Ball screw returns

I have an old IBL ball screw. I took it apart to repack it and one of the 3 returns is in sad shape.

It looks like it's melted on the outside and there is a hump on the inside.

I've never repacked a ball screw before so I don't know how much of an issue this is.

IBL (International Ballscrews Limited) were bought by Danaher (who also owned Thomson) and were known for a while as Thomson-IBL. It's not clear to me if there is a current connection with ThomsonLinear. I asked ThomsonLinear and they basically said we need to see a company website before we'll talk to you.

One option that occurred to me is to just grind out the hump with a micro dremel bit and try and reinforce the back side with some kind of filler.

I sent an email to ablservicesltd.com (UK) as their page says "A B Linear was born of the demise of Thompson IBL and therefore has an ingrained understanding of the product with over 20 years within their manufacturing team. A B Linear has an extensive stock of Thompson IBL ballscrews and parts and can carry out prompt and timely repairs for all Thompson IBL ball screws." We shall see. They may only do mail in repairs and this is something I feel I can just fix myself with new returns.

Again, this is the first time I've ever taken a ball nut/screw apart so I'm learning. If something above is idiotic on my part, apologies :-)

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Originally Posted by crazybrit

I have an old IBL ball screw. I took it apart to repack it and one of the 3 returns is in sad shape.

It looks like it's melted on the outside and there is a hump on the inside.

I've never repacked a ball screw before so I don't know how much of an issue this is.

IBL (International Ballscrews Limited) were bought by Danaher (who also owned Thomson) and were known for a while as Thomson-IBL. It's not clear to me if there is a current connection with ThomsonLinear. I asked ThomsonLinear and they basically said we need to see a company website before we'll talk to you.

One option that occurred to me is to just grind out the hump with a micro dremel bit and try and reinforce the back side with some kind of filler.

I sent an email to ablservicesltd.com (UK) as their page says "A B Linear was born of the demise of Thompson IBL and therefore has an ingrained understanding of the product with over 20 years within their manufacturing team. A B Linear has an extensive stock of Thompson IBL ballscrews and parts and can carry out prompt and timely repairs for all Thompson IBL ball screws." We shall see. They may only do mail in repairs and this is something I feel I can just fix myself with new returns.

Again, this is the first time I've ever taken a ball nut/screw apart so I'm learning. If something above is idiotic on my part, apologies :-)

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I thought International Ballscrews was still in business.

The first photo is that the back side of photo # 2 or are they separate pieces

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Originally Posted by mactec54

I thought International Ballscrews was still in business.

The first photo is that the back side of photo # 2 or are they separate pieces

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Not that I am aware of. And there are just 3 plastic pieces. One photo is the backs of the 3 returns, the other the "fronts" of the same returns. Same left->right ordering in each picture.

I suspect replacements could be 3D printed. Not sure what material, nylon I expect for durability. Advice welcomed.

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Originally Posted by crazybrit

Not that I am aware of. And there are just 3 plastic pieces. One photo is the backs of the 3 returns, the other the "fronts" of the same returns. Same left->right ordering in each picture.

I suspect replacements could be 3D printed. Not sure what material, nylon I expect for durability. Advice welcomed.

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Ok that makes sense, it looks like the screw was run to fast and melted the plastic, or a solvent was used that attacked the plastic, 3D printing would not be good enough for this part unless you could use a high temperature tough plastic, and I don't think the normal 3D printers can use these type of engineering plastic needed

They could be made using Peek, which would be the ideal material or AF Delrin may work, they could be machined

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Originally Posted by mactec54

Ok that makes sense, it looks like the screw was run to fast and melted the plastic, or a solvent was used that attacked the plastic, 3D printing would not be good enough for this part unless you could use a high temperature tough plastic, and I don't think the normal 3D printers can use these type of engineering plastic needed

They could be made using Peek, which would be the ideal material or AF Delrin may work, they could be machined

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Prusa i3 mk3 can print delrin with some tweaking. Or so I read.

But it may be easier to try and bodge the current setup, so the mill can be got running to then machine new ones out of delrin.

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Originally Posted by crazybrit

Prusa i3 mk3 can print delrin with some tweaking. Or so I read.

But it may be easier to try and bodge the current setup, so the mill can be got running to then machine new ones out of delrin.

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That would be a way to do it, I would use the Peek material over the Delrin, a 3D printed Delrin would be to soft, without carbon fiber added. If you are going to machine new ones then use Peek

There are some epoxy's that can get very hard, like Moglice which is expensive but would do the job until you could make some new ones

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Originally Posted by mactec54;2475246 I would use the Peek material over the Delrin, a 3D printed Delrin would be to soft, without carbon fiber added[/quote[

First, thanks for the advice, greatly appreciated. Second I assume you're recommending plain polyetheretherketone (the beige color) not the carbon or glass reinforced version (I guess delrin is available in reinforced also).

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There are some epoxy's that can get very hard, like Moglice which is expensive but would do the job until you could make some new ones

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I was pondering JB weld. I need to build up the backside (opposite where the balls run) as otherwise it's going to push back out and impede ball return. As far as the pump I was going to try and heat it and push it back in, else grind it off I guess.

I also need to reball it. I should probably do that (or at least inspect the existing balls under a microscope) before putting back in the modified existing returns .... so I can make new ones.

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Originally Posted by crazybrit

First, thanks for the advice, greatly appreciated. Second I assume you're recommending plain polyetheretherketone (the beige color) not the carbon or glass reinforced version (I guess delrin is available in reinforced also).

I was pondering JB weld. I need to build up the backside (opposite where the balls run) as otherwise it's going to push back out and impede ball return. As far as the pump I was going to try and heat it and push it back in, else grind it off I guess.

I also need to reball it. I should probably do that (or at least inspect the existing balls under a microscope) before putting back in the modified existing returns .... so I can make new ones.

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If you only need to build up the back then JB would do the trick, if you need any in the track that would be to soft, in the track you could drill a hole right through and put in a plastic plug ( tight fit ) and profile it to the shape you need on the inside, epoxy on the back side

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Originally Posted by mactec54

you could drill a hole right through and put in a plastic plug ( tight fit ) and profile it to the shape you need on the inside, epoxy on the back side

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You're full of good ideas. Thank you. I'll see if it will push back with heat, else drilling is a good idea and I'm sure just nylon would be fine for such a small area.

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Originally Posted by crazybrit

You're full of good ideas. Thank you. I'll see if it will push back with heat, else drilling is a good idea and I'm sure just nylon would be fine for such a small area.

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There is no load on them they are just a guide

...machine shop 101...need more engineers.

... du lernst immer übers probieren. das nennt man erfahrung.