# Another X2 Mod thread



## rythmnbls (Aug 31, 2013)

Inspired by a couple of threads by forum member Bill S, I decided to give my X2 mill some extra rigidity and Z travel.  Here are a few photos of progress.





Photo of the starting materials and the unsuspecting mill in the background. Shown are the base materials - 3"x4" square tubes with a .375" wall thickness and a 4"x6" square tube with a .375" wall thickness destined for the column support.









Photos of the assembled base showing the extent of the Z travel. There should be plenty of room for the rotary table with a 4 or 3 jaw chuck and work piece which is a machining operation I could never do previously.

I still have to mount the extended Z rack, and bolt the XY table to the base, tram all axes and throw some paint on it.

Some links to the original threads by Bill S
http://www.homemodelenginemachinist.com/f28/small-x2-mod-7479/
http://www.homemodelenginemachinist.com/f28/x2-upgrade-update-7779/
http://www.homemodelenginemachinist.com/f28/x2-mods-finished-7846/

Thanks for reading.

Steve.


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## MCRIPPPer (Aug 31, 2013)

wow! that is one crazy looking mini mill.


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## Wizard69 (Aug 31, 2013)

Nice Steve!    &#128540;&#128540;&#128540;


How much effort was required to get the Z square to the rest of the machine?


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## rythmnbls (Sep 8, 2013)

Work is progressing on the mill. The new extended Z rack has been drilled, countersunk and mounted.  Work has started on tramming the Z axis to the table. 




Photo of the mill with the completed Z rack mounted.

To get the X axis in alignment a .020" shim was needed under left table feet. It is now within .001" which I'm happy with, Y tram is within .007" and will have to wait till I buy some appropriate shim stock to dial it in.




Photo of tramming the mill.

I couldn't resist taking a few test cuts, here's shot of a .250" doc with .150" infeed in some 4140 square stock using a .5" endmill, although there was some resonance noise, there was no chatter or thumping that would have normally been expected with a cut like this, I'm very happy with the result so far.




And a closer shot of the completed cut, finish is pretty good for a roughing cut.





I still need to build a counterweight for the head, and paint the bare steel parts. Considering how much of an improvement this has been, I'm thinking it might be worth  hand scraping the ways and gibs as they are just rough milled at the moment. A decent vise wouldn't hurt either 


Thanks for reading.

Steve.


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## Tin Falcon (Sep 8, 2013)

Fill that tube with sand and it will be rock solid just drain out the sand before you try to move it LOL.
Tin


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## Wizard69 (Sep 8, 2013)

rythmnbls said:


> I couldn't resist taking a few test cuts, here's shot of a .250" doc with .150" infeed in some 4140 square stock using a .5" endmill, although there was some resonance noise, there was no chatter or thumping that would have normally been expected with a cut like this, I'm very happy with the result so far.
> 
> 
> Thanks for reading.
> ...


I wouldn't be able to resist either.   You have a very interesting build here, effectively a new mill!!!

Tin mentioned filling the tubes with sand and frankly doing something along those lines might be icing on the cake so to speak.   I'd seriously consider epoxy granite infill.   Of course you may need to spend three weeks at the Gym before you attempt to move it each time.


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## MarioM (Sep 8, 2013)

Good idea.  Interesting to have more Z travel on the mini mill.....many times I wished had a couple more inches.


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## rythmnbls (Sep 9, 2013)

Thanks for all the positive comments, much appreciated.



> Fill that tube with sand and it will be rock solid just drain out the sand before you try to move it LOL.
> 
> Tin mentioned filling the tubes with sand and frankly doing something  along those lines might be icing on the cake so to speak.   I'd  seriously consider epoxy granite infill.   Of course you may need to  spend three weeks at the Gym before you attempt to move it each time.


Very interesting comments, as I mentioned there was some resonance noise during the test cut which was probably amplified by the steel tubing, much like a bell.  I do like the idea of removable damping as there are assembly bolts that would be inaccessible if epoxy was used. Food for thought, thanks again for those ideas.

