A review of a Mini Mill from Little Machine Shop

[Modeler12]

Earlier I mentioned this little mill from Little Machine Shop and got several responses including a request to review this mill when I received and tried it out. Here is the start of this (perhaps ongoing) subject.

I will explain why I chose this model a bit later, but let me mention now that I had ordered the machine and tooling kit last Thursday. Today, Monday, it was at my front door. Not bad for a weekend delivery.

 

When I opened the smaller package of accessories I found the parts were all there as ordered. However, the first thing I noticed is that most metal parts were liberally coated with grease. Nothing new, of course, and perhaps necessary since all (or most) parts are made and shipped this way from China. I will be spending some time tomorrow 'degreasing'.

  

The same applies, of course, to the base and to a smaller extend to the top with its motor etc.

Overall, things are OK. The instruction manual, I am reading now, included a spare fuse on top. Not sure  yet where it goes, if needed.

 

I am going to skip over a lot of details later on and get into the guts of this thing (including why I think it is a neat little item for modeling work).

[jud]

Come on, you've had 12 minutes to post some more, I sit in anticipation, trying to be patent.

jud

Edited February 25, 2014 by jud

[Modeler12]

Come on, you've had 12 minutes to post some more, I sit in anticipation, trying to be patent.

jud

Ok Jud, please help me with the grease stuff.

Don't hold your breath, please.

[mtaylor]

Is it grease or cosmoline?   Either way, it's a pain. 

[jud]

Drop by, I have about 5 gallons of solvent in the shop, or you could use gasoline like we did when I was a kid to wash parts. If you have a buddy in auto or truck repair see if you can use their parts washer, save a lot of time and do a better job.

jud

[WackoWolf]

They all come with the grease on them, it's for protection. My Sherline had it on the machine, on the bed and etc

[Q A's Revenge]

Nice of you to take the time to do this Jay, I'm sure lots of folks are going to find your review very helpful. I'm also sure you're going to have lots of fun using this machine!

 

Vic.

[Modeler12]

OK. Here is an update. And Vic I am doing this also for my own 'review'. As I take these pictures I often realize something that I could have skipped over and learned the hard way later.

 

But first, here is the machine after cleaning it with some 'mineral spirits' or paint thinner. It was messy but not too bad. I then applied a thin coating of special oil designed for just that purpose. Then I started to assemble the various parts and learn what the controls and some of the features are. My admiral helped me steady the top when we mounted the top to the base with four screws. Note this is a rigid base model, not the type that you can rotate 45 degrees in both direction. Ones the unit is secured and checked for squareness, it should stay that way.

 

You can see that the overall design is simple and compact. The controls in front include a digital readout of the spindle speed, a forward/reverse switch (something I may never use), an emergency stop button and the speed control potentiometer. The large round disk you see to the left is the fine adjustment knob for the z-axis movement. The coarse adjustment is with a wheel similar to what you see for the x and y. The z wheel is in the back. The start/stop buttons are along the left side.
 

The table is 15.7 x 5.7 inches, a lot larger than the other machines I looked into when I did my search. Likewise the x travel is 11.8 inches, the y =5.9 inches and the z=8.7 inches. What I like also is that the screws and the wheels you see are in decimal inches (not fractions such as the Grizzly mini mill). You can also get the machine with mm, I believe.

 

There were a couple strange things while assembling some of the parts. The draw bar that pulls the collets up into the quill was loose inside the quill and not visible. When I tried to insert a collet, it would not work. I climbed on top and found the drawbar sitting loose but upside down. Then when I tried to mount the vise (a nice 3" precision type) the two special pieces, that fit into the holes of the vise, would not make proper contact. The feet of the serrated plates would not go down further. I had to take them apart and flip the feet over to let me make the correct adjustment.

But these were just little things that is part of my learning lessons.

 

 

The next step I want to take is to make some adjustments of the gibs, the thin strips of steel in the dovetail beds in all three axis. There are some set screws along each direction that can be loosened or tightened to reduce the backlash and stiffness of the bed.

In addition I want to check the squareness of the table and mount the vise so that it is parallel with the x-axis. It involves using a good dial indicator and a magnetic holder that I happen to have.

All of this is described in the manual that is included, of course.

So more later.

[Modeler12]

Here is Add #1.

The mill has a top spindle speed of 5000 rpm. Not bad, but not fast enough for those tiny drills we use.

