Still deciding which way to go for my C Beam Build (Workbee / Sphinx). Either will be 1000x1000 so the same question applies to both. Is there enough room within the C-Beam for a 10mm leadscrew in place of the 8mm. I can source the suitable bearings but would have to source the AB Nut to suit, but worst case is that I make my own. Has anyone got any experience of this? Chris
The issue isn't the size of the screw but getting the threaded nut to fit within the limited space available. From the center of the screw you have 12.4mm to the back of the channel and 9.1mm to the face of the plate. You need to verify the nut will work with these dimensions. Unless you have the capability to turn down the ends of the screw you'll also want to move up to a 10x16x5 bearing.
Planning on a 1000 x 1000mm machine which is on the limit for 8mm leadscrews so trying to cover potential issues before they arise.
Not done a whole lot of research ..... yet, but will link to what i have found when im back in the office on monday
You could get yourself a block of delrin and make your own antibacklash nuts. I did this for 1/2 inch lead screws and it works great.
This is what I found when creating my list. Of course, $$$ can get anything done, but I think this would be what everyone else would find. 10mm can be had in up to 12mm lead. I only found the 12mm with up to 8mm lead for AB nuts. The issue is that you can't get a block style AB nut. I've only been able to find this cylindrical AB nut. Here is an example of the 1/2" nut without backlash compensation. The same applies to the 3/8" screw. I did see these as well, but I'm not sure what the lead is. So you would have to end up making your own, as was mentioned above. Sorry for the giant pics.
Looking at this a little further i found these (I was actually pricing up for the upcoming sphinx build and these popped up in some search results by pure luck) ANTI-BACKLASH DELRIN NUT (standard) FOR CNC 10 mm M10 LEAD SCREW - 3 pieces | eBay It looks like its a 1.5mm pitch so may be a little slow compared to the 2mm pitch of the 8mm although not entirely sure how much of a differce it will make in the real world
Good find! The pitch won't change the speed, it's all about the lead.. 10mm per turn is 10mm per turn no matter the pitch Actually these look like single start 1.5mm leads way too slow! if they were 5 start 1.5mm pitch 10mm lead then you would be golden, the way they wrote M10 lead screw makes it a bit mis-"leading" pun intended
I am finishing up my 1m x 1m sphinx with 8mm leadscrews. The X axis does not sound right. Y and Z sound fine. I think the Y works well is because of the dual leadscrews. I would like to upgrade the X axis to 10mm. With the long weekend, I hope to get the cable management finished and my spoiler board. I want to do some cutting. I will use the X 8mm for now and see how it goes.
I’m running a 1x1 Sphinx with 8mm screws. It works but it is actually not very confidence inspiring at higher speeds. It seems like the critical speed for 1m x 8mm screw is about 5000mm/min (200 ipm). Another issue (at least with the Sphinx) is tha in order to eliminate backlash between the screw and the bearings you place the screw in compression. At 1m this can actually case the screw to bow. At some point I would like to modify my machine to put the screws under extension instead. You do want high speeds to be able to cut right. Especially if you plan to do aluminum. So, I think you can get by with 8mm. But is definitely approaching the limit. 12mm would leave more headroom.
There is excess on the leadscrews. You can build the Sphinx with the lead screws under tension without changing a thing.
Probably have to swap the end plates around so the bearing recess is on the other side.. But I agree anything over 250mm should be setup in tension.. Gary
Well yes-ish. It would require me to disassemble the machine to flip the end plates. Also I might need to increase the length of the spacers for the motor. I’m not sure the lock collar would fit there now. Has anyone done a sphinx in tension? If I ever get around to it I would also add thrust bearings between lock collar and plate to take axial forces.
Can you omit the lock collar on the motor end using the flexible coupling instead, setting the coupling against the washer and the washer against the bearing.
This turned into a hijack of this thread. If you want to follow this discussion you can check out Sphinx lead-screws in tension
