# Cheap Mini Mill



## ex_isp

Greetings all!  First time here... not actually a machinist, but a knife maker.

I need to be able to cut brass (only) that's no thicker than 1/4", 1/8th " wide slot, 1/2 to 3/4" long.  This is for making finger guards on knives where the blade goes into the handle.  Traditionally, I have done this by making a hole and then sitting with pin files for half a day.  OUCH!   

I have just seen a very affordable mill ($190) on the interwebz.  Now, I realize that this is a cheap, small, underpowered machine.
It only needs to be able to do the task I described above.  I don't even expect it to be able to cut the 1/4" deep slot in one pass.  8 to 10 passes would have to be better/faster by far, than the better part of a day spent with files.
Headstock speed is only 2000 rpm.  Passes would (I think) be shallow without much force.

I am looking for your opines on this machine.
http://www.ebay.com/itm/Metal-Mini-Milling-Machine-Micro-DIY-Woodworking-Power-Tool-for-Student-Hobby-/251811966308?hash=item3aa129ad64:g:U4MAAOSw3xJVXEAc  

Thoughts pro or con are highly appreciated!
Many thanks for your time!

Ex


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## JimDawson

Welcome Aboard Ex !

If I were making that cut with hand tools, I would drill the hole then use a jeweler's saw to rough it out then finish with a file.  Much faster.



ex_isp said:


> Now, I realize that this is a cheap, small, underpowered machine.



Yes, but for the price it seems reasonable.  I think it will do the job as you described.

The question you may need to ask yourself is:  ''If I had a bigger better machine could I do other operations that I'm currently doing by hand?''


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## rrjohnso2000

I'm pretty sure you would be disappointed in that particular product.


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## ex_isp

>>If I were making that cut with hand tools, I would drill the hole then use a jeweler's saw to rough it out then finish with a file. Much faster.
Embarrassed to say that I had not thought of the jewelers saw!

>>Welcome Aboard Ex !
Many thanks kind sir!

>>The question you may need to ask yourself is: ''If I had a bigger better machine could I do other operations that I'm currently doing by hand?''
Excellent point!  But likely, not.  Most everything else is forging, HT-ing, grinding, polishing.  Pretty well tooled on the other fronts.

Most of my knives are slab handled skinners.  
	

		
			
		

		
	







or






This little machine really would be the ideal size/cost for it's needs and if it has reasonable life, would be "the cats meow" for my needs.
The first thing I tried was putting a 2 axis vice on the drill press table but the drill press just has a bit too much run-out on the spindle, hence my search for 
a (real?) mill.


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## ex_isp

rrjohnso2000 said:


> I'm pretty sure you would be disappointed in that particular product.


Reasons please.  While I most often go out of my way to avoid far eastern pot metal tools and understand what Harbor Freight is/does,
some of their tools aren't as bad as others.  And this particular mill is less expensive than the comparable HF mill.  (bells going off?)
My thinking is that with light passes, maybe 10 minutes to cut my slot...?  With light passes, will it work?

What other might you suggest?

Chris


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## rrjohnso2000

It's not really a mill. It's more a toy. I don't say this lightly. I spent the last two years searching for a cheep quality mill.  The sherline and proxxon are really the only real options. 

The xy table and drill press should be able to be tweaked for your needs. Good luck getting it sorted


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## brino

I picked up some metal-cutting blades for my scroll saw here:
http://www.ebay.co.uk/itm/Pegas-90-...i-/252095879388?ssPageName=ADME:X:RTQ:GB:1123

I got a couple different tooth counts and they have worked very well on shallow cuts in brass even 1/2" thick.

-brino


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## JimDawson

ex_isp said:


> Reasons please. While I most often go out of my way to avoid far eastern pot metal tools and understand what Harbor Freight is/does, some of their tools aren't as bad as others. And this particular mill is less expensive than the comparable HF mill. (bells going off?)



The Harbor Freight Benchtop Mill/Drill is a lot more machine than the one on ebay.  Also about 3.5 times the cost.  Neither one of them will be a very stable machine compared to more expensive machines, but bolted together aluminum extrusions does not make for a very stable platform.