On my old drill press I made a mod to adapt the old Dremmel-like tool that I have had for years. I did the same here.

 

The mill's head (motor and all) moves up and down with the quill. So I made a simple bracket out of aluminum, drilled and tapped some holes and adapted it to the motor frame. Now I have not made any modifications to the mill. I simply took out two #8-32 screws and replaced them with two a bit longer. I still have the old screws should it be necessary to go back.

The Monkey Wards tool fits snugly inside the wooden part that is bolted to the bracket and all is fairly stout. Not perfect, mind you, but good enough for this little motor that goes fast but does not need much force to spin a small tool.

Now I can mount a work piece on the table and use the precise way of moving it x and y under the Monkey W tool. The fine control nob (the large disk in front) can help to control the z-axis should that be important.

 

 

I don't even know how fast the Monkey W goes, but my guess is around 10,000 rpm or more. It has 120 vac input and I wonder if anyone knows of a simple way to control the speed of this thing.

[capnharv2]

Glad to see it has fine feed in the Z axis Jay. I wish my Unimat mill had that (I can buy one on e-bay, but they get insane prices for them).

 

Looks like a fun and useful tool. I'm sure you'll have a good time with it.

 

Thanks,

 

Harvey

[Modeler12]

Glad to see it has fine feed in the Z axis Jay. I wish my Unimat mill had that (I can buy one on e-bay, but they get insane prices for them).

 

Looks like a fun and useful tool. I'm sure you'll have a good time with it.

 

Thanks,

 

Harvey

Harvey, as I am working with this little mill, I am finding other features that at first I did not consider important or at least did not think of.

 

Here is one more example: the digital spindle speed indicator.

On this model it is built in and right in front of my nose. The milling speed could be important and is related to the material being milled and the diameter of the cutting tool. On an other thread I saw a nice table of this and made a copy.

To get the indicator for the MicroLux machine from Micro Mark you would have to shell out an additional $140 plus.

[Modeler12]

I hope you don't mind if I continue with a lot of details. But here are some more.

 

I checked the table 'flatness' in the x direction by mounting a dial indicator as shown below. As you would expect there was virtually no difference in the readings as I moved the table back and forth. I have not yet checked the y direction nor the amount of back lash.

I mounted the vise and for that I again used the dial indicator to make sure the clamping faces of the vise were parallel with the x-axis. I used one of the parallel plates, one of a nice set shown below also. It took a few runs back and forth and some slight movements of the vise to get it to be with 0.001 inch. After tightening the nuts (which are difficult to get to because it requires a socket head wrench), I verified the readings again.

      
 

 

Here are some negatives:

The mill comes with several wrenches but not all that I have used thus far. Below you see theirs plus mine.

For example, to make adjustments of the gibs requires a 2mm Allen head wrench for the x and y direction, but a 2.5mm wrench for the z direction. Neither one was included.

Then for the table locks the Allen head screw is 3mm. Here it would be nice to have a small handle, similar to the one for the z-axis.

The nuts for the clamps used for the vise are recessed and difficult to reach unless you have a 10mm socket head wrench (which I have, but was not supplied).

The little ring to set the depth of drilling has another Allen head screw which is also difficult to reach. A knurled knob would be better.

The draw bar for the collets is hidden inside the motor casing. You reach it from the top with the bent wrench shown below. However it is a bit of hit and miss to use it. Then to loosen it with a small hammer, again it is a hit or miss. I made a small wooden block that fits through the hole on top so I can hit that to loosen the collet.

 

If nothing else these are a few nuisances but not too important. 

 

 

[garyshipwright]

On 2/26/2014 at 9:13 AM, Modeler12 said:

Harvey, as I am working with this little mill, I am finding other features that at first I did not consider important or at least did not think of.

 

Here is one more example: the digital spindle speed indicator.

On this model it is built in and right in front of my nose. The milling speed could be important and is related to the material being milled and the diameter of the cutting tool. On an other thread I saw a nice table of this and made a copy.

To get the indicator for the MicroLux machine from Micro Mark you would have to shell out an additional $140 plus.

 

On 2/26/2014 at 9:13 AM, Modeler12 said:

 

 

Edited January 29, 2020 by garyshipwright

[Q A's Revenge]

Hi Jay. Can you give a link to the thread with the nice table  sir. Wouldn't mind taken a look at it. Thanks and don't mind the details of this at all. Gary

Might be this one.

