Micro Mill HELP!!

Sethhoward

Sethhoward

Basic Member
Joined
Jun 20, 2003
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65
I purchased this Micro MIll yesterday http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=47158

I know zip about mills. I think I understand that I am suppossed to remove the drill chuck that came in it and replace it with an end mill holder to use end mills. How do I remove the chuck !?!? The thing they call a manual does not even mention anything but the drill chuck.

Please reply here or email me

sethhoward@hotmail.com


Thanks to all to help before I break something.

Seth
 
Hello Seth!
I have the same mill and might be some help to you.
This mill doesn't use collets to hold end mills. You just chuck em up in the drill chuck.
Once you have the stock battened down and the mill in run the mill head down so the mill is within 1/4" of the stock and then lock the head down with the set screw on the side of the upright. Now you get to use the micro adjuster to raise and lower the mill. On the left side of the head theres a knurled knob that you can push in and pull out. Push it in. If it doesn't go all the way in, turn the wheel on the front of the mill head till the slot meshes with the pin, you'll know when it does. Now you're set up for micro adjusting. Now turn the wheel to lower the mill till it touches the surface of the stock and then back it off a hair. Make sure the speed dial is set to zero and turn the power on to the motor, then turn the speed dial up to the desired speed. The more flutes on your end mill the slower you'll want to run it. Gotta give it time to cut. Now lower the bit into the stock about 10 thousandths and start your first run. The rest is just a repeat.
You'll figure it out quick. Get yourself some blocks of aluminum for milling blocks, say 2" thick by 3" by 6". They're great.
Hope this babble helped ya!!
 
Yup, milling blocks,
That's what you fix your stock to with dogs or clamps. I took a chunk of 2" thick alum and drilled and tapped it for 1/4" bolts. Now when I need to mill something I use the dogs I made out of 1/2" aluminum to hold it down. The aluminum is nice and grabby and won't scar up your stock.
The block is also good for precision drilling. I drilled a 3/8" hole in the center of it. When I'm working on folders I use it for my drilling station and run the mill nice and slow and let the bit run down into the 3/8 hole for clearance. Works especially well when using a precision ream on pivots.
You have the perfect drill press for drilling titanium! Just run it slow and back off the bit a lot to clear the debris and you'll never burn up or break a bit.
 
Sethhoward said:
I purchased this Micro MIll yesterday http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=47158

I know zip about mills. I think I understand that I am suppossed to remove the drill chuck that came in it and replace it with an end mill holder to use end mills. How do I remove the chuck !?!? The thing they call a manual does not even mention anything but the drill chuck.

Please reply here or email me

sethhoward@hotmail.com


Thanks to all to help before I break something.

Seth
Click to expand...

Seth, run the quill all the way down and see if there is an oblong slot thru the spindle. If there is, then you can use a special tapered punch to remove the drill chuck and it's shank. Then you can buy morse taper end mill holders.
 
That special tapered punch is known as a drift. It's wedge shaped and is driven into a slot in the spindle to force the drill chuck's MT2 tapered spindle out.

While I've never seen a draw bar on something with a spindle as small as one like yours, on most mills, the collets go in the bottom of the spindle and are drawn up by a long threaded bar that sticks out of the top od the spindle when in it's full up position. Make sure your machine doesn't have a draw bar before using a drift. If it does, then the procedure is to back the draw bar out a couple turns and whack it with a brass hammer lightly until the chuck or collet come loose.

Holding an endmill cutter in a drill chuck will only allow you to take very light cuts and you can probably expect poor accuracy as the chucks are not going to hold the cutter with any appreciable concentricity. As mentioned above, a couple MT2 end mill holders would be a lot better choice. HF lists a 1/2 and a 3/8 MT2 endmill holder for around $10.00 ea.

Having said that, you will grow to hate using a mill with an MT2 taper unless you use cutters with teh same size shaft all the time because it's a royal pain to change the endmill holders. If I were in your shoes and could swing it, I'd return that thing and spend a few more dollars for this model:

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=44991

It has a WAY more standard R8 taper spindle just like a real Bridgeport with a draw bar meaning it's a 30 second operation to change a collet and there are a HUGE number of things available to fit an R8 spindle. The machine is still very light weight but would be a lot more useful in my opinion.

Something like this would take you a lot closer to a real milling machine:

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=33686

I have seen them go on sale for $599.00. It's WAY more rigid than the minis, but at 700lbs is also a lot more difficult to deal with if you're in a small shop working by yourself. It really doesn't take up much more room than the mini, but does cost more and is harder to move. This mill/drill is sold under a lot of different names and is made by Rong Fu. It's real name is an RF31 and these things show up all the time used for around $500.00 and usually with a bunch of extra tooling. Just some things to think about.
 
