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



## WobblyHand (Mar 26, 2022)

Have a PM25MV with DRO.  I am finding with a 4" vise mounted in the middle table slot, I don't have a lot of usable Y travel, maybe 4".  The back of the vise hits the accordion and the DRO shield hits the SHCS that mounts the accordion bracket.  So I was thinking of removing the accordion and replacing it with a sheet of rubber hanging from the top accordion mount point.  I think this would eliminate both of my issues.  I might pick up close to an inch of Y, which would help a lot.

Has anyone done something similar?  Are there any the downsides of this?  What do I need to look out for?  Anything else I could try?


----------



## DavidR8 (Mar 26, 2022)

Give it a whirl, what's the worst that can happen?


----------



## WobblyHand (Mar 26, 2022)

DavidR8 said:


> Give it a whirl, what's the worst that can happen?


Only it being a time suck and the end result is awful.  Was really trying to find out if it was a _BAD_ idea.  Or if I was missing something really obvious.  Seems like I could pick up some travel.


----------



## mmcmdl (Mar 26, 2022)

Not going to hurt anything and if you gain something , go for it .   Most of the time , the accordian thing cracks up over time anyway and the chips still get behind it making it harder to clean .


----------



## John O (Mar 26, 2022)

Would you gain any by mounting the vise in the first slot?


----------



## WobblyHand (Mar 26, 2022)

John O said:


> Would you gain any by mounting the vise in the first slot?


Good idea.  I think I tried that, and found the middle slot gave the most usable travel for objects in the vise.  But I will check again, to be sure.  Definitely worth a try.


----------



## RJSakowski (Mar 26, 2022)

I was able to gain a 4.6 extra inches of x axis travel on my RF30 clone by cutting clearance in the base for the left side bearing housing.  I don't often need that extra travel but when I do it's nice to have it.  I made an extension for the left hand crank to take advantage of the extra travel.


My 12" RT overhangs the table at the rear and I lost about 1/2" of travel as a result.  Removing the mounting screws for the way shield and dropping the way shield gave me back full travel.


----------



## compact8 (Mar 27, 2022)

May be making an adaptor plate for the vice so that it can take up any positions instead of limited to the locations of the slots ? or switching to other types of vices that do not have fixed mounting holes.

For the DRO, may be slimming down the shield in some ways ? If the slot of the scale is facing down ( should be ), there may not be any need for the shield. On my mill I mounted the X-axis scale at the front in order not to affect the range of Y travel.


----------



## BGHansen (Mar 27, 2022)

No harm removing the accordion and going with sheet rubber.  My Bridgeport has a wide flap of rubber with a wooden dovetail on the top of the knee (mod by the previous owner).  When I clean chips, I never have any on the top of the knee; works well.

Bruce


----------



## rabler (Mar 27, 2022)

I've used this silicone-coated fiberglass fabric from McMaster as a chip shield. Oil resistant and tolerates high temperature. Probably overkill ...


----------



## Ken226 (Mar 27, 2022)

I added a 2" thick aluminum block between the column and bed,  and another between the head and column on my G0704 when I converted it to CNC.  I have 7" of Y travel now.

It's a pretty common mod for the G0704, which I believe is similar to the PM25.

Like this one:


----------



## WobblyHand (Mar 27, 2022)

So far, the piece of rubber sheet I had in mind has evaded my search efforts.  I remember seeing it last summer, but darn if I know where it is now.  Went to where I thought I saw it last, but it's either not there, or it's camouflaged quite well!  I'll continue to look for it - as it's probably in plain view.


----------



## mmcmdl (Mar 27, 2022)

WobblyHand said:


> So far, the piece of rubber sheet I had in mind has evaded my search efforts. I remember seeing it last summer, but darn if I know where it is now. Went to where I thought I saw it last, but it's either not there, or it's camouflaged quite well! I'll continue to look for it - as it's probably in plain view.


Glad to hear that . I'm not the only one that has things go MIA in the garage .   As soon as you replace it , the original will magically appear .


----------



## WobblyHand (Mar 27, 2022)

Ken226 said:


> I added a 2" thick aluminum block between the column and bed,  and another between the head and column on my G0704 when I converted it to CNC.  I have 7" of Y travel now.
> 
> It's a pretty common mod for the G0704, which I believe is similar to the PM25.