 

[Q A's Revenge]

Some folks make these for their mills:

 

http://www.machinistblog.com/wrenchhammer-combination-tool-for-mini-mill/

 

[Modeler12]

One more point I like to make about clamping parts to the table. I have this piece of 2 x 2 inch aluminum angle. I will be using this for a project I have in mind. It involves machining the end at 45 degrees (after I roughly hacksaw it to that shape). Here are some pictures of how it might work.

The reason I show this is to try out the set of 50 clamping pieces that came with the tooling package and the 1-2-3 blocks.

 

First I mounted the part on the vise. No problem of course, but I also wanted to find out how stiff it would be with a lot of overhang. Not that I would machine the left end this way, but even at that the vise held it very securely this way.

 

 

Then I tried out the blocks and clamps. As you can see, the first attempt was no good. The second one was better.

 

 

Finally, I have run the mill at various speeds and it is very quiet. The belt drive rather than gears makes the difference. But as yet I have not cut any material. I wanted to make sure I understood the various operations, controls, etc.

My first project will involve a simple block with rough edges and then making some fixtures I have had in mind from the day I considered buying a mini mill. But that will be another topic perhaps later if anyone is interested.

 

In conclusion to this evaluation, I like to mention that all and all I like the machine. It has several features that I think are better than other machines in this class (of course this is based on published information, not a first hand experience).

I had a couple questions during these last couple days and my contacts with Chris Woods at Little Machine Shop were excellent. He offered good advise promptly. Plus I found the information they publish on the web as well as in the manual are very helpful.

If any of you have further questions, let me know.

[usedtosail]

Thanks for the review Jay. This looks like a great set up and I especially like your Bracket for the Dremel.  I just wish I had an extra grand and a place to put the machine. Someday maybe...

 

You asked about speed control. I know you can get a foot switch that will control the speed, but you are probably looking for something that will retain a constant speed.

[Modeler12]

NIce hammer,Vic.

The one I am using dates from the thirties. Part of my wife's inheritance, I think.

I had to file one surface to make sure it was copper.

But all I use it for is to hit the wooden plug on top of the draw bar and some gentle tapping to align the vise.

 

A copy of your table is pinned to the wall next to the LMS mill.

Edited February 26, 2014 by Modeler12

[Modeler12]

Thanks for the review Jay. This looks like a great set up and I especially like your Bracket for the Dremel.  I just wish I had an extra grand and a place to put the machine. Someday maybe...

 

You asked about speed control. I know you can get a foot switch that will control the speed, but you are probably looking for something that will retain a constant speed.

You are right, Tom. This foot switch is what is on my wife's sewing machine. I'll need to look into that. Maybe it is possible to use a potentiometer instead of the spring loaded pedal.

[jud]

Might wire in a dimmer switch, (old floor headlight dimmer), with a pedal on the floor. think I would want any speed control up on the mill where I could adjust it separately from the on-off switch. Nice machine and it looks like you have enough tooling to use the thing right away. Have an old brass hammer like yours ad just as rough out in the shop, think it was Granddads.

happy milling

jud

Oh, before I forget, you ever get over to the dry side, bring a greasy old part with you and stop by, we can trade off with the parts brush.

jud

[Modeler12]

Might wire in a dimmer switch, (old floor headlight dimmer), with a pedal on the floor. think I would want any speed control up on the mill where I could adjust it separately from the on-off switch. Nice machine and it looks like you have enough tooling to use the thing right away. Have an old brass hammer like yours ad just as rough out in the shop, think it was Granddads.

happy milling

jud

Oh, before I forget, you ever get over to the dry side, bring a greasy old part with you and stop by, we can trade off with the parts brush.

jud

Thanks Jud. I might try something like that. Like I said though, I don't even know what the top speed of this thing is. I will have to go through some old records to see if I still have a manual. Haven't even looked at the model number yet.

 

You do live in the 'dry' parts of Oregon. I had never heard of Lexington, Oregon and it looks like you probably know every body in town.

[Modeler12]

Sorry, I keep finding things that are of interest (at least to me).

Vises, what kind do you have?

 

I now have one more, and this one is for my mini mill. I am talking about the 'precision vise' that is listed as an option with all the other milling machines, but was included in my tooling package. It is the one to the right of my old vise shown.   

