Workshop Pillar Drill seems to have packed up!!

[xeitosaphil]

I have a 240v single phase bench type pillar drill, and I am in the middle of a project drilling stainless steel. It has suddenly started to run slow when first started up, and I wondered if this could be a capacitor problem?

The drill itself is an aged Tull Chinese type DIY drill ( I know its cheap ), but it has worked fine with light use for many years without any trouble and completed many small projects.
I have tried to look online for a replacement capacitor, should I need one, but seem unable to find one the same spec?

The original one is a CBB25 7Hf + or - 5%, 350Vac 50Hz, two soldered terminal cylinder type. The motor itself is a 1/4hp 1.23Amp @1330rpm 220v-50hz single phase. ( all info taken off the sides of the original parts)

If it is the capacitor and I do need one, does anybody have any suggestions where I might get one that would be suitable. Have tried Maplins as they do one which is 8Hf but they say it would not be suitable?

Would a replacement capacitor have to be exactly the same spec, or are there some tolerances which might be acceptable? I have read (rightly or wrongly) that the voltage can be exceeded as they are Max rated, but what about the Capacitance value ?

As you can probably tell electrics/electronics is not my strong point.

Any advice would be most welcome, as I need to finish the project in hand.


Cheers Philip

 

[Vegable]

All the capacitor is doing is suppressing the arcs and sparks created by the motor so that you and your neighbours can still watch tv and listen to the radio without crackling. The drill will still run happily without it.
I suggest that the drive belt is slipping which is why it gets under way. You'll also find if you drill heavier stuff that the drill will slow down. So, either you've not tightend the drive belt or it has stretched and you need a new one. If you look on the side of the drive belt you'll see it's type and dimentions.
Mike

 

[earlybird]

Certainly check for belt slip as suggested. However, most pillar drills will have an induction type motor, which, depending on type, may require a capacitor to run properly, and maybe to start. Also, unlike brush type motors, a healthy induction motor won't slow down significantly under load, just a few % as it slips from synchronous speed. If it does slow considerably under load then the next stage will be burn-out!

 

[dylanwinter]

whenever my drills pack up it is the brushes -although they tend to be an all or nothing thing

ebay can often supply them

D

 

[VicS]

All the capacitor is doing is suppressing the arcs and sparks created by the motor so that you and your neighbours can still watch tv and listen to the radio without crackling. The drill will still run happily without it.
I suggest that the drive belt is slipping which is why it gets under way. You'll also find if you drill heavier stuff that the drill will slow down. So, either you've not tightend the drive belt or it has stretched and you need a new one. If you look on the side of the drive belt you'll see it's type and dimentions.
Mike

Only if its motor with a wound rotor with brushes and a commutator.

Isnt it more likely to be the capacitor that produces a phase shift to start an induction or squirrel cage (q,v,) motor The RPM suggests it is that type of motor

Like this which is the spare 1/2 hp motor for my lathe

 

[VicS]

I have a 240v single phase bench type pillar drill, and I am in the middle of a project drilling stainless steel. It has suddenly started to run slow when first started up, and I wondered if this could be a capacitor problem?

The drill itself is an aged Tull Chinese type DIY drill ( I know its cheap ), but it has worked fine with light use for many years without any trouble and completed many small projects.
I have tried to look online for a replacement capacitor, should I need one, but seem unable to find one the same spec?

The original one is a CBB25 7Hf + or - 5%, 350Vac 50Hz, two soldered terminal cylinder type. The motor itself is a 1/4hp 1.23Amp @1330rpm 220v-50hz single phase. ( all info taken off the sides of the original parts)

If it is the capacitor and I do need one, does anybody have any suggestions where I might get one that would be suitable. Have tried Maplins as they do one which is 8Hf but they say it would not be suitable?

Would a replacement capacitor have to be exactly the same spec, or are there some tolerances which might be acceptable? I have read (rightly or wrongly) that the voltage can be exceeded as they are Max rated, but what about the Capacitance value ?

As you can probably tell electrics/electronics is not my strong point.

Any advice would be most welcome, as I need to finish the project in hand.


Cheers Philip

Google "motor starting capacitors" or "motor run capacitors" if you think my post above sound right.

Id have though 8Hf one will be OK if the other details are OK ( No idea what capacity the one on my motor is.) but I dont think the capacitor is your trouble. I fear the motor is cream crackered but I'm not an electrical engineer!


but HF??? dont you mean μF ?