So the first block gives some Z height, and the second gives more Y travel?  Just asking to try to understand the modification.

If you could share a picture or two that would help.


----------



## Ken226 (Mar 27, 2022)

The lower block, between the column and bed adds 2" to the Y.

The one between the head and column keeps the spindle centered in the Y travel range. It extends the head forward, to it's original location after the lower spacer moved the column back 2".


  On mine, the extra 2" accommodates the vise overhanging the back of the table.


There no change to the Z height.
The spacers basically move the column rearward, 2".


----------



## WobblyHand (Mar 27, 2022)

Ken226 said:


> The lower block, between the column and bed adds 2" to the Y.
> 
> The one between the head and column keeps the spindle centered in the Y travel range. It extends the head forward, to it's original location after the lower spacer moved the column back 2".
> 
> ...


Thanks for the explanation!  As you could tell, I was a bit confused.
How thick is the lower block?  Still don't have a good mental picture of this, but getting there.


----------



## Ken226 (Mar 27, 2022)

It's 2" thick.

I also milled the head spacer at a slight angle to correct some Y axis tram error.   It's been about  5 years since I did this mod, but I seem to remember putting a .003 feeler gauge between the spacer and vise when I faced it, to correct the tram issue.


I'll fire up MS paint,  and paint a better explanation.


----------



## WobblyHand (Mar 27, 2022)

mmcmdl said:


> Glad to hear that . I'm not the only one that has things go MIA in the garage .   As soon as you replace it , the original will magically appear .


Finding a dark material in the recesses of a non well lit garage, usually doesn't go all that well.  This rubber isn't all that big,  might be 9-12 square feet sort of folded up like a small blanket.  I'll stumble over it sometime.  Probably this summer!


----------



## WobblyHand (Mar 27, 2022)

Ken226 said:


> It's 2" thick.
> 
> I also milled the head spacer at a slight angle to correct some Y axis tram error.   It's been about  5 years since I did this mod, but I seem to remember putting a .003 feeler gauge between the spacer and vise when I faced it, to correct the tram issue.


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.


----------



## compact8 (Mar 27, 2022)

Ken226 said:


> I added a 2" thick aluminum block between the column and bed,  and another between the head and column ...



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


----------



## Ken226 (Mar 27, 2022)

WobblyHand said:


> 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.










compact8 said:


> 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 (Mar 27, 2022)

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 (Mar 27, 2022)

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 (Mar 27, 2022)

WobblyHand said:


> 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 (Mar 27, 2022)

ConValSam said:


> 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 (Mar 27, 2022)

Ken226 said:


> 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 (Mar 27, 2022)

Ken226 said:


> 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.
> 
> ...


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 (Mar 27, 2022)

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 (Mar 28, 2022)

wildcatter said:


> 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 (Mar 28, 2022)

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.


----------



## WobblyHand (Mar 28, 2022)

sdavilla said:


> 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.


If the roller is mounted on the head why does one give up y travel?


----------



## Ken226 (Mar 28, 2022)

Just off the top of my head,  an extension off the back of the saddle casting wouldnt be difficult.  I'm sure if it was made of steel or 6061 it would be plenty rigid enough. 

Pics explain an idea in more detail, with fewer words.  I don't see any reason something like this wouldn't be doable.


----------



## WobblyHand (Mar 28, 2022)

My CAD skills pale compared to @Ken226 but, I was thinking of an interim solution of mounting a roller (green) to the head (brown) with some brackets (not modeled here).  The thin rubber sheet (magenta) is wrapped around the roller.  The rubber is fixed to the column at the bottom with a thin metal piece. The roller is spring loaded (with no ratchet) and just rolls and retracts as the head moves up and down.  I need to check if the roller hits when the head is down.  All other times, the roller is out of the way.


----------



## Ken226 (Mar 28, 2022)

WobblyHand said:


> My CAD skills pale compared to @Ken226 but, I was thinking of an interim solution of mounting a roller (green) to the head (brown) with some brackets (not modeled here).  The thin rubber sheet (magenta) is wrapped around the roller.  The rubber is fixed to the column at the bottom with a thin metal piece. The roller is spring loaded (with no ratchet) and just rolls and retracts as the head moves up and down.  I need to check if the roller hits when the head is down.  All other times, the roller is out of the way.
> View attachment 402112



You'll need some kinda wiper to keep little chips that stick to the rubber from building up inside the roller and gumming up the works, but it looks good.