Regards,

Steve.


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## rythmnbls (May 23, 2014)

This thread is a bit overdue for an update 
	

	
	
		
		

		
			





First up was a thorough cleaning, a few welds to lock everything in  place and a bit of paint to make it look nice and to cover my ugly welds  up.





Re-assembled..





Then I decided I wanted to convert it to CNC, so I purchased the figNoggle plans ( www.fignoggle.com ).

A progress shot of making the Y-axis mounting bracket, I really do need to get a better vise.





A pic of the completed bracket.





A couple of pics showing it mounted on the mill.








Next was zero backlash Y-axis leadscrew. I decided to try an acetal leadscrew nut based on this thread at HSM http://bbs.homeshopmachinist.net/threads/43645-Making-Acetal-leadscrew-nuts-the-easy-way as they should be a lot cheaper than ball screws. So I bought some precision acme 5/8-10 rod and some Delrin and went at it 

Pic of making the nut..




Turning the leadscrew..








Milling a keyway...





Completed leadscrew and nut.







Fitted to the mill.





I'm really pleased on how this turned out, the Y axis is really smooth and has no backlash at all.

The plan now is start on the X axis this weekend make some chips and hopefully not to much scrap. 

Happy memorial weekend to all.

Regards.

Steve


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## Shawn (May 24, 2014)

Very nice work. I am planning to brace up the column on my mill but you really take the cake with this mod. 

Shawn


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## rythmnbls (May 25, 2014)

Thanks Shawn.

The X axis screw is just about finished, it just needs a key slot milled.

The leadscrew is about 22.5 inches long and was a bit tricky getting the center holes drilled accurately. I had to make a bushing to fit the outboard end of the lathe spindle to stop it moving around during turning. I also had to use a bit of shim stock between the screw and the dial gauge to get it centered, in the end it all worked out pretty well.
Here are a few pics of the setup and progress.


Pic of the bushing, id is .625, od .800




Pic of the bushing installed.




Using the shim to dial in the leadscrew.




Pic of finish turning the the servo drive end of the shaft, the tool is a shear tool which gives a really nice finish on most steels. More info on the tool here. http://www.gadgetbuilder.com/VerticalShearBit.html




Finished drive end.




Single pointing an 8mm x 1.25 thread for the hand wheel retaining nut.




Turning done.




Thanks for reading.

Steve.


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## rythmnbls (Jun 7, 2014)

Continuing on..

Pic of making the X axis nut holder, this will have an acetal liner pressed into it when its completed.





Here I have just finished boring the hole for the liner. The flange will be milled to clear underside of the table.






Photo of the nut holder mounted in the saddle, showing the clearance to the table.






Photo of the completed nut, the screws are there for insurance as the liner was turned .003" oversize for a good tight press fit in the holder.






Photo of the completed leadscrew and nut.




...and mounted in the saddle.





This is the end plate that held the far end of the old lead screw, the old leadscrew has a bronze bushing attached which rotated in the bore of the plate. The conversion plans I bought do away with this bushing and use the servo motor to locate the leadscrew. I decided that I did not like this idea and will fit a 608 bearing in this plate to locate the leadscrew.






Photo of the plate with bearing pressed in.






Photo of the underside of the table after fitting the leadscrew and nut.






Photo of the far end of the table where the servo will mount.






Thats all the updates I have at the moment, I have made some test cuts with the new leadscrews fitted and I'm very pleased with the results, they are very smooth and the zero backlash is a real plus.

Thanks for reading.

Steve.


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## rythmnbls (Jul 6, 2014)

A few more parts have been crossed off the check list, most of which are for the Z axis.

Here's a pic of the general layout. The leadscrew nut is mounted on the top bracket and the leadscrew is attached to the mill head by a bearing block and motor plate.






