Oil or grease for a Wadkin BGY3 disc sander motor?

[sploo]

I'm in the process of cleaning up a Wadkin BGY3 disc sander, and I notice that the motor has ports at either end (see photo). The (digital) copy of the manual I have doesn't mention anything about maintenance, so does anyone know if these ports are for oil or grease, and if so, what type?

 

[ChaiLatte]

A general purpose grease, nothing special.

Motors need very little grease. See here for excess greasing:

https://www.ukworkshop.co.uk/threads/how-do-i-lubricate-old-brook-motor.145864/

Read also the good advice in that thread concerning either refreshing the existing bearings or replacing wiht new.

 

[deema]

I would replace the bearings with sealed for life units, ie 2RS (rubber seals) replacing then with SKF, FAG or NSK is cheap, and it’s almost certain the grease in the existing bearings is hard / denatured.

Answering your original question, grease.

 

[sploo]

Got the front off the motor and unsurprised to see a wave washer, and a load of long hardened grease...

Slightly surprised though to find a shielded bearing. Not what I was expecting on a motor with a grease nipple. Maybe not original?

Its grease has long since left this world though, as it spins freely.

 

[deema]

Looks like someone has changed the bearings before A wave washer is normal. That’s a metal shield bearing used to help dissipate heat in say continuous / high load applications. If you’re going to be using it for hours at a time metal shield C3 clearance would be the way to go for the front bearing. If you’re using it intermittently I would use standard clearance bearings, 2RS to guard against dust.

 

[sploo]

Definitely won't be running for hours, so 2RS with standard clearance makes sense. Fortunately relatively cheap too.

I assume the rear bearing is the same size, but I need to remove the centrifugal clutch to get at it, so haven't had chance yet.

 

[deema]

They are usually a smaller bearing, not loaded as much so they save a few pennies.

 

[sploo]

They are usually a smaller bearing, not loaded as much so they save a few pennies.

Yep. That's why I haven't placed an order until I can get at it

 

[Sideways]

I opened an old ASEA brand motor last week and found this inside. No grease nipples on this motor but it did have open bearings and was designed with a push on cup at the rear and a retainer at the front to keep the grease in the bearings and out of the windings.
It also required a separate rubber seal around the shaft at the front.
It's a quality motor, nicely made, but I've also bought 2RS bearings (NSK in my case) to refresh it.

 

[deema]

Those bearings are over packed with grease. They should be packed such that the internal volume is about 1/3 to 1/2 full of grease. Too much and the bearing can overheat.

 

[sploo]

Got the clutch off this evening, and sure enough it's a slightly smaller 6205 bearing on the rear (6206 on the front). It was another shielded bearing, so again likely not original. Like the 6206, any grease inside has long gone (both spin freely). I've ordered a pair of sealed SFK bearings.

I'm hoping I won't have to replace the sander's main spindle bearings, as at least one is a chunky (and expensive) 6308. Haven't taken enough apart to get to the second one yet.

 

[deema]

A 6308 shouldn’t be too expensive, a bit more than the others and should be around £15 for 2RS

 

[sploo]

I usually buy SKF or FAG, which can be a bit more expensive. Though I see Dunlop do one for a reasonably price. Cross fingers I won't need any.

 

[deema]

I’ve used Dunlop on a couple of my own machines, just to try them out. They haven’t really been hard tested as I’m not earning a living from them. However, after about seven years of hobby use they are all still good. The price I found was for a SKF 6308 jus5 for a quick google search.

We only fit main brand bearings on anything we are restoring that we arn’t going to keep ourselves. For the small difference in price for me, it just isn’t worth going cheap as the damage they do if they seize and you’re not aware is too expensive/ time consuming to fix.

 

[sploo]

Yep - I've always taken the attitude that the time and effort required to strip down a machine to replace a bearing is way more than the added cost of a good quality bearing (on the assumption it means you won't have to replace it again - at least for a while).

I recently did the wheel bearings on my bandsaw (~20 years old from new, with quite a bit of use in the early years). The originals were definitely trash, so it got some good new SKF replacements.

 

[Daniel2]

I usually buy SKF or FAG, which can be a bit more expensive. Though I see Dunlop do one for a reasonably price. Cross fingers I won't need any.

Just as one might consider going to SKF or FAG for vehicle tyres...

 

[Daniel2]

Those bearings are over packed with grease. They should be packed such that the internal volume is about 1/3 to 1/2 full of grease. Too much and the bearing can overheat.

Thanks @deema
Everyday a school day, as they say.

 

[sploo]

Just as one might consider going to SKF or FAG for vehicle tyres...

You've now got me picturing rubber Dunlop bearings and smooth steel SKF tyres

 

[sploo]

So I'm not saying that the second of the pin nuts on the spindle was hard to remove... but after bending two cheap pin spanners I machined one from 10mm thick steel plate, and used a pipe for leverage whilst bracing the other end of the spindle using a pipe wrench locked against its key

Unfortunately, all attempts to then try to press the spindle out failed. The machine is too big to put into my hydraulic press, and any combination of clamps and screws I could put together just wouldn't get it to budge.

I was hoping to get the bearings out to inspect/clean/re-grease them. I've settled for the lesser option of popping off just the seals I can access, and letting some solvent sit in them seems to have gotten all the old grease out. Once they've thoroughly dried I'll re-grease them and hope they're good.

 

[deema]

Which way are you trying to withdraw the spindle?