If price is the primary consideration, then the one on ebay will get the job done with light cuts and reasonable care.  Another option might be a router and router table along with a guide or some fixturing.


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## mikey

JimDawson said:


> Welcome Aboard Ex !
> 
> The question you may need to ask yourself is:  ''If I had a bigger better machine could I do other operations that I'm currently doing by hand?''



I agree with Jim. Once you experience the utility of a milling machine your scope of possibilities opens up and it will become far more useful than you might realize. One area it might be useful in is the making of tools that will make your knifemaking tasks simpler. 

A mill is also able to drill far more accurately than just about any other tool in the shop and it will bore extremely accurate holes that you cannot otherwise make. Then there are the abilities to make stuff flat, of precise dimensions and with profiles that are cumbersome to otherwise do. A mill greatly expands your capabilities so if you spend money, buy one that will perform for you.

The smallest mill I know of is the Sherline mill; it is  extremely accurate and capable for its size. I see them come up on Craigslist from time to time. Money spent here might be a wise investment. 

Have a care, however; the next thing you know you'll be wanting a lathe and wind up like the rest of us hapless toolaholics.


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## fleckner's garage

I thought a hf benchtop would suit me for some small aluminum key way slots I needed. 8 moths later I drug home a 4000lb Kearney and Trecker and I just play with metal for a hobby. Buy something 2-3 times bigger/stiffer/more powerful than you think you need


Sent from my iPhone using Tapatalk


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## T Bredehoft

ex_isp said:


> Reasons please.



Studying the images of the "Mill" the column is attached to the "table" by four screws, approximately the size of a 6-32 screw, certainly not as big as 1/4 - 20.  Comparing the mass of the column vs the mass of the 'table', I'd be afraid that instead of vibrating during a cut, it would lean to one side or the other. It is not built heavy enough to be called a mill. Machining even 1/8 brass would overload it's rigidity.


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## chips&more

Going to that fleabay sight and looking at the examples it can make. They are all made out of wood and plastic. The spindle speed is 2K rpm. I’ll bet that vise is made out of plastic. It has leave it and run away, written all over it.


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## ex_isp

Well, I thank you guys all!!!  I looked a little further and found an 8 yr old large/HEAVY (150 lbs) HF machine that came with 16 collets (1 of them has a chuck in it) that has been in use by a pro gunsmith since new.
When I got to Tucson from Phoenix, he said he was hoping I wouldn't show up for another hr as he was still using it.  He was using it to cut dovetails in pistol barrels and loves it but he's 78, retiring and moving to Louisiana.
So, 8 yrs ago, this was an $800 machine with what he described as $200-$300 worth of accessories.  

I got it for $400 and a half tank of gas.  I'm delighted and glad for the strong suggestions to get something a little bigger.  Next couple days I'll get some photos of it and shoot them up
to my photobucket so "ya'll" can see which one it is.  Guy was cutting pretty tough steel with it when I got there and it was not complaining at the load.

Thanks to all!

Chris


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## ex_isp

Today, I did a test cut in the brass with a 1/8" dremmel bit in the collet as I don't have real cutters yet.  Was able to chew through over 50% of the 1/4" thickness of stock
in a single pass with no strain at all.  I'm impressed and must agree, the Chinese ebay machine would not have done that.  Again, THANKS for pushing me towards the 
larger machine!!!

Here's the machine and accessories that came with it.  I think I stole it for $400.


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## brav65

Hey ex_isp good find!  When I was looking for a mill a couple years ago there was not much to be had somI got a PM-25. Are you part of the Valley Metal group?  If no send me a PM and I can get you information about the group.  It is a nice bunch of guys that shares ideas and helps eachother out.


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## ex_isp

Thanks brav65!  Signed up!


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## ex_isp

Found what appears to be a good idea for modding the gibs and set screws.  Check this and comment please!

http://benchtopmachineshop.blogspot.ru/2013/06/mill-gibs.html


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## mikey

I've seen this gib screw arrangement on Asian machines before. In fact, my Emco lathe has divots for the gib adjusters too. They allow for adjustment and a method for keeping the gib from moving, all at the same time. The difference is in how this is executed.