A few shots of drilling the leadscrew clearance hole in the top plate. Since I don't have a boring bar and the drill's morse taper doesn't match that of the quill in the mill, I had to use the faceplate in the lathe. This is the first time I've used that faceplate so I was quite pleased with the result.










A shot of the upper z-axis parts, a lot of drilling tapping and counter-boring.






Here's a shot of bracket sitting on the mill, I intend to mount the assembly further forward than is called for in the plans as I want to add a counter weight pulley system which will attach to the motor base plate just behind the leadscrew. Fortunately, the belt drive conversion moves the motor forward otherwise there'd be no room.






A start has been made on the lower bearing block. One advantage of the extra rigidity of the new mill base is the ability to take a full depth side milling pass like this. Material thickness is 1.25". The mill will happily take .040" at this depth.






Here's the bearing block with most of the milling ops completed.






Countersinking / deburring the mounting slots






Counter-boring the holes for the top bearing.






That's all I have for now, thanks for reading.

Steve.


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## AFCarbon15 (Jul 10, 2014)

Awesome !!

I joined this forum just for the machining tips.  I'm no machinist, but having always wanted a mini-mill, I finally bought an x2.  I love seeing all the mods.  While most of it is still over my head, as I learn through smaller projects, I can see the how's and why's of most of the mods.  Please Please Please keep the ideas coming.  And I'm really liking the individual parts and WIP pics.  Really helps us amateurs and wannabees see how it all comes together.


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## rythmnbls (Jul 10, 2014)

> Awesome !!
> 
> I joined this forum just for the machining tips.  I'm no machinist, but  having always wanted a mini-mill, I finally bought an x2.  I love seeing  all the mods.  While most of it is still over my head, as I learn  through smaller projects, I can see the how's and why's of most of the  mods.  Please Please Please keep the ideas coming.  And I'm really  liking the individual parts and WIP pics.  Really helps us amateurs and  wannabees see how it all comes together.


Thank you for the feedback Thm: It is very much appreciated.

BTW I'm no machinist either, I'm just a hobbyist and an amateur.

I did manage to get a bit more done on the Z axis parts. The leadscrew has been machined, just a basic turning job with a couple of shoulders machined on one end. The first shoulder was single point threaded to fit two 10mm x 1mm locknuts and the others were turned fit the bearings and the drive pulley. Here's a pic.






And a pic showing the bits before assembly....






...and assembled.






And finally a shot next to a 6" scale.





Next up is a counterweight system for the mill head, I don't want to fit the z-axis parts till it is done, I'm also planning on filling the tubular steel sections with an epoxy-granite mix of some sort.

Thanks for reading.

Steve.


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## rythmnbls (Jul 27, 2014)

A small update this week..

The counterweight system was put on the back burner when I realized I needed to get the Z axis bits mounted first to provide an attachment point for the counterweight. Here's the Z axis motor mount along with the bearing block which will also provide the attachment for the counter weight.






And a photo of it mounted on the mill.






And finally a photo with the motor in position and a view of the upper leadscrew nut mount.





That's all I have for now, thanks for reading.

Steve.


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## charlieuk (Aug 22, 2014)

rythmnbls said:


> Inspired by a couple of threads by forum member Bill S, I decided to give my X2 mill some extra rigidity and Z travel.  Here are a few photos of progress.
> 
> 
> 
> ...




I am just starting on doing a similar mod to mine with a steel frame what overall hight did you end up going for for the main post to maximise travel?


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## rythmnbls (Aug 22, 2014)

The main post is 36" x 4" x 6", the two outside base pieces are 4" x 3" x 24" and the inner base piece is 4" x 3" x 18", all pieces have a wall thickness of .350-.375"

Regards.

Steve.


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## charlieuk (Aug 22, 2014)

rythmnbls said:


> The main post is 36" x 4" x 6", the two outside base pieces are 4" x 3" x 24" and the inner base piece is 4" x 3" x 18", all pieces have a wall thickness of .350-.375"
> 
> Regards.
> 
> Steve.



