Project of the Month built by driller1432

Help Support Home Model Engine Machinist by donating using the link above or becoming a Supporting Member.
Home Model Engine Machinist > CNC and 3-D Printers > CNC Machines and Conversions > Another Sieg X2 CNC conversion

Reply
 
Thread Tools
Old 09-19-2010, 04:45 PM   #11
spuddevans
 
spuddevans's Avatar
 
Join Date: Feb 2008
Posts: 204
Liked 12 Times on 12 Posts

Default Re: Another Sieg X2 CNC conversion

I havent done much today ( well nothing actually ), but Krymis' post asking about tramming a X2 and so I went out with my camera and took some pics of what I did yesteday.

As I "almost" described above, I have currently got my X2 mill in bits and spent the afternoon tramming the head to the column.

This procedure is much easier if you have the column laying flat on your bench, not that it would be impossible to do while the column is attached to the base, but it involves taking the head off and on again a number of times.

This is a photo showing the initial setup of the column lying on it's back with the head in place ( I have removed the pinion from the head so that it can just slide up and down unhindered ) at the top of the column. I have adjusted the jibs until I cannot feel any slop or side to side play, but not so tight that the head cannot be moved. Then I chucked a 12" 10mm piece of silver-steel into the chuck, mounted a Dti on the bottom end of the column and aligned the dti with the bar.




Now just before you think that you dont have a perfectly straight "test" bar to use, there is a work-around. Just rotate the bar thru 360 degrees, note the high and low readings, find the middle of the 2 readings and then make a note of that reading.

Then slide the head as far down the column as you can towards the Dti to take a 2nd reading, and repeat the above "averaging" reading.




If (without any adjustment) you have an identical reading as the top then double check it. If it is still identical then quickly think of 7 numbers for next weeks lotto!!!

But most likely it will not be the same, on mine I had an average difference of 0.30mm lower at the bottom than the top readings.

So now we have to shim the head to correct it. So loosen the jib screws a little to make it easier to slip off the column, and slide the head off the column and place it upside down and loosen the 4 screws that hold the 2 castings together that make up the head.



If, like mine, yours is painted over you might have to remove the 4 screws completely and then give the top casting a little tap with the handle of a screwdriver to break the paint seal. I then discovered that the paint was also covering some of the mating surfaces, so I very gently used a file to get the worst of the paint off, but I didnt file down to expose bare metal, then I put a sheet of wet-and-dry sandpaper on my surface plate and with some light oil for lubrication I rubbed the mating surfaces of both halves of the head until I got rid of all the offending paint.

Having done that I wondered if I had made it any better, so I put it all back together and mounted it back on the column, adjusted the jibs again, and went through the same checking procedure as I described above. Amazingly there wasnt much difference, just a bit worse than before :doh:

Anyway, I took the head off again, loosened the 4 bolts shown above, and got my very expensive shim material (tinfoil), and folded up 4 thicknesses of it and inserted the shim at the bottom edge of the casting, tightened the bolts, remounted the head onto the column and adjusted the jibs again, and re-checked it.

On mine it reduced the difference to 0.20ish mm, so I removed the head and folded up 12thicknesses of foil and re-mounted and re-checked... difference was down to 0.08. So it was "Off with it's Head!!" again and this time tried 14 thicknesses of foil.

This time it was close enough for me, actually a little over, but at a later point I plan some other mods that will give me an easier way of adjustment, so I am happy to be within 0.04mm over 12 inches.


Here's a pic of the shim in place, sorry the pic isnt great quality, this is a really well cropped fragment of a closeup.




Now, once you have got the shim to the right thickness, this time only tighten the 4 bolts slightly ( loose enough to make rotational adjustment ) Then remount the head, adjust jibs, and then move the Dti round to measure the side-ways movement of the bar.



Make a note of the reading as before, and then



Note reading as before.

This adjustment is much easier than the 1st one. Very importantly, retract the Dti before making any adjustments. Then just use a deadblow hammer to GENTLY tap the relevent top head casting corner in the relevent direction, re-introduce the Dti and then check again.

Once you have it aligned to your satisfaction then loosen the jibs and very gently remove the head, and really really gently put the head upside down again and then tighten the 4 mounting bolts up fully. You have to be really gentle with it so as not to disturb the settings before you tighten the bolts.