The milling machine he has is small, it can't handle anything over 5/16". The chuck is 1/4" but I've got some 5/16" mills that are shanked that I use in mine. This thing isn't built for heavy machining, it's a table top mini mill. I fried the control board on mine just running a 1/4" end mill in it for too long. Gotta watch out what you do with it and not go beyond it's capacity.
 
OK, I bought this thing to be able to slot brass, 416 stainless, and wrought iron guards and mill some mortesed tang handles. Will this machine not do that? I am asking because I do not know. If I need to go spend another $200 I will but I don't want to if I don't need to.


Seth
 
Seth, did you find the slot thru the spindle that allows you to use a drift punch to remove the chuck arbor?

If you did, then just get yourself some MT end mill holders, a drill drift from Enco, and your machine will do what you want.

If it has a threaded spindle nose that can't be removed, then you bought the wrong machine.
 
Sethhoward said:
OK, I bought this thing to be able to slot brass, 416 stainless, and wrought iron guards and mill some mortesed tang handles. Will this machine not do that? I am asking because I do not know. If I need to go spend another $200 I will but I don't want to if I don't need to.


Seth
Click to expand...

Seth, I have this exact mill, actually i now have 2 of them, i broke the motor gear on the 1st one so i ordered another one and i'm keeping the other for parts. It's a cheap piece of junk actually but I cant live without mine now. End mills tend to jump around due to the amount of slop in the table and head, if your only going to slot soft metals you might be ok if you tighten the set screws in the table and head, it makes moving the table harder. i'm pretty sure you can use a collet with this mill and it probably wouldnt jump around as much. I know its a hassle but if you can afford a better mill, you probably should. All I really use mine for is cutting the locks on liners, relieving the bolster for the lock tab, cutting down material thats too thick and i hope to use it for cutting a slot for the button on autos.
 
I found out how to remove the drill chuck and have been playing with end mills in the end mill holder I bought.

I wil look into tightening the set screws.

Thanks all.


Seth
 
The difference between the mill you got and one that is the next class up is that to slot a guard in 1/4 brass with that machine, you'll have to do it in several passes whereas the heavier machine would let you take the cut in one pass. Besides all the play in the ways, even though it weighs a hundred pounds,it's really a lightweight when presented with the lateral loads involved in milling. It's got a lot of flex built into it
 
It's not a huge improvement in rigidity, although by the weight and pics it does look a little beefier, but having the R8 spindle will make your life a lot better.

You'll need a collet set like this:

http://www.use-enco.com/CGI/INSRIT?PMAKA=891-6076&PMPXNO=3905715&PARTPG=INLMK32

Then you'll be able to correctly hold and easily change any common straight shank tool that you'd want to use. You will still be restricted to taking pretty light cuts, but it's a step in the right direction.
 
Nope, in my admittedly limited experience, you'll be a heck of a lot happier in the long run. All the reasons the other guys have pointed out become really obvious and especially to a newcomer to machining, really frustrating, really fast.

Using my friends micro mill was great on some plastic jigs, and small aluminium bits, but as soon as I tried it on steel, it just chattered around like crazy, then he smacked me upside the head and pointed me at the bigger unit. For the record, they were different brands but basically the same tools.

You'll be happy you upgraded.

Jon
 
I guess I could just send all my guards to you Tom ; ) I liked your milling machine.



Seth
 
milling cutters in a drill chuck! When I was an apprentice that would earn you a hard crack on the side of the head by the instructor. The cutter is only being supported by three little jaws in the chuck. It will screw up the chuck, the cutter (it likes consistant pressure) and the job. Take the colletts.
Also, don't buy cheapass drills or cutters, you will just have to replace them and they cannot do the job well, especially on stainless steel. You may want to get some water soluble cutting oil and just spray it on from time to time when machining steel. Do a search for milling cutting speeds because if your cutter rpm is too high you will burn the cutter and it will be history.
My 2 cents worth, have fun. :)
Mike
 
I'm with these guys!! Shoot, if I could afford it I'd have a humongous cnc mill sittin in my shop but I'm blessed to have the little bugger I got right now. It slots guards fine, even in titanium, You just can't hog it. If you're going be making folders, it's the best little drill press you can have, especially for ti. I'll get some knives made and eventually save up for a bridgeport. Till then, my little table topper will suffice.
 
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