# X2 Mini Mill Mods



## gwapoboy (Dec 7, 2014)

Hello Everybody,

I am new to this forum, so hope this is the right area. Just a bit about me I am an apprentice tool and die maker and enjoy machining. Anyways I picked up a Mini Mill from Busy Bee Tools here in Canada. Its an X2 variation, MT3 Collet. I am wondering what modifications you guys suggest, I have cleaned it off, reburred some areas, re lubricated it properly. I am wanting to do modifications to make it more rigid and precise. I am hoping to be able to get it set up so I can machine aluminum paintball parts to tolerances of 0.001" to 0.005". 

Thanks in Advance


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## velocette (Dec 7, 2014)

Hi
you have a popular mill with home machinists and by your post are already on track to make it a more usable machine.
The common mods are belt drive, column stiffener on the tilt column model, power feed on the table, bigger motor I can vouch for that, An "Air Spring" instead of the silly spring return. 
You can use the automotive type of  About 24 kg load and 220 mm travel and fabricate your own fittings.

added photo of much modded X2 Mill

Eric


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## bmac2 (Dec 7, 2014)

Hi gwapoboy and welcome to the forum. wEc1
Ill assume you have CT133? If so I have the same mill and have to agree with *velocette *for mods. If youre looking to improve the accuracy of your mill stiffen up the column. Mine has a nice hunk of ¾ plate. About 3 months after I got the mill I was getting tired of wearing ear protection and did the swap to belt drive. I was ready to order the kit from Little Machine Shop when I read a post from someone that the spindle was slightly smaller on the CT133 so he had to rework the large pulley to get it to work. In the end I just made mine based the drawings available at http://myplace.frontier.com/~wgmumaw/MiniMill Belt Drive/MiniMill conversion.html
Using the dimensions for the pulleys from Jerry Rollett design (PDF file below the last picture). It went together easily and I no longer need the ear guards. I think the Air Springs are next on my wish list. And hey if its accurate enough for me to make an internal combustion engine, it should be good for paint ball.Thm: 











View attachment Jerry Rollett Belt Drive.pdf


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## gwapoboy (Dec 7, 2014)

bmac2 said:


> Hi gwapoboy and welcome to the forum. wEc1
> Ill assume you have CT133? If so I have the same mill and have to agree with *velocette *for mods. If youre looking to improve the accuracy of your mill stiffen up the column. Mine has a nice hunk of ¾ plate. About 3 months after I got the mill I was getting tired of wearing ear protection and did the swap to belt drive. I was ready to order the kit from Little Machine Shop when I read a post from someone that the spindle was slightly smaller on the CT133 so he had to rework the large pulley to get it to work. In the end I just made mine based the drawings available at http://myplace.frontier.com/~wgmumaw/MiniMill Belt Drive/MiniMill conversion.html
> Using the dimensions for the pulleys from Jerry Rollett design (PDF file below the last picture). It went together easily and I no longer need the ear guards. I think the Air Springs are next on my wish list. And hey if its accurate enough for me to make an internal combustion engine, it should be good for paint ball.Thm:



Hello, thanks for the Welcome. Yes I have the CT133. Did you Tramm your mill and/or find the head stock has a slight inward angle?


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## gwapoboy (Dec 7, 2014)

velocette said:


> Hi
> you have a popular mill with home machinists and by your post are already on track to make it a more usable machine.
> The common mods are belt drive, column stiffener on the tilt column model, power feed on the table, bigger motor I can vouch for that, An "Air Spring" instead of the silly spring return.
> You can use the automotive type of  About 24 kg load and 220 mm travel and fabricate your own fittings.
> ...



What and how did you upgrade the motor on your mill?


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## chucketn (Dec 8, 2014)

Hi, gwapoboy. I know the motor question wasn't directed to me, but, I replaced the oem controller and motor on my X2 with a motor and controller from a tread mill. Went from 3/4 Chinese HP to 2.5 US horsepower. I also have the belt drive and air spring mods, as well as a Shumatec DRO on X,Y, and Z. Also added a tach pickup that works with Shumatec.