The one that came with my LMS package has a three inch width and one inch depth. It looks like it came out of a precision grinding lab. All surfaces are flat, smooth and claimed to be at right angles to each other. Looking at some of the details, such as the corners and where they mate the mill surfaces, I do not doubt that.
The problem is that it really takes some getting used to how this thing works. Here are comments from Chis at Little Machine Shop when I asked him about how to tighten the vise:

Those vises are a learning experience. It’s always a hassle to move between grooves.

 

My trick is to use a hex (Allen) wrench without a ball on the end. Then you can lever the screw up and down to either move the jaw or fit the pin in a groove. . . .

 

Nevertheless, the vise is great. Just look at  the sharp edges and some of the corner details. . . .

 

I am sure other sources besides LMS provide the same kind of vise (although smaller?).

 

I have two other vises for this kind of work. But both are larger and more intended for 'quick action'. I really like the one that has an open saddle with unusual screw design. But it is too large for the mill and I will keep it on my old table drill press.

 

 

I was just curious what vises means to others here. Bench vises, table top vises,  . . . . . .

 

[mtaylor]

For my mill, I have one very similar that's sold by MM.  Just about the same size.  Bench vise is a small 3" wide that I found at Lowe's.   Nothing bigger, but at times, I wish they were smaller.  I also have the magnetic/rubber jaw inserts so as not to damage the wood.

[Q A's Revenge]

This is the 4 inch vice that normally lives on my mill, with the 2 inch screwless vice clamped into it to make angle cuts. I don't have a tilting vice so this works well.

I have a sine bar for accurate angle setting when required. The 4" is a bit of a lump at almost exactly 12 Kg. Hard to see in the pictures but I made a couple of bushes that are a press fit in the mounting holes. These were made to be a snug fit in the tee slots on my mill so I can just drop the vice in place and know it's within 001" square to the table. I'm not generally in a rush so check it with a DTI as well but the bushes are still a time saver.

 

Vic.

 

[Modeler12]

Clever Vic. I will have to remember this.

That old vise I showed earlier may not be very accurate, but for a pinch this might work.

 

PS I like the top of your work bench. Classy!!!

Edited February 28, 2014 by Modeler12

[Q A's Revenge]

Screwless vices are available in two slightly different types. Not tried type 2 yet.

 

http://www.arceurotrade.co.uk/Catalogue/Workholding/Machine-Vices

[Modeler12]

There is another way to tilt a part on the mill. It involves a tilting table.

This one is available from Little Machine Shop (item 3878).

But my guess is that it would be handy only if you do a lot of this kind of milling.

 

[Modeler12]

Screwless vices are available in two slightly different types. Not tried type 2 yet.

 

http://www.arceurotrade.co.uk/Catalogue/Workholding/Machine-Vices

Great series of vises from this company, Vic.

 

I hate to mention this, but I asked the guy at Little Machine Shop about how, and why there is not a spring to push the bolt up. Kind of like the type 2 you mention. I have a whole bunch of springs and might just try this on the one I have. I am sure you could also.

 

Just as a side line. When I looked into a mill, I also compared prices for vises. Hmmm, no rhyme intended.

But even for a 2" wide Type 1 (as you call it), I would have paid $44.95 (plus our tax of 8%) by LMS.

If I had ordered that from Micro Mark it would have been $69.50 (plus tax) for the same, identical item made in China.

[WackoWolf]

Micro Mark to me is way over price on almost all there stuff, but it comes down to the point of they have stuff you can't always fine any where else. This is just my option and I have bought stuff from them at times because I couldn't fine it anywhere else or had to order it from out of the country and it would have cost more.

[Modeler12]

Micro Mark to me is way over price on almost all there stuff, but it comes down to the point of they have stuff you can't always fine any where else. This is just my option and I have bought stuff from them at times because I couldn't fine it anywhere else or had to order it from out of the country and it would have cost more.

I agree. But at least now I have another source for some of the tooling and parts for my equipment.

 

Here is another gripe I have. 'Shipping and Handling' charges. 

I can understand that companies charge me for shipping. But 'Handling' should be part of their overhead.

I find it ridiculous when I receive a small part in the mail with $2 postage, but I was charged $6 for it.

 

Those of you who live outside the US may then even have to pay 'import duties'. And I wonder how much that can add.