Then it is just a case of re-mounting the head onto the column and checking it one (hopefully) last time to make sure it is still ok in both ways.


And there you go, the head should now be aligned with the column.


Some may wonder just why go to all this bother, what difference does it make? Well imagine that you have to drill a hole, maybe 1st you chuck up a spotting drill or centre drill to start the hole. Then you raise the head up and chuck a full length drillbit and then you notice that the longer drillbit is not perfectly lined up with the spotting drill's hole. This is because the head is further up the column with the drillbit than the short centre drill or spotting drill, and so if the head is not totally in line with the dovetail ways of the column this will introduce this error.

There may well be other implications of not having it fully aligned, but I'll leave it for other to add them. Suffice to say that a properly alligned and trammed mill should work a lot better than one that is not.


This is just the 1st part of tramming the X2, but there is plenty of info on the 2nd step, especially Bog's tramming tool build thread, well worth checking out. That's on my To-Make list


Tim


__________________
Measure with a micrometer, mark with chalk, cut with an axe.
spuddevans is offline  
 
Reply With Quote
Old 09-28-2010, 08:42 PM   #12
spuddevans
 
spuddevans's Avatar
 
Join Date: Feb 2008
Posts: 204
Liked 12 Times on 12 Posts

Default Re: Another Sieg X2 CNC conversion

Well, after ordering them on the 13th of this month, the Ballscrews arrived today from China. Here's a shot of the longest one sitting on my mill table. They may not be the best in the world, but for me they will do just nicely. If needs be they can be upgraded at a later point if the need arises, but I think they will do just fine for my home use.




I also have got most of the ali' that I need for the stepper mounts, and I also have the bearings, pulleys and couplings that I need ( I think )


Here's a shot of the ballscrew with the Ballnut removed and all the (4 ballbearings and the white plastic "wiper" for keeping debris out of the ballnut. The little orange recessed bits on the ballnut are re-circulation passages for the ballbearings to run through.




I have seen that other folks have used a homemade split collet to protect the ballscrew while machining the ends, but as I have an ER32 collet setup on my lathe that I have used to clamp (relatively) soft brass without causing damage any to it, I decided to use it to hold the ballscrew in the lathe, and it worked ok.




These ballscrews are hardened, but only on the outside, so I used carbide tooling. It worked really well, much easier than I was expecting, I was able to take 0.2mm cuts even on the hardened sections. So I turned down the end to 10mm diameter for a length of about 10mm ish (thats a metric "ish" by the way).

Then I extended the ballscre out a bit more until I had about 40mm sticking out of the chuck in total. I then turned down the rest to 11.95mm-11.98mm. This is to fit a 12mm id bearing. Once I got a nice close sliding fit I marked off the 10mm or so that was left between the bearing and the 10mm section and set about threading it M12.



The end result is here:-




Now the less-than-completely-blind of you may well have noticed that the thread does not appear to be that clean. I would like to say that it is completely an anomaly caused by the phases of the 3rd moon of jupiter, but I cant. I made the mistake of using a threading tool that had 0 degrees top relief. This kinda shredded its way through the thread. I only realised this about half-way to depth, and so after I realised it I carefully removed the toolbit from the QC holder and ground some top relief on it and replaced it. Threading went much better after this. Anyway, even though it looks kinda rough, it will be ok for this.

But before I cut the thread to full depth I hunted high and low through the workshop to try and find even one M12 nut, but I didnt have anything M12. So I dug a little 20mm round steel bar out of the "scrap" pile and set about drilling and tapping it M12. Handily it had a central hole already there.

I then clamped my 3jaw onto the mill table to hold and drill the steel "nut".



Once this was done I was able to cut the thread to full depth, testing with my "nut" to make sure it fit ok. (having a M12 die would have been really helpful)


Here's a shot of the completed machined-end with double row angular contact bearing, small space for locknuts, and then the oldham coupling in place.





The one thing I was kinda dreading was haveing to repack the ballnut with the 48 ballbearings, so much so I had been contemplating turning the ballscrews without removing the ballnuts, but that would not have been a safe thing for me to do. However, it turned out to be a fairly simple process with these ballnuts. In fact the easiest way seemed to be to just start the ballscrew in the empty ballnut ( they have a plastic wiper on each end that are threaded to match the ballscrew) and just pop in about a third of the balls and "jiggle" the screw and nut while gently turning the screw into the nut a couple of rotations, then add another third of the ballbearings, jiggle and then repeat for the last third. They all went in and the screw turns without any binding or feelable backlash.


