Newbie Sieg X3 and or Warco WM18 CNC conversions

[Doddy]

Also, check the length of your double ballnuts on the y axis: you can probably fit about 23cm of screw in there before it hits the column, so if your nut is 10cm long you'll restrict your travel to 13cm.

THIS!, eyeball the axis broken down as a sanity check!

I don't remember grinding my nuts on the Y, but defo on the X.

[CNCMEBABY]

Thanks Mat,

Is it an X3 you've converted?

I've double checked the ball nut diagrams and read them correctly now I think.

A 1204 with a ball nut height of 30mm would fit within the existing brass nut housing for ease of machining and single ball nut might be a better choice for the Y given the travel issue you mentioned. Just thinking, it could be feasible to have the regular ball nut (or indeed a double nut) mounted backwards on the screw to gain the maximum amount of travel. Would need to offset the BK mounting further forward from the front of the saddle but that should be easy enough with a suitable lump of aluminium. It would protrude more and really necessitate the stepper going off to the side with the pulleys and belt or I'd never get past the thing in the garage .Following on from that it might just be easier to use the same 1204 for the X in that case. I'll have a look at it shortly - the table is already off so should be easy enough to work out. Glad I haven't ordered just yet.

Shows the value of this site and the experience on here again for me..

Not sure if I want to grind my nuts!!

[Mat]

Is it an X3 you've converted?

Yes, though it's not 100% complete yet, the mechanicals are done and I've got the motors spinning in the bench but I've not put it all together yet.
Also, I went with these massive 8Nm Nema 34 steppers that a friend donated and the mounts are made are massive so I'm already planning Mk2 !

Just thinking, it could be feasible to have the regular ball nut (or indeed a double nut) mounted backwards on the screw to gain the maximum amount of travel. Would need to offset the BK mounting further forward from the front of the saddle but that should be easy enough with a suitable lump of aluminium. It would protrude more and really necessitate the stepper going off to the side with the pulleys and belt or I'd never get past the thing in the garage .

Yes you can push the nuts forward to gain space and you'll get more space on the underside, but you don't gain any headroom.

Another thought: if you're planning to offset the stepper, on Y you'll need to offset upwards as there's no space to go sideways, you've got maybe 80mm width until you hit the dovetails.

I'm currently modelling a homebrew double nut 1204 solution:




In theory the length will end up being 74-77mm so would need extra space on the Y.

Not sure if I want to grind my nuts!!

It's not ideal, but it's not too horrific. You'll need to take the nuts apart to clean them after grinding - daunting if you've never done it but there are vids out there and all you need is grease get the balls to stay in place as you load them back in.

[CNCMEBABY]

Yes you can push the nuts forward to gain space and you'll get more space on the underside, but you don't gain any headroom.

That sounds good...

Another thought: if you're planning to offset the stepper, on Y you'll need to offset upwards as there's no space to go sideways, you've got maybe 80mm width until you hit the dovetails.

Maybe it won't be so critical to offset the Y in that case as I'll be losing the power feed from the end and all the space it takes up. I could retain the pulley drive and have the stepper on the same plane but just offset it towards the rear a bit, losing one of the pulley thicknesses from the equation.

I might have to draw my ideas up in Fusion tonight, I have the saddle modelled up already and a picture speaks more words after all, but then I might just measure up again get the screws ordered and take it from there.

[CNCMEBABY]

THIS!, eyeball the axis broken down as a sanity check!

Been having a good measure up. With the saddle all the way back to the column there is 5mm of existing leadscrew nut covered up, this being the backlash adjusting part of the nut. This could be removed in the quest for the greatest X travel if required. Even without removing that 5mm of metal I reckon I can get 200mm of X travel including a nut on the end of the screw to prevent accidental over-travel. So plenty of travel for the 160mm table with a safety margin.

I might put a couple of belville washers in to preload the nut to account for any backlash a la Jonathan's micro lathe job here. This is due to me using the 1204 and there not being a double nut option. The bonus is I can get the nuts in just without having to grind them - the 1204 ball nut height at the flat of the flange is 30mm with the leadscrew nut coming in at 35mm. Just enough meat...

