendency to want to rock and rotate in its bore.  With the added rigidity I think I should notice a difference when plunge milling and climb milling and the fact that the quill cant rock in its bore I should also have greater accuracy all around.
Last thoughts:  I am not sure if I am crazy about the locking handle.  Maybe a longer handle with more protrusion or does anyone have a different idea for locking it that would be quick and easy?  
Thanks for all who commented and shared their designs and ideas.


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## 9t8z28 (Jan 20, 2021)

Heres the final product.  A made a shield to go around the complete quill stop to keep swarf from entering the PDF gearbox.  I took a piece of .040” aluminum sheet, bent it to shape and secured it to the front cover.  Hopefully I dont get anymore addition vibrations.  Now I just need to find a way to get rid of the red “caution change speed with the machine stopped” Warning label. Let me know what you think or what I could have done differently


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## CrossSlide (Jan 21, 2021)

Very nice!


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