On my Emco, the divots are machined carefully and precisely at 90 degrees, and coned inserts fit into those divots; the gib screws bear on the back of the inserts and not directly on the gib. The benefit, obviously, is that this arrangement does not distort the holes in the gib. The pic below shows the inserts on my compound gib; the one on my saddle is the same. The insert shown fits in a vertical slot that locates the gib and keeps it from sliding around; the rest of the gib screws are in coned holes, not slots.




My Rong Fu mill has gib locks that are the same as the mill in the article. When either the Y or X axis is locked the locking screws actually screw down on the gib, digging into the back of a cast iron gib. If I lock it really hard there is a risk of damage or possibly cracking the gib. To get around that I made inserts with noses ground at the angle of the gib in front and flat in the back. They slip into the gib lock holes and the gib locking screws bear on the inserts. Now, when I lock the axis it locks solidly and I'm not concerned about damage or cracks.

Some guys use ball bearings instead of tapering the nose of an insert and that works well for gib locks, not for gib adjusters. Anyway, food for thought.


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## ex_isp

More great information Mikey and thanks!!!  

Today, now that I'm starting to get some bits in, I decided just to play and make myself a fancy bit holder.
Sorry it's blurry, was holding cam with one hand and light with other.  This is a piece of Maple burl that I
really like for my knife scales, but it's too small to use for that, so...


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## mikey

Those look like burrs. I assume you have some end mills coming for your brass slotting work, too, right?

I love burled wood - beautiful patterns that only nature can make.


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## Subwayrocket

That little $400 looks alot better than the one you originally posted . It should do the job ...probably give you "the bug" too ...then you'll be wanting to do more/bigger . Congrats !


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## rrjohnso2000

Those are some nice knifes. 
I would say you did real good with your purchase. 
I found some videos of the original one you were considering, so you can feel even better about spending a little more.


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## ex_isp

mikey said:


> Those look like burrs. I assume you have some end mills coming for your brass slotting work, too, right?
> 
> I love burled wood - beautiful patterns that only nature can make.



I've cut several guards already, just using the burrs.  Remember, I am brand new to milling.  If I'm correct, an end mill has less flutes? Like 2 or 4 as opposed to 
8 or so like the burr has?

That burl was a drop I had that was too short to make handle scales from so a tad of high gloss spray lacquer and some holes.  Made sense to me.  There are so
many materials to use for scales, but I also just love the look of burl and the feel of real wood!


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## ex_isp

rrjohnso2000 said:


> Those are some nice knifes.
> I would say you did real good with your purchase.
> I found some videos of the original one you were considering, so you can feel even better about spending a little more.



Thank you for the knife comment!  Here are some more.   http://stevespages.com/knives.htm  
Page is WAY behind on being updated with new knives.  I have about 35 to post but have been re-doing the shop and now
working to resolve some issues on a Kukri... A Nepalese Gurkha, curved machete.  Puts a tremendous amount of stress in the steel
to forge one of them.  I've normalized and annealed 4 times now to relax it enough so that it doesn't warp or shatter when I do the heat treat
on it.  Heat treating 2 blades today.

I already feel good abut the X2 as opposed to my original thinking on the smaller one!  Everyone was pretty convincing that
the smaller one would surely leave me wanting for better performance or hung out to dry when it failed.  Then
*T Bredehoft* mentioned the aluminum column and the #6 screws, I knew.  Thanks "T" for pointing that out!  And to all
for continuing suggestions of a bigger machine!


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## mikey

I like/use 2-flute Hi-helix end mills for brass (all non-ferrous metals). For slotting, I would use an end mill just under the size of the slot and sneak up on the width. Be sure the brass work piece is solidly clamped, no coolant. You will be very pleased with how an end mill cuts vs a burr.


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## ex_isp

Subwayrocket said:


> That little $400 looks alot better than the one you originally posted . It should do the job ...probably give you "the bug" too ...then you'll be wanting to do more/bigger . Congrats !