I'm currently modelling a homebrew double nut 1204 solution:




In theory the length will end up being 74-77mm so would need extra space on the Y.

Having said the all above and read your plan for the antibacklash double 1204 nut, an easy double nut solution would appear to be to bore out the existing leadscrew nut as planned anyway for the first ball nut and mount another back to back with belvilles between to preload and use a couple of the mounting holes on the ballnut flanges between with one flange threaded and the other opened out slightly to use bolts to apply the preload. Then the space created by all that can be used to mount the stepper with the shaft facing out and on the left hand side of the saddle. I plan off-stands made from aluminium block for the spacing for the mounting plate off the front of the saddle.

[dazp1976]

Been having a good measure up. With the saddle all the way back to the column there is 5mm of existing leadscrew nut covered up, this being the backlash adjusting part of the nut. This could be removed in the quest for the greatest X travel if required. Even without removing that 5mm of metal I reckon I can get 200mm of X travel including a nut on the end of the screw to prevent accidental over-travel. So plenty of travel for the 160mm table with a safety margin.
Having said the all above and read your plan for the antibacklash double 1204 nut, an easy double nut solution would appear to be to bore out the existing leadscrew nut as planned anyway for the first ball nut and mount another back to back with belvilles between to preload and use a couple of the mounting holes on the ballnut flanges between with one flange threaded and the other opened out slightly to use bolts to apply the preload. Then the space created by all that can be used to mount the stepper with the shaft facing out and on the left hand side of the saddle. I plan off-stands made from aluminium block for the spacing for the mounting plate off the front of the saddle.

I basically didn't like the amount of front overhang so wanted my saddle to move closer to the column.
I cut my base slot a bit, made some new bolt holes instead of using the large central one on the carriage.
Managed to get my saddle to move further back by 15mm. Overall I got 204mm movement from it with barely any extra overhang.

However. My throat is only 185mm but at least I don't need to hang off the front a mile. Later on I'll stick a 20mm spacer between the slide and head. Then I could use the whole 204mm.

This is on an Amat25lv similar to the Warco machine.

[CNCMEBABY]

All the ball screws, nuts and pulleys arrived in pretty short order from Fred at BST. He was exceedingly helpful with my questions, raised issues I hadn't foreseen and coped with my hand drawn diagrams admirably.

I got given a really nice control box donated from a friend, unfortunately I'm having trouble uploading the photo, I'll try again later in the build when it's been repopulated with shiny stuff. I'll post a list of the hardware I've bought for the control side at the same time.

I've been milling out the X and Y ballnut holders from the old brass acme leadscrew nuts. The Y nut was clocked from the front of the table as being 0.002" out of square so compensated for this in the vice on the mill then faced and bored the ballnut hole and bolt holes. I ran into some problems in the process on the second mount as evidenced in the photos below. I had a cutter slip in the collet which accounts for some of the problem, the other marks in the bore are a result of the previous threading showing through but the final mounting hole is true and the otherwise ready to start the fitting of the ball screws.



I will get a good bit of extra table travel in the Y axis towards the column as dazp1976 says above on his similar machine.

On final disassembly of the old Z axis bits I found that the damper had long since given up the ghost - I wonder whether to get another or just rely on the power of the stepper?

[CNCMEBABY]

Hi All,

Trust you all had a safe and good festive period.

I've spent a vast amount of time getting to grips with Fusion 360 and been modelling up as much of the X3 as possible with as much accuracy as I reckon I need. Link to fusion design here https://a360.co/3EeD874.

I also spent a large amount of time in the shed making my Y axis stepper mount plate, much swarf, many broken cutters from trying to get used to machining with a flexible machine and a low powered router head. (BOXZY robot)
So here it is, my Y axis plate with stepper mounted at the rear so that it doesn't stick out the front too far and take up too much room in what is already a small space.

Any suggestions for good pulleys and belt to stop backlash before it gets introduced much appreciated - I've seen mentions of HTD5 and am thinking 15mm with 18 tooth pulleys.

Cheers all.