So, that is the Y-axis ballscrew machined on one end ( I dont think I need to machine the other end ), next up will be the long X-axis ballscrew which will get an identical end machined on it, and then the Z ballscrew which will be a little simpler.


Tim


__________________
Measure with a micrometer, mark with chalk, cut with an axe.
spuddevans is offline  
 
Reply With Quote
Old 10-19-2010, 08:27 PM   #13
spuddevans
 
spuddevans's Avatar
 
Join Date: Feb 2008
Posts: 204
Liked 12 Times on 12 Posts

Default Re: Another Sieg X2 CNC conversion

Here's a little update on this one, I have been making some progress on this.

A couple of days ago I stripped down the mill table to do some preparation work on the table. I had to dig out some of the casting in order to make room for the BallNut for the X-axis to fit in. Not having access to an angle grinder I turned to less gainly methods. I started out by drilling as much away as I could, and then it hit me that I could fix it to my lathe and mill it that way, so I finished the job off in that manner.

I dont have any in-progress pics as it was a fairly dirty job and I value the working status of my camera But I do have an "After" pic.






The slot is to allow the body of the Ballnut to sit low enough in the casting. It was after this that another problem raised it's head. After milling out the casting for the ballnut I tried the ballscrew complete with ballnut in-situ to see how it fitted. This photo shows what the problem was.






Ack!!! the top half of the ballnut's flange would not fit under the mill table. Then double Ack!!! the whole of the ballnut was hardened, my hacksaw would just skate over it without hardly marking it. Still not having an angle grinder I turned to my trusty bench grinder. A very dusty hour ( or so ) later I had this;




And this is how it looks in place ( minus the ballscrew as I havent had chance to re-pack the ballnut )




After that I started cutting some Ali for making the mountings for the steppers, but then I was rudely interrupted by the call of the wild (my dinner), no pics as I'm pretty sure that most of you have seen 2 pieces of rough cut ali before :scratch:


Tim
__________________
Measure with a micrometer, mark with chalk, cut with an axe.
spuddevans is offline  
 
Reply With Quote
Old 10-20-2010, 11:51 AM   #14
spuddevans
 
spuddevans's Avatar
 
Join Date: Feb 2008
Posts: 204
Liked 12 Times on 12 Posts

Default Re: Another Sieg X2 CNC conversion

I got some more done today on the stepper motor mounting hardware. The 1st problem was the raised ring on the stepper motor.






So I set up my boring bar on my mill and cut out the needed part. I didnt really calculate it out but just marked out where the edge of the ring should be, then marked the centre and then just edged the boring bar very slightly into the work and adjusted it by eye to be centered.




Then I did it again for the other support.







Next will be drilling and tapping for fixings, boring out the thicker plate for the bearing and mounting holes to attach to the mill table.


Tim
__________________
Measure with a micrometer, mark with chalk, cut with an axe.
spuddevans is offline  
 
Reply With Quote
Old 11-05-2010, 03:57 PM   #15
spuddevans
 
spuddevans's Avatar
 
Join Date: Feb 2008
Posts: 204
Liked 12 Times on 12 Posts

Default Re: Another Sieg X2 CNC conversion

A little update, I havent forgotten this one, just not had much workshop time lately. But I have managed to get out there for a couple of hours this week.

I got started on the thicker mounting plate, boring out the pocket for the Angular Contact bearing, and wonder of wonders, I managed to get a really nice snug, "finger-press" fit. I bored it to the depth of the bearing minus about 0.5mm.

I then made up a bracket to hold the bearing into the pocket out of some 1/8" steel plate, drilled it for 4 mounting screws and drilled and tapped the corresponding holes in the mounting plate.

I then marked up, drilled and counterbored the mounting plate for the side support plates. Then the corresponding holes were drilled and tapped in the side plates.

Then I drilled and counterbored the mounting holes for attaching the whole assembly to the mill table.

Here's a pic of all the parts as they stand today.




And a mockup of them





Closer view of the coupling (minus the lock nuts on the ballscrew)




Next will be a trial fit on the mill itself, and if that goes well it will be on to the Y-axis.

