# Pm25mv Stuck Head.



## sbx (Jul 12, 2015)

Hey all. So I'm having a heck of a time getting the mill's head off of the column. It seems to be stuck on pretty good. I've removed the 3 bolts and the single center cap screw and the set screw (verified that there was only one) on the right side of the head casting. 

The head freely rotates and I can't see any other obstruction.

Any ideas or nuances I'm missing?

Thanks in advance for any help.


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## brav65 (Jul 12, 2015)

I had the same issue and ended up lifting my head up off the column.  I could never figure out how the two pieces came apart.  Let me know what your solution is.


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## Silverbullet (Jul 12, 2015)

Does the rotate with a gear ? Ya might have to remove the shaft that rotates it , if the gear locks in the worm it may need to be pulled ? Ck your parts diagram if you have one .


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## tmarks11 (Jul 12, 2015)

I don't know what all these components do, but does this look like what you have taken out? 

EDIT: You said you verified only one set-screw on the right of the head.  Are you sure that there isn't another one hiding in the same hole?  A quick google of "taking G0704 head apart" reveals that people report there are TWO set-screws stacked in the same hole on the right hand side of the head.  Take a look and see if that is true on your machine.


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## sbx (Jul 12, 2015)

Tmarks11 - I am trying to remove the head casting that attaches to the Z slide casting you show in your diagram. It is attached to the circular plug/shaft in the center of the Z Slide. It freely rotates around the shaft, but will not budge when attempting to pull it off. 

I did double (and triple) check for the set screw and multiple stacked set screws. There was only one present. I soaked it overnight with some PB  Blaster. Heading out the the shop now to try again. 

The only other things I can think of are plastic wedges lightly tapped in between the castings, or figuring out some sort of expander/puller to work against the center bolt hole and the casting.

I can't remove the whole slide, because I am trying to diagnose an issue with the Z lead screw binding (which is most likely the result of my earlier failed attempts at removing the head, and forgetting I removed  a cap screw from the slide bottom).. Man. I wish I wouldn't have started the dissasembly at all. Was trying to clean all the mating surfaces from shipping grease on my new machine.

Will update if I have any luck. But any continued thoughts would be apprecaited. 

sbx


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## brav65 (Jul 12, 2015)

sbx said:


> Tmarks11 - I am trying to remove the head casting that attaches to the Z slide casting you show in your diagram. It is attached to the circular plug/shaft in the center of the Z Slide. It freely rotates around the shaft, but will not budge when attempting to pull it off.
> 
> I did double (and triple) check for the set screw and multiple stacked set screws. There was only one present. I soaked it overnight with some PB  Blaster. Heading out the the shop now to try again.
> 
> ...





I have had exactly the same issue, along with the lead screw issue you mention.  I have been too busy to pull it all apart again to try and diagnose what the issue is.


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## tmarks11 (Jul 12, 2015)

sbx said:


> The only other things I can think of are plastic wedges lightly tapped in between the castings, or figuring out some sort of expander/puller to work against the center bolt hole and the casting.



A thread on the G0704 head removal over at the zone recommended lowering the head all the way down to the table and sitting it on some wooden blocks to take the weight.  Maybe it just isn't sliding free due to the weight of the head cocking it one that support shaft.  Taking some of the weight off might let it slide straight out.


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## wrmiller (Jul 12, 2015)

tmarks11 said:


> A thread on the G0704 head removal over at the zone recommended lowering the head all the way down to the table and sitting it on some wooden blocks to take the weight.  Maybe it just isn't sliding free due to the weight of the head cocking it one that support shaft.  Taking some of the weight off might let it slide straight out.



This is exactly what I do to remove the head on my PM-25. I rotate the top of the head to the left, lower the head so that the electronics box is resting on the table, and use the Y-axis to walk the table and head away from the column.


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## sbx (Jul 12, 2015)

OK. So I fixed my problem without having to remove the mill head. I never could get it off. My issue was the z spacer which attaches to the leadscrew. I ended up pulling the z handwheel and the leadscrew bracket. That allowed me to re align the bracket to the z slide. So crisis averted. Once I got that bolted back on correctly everything was well again.

For extra info. I had lowered the head onto blocks of wood on the table as was suggested. So it was fully supported and on its side. Still didn't budge.

Just glad I got it fixed and was able to make my first chips with my new mill


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## qualitymachinetools (Jul 13, 2015)

Hmm I was thinking maybe the set screw on the right side, but you said you already checked that. 

There are 2 of them, one is very short, and the other one is about 3/4 of an inch long. 

I just took mine off, and it seems like you weren't leaving any steps out, did it move at all or is it stuck pretty good?


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## brav65 (Jul 13, 2015)

qualitymachinetools said:


> Hmm I was thinking maybe the set screw on the right side, but you said you already checked that.
> 
> There are 2 of them, one is very short, and the other one is about 3/4 of an inch long.
> 
> I just took mine off, and it seems like you weren't leaving any steps out, did it move at all or is it stuck pretty good?




Matt, 

Do you have the exploded view for the PM-25 yet?  It would be nice to have when working on the mill.


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## qualitymachinetools (Jul 13, 2015)

You read my mind, I am getting them ready now. Not the full manual yet, but do have the drawings to look at


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## sbx (Jul 13, 2015)

Matt - Thanks for jumping in, and for the parts diagrams. I did not see 2 set screws. Just the single 3/4" one. But I probed in after with the hex key, used a flashlight to check, etc. If its in there, its pretty well hidden or maybe something else is stuck in the hex opening.

I was able to solve the issue I had without removing the heads, so I am just for adding info for others if they ever need it. The head was able to rotate, and had a small amount of wobble back and forth. Maybe 1/16" of play. I'll pull the set screw again tonight and check again just to know. Will report back if I find anything.


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## brav65 (Jul 13, 2015)

qualitymachinetools said:


> You read my mind, I am getting them ready now. Not the full manual yet, but do have the drawings to look at



Thanks Matt your the Bomb!


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## SWATrous (Jul 18, 2015)

Those are super nice to have, gonna have to print 'em out on 11x17 for reference.


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## 2bob (Jul 30, 2015)

Hi just dropped in to see what's going on , I can give a bit of info . Your on track with the 2 grub screws in the same hole on the lower right hand side of the rotation part of the head. Use 3mm Allen key remove the first screw it's a locking screw the second screw is the adjusting screw it runs in a grove an has to be wound back to come out of the grove  that's why the head will not come off ,remove 3 nuts if it's a 3 bolt head  remove centre  larger Allen screw an the head off it comes.  Just remember that when it goes back on that the adjusting screw is knot hard screwed in-- it has to be adjusted one turn back so the head can turn,then the longer locking screw holds the adjusting screw it in place. Hope that helps


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