# I just bought a LMS 3990 mill; now what?!



## ARC-170 (Nov 20, 2018)

After looking for the past 2 months, I finally decided to get a small mill. I was looking at the bigger RF-25/30 clones, but the -30 was way too big and the -20's I saw were in bad shape. I came to the conclusion that a smaller mill would suit my needs and one came up that was a good deal. It was $800 for the mill with vise and rotary table. The mill is about $1,300 out the door new and the rotary table looks like it's comparable to the $500 one.

I teach engineering and design at a high school and was looking for something to use at home to create lessons and build stuff (for work and for me) so I wouldn't have to stay at work late, go in on weekends or go in the summer. It's 60 miles round trip and I'd have to bring my kids. I also realized I've never made anything really large, and if I ever needed to, I have bigger machines at work for the few times I might need one. It also needed to fit in my garage. So, small mill it is!




This is a LMS 3990 Hi HiTorque mill. It was a prop on a reality show, according to the seller. He told me they added black paint "aging" to make it look grungier. The show was about how to quickly make guns. Everything works fine, though.

It also came with:
-most of the wrenches
-3" vise
-rotary table and tailstock (not the same one sold by LMS, according to the guy who helped me there)

I stopped at LMS on my way home and picked up a few missing pieces: a vise mounting kit and spanner wrench.
I also got some way oil, grease, oiler can, collet set, edge/center finder, center drills, and a parallel set.
I'll get some cutter bits and a clamp kit later.

There is lots of brass swarf on the table and it's a bit dusty and slightly dirty, but otherwise looks like I could use it. I have another project taking up space in the garage at the moment, so I will wait until that's cleared away before setting this up. I think I will find a tool chest on CL and place this on top.

The one issue it has is the vise is missing the pieces on the bottom that align it in the slots. These can't be purchased separately; they come with the vise. I'll need to make some.

Anything else I should know in the meantime?


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## hman (Nov 20, 2018)

Nice looking mill, and I envy your proximity to LMS!
You'll probably want a clamping kit (for things that won't conveniently fit in the vise) ...
https://littlemachineshop.com/products/product_view.php?ProductID=1144
... possibly an X axis power feed (because cranking gets tiresome) ...
https://littlemachineshop.com/products/product_view.php?ProductID=5112&category=
... and eventually, a DRO.  

I've had an HF 44991 mini-mill for a number of years, added several LMS goodies (belt drive, hydraulic lifter, table feed, etc.) when I could afford them.  Might do without some of the others, but I can't even imagine doing without a the DRO!


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## Asm109 (Nov 20, 2018)

You don't need the keys for the vise.  You need a dial test indicator and a way to clamp it to the spindle or in a collet.
You tap the vise into alignment so the indicator shows no motion as you crank the table past the indicator.
Snug one vise bolt and leave the other one loose so the vise pivots around one point.
After a bit of practice you can indicate the vise in to less than 0.001 inches across the width of the jaws in just a couple minutes.

I have never used the keys that came with my vise.


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## wrmiller (Nov 21, 2018)

I had one of these years back, and it served me well.

For a short answer to your "now what?" question: 

You need to be able to hold a piece of material on the table. Vise and/or clamp kit will work. You may also eventually need parallels and/or 123 blocks to aid in various workpiece setups.

You need a basic set of cutters/endmills, and R8 collets to hold them in the spindle.

You need some basic measuring devices, e.g., calipers. A machinist rule (12"?) also comes in handy. You may want a set of micrometers as well.

You will add more tooling as you go, depending on what kind of work you are trying to accomplish. As many here have said (including myself), procuring the machine is just the beginning.


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## coherent (Nov 21, 2018)

I had one. Bought it new from LMS.  I converted it to CNC. Was a nice little mill and I learned a lot with it. When I moved up to a larger mill I pretty much broke even. It's a great candidate and fun project if you ever want to CNC it!


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## mickri (Nov 21, 2018)

I went with ER32 metric collets with an ER32/R8 chuck for the mill and a ER32/mt2 chuck for the lathe.  That way you can use the same collets on both the mill and the lathe.   Buy a couple of extra collet nuts.  They will come in handy when switching between different collets.  I went with the metric collets because there is no gaps in the coverage from 2 mm to 21 mm.  ER32 imperial collets and R8 collets have gaps in the coverage.

You are on you way.  Have fun.


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## pontiac428 (Nov 21, 2018)

Good advice from mickri on the ER32 collets.  

The T-slot nuts can be ordered from McMaster, along with whatever type of studs, nuts, and washers you need.  They are cheap.  You just need to know the width and thread size you want to work with.  I'd recommend 3/8" studs as a starting point.  Or you can buy an Enco/Grizzly/HF mill table hold-down set (they are all the same, find the best deal) and be well-equipped for anything you find yourself working on.

After you get initially set up, you will be able to make your own tools and fixtures instead of buying them.


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## flycutter13 (Nov 25, 2018)

You mentioned placing your mill on a tool chest.  I would make sure that the tool chest or whatever you place it on is rigid enough.  Heavier cuts can cause vibration that can shake the workbench or if the chest has wheels, even make the whole operation start to creep around.


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## ARC-170 (Nov 25, 2018)

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flycutter13 said:



			You mentioned placing your mill on a tool chest.  I would make sure that the tool chest or whatever you place it on is rigid enough.  Heavier cuts can cause vibration that can shake the workbench or if the chest has wheels, even make the whole operation start to creep around.
		
Click to expand...

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My plan is to put it on a tool chest with wheels for now, then when I figure out where this machine will live, I will take the wheels off.

Used tool chests come up on CL often enough, but there are many specials now that I might take advantage of. I'd prefer a red box with black drawers so everything matches, but I can always paint one.


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