Converting an Angle Grinder into a Polisher…?

The other thing to consider is that with the angle grinder running at reduced speed the cooling air flow would be much reduces and the motor would heat up very quickly and burn the motor out.

The duty cycle and most power tools at full speed is not much more the 10% 10% running 90% not running and cooling down.

I have a pile of burnt out angle grinders in the workshop that was used to polish stainless steel with a cotton mop.
 
Fitzroy said:
Apropros this thread http://www.ybw.com/forums/showthread.php?380062-Sander-to-flatten-gelcoat, I wondered how easy it would be to add a rheostat to a 240v angle grinder, to bring the revs down and allow it to polish?

What components do you need? Where do you get them from?

Thanks.
Click to expand...

I have a variable speed angle grinder that I use for polishing.
I've done my boat three or four times with it and its been very effective and not burnt out so far.
The big problem is that it is so heavy, I use a length of shock cord from the main halliard to carry much of the weight which makes it manageable, a dedicated polisher would be much better but I couldn't justify the price.
 
nimbusgb said:
You need a proper speed controller.

Far easier and safer to just buy a polisher, something like this http://www.ebay.co.uk/itm/CAR-POLISHER-BUFFER-SOFT-START-6-SPEED-BODY-SHOP-/270389557911
Click to expand...

galadriel said:
I would suspect that the motor would lack torque, the gearing is all wrong.
Click to expand...

I hear what you’re saying - but this guy’s done it for peanuts…

Bertramdriver said:
I've just invested £7.50 in a 4kw rheostat? Bought on eBay which allows infinite voltage reduction from 220 volts downwards.
Connected to my angle grinder fitted with a 150 mm backing pad £9.95 eBay I now have a slow rotation polisher that is light enough for my arthritic hands to hold. Much better than those two handed Silverline weapons
Click to expand...

Question is, how?
 
Electronic speed controls are essentially the same as a light dimmer. It turns the power on for a short or variable length of time on each cycle. This reduces the power to the grinder so reduces speed. Unfortunately this will mean that it will slow down when you make it work and speed up when you take it off. As said many drills have this electronic speed control which is useful. It is no where as near as good as speed reduction by gearing. This raises the torque as the speed is reduced. Hence purpose built buffers are far better. But hey give the rheostat (electronic speedcontrol a go it is cheap enough). Usually they have a plug and a socket and are simply connected into the power lead.
here is one sold as a kit (note the funny looking oz plugs and sockets) http://www.altronics.com.au/index.asp?area=item&id=K6035 NB $75 is 41 squid less 10% Oz tax plus postage and whatever it costs to get it into UK.
I am sure something similar must be available in UK either as akit or as a finished device. good luck olewill
 
William_H said:
Electronic speed controls are essentially the same as a light dimmer. It turns the power on for a short or variable length of time on each cycle. This reduces the power to the grinder so reduces speed. Unfortunately this will mean that it will slow down when you make it work and speed up when you take it off. As said many drills have this electronic speed control which is useful. It is no where as near as good as speed reduction by gearing. This raises the torque as the speed is reduced. Hence purpose built buffers are far better. But hey give the rheostat (electronic speedcontrol a go it is cheap enough). Usually they have a plug and a socket and are simply connected into the power lead.
here is one sold as a kit (note the funny looking oz plugs and sockets) http://www.altronics.com.au/index.asp?area=item&id=K6035 NB $75 is 41 squid less 10% Oz tax plus postage and whatever it costs to get it into UK.
I am sure something similar must be available in UK either as akit or as a finished device. good luck olewill
Click to expand...

Thanks for that – so they do exist! The point about torque seems key, but it’s surely worth experimenting if the bits can be found for peanuts…

theoldsalt said:
Speed control for an angle grinder ?

Something like this?

http://www.ebay.co.uk/itm/SAW-SPEED...ial_Automation_Control_ET&hash=item1c39440c27

Trouble is you are half way to the price of a proper polisher !!
Click to expand...

Yes.

Now how about one of these (not sure what the differences are) – put into a generic plastic box…?

http://www.amazon.co.uk/4000W-Elect...3&keywords=ac+speed+controller+-trigger+-lock

http://www.amazon.co.uk/4000W-Power...4&keywords=ac+speed+controller+-trigger+-lock
 
You must log in or register to reply here.

Share this page

Top