Cheers many thanks soon as i can sort a blade for my chop saw i will get to work.


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## rythmnbls (Aug 24, 2014)

Most of the counterweight parts have been completed, it consists of two rollers supported by 608 size ball bearings, a recycled crucible from my casting furnace and a length of stainless steel cable. 

Here's a pic of turning one of the bearing journals for the front roller.




A pic showing the front and rear rollers with the cable in place.





The cable attaches to the rear of the bearing block as shown here..




..and finally the crucible with 25lbs of lead stacked on it, with this amount of weight the mill head feels almost weighless when raising or lowering it.





Next I have dust off the furnace and melt the lead into the crucible and make some new cable attachments for the crucible.

Thats all I have for now, thanks for reading.

Steve.


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## rythmnbls (Sep 14, 2014)

Time for another update...

The counter-weight is done, I setup my old casting furnace and put it to use as you can see here..




A view inside the furnace after it cooled.




Next up was a mount for the x-axis motor, the first job was to drill four counter-bored holes to accept some SHCS in the table x-axis end plate. These screws will hold the motor mount blocks.




Here's a couple of photos showing the arrangement of the end-plate, the motor mounts and coupling.







I decided to take a break from making parts and assemble the control box. Here's a work in progress pic of installing the internal wiring.




And a photo of testing the control box with Linuxcnc, all axes tested out ok which was a relief.




All that is left to do is make the Z-axis nut and fit the Y-axis handle with a toothed drive pulley, hopefully I'll get those done by next weekend as I'm looking forward to making some chips. ;D

Thanks for reading.

Steve.


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## rythmnbls (Sep 28, 2014)

Final update.

The z-axis nut is done, it was made from some round bar stock and .5" plate. Here's a shot of it after completion.




The last job was fit a 30 tooth pulley to the y-axis hand wheel.







Then it was just a matter of assembling all the bits.

The z-axis completed..







A shot of the assembled mill with the control unit.




This completes the build, I have spent most of the weekend getting to know the software, jogging axes to and fro and grining like a schoolboy 

At some point in the future when all the wiring has been tidied up I will fill the steel tubes with an epoxy granite/concrete mix to add some damping.

Thanks for reading.

Steve.


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## rythmnbls (Oct 19, 2014)

Postscript update..

Here's a clip of the mill cutting an airfoil profile which is intended to be the top half of a compressor blade. This is just a test, but I was pleased with the result.

[ame]https://www.youtube.com/watch?v=fBVByTEIfXM[/ame]

And a pic of the completed test piece.





Thanks for reading.

Steve.


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## expertdb (Jan 29, 2015)

rythmnbls said:


> The main post is 36" x 4" x 6", the two outside base pieces are 4" x 3" x 24" and the inner base piece is 4" x 3" x 18", all pieces have a wall thickness of .350-.375"
> 
> Regards.
> 
> Steve.



Excuse me , what is the method of connecting a main pillar and two side base pieces? 
Did you use welding or bolting?

Thanks


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## Swifty (Jan 29, 2015)

Hi expertdb, post 9 mentions that it is welded together, you can even see it in the pictures.

Paul.


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## expertdb (Jan 30, 2015)

Thanks, but I see some holes  outside of  base piece. I think it is first fixed by screws, and then weld together. Is that so?
Sorry for my google english.


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## /// (Jan 30, 2015)

Hi Steve, apologies if I missed it in an earlier post, just wondering what servo's are you using?
They look plenty capable in the video, nice work.


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## rythmnbls (Jan 30, 2015)

Hi Guys, thanks for the interest.

expertdb,

The pillar and column are bolted and welded together, initially I wasn't going to weld it but I decided to add a few beads as extra insurance against crashes.

///,

The servos are 350oz inch units from Automation Tech Inc.
Here's a link.. http://www.automationtechnologiesinc.com/products-page/nema23-m-dc-servo-motor

They work very well, I'm not close to using them at full capacity yet. I have a lot to learn when it comes to cnc so I'm taking it slowly.

