sliding bearings

[lee hawkins 1Participant @leehawkins1]

Hello all

Been a member on here few years now , not posted much for a long while, few years I recon, please dont feel like i only want to talk to you all, is only when I need something.

I have this project, building longer rails on a chop saw, I have the rails, they are 25mm hardened steel shafts, I was thinking on using bronze bearings, but found some mild steel thick wall ferruls 50mm long 40mm od exact slide fit 25mm id

Will these mild steel ferulls/bearings be ok for wear on a hardened steel shaft

lee

[lee hawkins 1Participant @leehawkins1]

[Brian WoodParticipant @brianwood45127]

Hello Lee,

You would do better with cast iron, it is a recognised bearing material for steels hard and soft and provides it's own lubrication with the carbon content, a nice bonus to avoid grinding bearings/shaft with oil bound dust from the sawing

Regards

Brian

[EmgeeParticipant @emgee]

Hi Lee, If the new parts allow a good sliding fit I would go with them but use a silicone spray lubricant.

When they become too worn for the accuracy required you can bore them out and fit bushes to suit.

Emgee

[Chris Evans 6Participant @chrisevans6]

Linear (spelling?) bearings are cheap and having multiple ball bearing glide really easy. Use your mild steel until they wear out, I guess it will be a long time.

[HOWARDTParticipant @howardt]

I would use proprietary bearings from either Oilite (impregnated bronze) or Igus (engineering plastics). They are both relatively cheap and obtainable.

[Nick HulmeParticipant @nickhulme30114]

+1 for Linear Bearings, that's what some of the top chop saw manufacturers use, ideally you should have scraper seals to stop debris getting into the bearings.
I wouldn't use Silicone Oil on anything with metal to metal sliding components, it's unsuitable, Silicone Oil is great for metal to plastic and plastic to plastic though.

– Nick

[EmgeeParticipant @emgee]

Posted by Nick Hulme on 02/03/2018 18:52:05:

I wouldn't use Silicone Oil on anything with metal to metal sliding components, it's unsuitable, Silicone Oil is great for metal to plastic and plastic to plastic though.

– Nick

Nick, check this out for the difference between "silicone oil" and "silicone spray lubricant"

**LINK**

Emgee

[Anonymous]

Posted by Emgee on 02/03/2018 20:58:39:

Posted by Nick Hulme on 02/03/2018 18:52:05:

I wouldn't use Silicone Oil on anything with metal to metal sliding components, it's unsuitable, Silicone Oil is great for metal to plastic and plastic to plastic though.

– Nick

Nick, check this out for the difference between "silicone oil" and "silicone spray lubricant"

**LINK**

Emgee

It's still Silicone though be it in oil, spray or grease form which as stated isn't really for metal to metal contact no matter what the advertising blurb says.

[EmgeeParticipant @emgee]

Posted by Mick Berrisford on 02/03/2018 22:24:20:

Posted by Emgee on 02/03/2018 20:58:39:

Posted by Nick Hulme on 02/03/2018 18:52:05:

I wouldn't use Silicone Oil on anything with metal to metal sliding components, it's unsuitable, Silicone Oil is great for metal to plastic and plastic to plastic though.

– Nick

Nick, check this out for the difference between "silicone oil" and "silicone spray lubricant"

**LINK**

EmgeeIt's still Silicone though be it in oil, spray or grease form which as stated isn't really for metal to metal contact no matter what the advertising blurb says.

Mick, I have used the silicone spray lubricant without problems on machine slides, after spraying it dries off and leaves a slippery surface coating on metals.
I have also used silicone oil, the manufacturer's recommended lubricant for fan bearings working in high temp situations.

Emgee

[Grindstone CowboyParticipant @grindstonecowboy]

Just to add fuel to the silicone oil 'fire', it has long been a bone of contention in airgun circles – after a lot of reading the pros and cons, I now only use moly-based grease for mine. A pretty good explanation can be found on this page **LINK**

Regards,

Rob

[lee hawkins 1Participant @leehawkins1]

Thanks everyone for your ideas

I am no professional engineer, but do like to do things that make a proper job, So I have opted for the oilite bronze bush, these here http://www.ashleypower.co.uk/store.php/products/amc253550-metric-plain-oilite-bush

Ive been having a study of these bushes, what I have learnt , is that these bushes need to be pressed in so as to close them down to get them to fit the shaft, so when you order them at what I need 25mm id , they are a fraction over that size Is this correct ?

Thanks

Lee

[Michael GilliganParticipant @michaelgilligan61133]

Lee,

May I refer you to this thread: **LINK**

http://www.model-engineer.co.uk/forums/postings.asp?th=124276

I think you should find all the Oilite information that you need.

MichaelG.

[lee hawkins 1Participant @leehawkins1]

Thanks MichaelG

Will do.

[Ian S CParticipant @iansc]

I think I would try Oilite sintered iron bushes in this situation, they work the same way as the bronze Oilite bushes.

Ian S C

[lee hawkins 1Participant @leehawkins1]

Ian,

Iron Bushes, only place I can find these are from companies located in India, do you know Where i could buy these in the UK

or what about these  https://www.bearingboys.co.uk/BU-Type-Bearings/MB2550BU-Split-Bearing-Bush-14894-p

Thank

lee

Edited By lee hawkins 1 on 03/03/2018 12:54:22

Edited By lee hawkins 1 on 03/03/2018 13:13:22

[Ian S CParticipant @iansc]

Sorry Lee, I'm at the other end of Earth, in NZ.

Ian S C

[lee hawkins 1Participant @leehawkins1]

Ha ha no worries Ian

Thanks

lee

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