Chuck


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## gwapoboy (Dec 8, 2014)

chucketn said:


> Hi, gwapoboy. I know the motor question wasn't directed to me, but, I replaced the oem controller and motor on my X2 with a motor and controller from a tread mill. Went from 3/4 Chinese HP to 2.5 US horsepower. I also have the belt drive and air spring mods, as well as a Shumatec DRO on X,Y, and Z. Also added a tach pickup that works with Shumatec.
> 
> Chuck



Hmm might have to look into that. I am actually in the process of putting on Igaging DRO's on it , should be accurate enough for what I am working on. Did you find the Belt Drive conversion effected the amount of torque you got from the motor at all?


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## chucketn (Dec 8, 2014)

Actually, my X2 was second hand, and came with the belt drive and scales for the DRO installed. I added the Shumatec, the tach, the tread mill motor and controller, and a power feed to the X axis. I don't know what it sounded like with the gear drive. I do like the belt drive as it will slip usually before breaking end mills.

Chuck


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## gwapoboy (Dec 8, 2014)

chucketn said:


> Actually, my X2 was second hand, and came with the belt drive and scales for the DRO installed. I added the Shumatec, the tach, the tread mill motor and controller, and a power feed to the X axis. I don't know what it sounded like with the gear drive. I do like the belt drive as it will slip usually before breaking end mills.
> 
> Chuck



Fair enough, I will have to look into the Thread mill motor idea, aswell as look into maybe doing the belt drive conversion if if LMS version will work with mine. One thing I was wondering is i was reading how people had to add shim stock to get there headstock all aligned to the column, what I was wondering is if you took the headstock completely apart and with a surface grinder ground(Not taking much material off ofcourse) the surfaces where the two pieces of the headstock come together would that possible improve it? Just an idea I had not sure if it would work or not.


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## chucketn (Dec 8, 2014)

I have only had the head off when I added the air spring and extended rack for Z (forgot to add that last post). When reassembled the tram adjusted up nicely, so I didn't have to add shims. My X2 still has the tilt capability, though I never use it, and stays in tram nicely.
Treadmills to salvage aren't too common here any more. Glad I got mine when I did.
Where are you located?

Chuck


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## velocette (Dec 8, 2014)

Hi
The motor is a 1.25  hp treadmill motor with a Minarik MM23000 series AC to DC speed controller with a "Poly Vee" Belt drive.
The ribbed belts are far superior to a vee belt for this application and allow you to use the full power of the motor when used on heavy cuts.
The pulley diameters on my setup are bigger than the commercial available ones to cope with the extra power.
Use  10 - 0 - 10 Ampere Meter on the motor leads and use the reading to verify the load on the motor when at work.
Set the Control Limit to trip on the controller to the Motor Horse Power and not at  150% this will be 5 amps @ 180 volts to give reasonable protection to the motor and the cutters. 
A computer fan on the motor to assist cooling on low RPM.
The motor mount is fixed with a couple of bolts in holes drilled and tapped in the top of the gearbox.
The Air Spring is fixed to the 24 mm columns by a yoke at the top as the bigger motor had to be "shoehorned" in to fit.

Added more photos   

Eric


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## bmac2 (Dec 8, 2014)

Hi Gwapoboy. In reply to your PM.
Ok the vice. I picked up my mill used off kijiji and with all that extra cash burning a hole in my pocket bought the 4 x 4 Kurt knock off from Busy Bee. Stay away, its a piece of crap. The casting is full of pits and poorly machined. The face on the fixed jaw isnt at 90deg and the moving jaw lifts when the vice is closed despite attempts to adjust it. The beast 5.125 inches tall when on the rotary base and 4 with it removed.


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## bmac2 (Dec 8, 2014)

What Im using is the Groz 4x4 low profile vise (Busy Bee no. B2108). Very nicely machined, smooth operation, spot on alignment, and an overall height is only 2.625 This is a huge benefit on a mill with only 7 inches of Z axis travel.


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## bmac2 (Dec 8, 2014)

The plate is 14.375 x 4 x .75 running from just under the power box down the length of the column with a 2x2x.125 recess around the washer. The 8 ¼&#8221;-20 cap screws are spaced so the plate could be bolted down in the outside slots on the milling table. This makes boring the bolt hole and milling the recess a lot easier.


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## bmac2 (Dec 8, 2014)

Damn. Dont know what happened there. I guess two pictures are better than none. ;D
My head stock does have a slight inward angle but its only a couple of thou and I dont worry about it.


