Pm-25mv z-axis travel

[higgite]

10" is not a lot of room on a milling machine. With the vise and tooling in there, things are going to be tight! My Sherline mill has about 14" of space under the spindle and I can just get my little 4" rotary table and a Blake Co-axial indicator in there; these tools wouldn't fit on a PM 25.

Mike,
I see your point about room for RTs, tools and such, but I might respectfully point out that David’s mill has 12” max from spindle to table. The head only moves 10”. But even with 12” clearance, I can see how an RT with a chuck on top and a work piece mounted might limit tool space.

FWIW, the spindle to table clearance (to nearest 0.1”) on my LMS 5500 (Sieg SX2.7) is 12.3” max and 0.6” min with the quill drawn up in the “home” position, not extended. I actually didn’t know it would get that low to the table until I tried it just now. I’m not sure how practical that is, but I know now that if I ever need to use it as a panini press, it’s up to the task.

Meanwhile, back at the ranch, the head travel measures 11.7” top to bottom (vs 11.6” advertised). Quill travel is 2.8” (as advertised).

Tom

 

[mikey]

I understand that the PM 25 has 12" of room from the spindle to the table and 10" of spindle travel. It is still not a lot of room once you add the vise or rotab or dividing head, then add the drill chuck/ER chuck/flycutter/etc. The further away from the base of the column you are forced to work at the less stable the head/spindle/tool is.

I am in no way dissing the PM 25 or any other mill. I just wanted to make David aware of the work envelope thing because he will need to contend with that, as all of us do.

 

[Chewy]

David, when I looked at the spec's a couple of years ago, I moved up to the PM 30. It has a couple of inches more Z, but more important, it has 3" quill travel vs 2" with the PM 25. It may not seem like much, but when you start switching operations, that extra inch helps by decreasing the Z hand cranking. If you get the drill chuck that Matt sells, it will eat up the real estate in a hurry. Either way, they are both good machines and you will proabaly be happy with them.

 

[DavidR8]

Thanks all.
What I was attempting to reconcile was the PM-25MV specs against another 25 class machine.
Specs on the latter are 11”’ of z-axis travel plus 2” of spindle travel.
That roughly aligns with the measurements @ErichKeane provided.


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[higgite]

Thanks all.
What I was attempting to reconcile was the PM-25MV specs against another 25 class machine.
Specs on the latter are 11”’ of z-axis travel plus 2” of spindle travel.
That roughly aligns with the measurements @ErichKeane provided.


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David, what are the comparative maximum spindle to table distances (let's call it headroom for brevity) of the two machines that you're comparing? As Mike pointed out, regardless of how far the head will travel up and down, you have to have enough headroom to set up your work and still have room for drill chucks and bits, fly cutters, RTs, etc. Z-axis travel doesn't necessarily translate to headroom. For instance, the PM-25MV has 10" of travel and 12" of max headroom. My mill has 2.3" more travel than the PM machine but actually has 0.3" less max headroom.

Tom

 

[DavidR8]

David, what are the comparative maximum spindle to table distances (let's call it headroom for brevity) of the two machines that you're comparing? As Mike pointed out, regardless of how far the head will travel up and down, you have to have enough headroom to set up your work and still have room for drill chucks and bits, fly cutters, RTs, etc. Z-axis travel doesn't necessarily translate to headroom. For instance, the PM-25MV has 10" of travel and 12" of max headroom. My mill has 2.3" more travel than the PM machine but actually has 0.3" less max headroom.

Tom

Thanks Tom, in fact all except for the RF 30 and 40 I’m also considering show 13” of headroom above the table.

The RF 30 shows 18 7/8” headroom.

RF-40 I’m looking at has similar headroom


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[erikmannie]

I am surprised that somebody hasn't come out with low profile milling vises (shipped with no swivel base!).

It seems like every inch of vertical real estate has a lot of value. This is why we all have swivel bases that we are not using taking up space.

Probably one reason that the Bridgeport knee mills were so popular is that they offer a whopping 16" of knee and 5" of quill travel: https://www.worldwidemachinetool.com/product/new-bridgeport-mill/ Man, those are crazy expensive!

 

[higgite]

I am surprised that somebody hasn't come out with low profile milling vises (shipped with no swivel base!).

Just to name a few with no swivel base:

Home

www.kurtworkholding.com

Glacern Machine Tools - CNC Machine Vises

Glacern Machine Tools manufacturers CNC Machine Vises, Precision Tool Holders, and Indexable Milling Cutters for vertical and horizontal cnc milling machines.

glacern.com

30553-SET - 5 in. Machinist Vise

The 5 in. (127 mm) Machinist Vise is a sturdy CNC vise that provides a rigid backstop and prevents lifting of jaws when tightened

www.tormach.com

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

https://littlemachineshop.com/products/product_view.php?ProductID=1879&category=1963256912 (available with or without swivel base)

Tom

 

[darkzero]

I am surprised that somebody hasn't come out with low profile milling vises (shipped with no swivel base!).

It seems like every inch of vertical real estate has a lot of value. This is why we all have swivel bases that we are not using taking up space.

Probably one reason that the Bridgeport knee mills were so popular is that they offer a whopping 16" of knee and 5" of quill travel: https://www.worldwidemachinetool.com/product/new-bridgeport-mill/ Man, those are crazy expensive!

Many milling vises don't include a swivel base, they are usually an optional purchase. I don't even own a swivel base. Ok well I do, the 4" vise that came with my mill has a swivel base but that vise has just been sitting in a box in the corner since I got it.

Kurt/angle lock style & CNC style vises aren't really that tall considering the leadscrew & angle lock feature. Need some mass on the vise for rigidity otherwise they will flex. Can always use a drill press vise but they may not hold parts well for heavy milling.

There's also toolmaker's/screwless/grinding vises that are pretty low profile.

But if you need something very low profile, you can make or buy one of these. But these won't supply nearly the same amount of clamping pressure as a Kurt style vise. Have to be careful not to over stress the t-slots on the table.

There are other hobby mills available with more capacity. My PM45 is a bench top class RF-45 style mill/drill that has like 17" spindle to table distance, 15" head travel, & 5" quill travel. Well something like that, I forget, but I have yet to run out of Z distance on the stuff I work on. Plenty of options out there if a knee mill isn't feasible.

 

[erikmannie]

Many milling vises don't include a swivel base, they are usually an optional purchase. I don't even own a swivel base. Ok well I do, the 4" vise that came with my mill has a swivel base but that vise has just been sitting in a box in the corner since I got it.

Kurt/angle lock style & CNC style vises aren't really that tall considering the leadscrew & angle lock feature. Need some mass on the vise for rigidity otherwise they will flex. Can always use a drill press vise but they may not hold parts well for heavy milling.

There's also toolmaker's/screwless/grinding vises that are pretty low profile.

But if you need something very low profile, you can make or buy one of these. But these won't supply nearly the same amount of clamping pressure as a Kurt style vise. Have to be careful not to over stress the t-slots on the table.

View attachment 313772

There are other hobby mills available with more capacity. My PM45 is a bench top class RF-45 style mill/drill that has like 17" spindle to table distance, 15" head travel, & 5" quill travel. Well something like that, I forget, but I have yet to run out of Z distance on the stuff I work on. Plenty of options out there if a knee mill isn't feasible.

I have never seen any setup as shown in the photo. I would be afraid that I would scratch my table if I used that.