Next investment will be to build and auto hammer so I can (in reasonable time) make my own Damascus billets rather than buy someone elses.
Spent a week in SLC, Ut in July with a master smith, specifically to work on Damascus.  While most Damascus recipes don't make near the blade 
that O1 does, I have a recipe for it that uses O1, 5160, 51200 and 15N20 that should be MUCH more than a wall hanger.  With the combined properties
of the above steels, I'm expecting a LOT of performance and durability.


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## ex_isp

mikey said:


> I like/use 2-flute Hi-helix end mills for brass (all non-ferrous metals). For slotting, I would use an end mill just under the size of the slot and sneak up on the width. Be sure the brass work piece is solidly clamped, no coolant. You will be very pleased with how an end mill cuts vs a burr.



Thank you for that!  I have only used burrs but will get some 2 fluted mills ordered tonight.


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## brino

ex_isp said:


> Thanks "T" for pointing that out! And to all for continuing suggestions of a bigger machine!



Hey it always lots of fun to spend someone else's money!



ex_isp said:


> Next investment will be to build and auto hammer so I can (in reasonable time) make my own Damascus billets rather than buy someone elses.



That would be a build thread that I would follow!

-brino


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## ex_isp

ex_isp said: ↑
Next investment will be to build and auto hammer so I can (in reasonable time) make my own Damascus billets rather than buy someone elses.

brino said:
That would be build thread that I would follow!
-brino

I will make a point of posting on that project!  In the meantime...
There are many forms of auto hammers.  Air, hydraulic, eccentric, spring, etc...
Many share component design from other hammers.
Here is a page with several "truck spring hammers", fondly called
*Appalachian Power Hammers *
http://www.appaltree.net/rusty/index.htm 
and some other types
http://anvilfire.com/power/jyh-cat.htm


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## T Bredehoft

ex_isp said:


> *T Bredehoft* mentioned the aluminum column



Glad I could help. When I noticed those screws I knew the machine wouldn't work metal.

Tom


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## brino

ex_isp,

I guess we are getting a little further away from the "Cheap Mini Mill" title, but it is your thread.......

Thanks for those links, that is very interesting.
I had looked for plans several years back and found many examples, but not much detail.

I wish the Rusty/Dusty/Super Rusty plans were available in PDF......I would have bought them already!

-brino


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## ex_isp

If I had a creek next to my house, I'd build a concrete funnel and channel the water to run a water wheel for this:


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## ex_isp

Here's another interesting design that one could build for not too much time or cash


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## Charles Spencer

ex_isp said:


> Today, I did a test cut in the brass with a 1/8" dremmel bit in the collet as I don't have real cutters yet. Was able to chew through over 50% of the 1/4" thickness of stock
> in a single pass with no strain at all. I'm impressed and must agree, the Chinese ebay machine would not have done that. Again, THANKS for pushing me towards the
> larger machine!!!



By the way there is a ton of information available online for your machine.  Just look up Sieg X2 mini mill.  For example, here's one:

http://www.hossmachine.info/


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## ex_isp

Thanks Charles!  Truly a lot of info there!


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## ex_isp

brino said:


> ex_isp,
> 
> I guess we are getting a little further away from the "Cheap Mini Mill" title, but it is your thread.......
> 
> Thanks for those links, that is very interesting.
> I had looked for plans several years back and found many examples, but not much detail.
> 
> I wish the Rusty/Dusty/Super Rusty plans were available in PDF......I would have bought them already!
> 
> -brino



Ah, what's a wee tad o thread drift amongst friends?    Especially if there is still good info coming from it!


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## ex_isp

Meanwhile, back at the ranch...

I would guess the two fluted "bits" to require much higher rpm than a bur, to keep it cutting with less tendency to hop or chatter...  yes?
The burrs cut fine all the way down to 700-800 rpm (~).  I'm guessing the I'd want to run a two fluted at 2000 rpm or so.


