Capacitor for a bench drill

[Eff1n2ret]

I have a bench drill which I didn't use for many years, and was stored outside under cover. It now generates insufficient power to drive the belt, although I can get the motor to run by manually spinning the pulley on the shaft. I haven't looked inside the casing of the motor, but it runs quite freely under no load. I saw an internet video which suggested that the capacitor is at fault. I took that off, and the motor still starts by hand and runs, so I will try a new capacitor.

It is a type CBB60 SH, 6.5uF (+/- 5% Class B, if that is relevant) 450V AC 50/60Hz.

I see on Lazada a lot of capacitors for fans, some rated at 6uF and 8uF. There are also some designated CBB60, seem to be for washing machines and the like. The nearest on offer is 6.3uF, then 8uF.

My two questions are:- 1) Will the 6.3uF work ok? 2) Is there any advantage or danger to fitting 8uF?

I have a very feeble grasp of matters electric, so simple explanations would be appreciated.

[xylophone]

The 6.3 uf will be fine IMO.

[Crossy]

6.3uF will be just fine, these devices are not tight tolerance anyway.

 

Any AC rated (i.e. motor) capacitor will do the job, take the old one to your local electrical emporium or hunt out something similar on Lazada.

 

[Eff1n2ret]

Thanks, chaps.

[OneMoreFarang]

48 minutes ago, Crossy said:

6.3uF will be just fine, these devices are not tight tolerance anyway.

 

Any AC rated (i.e. motor) capacitor will do the job, take the old one to your local electrical emporium or hunt out something similar on Lazada.

 

Just to make sure there is no misunderstanding: The capacitor must be rated for the correct voltage. In this case at least 450V.

 

[impulse]

When you buy the capacitor, buy a can of WD40 and spray down the center of the motor, making sure you soak the bearings on each end of the motor.  It'll drip and it will make a mess, so be ready with some paper towels underneath.  You can do the same with light oil, but you risk munging up the works with the grunge that's built up over the years.  WD40 flows out nicely, taking the chips with it.

 

Personally, I'd try the WD40 before I even went for the capacitor, but that's because I always have some laying around (along with duct tape).  Capacitors, not so much.

[Crossy]

16 minutes ago, OneMoreFarang said:

Just to make sure there is no misunderstanding: The capacitor must be rated for the correct voltage. In this case at least 450V.

 

 

And, AC rated, hence my saying a motor capacitor.

[sometimewoodworker]

19 hours ago, impulse said:

When you buy the capacitor, buy a can of WD40 and spray down the center of the motor, making sure you soak the bearings on each end of the motor. 

While it is quite possible that the WD40 may be a good way of cleaning out the gunk it will also dilute and wash out the grease packing the the bearings so if you take the advice make sure that the bearings get sufficient lubricants after that. It is also possible that, if you don’t use enough to completely wash out the bearings completely you may be adding a slurry of dust, muck and grease into the bearing races.

 

I would suggest compressed air as a better way to get stuff out.

[impulse]

1 hour ago, sometimewoodworker said:

While it is quite possible that the WD40 may be a good way of cleaning out the gunk it will also dilute and wash out the grease packing the the bearings so if you take the advice make sure that the bearings get sufficient lubricants after that. It is also possible that, if you don’t use enough to completely wash out the bearings completely you may be adding a slurry of dust, muck and grease into the bearing races.

 

I would suggest compressed air as a better way to get stuff out.

Obviously, do what you think is right. 

 

But my bet is that a lot more guys have a can of WD40 around the house than a compressor.  And it’s certainly cheaper to buy the WD40 than a compressor.  And spraying compressed air into the works just drives the mung (that’s what we call congealed, dusty grease) and corrosion deeper.

 

The most common problem with a drill press that’s been idle for too long is that the grease has lost its aromatics and congealed, along with some corrosion and dust that’s gotten into the mix.  WD40 will wash some of the grease away, but it also replaces the aromatics and the grease that’s left is renewed as a lubricant instead of a blob of thick wax.  That’s especially true if the bearings are sintered bronze, where the grease is actually in the pore space. 

 

And if it’s a ball bearing, I challenge anyone to remove all the grease with WD40 without soaking the bearing for an extended period.  You’ll remove some of the grease, but not the majority with a spray.  And the grease that remains will be a better lubricant than the dried up stuff.

 

The best solution is to take off the endplates, clean out the corrosion and mung and soak then re-lube the bearings properly.   But that’s quite a job.

 

Bottom line, if it moves and it shouldn’t, duct tape.  If it doesn’t move and it should, WD40.

[VocalNeal]

1 hour ago, sometimewoodworker said:

While it is quite possible that the WD40 may be a good way of cleaning out the gunk it will also dilute and wash out the grease packing the the bearings so if you take the advice make sure that the bearings get sufficient lubricants after that. It is also possible that, if you don’t use enough to completely wash out the bearings completely you may be adding a slurry of dust, muck and grease into the bearing races.

 

I would suggest compressed air as a better way to get stuff out.

 

One can buy cans of spray grease in any decent hardware or automotive store. Cans of "air duster" if not in any decent hardware or automotive store will be in PC or electronics stores.

Edited November 13, 2023 by VocalNeal

[Muhendis]

I also have starting problems with my drill press and with my lathe.

The lathe will start in the lower gears which suggests it's not a capacitor problem.

Maybe it could do with a strip down and clean problem is it worked fine in UK Could be an environment problem?

 

The drill press rarely starts unaided but, once again, it was fine in the UK. 

 

Perhaps an air conditioner?

[sometimewoodworker]

6 hours ago, impulse said:

But my bet is that a lot more guys have a can of WD40 around the house than a compressor.  And it’s certainly cheaper to buy the WD40 than a compressor.  And spraying compressed air into the works just drives the mung (that’s what we call congealed, dusty grease) and corrosion deeper.

While you may have a can or WD40 if it is the standard, rather than one of the more specialist versions, then is is not,and never was, designed as an effective lubricant. It certainly does give some small amount of lubricant but is not the product to use for the job. The very name tells you the job it was designed to do, it is a Water Dispersement, and the lubricant is a side effect not a primary purpose. 

[bluejets]

Yes, I'd tend to forget the WD40 also.

It's not going to help anything one bit, only cause a mess.

 

If the motor uses a centrifugal switch, this might require attention after all the years, however, leave well alone until the new cap is fitted.

If all ok then forget it.

You'll more than likely cause more damage than do any good trying to get to it so if it looks like it may need attention, take it to a good repair shop.

As above, forget the fan caps as they will not work.

 

Edited November 15, 2023 by bluejets