Getting a little more Y travel, looking for some additional ideas

[Ken226]

So doesn't the 2" high column spacer raise the head? Then you lower the head, and offset in the Y direction with the second block?

Maybe our mills are different. My column bolts to the base with 4 bolts. Any spacer between the column and the base would raise the head.

I think I understand the solution well enough to implement this if I need to.

Unless the PM25 is more different than I thought, a spacer should move the column rearward, not up. I looked up some pics of the PM25 and it looks very similar.

I circled and added captions to the spacers in this pic.

Does it affect the rigidity of the machine ? using steel will be better I believe ?

I used the machine for a few years before the spacers, and over 5 years since. I've never noticed a difference in rigidity. I suspect the compressive strength of the aluminum is far in excess of any cutting forces that little mill can generate. I even crashed it once and snapped a 3/8" end mill in half. The head and column didn't budge.

This is a common mod to the G0704 CNC conversion. I downloaded the plans for the spacers from hosscnc.com years ago. The plans called for 6061 aluminum. I did a search and found a few old threads here, and on other forums referencing this mod.

I saw an old most from @RJSakowski mentioning having done it in his. Since mine is a G0704, and he's actually done it on a PM25, perhaps he would be willing to chime in.

 

[ConValSam]

What type of vise do you use? Have you considered a smaller vise? Or a screwless style?

I use a 3" screwless on my mill and it provides plenty of holding power and doesn't have the Y travel robbing casting ahead of the fixed jaw.

Just a thought.

 

[WobblyHand]

Thanks for the extra pictures. My mill is a little different. Here is a picture of the base.

So if I were to pick up these attachment points, it would be different than your design. Not impossible, but different. Haven't checked the backside, maybe there is enough meat to have bolt holes on that side.

 

[Ken226]

Thanks for the extra pictures. My mill is a little different. Here is a picture of the base.
View attachment 401951
So if I were to pick up these attachment points, it would be different than your design. Not impossible, but different. Haven't checked the backside, maybe there is enough meat to have bolt holes on that side.

I can see why you were confused now. Totally different design there.

 

[WobblyHand]

What type of vise do you use? Have you considered a smaller vise? Or a screwless style?

I use a 3" screwless on my mill and it provides plenty of holding power and doesn't have the Y travel robbing casting ahead of the fixed jaw.

Just a thought.

Kurt DX4. I have a 3" toolmakers vise as well. I really wanted to machine a 5" long section in Y, which the Kurt can hold.

I should just figure out how to mount the Kurt sideways. The tee-slots don't line up with the vise hole spacing, so I have to put in some extra clamps. Then I could use the X power feed, which would be a lot nicer.

 

[WobblyHand]

I can see why you were confused now. Totally different design there.

Yes it is. From your perspective on your mill it was obvious, but I didn't know your mill's configuration. So I was stuck in PM25 land, trying to make sense of what you were saying! But all is good now.

 

[RJSakowski]

Unless the PM25 is more different than I thought, a spacer should move the column rearward, not up. I looked up some pics of the PM25 and it looks very similar.

I circled and added captions to the spacers in this pic.








I used the machine for a few years before the spacers, and over 5 years since. I've never noticed a difference in rigidity. I suspect the compressive strength of the aluminum is far in excess of any cutting forces that little mill can generate. I even crashed it once and snapped a 3/8" end mill in half. The head and column didn't budge.

This is a common mod to the G0704 CNC conversion. I downloaded the plans for the spacers from hosscnc.com years ago. The plans called for 6061 aluminum. I did a search and found a few old threads here, and on other forums referencing this mod.

I saw an old most from @RJSakowski mentioning having done it in his. Since mine is a G0704, and he's actually done it on a PM25, perhaps he would be willing to chime in.

It wasn't me. My RF30 clone is a round column mill and has a horizontal flange. I did extend my drill press though, increasing swing from 13" to 18" and my vertical travel by 7".

 

[wildcatter]

You may not get anymore room from rubber sheet. I am using rubber sheet now and find it bunches up between the column and the table. I was looking to switch to accordion type material but it was too expensive.

 

[WobblyHand]

You may not get anymore room from rubber sheet. I am using rubber sheet now and find it bunches up between the column and the table. I was looking to switch to accordion type material but it was too expensive.

How thick is the rubber sheet on your mill? I am still looking into doing this. Was thinking of something like a window shade with rubber. Head up, the sheet unwinds. Head down, the sheet winds up. Don't know if I can make a window shade only 5" wide and still have it work! The roller would be on the top, so it would be out of the way.

I did mount my vise sideways, and still almost ran out of Y. I managed to mill the piece I wanted, but giving up almost 2" of Y isn't good. Definitely going to make some modifications to get back some of the Y.

 

[sdavilla]

My PM30-MV had the rubber sheet. Could not stand the bunching up. Thought about window shade idea but giving up at least 1" of travel from the roller would hurt. Went the good old accordion type. 1" tall so that it's heavy enough to stay flat. Right now, the accordion cover squeezes down to 3/8" in thickness and I'm spanning about 8.3" easy. It would be fine for 12". Good old McMaster.