Regards.

Steve.


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## expertdb (Jan 31, 2015)

Thanks for your answer. 

And my last question (maybe ).  How many bolts you used for rigid connection of main pillar and original column of mill?


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## rythmnbls (Jan 31, 2015)

There are 8 bolts holding the column to the main pillar. You can see the holes in this photo.





There are 4 steel plates 1" * 1/4" * 6" (6mm * 25mm * 150mm) long that are drilled and tapped with two holes that are inside the original column to clamp the column to the pillar. I also drilled the rear of the pillar with the same bolt pattern so I could get a long allen wrench to reach the bolt heads.

I hope that is clear 

If you watch the video, you can see the bottom ends of the clamp plates protruding from the column

Regards.

Steve.


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## /// (Jan 31, 2015)

rythmnbls said:


> The servos are 350oz inch units from Automation Tech Inc.
> Here's a link.. http://www.automationtechnologiesinc.com/products-page/nema23-m-dc-servo-motor



Cheers Steve.
Getting grand ideas of CNCifying my now redundant 7x14 lathe and I think these would be perfect, got the Gecko servo drives already.


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## rythmnbls (Jul 19, 2015)

One more update ...

While I've been pretty happy with the performance of the mill in general and have enjoyed using it with the CNC conversion, one last thing to be addressed is the vibration damping of the new base and column. During heavier cuts there can be a lot of resonance noise which can sound pretty bad at times. 

The last ( I hope ) mod to the column and base was to fill them with epoxy granite/concrete. This will hopefully provide the vibration absorption with some more mass and rigidity that the mill needs. Another reason for this mod is I want to try some carbide tooling in some nickel alloys and I don't want to chip the tooling from excessive vibration.

Here are pics of the top of the column filled with epoxy granite, also visible are the clamping plates used to hold the Z ways to the column.








In case anyone is wondering, there are tubes embedded in the epoxy granite to allow access to the lower bolts holding the Z axis ways. This will allow for dis-assembly or loosening for tramming.

Thanks for reading.

Steve.


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## petertha (Jul 19, 2015)

rythmnbls said:


> ... was to fill them with epoxy granite/concrete. This will hopefully provide the vibration absorption with some more mass and rigidity... Steve.


 
That's interesting. I've heard of people doing this on CNC router frames with good results. Keep us informed how it performs. When you say 'granite/concrete', what exactly is the aggregate medium? (granite chips, quartz sand, a mixture?). Also curious what kind of epoxy resin you used.


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## rythmnbls (Jul 19, 2015)

Hi Peter, thanks for your reply.



> When you say 'granite/concrete', what exactly is the aggregate medium?  (granite chips, quartz sand, a mixture?). Also curious what kind of  epoxy resin you used.


I based my mix on the mixture at the cnccookbook site. Instead of using 62% gravel 23% sand 14% epoxy, I used an 80lb bag of Quikrete, my reasoning is that it has sand and gravel in similar proportions plus it has finer material in the form of cement powder to further fill in the gaps. I used 6 parts of Quikrete to 1 part of epoxy by volume. The epoxy I used was West System 105 resin with 206 hardener. I used the slower hardener as ambient temps in the shop were about 80-90 degrees f.

Regards,

Steve.


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## rythmnbls (Aug 9, 2015)

> That's interesting. I've heard of people doing this on CNC router frames with good results. Keep us informed how it performs.


I spent the day making an adapter to mount a dial indicator to the ways of my lathe, this gave me my first real test of the mill since the epoxy granite fill.  All I can say is, wow! what a difference, the vibration absorption has radically improved. Any moderately heavy cut previously would result in lots of noise presumably amplified by the hollow steel tubular members of the frame, now there is barely any.  I tested heavier cuts until the slop in the dovetails of the table became a factor. 

At this point I think the new frame is a success, but it has revealed that the fit and finish of the ways are below par and need to be addressed.

Regards,

Steve.


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