Tim
__________________
Measure with a micrometer, mark with chalk, cut with an axe.
spuddevans is offline  
 
Reply With Quote
Old 11-06-2010, 12:38 AM   #16
1hand
 
Join Date: Feb 2009
Posts: 914
Liked 49 Times on 46 Posts
Likes Given: 5

Default Re: Another Sieg X2 CNC conversion

Tim thats looking good. Pretty soon you be making swarf like crazy!

Will you be using Mach 3?

Matt
1hand is offline  
 
Reply With Quote
Old 11-06-2010, 02:05 AM   #17
multihobbyguy
 
Join Date: Jul 2009
Posts: 44
Liked 4 Times on 4 Posts

Default Re: Another Sieg X2 CNC conversion

I just wanted to say thanks for taking the time to take pictures and document your progress, Thanks, Chris.
__________________
Chris
Fairfax Station VA, 22039
multihobbyguy is offline  
 
Reply With Quote
Old 11-06-2010, 07:22 AM   #18
spuddevans
 
spuddevans's Avatar
 
Join Date: Feb 2008
Posts: 204
Liked 12 Times on 12 Posts

Default Re: Another Sieg X2 CNC conversion

Quote:
Originally Posted by 1hand
Will you be using Mach 3?
Hi Matt, yes I'm using the demo version of Mach3 at the moment, when I've got it all running I'll see about getting the full version.

Quote:
Originally Posted by multihobbyguy
I just wanted to thanks for taking the time to take pictures and document your progress, Thanks, Chris.
You're very welcome, I've actually felt a bit guilty for not taking more "in-progress" pics rather than the "after-progress" pics I have taken. For some reason on this build I seem to have a lot more oil and grease on my hands than previous builds and I just cant bring myself to use my (nearly) new camera with grubby hands.


Tim
__________________
Measure with a micrometer, mark with chalk, cut with an axe.
spuddevans is offline  
 
Reply With Quote
Old 11-06-2010, 11:41 AM   #19
ttrikalin
 
Join Date: Sep 2009
Posts: 479
Liked 21 Times on 21 Posts
Likes Given: 7

Default Re: Another Sieg X2 CNC conversion



wow, this is very instructive.

BTW, do you have to preload the balls in the nut to achieve no backlash? How is this done in practice?

t
__________________
tom in MA, US

http://web.me.com/ttrikalin/toms_corner/Home.html
ttrikalin is offline  
 
Reply With Quote
Old 11-06-2010, 12:59 PM   #20
spuddevans
 
spuddevans's Avatar
 
Join Date: Feb 2008
Posts: 204
Liked 12 Times on 12 Posts

Default Re: Another Sieg X2 CNC conversion

Quote:
Originally Posted by ttrikalin
BTW, do you have to preload the balls in the nut to achieve no backlash? How is this done in practice?
Hi there Tom,

The nuts that I have are "anti-backlash" in that they come with slightly larger balls installed to reduce the backlash.( I think that is what they mean by "Pre-loaded" ) I say reduce because there is bound to be some measure of backlash in a single nut system, with a double nut system it is possible to get even less backlash due to being able to adjust the loading between the 2 nuts. But on such a small mill as an X2 there isnt much room for installing 2 ballnuts without doing some major surgery with an angle-grinder.

Of course, to machine the ends of the ballscrew you have to remove the nut, which in my case meant letting all the balls out because I did not realise, until another forum member pointed it out to me, that you can simply insert a 14.4mm diameter round piece of wood/metal/plastic into the nut as you unscrew the screw out of the nut and that will hold all the balls in place until you reverse the procedure to re-insert the screw into said nut.

If you do want to remove the balls, place a folded soft cloth on your workbench 1st to catch the balls and stop them bouncing ( and they can bounce into the ether, never to be found again or at least not until you buy a thousand replacements )


Hope this answers,


Tim


__________________
Measure with a micrometer, mark with chalk, cut with an axe.
spuddevans is offline  
 
Reply With Quote
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
New Sieg XN2 techonehundred The Break Room 5 06-15-2011 07:23 PM
Sieg X1 conversion Robotguy CNC Machines and Conversions 0 12-29-2010 08:34 AM
Sieg X1 cfellows Tools 11 10-19-2009 02:31 AM
Sieg X3 lugnut Tools 4 08-18-2009 01:17 AM
Sieg x3 firebird General Engine Discussion 17 04-27-2008 04:34 PM



Newest Threads






- Top - Member List