LMS Mill

As Bill has said there are some things that are more desirable on the PM. I think you will find on any machine that there are things more desirable.
On the LMS mill we have, like the one you listed, I have found things that did not sit me. I have made many modifications.
I never did metal machining before my son bought this mill. I have good engineering and mechanical skills to redesign things to suit my needs.
This is one point I think I am trying to point out. On most machines you will find things that don't suit and you will modify. That is part of the fun.
If I had the choice and it was my money I would be buying a nice knee mill.:)
The bottom line is you need to know your budget, needs, future needs, space available and do lots of research. You have seemed to done most of this. Now you make a purchase and live with it. Easier said then done for sure because there always be that what if and like computers that new model you wish you waited for. (boy I can babble) :)
I haven't seen any points made by members here that seem misleading or incorrect but then once again I am not a pro.
Good luck on your purchase and most importantly have fun.

Have a great day!
Ed

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wrmiller19 said:
Hey Doug,

First off, this is just MY opinion, OK? Both configurations will work, obviously, but I'm not real happy with this mechanism on the LMS. As to the reason why:

When I first was learning at my friends gunsmithing business, he had BP clone. I was taught (and became accustomed to) bringing the table close to the cutter with the knee crank, touching the cutter to the work surface by bringing the quil down and locking it, setting the Z zero on the knee dial (he only had a two-axis DRO) and then bumping the Z handle down to clear the cutter from the work. This set my Z-axis reference, or zero. I'm sure the machinists here would describe a different way, but this worked well, and quickly, for the bulk of the machining we did in the shop.

My first little mill like this was back in 2000 and I bought it from a guy who advertised in the Home Shop Machinist. He basically took the cheap Chinese mill and modified it with a R-8 spindle (not available back then), class 7 bearings, a quill that went about 1.5", and a leadscrew for the Z axis very similar to the one on the PM machines. Add the solid column, and inch leadscrews and it was quite the little machine. He put so much work in this thing that he wasn't making much money on each one, and he still had to compete with the HF crowd that figured price was everything, even if the machine wasn't the same... ;)

Anyway, the transition from the big mill to this little one was very minimal, with the primary difference being where the Z-axis knob was located.

Now I have this LMS machine that has no qilll and the slop on the Z-axis fine feed knob is about a full turn or more. Couple that with the lack of feel on the knob/rack-and-pinion interface, and I am not quite sure when the head actually starts to move. Which is why I bought the DRO, so I can better track the absolute movement of the Z-axis regardless of how much slop is in the mechanism. A rather expensive fix you might say, but I like having a readout instead of trying to count handle turns anyway. As I have said before, I'm not a machinist, I just like using some of their machines to make things. :)

The PM-25 has almost the exact configuration, albeit in a larger package, as the mill I had years ago. I didn't get it because I was afraid of the extra weight and my ability to manhandle it around by myself without any lifts or other mechanical assistance. I goofed, because I managed to muscle around my 300 lb South Bend without too much trouble (minor muscle pulls and my hip complaining doesn't count). Oh well, lesson learned.

With the air spring, the LMS mill has over 10" of Z-axis travel. The PM has 13", and the quill. The PM has more Y-axis travel too, which I will have to work around on the LMS machine. And a Z-axis leadscrew w/quill. I thought about trying to modify the LMS mill to approximate the one I had years ago, but if I disassemble my LMS mill, I have nothing to make the mods with... :(

Buyers remorse? Probably. More like not completely thinking this through before I jumped. I will eventually get the PM machine, and maybe relegate the LMS to precision drill press duty. :)

But keep in mind, this is just me. Others have and like the little LMS machine, and it does pretty decent work for me. It's just not quite what I want for the work I want to do or how I do it. I'm just expressing my experience. Not trying to influence your decision.

Bill
Click to expand...


Im still setting mine up when I have the time getting the DRO Y axis is the last thing Im working on. I agree 1000% about the Z axis fine feed and its terrible. I did add a 12" Shars magnetic scale with the remote readout I stuck to the plate above the operation box. I also upgraded the accordian cover on Y axis which costs me a little movemen each way but I dont think its a big deal at this point. I had not heard of the PM machines before I bought this or I probably would have done so. But Im still happy with the LMS and if anyone has or knows how to add a quill function for even just an inch or two of travel Id be interested. I still have to add a X power feed when I can find the coin later on this summer. For now its getting to be shooting season and the 3 Gun stuff moves up to the top of priorities. I also still have to add the tach kit I got from a guy who makes them with the LED 7 segment lights and a extra cable to hook up the reversing switch at macpod. I have a couple things I had to do for my Akdal mags and a other minor couple things but now I can slow down and just enjoy playing with the mill. Its a hobby unto itself and a very zen kind of hobby.
And one more thing. I did add the air spring kit. And while it works in a manor of speaking there is a lot of flex.
When I get it all done I will post a before and after pic. That may be a week or so with what else I have on my plate.
 
Once my air spring was properly adjusted, it doesn't flex at all and works well.

Bill
 
Is the air spring from lms? What exactly is flexing? Just curious.
Ours is a lms and I don't have any sort of problem with it.
It works great but when trying to use it more like a drill press I didn't like the resistance of bringing head back up quickly.
Other than that it works great and got rid of that arm that supported the head. In somethings the arm would get in the way.

Ed

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