Polishing plastics with the cage grinder

[Matthew]

Hello,

I have some plastic telephone cases I'd like to polish, but I lack the elbow grease to do it manually.

Can I use buffing mops on the grinder in the cage, assuming I put the grinding wheels back on once I'm finished? Is this a terrible idea?

Thanks

Matthew

[Matt Rutter]

There is an actual buffing machine in the cage, so you don't need to mess with the grinder....

Matt

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[Ant -]

The headlights on my car are a little hazey so I need to buff them up and a friend of mine advised me against using a power tool to do this as it tends to generate heat in the lens material that can cause it to fracture. If this is an old bacolite or how ever its spelt then those are fine one cured but the material is toxic I wouldn't want to make it into breathable particals myself. No idea if there are other issues with it and not in a position to be able to ok it but thought I'd share those cautions.

Kind regards

Ant

On Sat, 4 Sep 2021, 22:14 Matthew, <Mat...@marrold.co.uk> wrote:

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[Matthew]

Matt - hadn't spotted that, I'll have a look next time.

Ant - These are ABS plastic. I'm not overly concerned about them cracking, they've already been abused but thanks for the heads up.

[Matthew]

Hello,

I found the buffing machine. The spindle is missing a grub screw and the other's hex drive has seen better days. I'm not sure what size they are - the thread is certainly courser than your average "M" bolt. Could someone identify them so I can order some new ones? Alternatively we could order a new spindle.

I was using T Cut as thats the general recommendation for these phones but it seemed a little inefficient, I suspect I could go slightly more abrasive. Does anyone recommend any cutting compounds for ABS plastic? I've seen white used. I don't need anything too abrasive or a mirror finish..

Thanks

Matthew

[Adrian Godwin]

These are the commonly used polishes for pinball machines. T-Cut is probably close to Novus no 2. No 1 is a clear liquid while 2 and 3 are an abrasive slurry. 

https://www.ebay.co.uk/itm/384326379237

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[deanforbes]

they were purchased from 

https://www.metalpolishingsupplies.co.uk/adapters-and-tooling/

I dont think it ever had more than one grub screw done up and it was tight - is the spindle loose 

If we need a new one we need a new one .....

Just check which direction of the "screw" on the spindle is and order the same 

[Matthew H]

Ah, looks like they only have one grub screw, either way I couldn't get it tight enough to eliminate some play in the spindle which resulted in some vibration.

I'll have another look next time I'm in.

Cheers

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[Matthew H]

Also Adrian - Thanks, I'll get some of those at some point and have a go.

[Matthew]

Does anyone know how to adjust the speed of the buffing machine? There are spindles top and bottom to change the ratio, but no obvious way to release the tension on the belt.

Thanks

[Jonathan Hodgson]

If by "buffing machine" you mean the Union Graduate Wood Lathe that is in the cage set up as a buffer, I haven't done it myself, but I found this thread where they are talking about the mechanism to do it, so maybe you can work out which bits they are referring to.

https://www.ukworkshop.co.uk/threads/info-requested-on-union-graduate-bowl-lathe.63179/

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[Jonathan Hodgson]

From the diagrams it seems it's the same sort of arrangement as the Myford. The motor (which in this case is behind a plate near the base of the unit) is on a plate that swings to change the tension.

http://www.lkctraining.co.uk/S7-WoodLathe/Graduate%20Lathe%20Handbook.pdf

[Matthew H]

Hi Jonathan,

Yes that's the one - really helpful thanks. It did look like the motor was on some tilting mechanism - I'll take a torch next time so I can have a better look.

Thanks

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[deanforbes]

it been used at that speed for about 8 years to polish a wide variety of materials - what is the issue you are having?