----------



## WobblyHand (Mar 29, 2022)

Ken226 said:


> You'll need some kinda wiper to keep little chips that stick to the rubber from building up inside the roller and gumming up the works, but it looks good.


Good point.  Might the wiper be a brush like thing or more like a windshield wiper insert?  Or a thicker piece of rubber edge like a squeegee?  Maybe I can find a squeegee insert.

Found a inoperable old window shade to take apart.  I'll see if I can modify it for this use.  If nothing else it will give me something to take apart and see how it really works.  I've seen some pictures, but they don't show the details that I'm interested in.


----------



## Ken226 (Mar 29, 2022)

WobblyHand said:


> Good point.  Might the wiper be a brush like thing or more like a windshield wiper insert?  Or a thicker piece of rubber edge like a squeegee?  Maybe I can find a squeegee insert.



Im not sure which would work better.  You might have to try a couple ideas to find one that works.  Your in experimental territory with this idea.

I'm curious to see how it turns out.


----------



## WobblyHand (Mar 29, 2022)

Ken226 said:


> Im not sure which would work better.  You might have to try a couple ideas to find one that works.  Your in experimental territory with this idea.
> 
> I'm curious to see how it turns out.


Seriously experimental.  In Rube Goldberg territory.   

Speaking of which, I took apart an old window shade and pulled out the innards.  This shade was retired for not working.  It didn't want to come apart, so I put the whole roller in the lathe and turned down the cardboard tube diameter until it weakened enough to pull off the crimped ferrule.  It seems that the spring was (still is) totally wound up because of the ratchet mechanism.  Have to figure out how to clamp the spring safely and un-tension the spring.  Don't want the spring flinging about (really dangerous).  Then I need to reduce the spring assembly length from 8" to 4".  Don't know if the spring tension will be adequate for that, but there's only one way to find out.  BTW, cardboard tubes are awful things to turn on a lathe. They turn initially, but then tear.  Cut a 6" piece of PVC 1/2" Schedule 40 pipe, which has nearly the same diameters, to use as the new roller.


The tube that the spring is wrapped around seems to be some kind of grey plastic.  The spring is retained by a slot cut on the right hand side of the tube.  The slot appears to be made with a handsaw of some sort.  Pretty cheap mechanism, but it worked for 20 years or so.


----------



## sdavilla (Mar 29, 2022)

WobblyHand said:


> If the roller is mounted on the head why does one give up y travel?



Ahh, that bellows. the PM30-MV defaults with an accordion style chip cover for the column side. I misunderstood and though this was in reference to the one covering the y slides. See below for the "other" one.


----------



## WobblyHand (Mar 29, 2022)

Have managed to unwind the spring in the roller.  Was kind of difficult, since the pawls had become magnetized and were attracted to the ratchet wheel, and the spring was overwound.  So I would release the pawls and get a whopping turn at a time, before the pawls re-engaged.  These pawls have no springs, they are just loose on pivots.  But somehow they would find their way back into the ratchet.  Used a demagnetizer that I made with 6 magnets, mounted the demag unit in my lathe and spun it next to the ratchet mechanism.  I think it helped, and was able manage the pawls a little easier and release the tension from the spring.  Now need to find my hard wire cutters to cut the spring.  I will cut the spring in half, and reduce the size of the spring rod to 4".


----------



## WobblyHand (Mar 29, 2022)

sdavilla said:


> Ahh, that bellows. the PM30-MV defaults with an accordion style chip cover for the column side. I misunderstood and though this was in reference to the one covering the y slides. See below for the "other" one.
> 
> View attachment 402249


That's pretty nice for the y bellows.  My PM25 uses a rubber sheet for that.  Yes, I was talking about the Z bellows and the bracket holding it in place.  If it was 10-20mm higher, I'd have less of a problem.  Maybe I can just raise the bracket or reduce its depth.  That's worth checking out.


----------



## WobblyHand (Mar 29, 2022)

Have no idea why I am doing this still, but this miniature rubber window roller is fascinating me.  Shortened the spring and the stem.  Was awkward but couldn't easily remove the spring so had to do it in place.  For reference, the PVC is 6" long.  Need to remove the pawls which are attached with rivets.


----------

