Thread: Bench grinder problems

I've done this before, but trying to remember details! May vary with different grinders.
Once the wheels and mounting flanges are off you should be able to see each bearing. Are they still sealed? With all the grit flying around you'd hope so! The seal may have the part number embossed on it, or etched into the outer race? See if you can buy replacements...compare prices with a new grinder.
Check to see if there is a circlip retaining the bearings, if so remove them. You should then be able to press or gently knock one end of the shaft and push the bearing out the far side. The guts of the motor (commutator?) is all attached so may limit what you can achieve, so go steady. Push the shaft out the other way to get the other bearing.

Hope that helps a bit.

Originally Posted by Andy Mac

Once the wheels and mounting flanges are off you should be able to see each bearing.

Hope that helps a bit.

unfortunately the grinder is not like that the motor case is made from 3 cast and machined parts, the main body and 2 bolted on flange like parts (the standard sort of make) anyway i had taken the whole thing apart and cleaned it all out but the case .......i unscrewed the flanges on the case but they wouldn't budge i believe the bearings are mounted on the inside of these flanges ..........looking from the out side to where the spindle goes into the motor there are some taped holes for the guards to be mounted and a machined ring that i believe is pressed on to the flanges (im sure they are not the bearings) from the holes i think the bearings are something like 5-10mm in the flanges so......... any ideas on how to take the motor case to bits? will i need some kind of puller to pull it apart or can i do it another way?

as for if the seal is broken i have no idea but they spin freely with no ratell it just sounds like they are dry

thanks for you help

Patrick

Edit: just went down to the shed and ran my hand the joins of the motor case and found a crack no wider than a thou Erika i thought so i got a small chisel, positioned it in the crack and gave it a hard tap with the hammer, rolled it over and did the same to the other side then it it simply pulled apart a bit more work and i got the other side off but the shaft is still stuck on the bearing. ill try again tomorrow to gently take out the bad bearing and work on finding a replacement

latter ill post some pic's for anyone who wants to see and i think ill paint this grinder

oh and anyone who can should go to that Toowoomba swap meet it is so good you will find everything you want oh anyone who wants a really good center lathe, there is a Colchester triumph 2000 for sale up there for $7000 i personally recommend this lathe
and i wish i could have got it myself there was also a miller, tones of tooling for everything, an old Hercus lathe oh and a rare hand plainer (one for the collectors) if you can check out the swap

Patrick

pick one end and give the shaft a good thump a few times with a heavy piece of wood(so it doesnt damage any threads) and see if that makes anything move usually the bearings are just pressed in lightly from the inside of the caste covers. once its apart get 2 new bearings they arnt very expensive. beware i had a grinder that the stator ( the bit thats fixed solid inside the outer casing) had come loose and was touching the rotor that made strange noises . best get a proffessional to fix that if its the problem

Originally Posted by tanii51

beware i had a grinder that the stator ( the bit thats fixed solid inside the outer casing) had come loose and was touching the rotor that made strange noises . best get a proffessional to fix that if its the problem

thanks for the advise im sure its the bearing as i got a good feel of it and it is dry and corroding a bit (thats why i cant get the shaft off ) ill try and find some new bearings tomorrow ..........ill keep the an eye out when im putting it back together that the stator doesn't touch

Patrick

ok tried again today to get the bearings out. i made a quick home made puller and got one bearing out, the one that was stuck in the case without the shaft. still cant get the shaft off the other bearing and case i think they were heated in. will try and make a pusher for it

another thing that im concerned about is the rotor (not sure what its called but the thing in the middle of the shaft) it has a few dings and gouges in it should i be concerned about it?

Patrick

Edit: 6-02-09

bearings off and im really happy with it all, i don't think ill have any problems putting new ones in