isel ballscrew question

[rzmac]

Hello. I have some 25mm isel ballscrews / ballnuts (213 700 0005) and am at the stage where I need to insert the ballnuts into the mounting blocks. It is a tight fit and I am wondering if anybody can describe what they did to press the ballnuts into the blocks.

1. Did you lube the outside of the ballnut? If so, with what?
2. Ballscrew in or out of the ballnut? I see advantages to both...
3. I have a number of the press-type fixtures that I have used for other projects (think short tube section with a plate welded to one end, hole in the middle of the plate, threaded rod, another loose end plate and plenty of elbow grease). Is it okay to compress the ballscrew in this manner in order to force it into the mounting block?

Sorry if these questions seem ridiculous. I have never handled a ballscrew before and I don't want to mess them up.


thanks,


steve

[kawazuki]

Hello. I have some 25mm isel ballscrews / ballnuts (213 700 0005) and am at the stage where I need to insert the ballnuts into the mounting blocks. It is a tight fit and I am wondering if anybody can describe what they did to press the ballnuts into the blocks.

1. Did you lube the outside of the ballnut? If so, with what?
2. Ballscrew in or out of the ballnut? I see advantages to both...
3. I have a number of the press-type fixtures that I have used for other projects (think short tube section with a plate welded to one end, hole in the middle of the plate, threaded rod, another loose end plate and plenty of elbow grease). Is it okay to compress the ballscrew in this manner in order to force it into the mounting block?

Sorry if these questions seem ridiculous. I have never handled a ballscrew before and I don't want to mess them up.

thanks,

steve

From ISEL site....

For the 25mm Ballscrew system ISEL only has the Variant 3 type of nut. It needs to be used in combination with the MountingBlocks. Since these provide the pre tension on the system.

The bearing blocks shown seem to have set screw retainers in the sides implying that a sliding fit is required! I would have thought any type of a press fit would screw up the nut + it makes for any servicing / replacement somewhat tricky later down the line.....IMHO

[The Blight]

I have several 16mm ISEL screws, and I have machined my own mounts with a sliding fit between the nut and hole. Pressing it in seems like a bad idea if you want to take it out again at some point (to service or replase). How tight a fit is it?

Oh and only one of the screws in the side is for retaining the nut. The other is to eliminate backlash.

[rzmac]

I have several 16mm ISEL screws, and I have machined my own mounts with a sliding fit between the nut and hole. Pressing it in seems like a bad idea if you want to take it out again at some point (to service or replase). How tight a fit is it?

Oh and only one of the screws in the side is for retaining the nut. The other is to eliminate backlash.

Hmm... I have the correct mounting blocks, but they seem to be a little snugger than I would have expected. I can insert the ballnut about 1/16th of an inch before it binds. Pressing on something that has a relief cut though 50% of its diameter seems like a really bad idea.

I am wondering about heating the block up to ~175F in the oven and then inserting the ballnut. Or I could coat the whole affair in STP and pray that it does not bind?

[Kipper]

Hmm... I have the correct mounting blocks, but they seem to be a little snugger than I would have expected. I can insert the ballnut about 1/16th of an inch before it binds. Pressing on something that has a relief cut though 50% of its diameter seems like a really bad idea.

I am wondering about heating the block up to ~175F in the oven and then inserting the ballnut. Or I could coat the whole affair in STP and pray that it does not bind?

I too made my own....an "H7" fit......warming the housing (AL) works just fine for removal and the housing has a grubscrew and the adjuster for the preload+ lube in it also....way better than buying the Isel supplied housings as in my case they wouldn't have fitted the machine. If you like I can post some images?

[rzmac]

I too made my own....an "H7" fit......warming the housing (AL) works just fine for removal and the housing has a grubscrew and the adjuster for the preload+ lube in it also....way better than buying the Isel supplied housings as in my case they wouldn't have fitted the machine. If you like I can post some images?

Hi Kipper. I already spent for the mounting blocks, but it would be interesting to see yours. It would be hard for me to make anything like that that right now as my mill is in little bits. :-) There is no way to go back to manual milling either, as my sadle has been milled at bit to accomodate the isel blocks. As a result, the old acme hardware will no longer mount - I am 110% comitted!

Still - the info about warming is encouraging and I am going to take a crack at it tomorrow morning and see where I get to.

I have steppers turning, motor mounts made, ballscrews machined, all the thrust bearings / spacers and a mill that is ready for assembly. I am hoping to have Mach controlled Y-axis motion by this time next week and motion on the X-axis the week after.



thanks!

steve

[M250cnc]

Hi Steve,

Seconded about not just pressing in the ball nuts as you have to be able to turn them in the housing to line up the hole with the set screw.

Make sure you have no burrs on the nut, or in the hole before you start

One method is to ease the hole in the housing with abrasive then just push the nut in, slight force can be used "Flypress Ideal" then remove, these parts must be lubricated to avoid scoring on the housing, remove the nut use abrasive on witness marks and repeat until you have the sliding fit you require you could also use a hole scraper as the more preferred method

Phil

[Kipper]

Hi Kipper. I already spent for the mounting blocks, but it would be interesting to see yours. It would be hard for me to make anything like that that right now as my mill is in little bits. :-) There is no way to go back to manual milling either, as my sadle has been milled at bit to accomodate the isel blocks. As a result, the old acme hardware will no longer mount - I am 110% comitted!

Still - the info about warming is encouraging and I am going to take a crack at it tomorrow morning and see where I get to.

I have steppers turning, motor mounts made, ballscrews machined, all the thrust bearings / spacers and a mill that is ready for assembly. I am hoping to have Mach controlled Y-axis motion by this time next week and motion on the X-axis the week after.



thanks!

steve

You're in the same boat as I was...I made mine on a lathe Hopefully these will help a little?

[digits]

I've got some of those ISEL screws and nuts myself - I don't remember having to use much force to insert the nuts into the blocks. I'd be careful about using too much heat - aren't those nuts part-plastic?

Hi Kipper - which Warco mill is that you've converted?

[Kipper]

I've got some of those ISEL screws and nuts myself - I don't remember having to use much force to insert the nuts into the blocks. I'd be careful about using too much heat - aren't those nuts part-plastic?

Hi Kipper - which Warco mill is that you've converted?

It's an RF40 (Major GH)

[pupetxls]

Hi there,

Sorry to bump in on an old thread, but I'd have some questions for you ISEL stuff owners.
I'm planing to get some ballscrews and nuts from ISEL, but in their documentation I see Class 7 of DIN69051, wich seem to be quite poor. They rate repeatability at 0.01mm / 300mm travel.

I assume it's ok for easy jobs, but for complex and big works, I assume this would quickly add up to a bad result. I'm in the range of 500.000 lines in the Gcode on 2m parts in length.

Could anybody shed a light on me with this one?

Thanks in advance,
Take care,
Pupet