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## mikey

See this discussion: http://hobby-machinist.com/threads/need-new-end-mills-for-my-g0704.50192/

I would download and print out those pdf files I planted there. They give you the cutting speeds for end mills in different materials based on whether the end mill is a finishing or a roughing end mill and how much of the cutter is buried in the cut. Once you know the cutting speed in surface feet/minute (SFM), you plug it into a formula:
*
RPM = (SFM X 3.82) / Diameter*, where SFM is the cutting speed from the table in surface feet per minute and Diameter is the diameter of the end mill you're using expressed in decimals, such as 0.375 for a 3/8" diameter end mill. The 3.82 is often rounded to 4 by many folks. The result will be your mills rpm for cutting that material with that depth of cut. Note that cutting speed varies slightly by the type of cut you're making - profiling or slot cutting. This gives you a starting point for your rpm. For many non-ferrous metals the calculated rpm will be higher than your mill can achieve; in that case run at top speed and adjust your feed accordingly.

You will learn how an end mill feels and sounds when it is cutting well and when it isn't. A clean cutting end mill will offer a slight resistance to feed when your feed rate is right and will have a steady hiss or drone. If it vibrates or chatters then alter your feed - slow it or speed up and see what it does. The same is done with speed - slow it or speed it up and see how the cut progresses. I know this sounds rather primitive but learning how metal likes to be cut is more a feel/sound thing than you might think. I mention this here because you don't have a way to calculate or set your feed based on inch/minute or by chip load so use your other senses instead. 

There is more to milling than this but it should get you started. The thread referenced above also has other information that will be useful to you.


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## ex_isp

I just had this feeling I was going to really enjoy this forum!  Very good info Mikey!  I have always had a very good feel for feed rates in things from tooling to heavy equip.  I'm glad it applies here as well!
Have experienced same with the burrs I've been using to cut, but understand that a real end mill bit will cut faster and perhaps smooth with correct feed pressure and rpm.


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## mikey

Anybody who can forge a knife from raw steel has to be mechanically inclined so you'll take to the mill with no problem. As everyone has said here, the mill will be very, very useful to you in ways you cannot imagine right now. Glad you stepped up to something that has a chance of doing some real work.

As you go along you will have questions - don't be afraid to ask them. There are some really knowledgeable folks here who will step up. Welcome to the HM forum - best site of its kind on the net!


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## ex_isp

mikey said:


> Welcome to the HM forum - best site of its kind on the net!



Echoed my opinion exactly!!!


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## ex_isp

Received a 10 pk of 2 flute end mill bits and tried them on the brass I use...
I suppose it goes without saying, but WOW.  3 or 4 or times the cutting speed vs
the burrs I'd been using.  Many thanks again guys!!!

BTW, I got the 10  pk for 8.95 shipped off fleabay.  They are plenty tough for the brass.
Don't know hoe they'd run on steel, but I really don't have a need to mill steel at this point.
May pick up some stainless to use as finger guards, but not yet.


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## ex_isp

Finished the Kukri a couple days ago.  Not for sale so it won't be on my sale site, but I thought I'd stick it in here for laughs.  Pretty crude considering I 
started with 1/8" X 1.5" flat 1095 which left me no room to grind hammer marks out.  Putting that longitudinal bend in it was definitely an experience!
Simple oak handle, and a brass guard (not traditional on a Kukri).
And a photo of the mill bit holder I
	

		
			
		

		
	






	

		
			
		

		
	
 felt compelled to make from a drop piece of maple burl.


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## kwoodhands

Make sure you have a collet for the size end mill you buy.Either that or use an endmill holder ,#3 Morse taper or R-8 depends on your spindle. I would use a 4 flute HSS  1/4" x 3/4" long cutter with a 3/8" shank.You should be able to cut the slot in 2 or 3 passes without lubricant.

mike


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## ex_isp

Thanks Mike!  The machine did come with a pretty full set of collets for it ranging from 1/8th" through 3/4".
See here





And, since really all I'm using it for right now is to cut slots in brass, I ordered a bunch of 1/8th" bits.
See up just a couple of posts to the assortment in the maple block.  Appreciate the input, always!!!  
Can add other sizes of bits as I need them.  Should order some up to 3/16ths" as I will be needing them 
to use on thicker blades.


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