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## gwapoboy (Dec 9, 2014)

bmac2 said:


> What Im using is the Groz 4x4 low profile vise (Busy Bee no. B2108). Very nicely machined, smooth operation, spot on alignment, and an overall height is only 2.625 This is a huge benefit on a mill with only 7 inches of Z axis travel.



Hey, thank you for the reply. Damn that was actually very helpful. I hadnt even thought of that vise, But that looks like it would work perfect for what I need it for, you find it effects the travel at all of the table?


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## gwapoboy (Dec 9, 2014)

bmac2 said:


> The plate is 14.375 x 4 x .75 running from just under the power box down the length of the column with a 2x2x.125 recess around the washer. The 8 ¼-20 cap screws are spaced so the plate could be bolted down in the outside slots on the milling table. This makes boring the bolt hole and milling the recess a lot easier.



What did you recess around the washer?


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## velocette (Dec 9, 2014)

Hi
"This is a huge benefit on a mill with only 7 inches of &#8220;Z&#8221; axis travel."
This can be improved on to increase the travel to 11 inches with a longer "Air Spring" and a longer rack.
Added more photos to explain.

Eric


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## bmac2 (Dec 9, 2014)

gwapoboy said:


> What did you recess around the washer?




If you have a close look at the plate you can see that the bolt is a little short. Putting a shallow recess in the plate just gives it a couple more threads


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## velocette (Dec 9, 2014)

bmac2 said:


> If you have a close look at the plate you can see that the bolt is a little short. Putting a shallow recess in the plate just gives it a couple more threads


Hi to all
Looking at the photo can I suggest the the stiffener be anchored to the base by a suitable bracket bolted to the base.
This can be easily detached if you ever need to use the column tilt.

Eric


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## bmac2 (Dec 9, 2014)

Hi Eric
Thats a good idea. Anything that will help with the rigidity of the machine. Personally I have an absolute distain for tilting the column. I had such a miserable time getting it to where it is. 
This is as far as Ive gotten with the gas springs (I know. The springs are upside down in my drawing*bang*). But I have found local supplier. Defenatly have to get the longer rack.


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## gwapoboy (Dec 13, 2014)

bmac2 said:


> What Im using is the Groz 4x4 low profile vise (Busy Bee no. B2108). Very nicely machined, smooth operation, spot on alignment, and an overall height is only 2.625 This is a huge benefit on a mill with only 7 inches of Z axis travel.




Do you find it limites the tables x and/or Y movement at all?


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## bmac2 (Dec 14, 2014)

gwapoboy said:


> Do you find it limites the tables x and/or Y movement at all?



Hi gwapoboy
Technically it does shorten the Y axis but by such a small amount I dont think it counts. By the time the head end of the vise is squashing the billows, the table is within about ¼ of hitting the base. No effect on the X axis.


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## MCRIPPPer (Dec 14, 2014)

one of the best mods for a mini mill is a power feed unit with a raid travel. makes aligning vise much quicker and just makes life alot easier. 

here is my version of the power feed. 

http://www.homemodelenginemachinist.com/showthread.php?t=22076


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## bmac2 (Dec 15, 2014)

Hay MCRIPPPer
I just read your thread the other day linked off Guss power feed build. Started me thinking that I have a broken variable speed cordless in the garage:idea:. It didnt like the dropped/sudden stop off a ladder this past summer but the motor and gear box are still good. Good use of the 3 Rs *R*educe  *R*euse  *R*ecycle. That a foosball table?Thm:


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## MCRIPPPer (Dec 15, 2014)

yea it is a fooz table lol. super sturdy because its designed for people getting too cought up in the game.


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## velocette (Dec 15, 2014)

bmac2 said:


> Hi gwapoboy
> Technically it does shorten the Y axis but by such a small amount I don&#8217;t think it counts. By the time the head end of the vise is squashing the billows, the table is within about ¼&#8221; of hitting the base. No effect on the X axis.



Hi 
If you need the last 1/4 inch you can mill off the vice body or move the hold down bolts to the centre slot in the table.

Eric


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## zoltan (Feb 12, 2015)

Have you considered upgrading to the LMS solid column and base, and getting rid of the stupid pivot entirely? It does cost $250, but I did it and am so happy I did.

http://www.littlemachineshop.com/products/product_view.php?ProductID=4307
http://www.littlemachineshop.com/products/product_view.php?ProductID=4308


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