Hopefully an electrical engineer will be along soon.

 

[xeitosaphil]

All the capacitor is doing is suppressing the arcs and sparks created by the motor so that you and your neighbours can still watch tv and listen to the radio without crackling. The drill will still run happily without it.
I suggest that the drive belt is slipping which is why it gets under way. You'll also find if you drill heavier stuff that the drill will slow down. So, either you've not tightend the drive belt or it has stretched and you need a new one. If you look on the side of the drive belt you'll see it's type and dimentions.
Mike

Hi Mike

Sorry I don't wish to seem to be ungrateful for your reply , but are you sure you have that right?

Wiki tends to suggest differently https://en.wikipedia.org/wiki/Motor_capacitor

It is possible according to this link, that mine may be a run capacitor and the values seem to be quite close as well , but of course I might be completely wrong.



Are you sure you are not getting mixed up with a interference suppressor?


Philip

 

[VicS]

Hi Mike

Sorry I don't wish to seem to be ungrateful for your reply , but are you sure you have that right?

Wiki tends to suggest differently https://en.wikipedia.org/wiki/Motor_capacitor

It is possible according to this link, that mine may be a run capacitor and the values seem to be quite close as well , but of course I might be completely wrong.



Are you sure you are not getting mixed up with a interference suppressor?


Philip

Read mt posts above! #5 an #6

 

[xeitosaphil]

Google "motor starting capacitors" or "motor run capacitors" if you think my post above sound right.

Id have though 8Hf one will be OK if the other details are OK ( No idea what capacity the one on my motor is.) but I dont think the capacitor is your trouble. I fear the motor is cream crackered but I'm not an electrical engineer!


but HF??? dont you mean μF ?

Hopefully an electrical engineer will be along soon.

Hi Vic,

I was so long replying to mike I didn't get to read your post until now. Yes I think it as you say either a start or run capacitor.
I asked Maplins for the rating of their 8HF but they couldn't tell me what it was? I don't know if it will make any difference or if capacitors are actually rated for different loads?

" but HF??? dont you mean μF ? "

You are absolutely right about the above, but I couldn't find the correct symbol on my key board and H was the closest I could find.

I was hoping it might be the capacitor, and not sure if I can test it with my electrical tester because if I need to get the motor tested, by the time they have done that, it will probably be half the cost of a complete new machine. I did think of maybe a ebay s/h motor but that might be no better?

 

[Champagne Murphy]

Just had the same thing yesterday! Motor slowed for quite some while, then stopped. Turned out to be a fuse blowing slowly. Never had that before.

 

[lw395]

I had a cheap Chinese pillar drill with almost exactly these symptoms due to the capacitor failing.
I was able to measure the capacitance as I have a suitable meter, it had dropped by about 90% IIRC.
I bought a new capacitor on ebay for a few pounds.
I would suggest getting as close as possible to the original value, try searching ebay for '7 microfarad' or similar. 6 or 8 would probably be fine though.
microfarad is muF sometimes written uF when on a limited keyboard.
I would get one sold as a motor capacitor, as similar as poss to the original. They handle a fair bit of current, a cap intended for say a power supply might have the voltage rating but not do the job.

 

[xeitosaphil]

Just had the same thing yesterday! Motor slowed for quite some while, then stopped. Turned out to be a fuse blowing slowly. Never had that before.

Will keep that in mind, but mine starts and runs but just quite slowly with no torque.

Thinking about it now, it might not be the capacitor if that's the case, perhaps I should look around for another motor or complete machine?

Just seems a waste, everything else is ok.

 

[VicS]

Hi Vic,

I was so long replying to mike I didn't get to read your post until now. Yes I think it as you say either a start or run capacitor.
I asked Maplins for the rating of their 8HF but they couldn't tell me what it was? I don't know if it will make any difference or if capacitors are actually rated for different loads?

" but HF??? dont you mean μF ? "

You are absolutely right about the above, but I couldn't find the correct symbol on my key board and H was the closest I could find.

I was hoping it might be the capacitor, and not sure if I can test it with my electrical tester because if I need to get the motor tested, by the time they have done that, it will probably be half the cost of a complete new machine. I did think of maybe a ebay s/h motor but that might be no better?

It'll be the 350V rating that will be important. A lower rated one will probably go bang!

If its just a starting capacitor you might be able to test the motor without the capacitor by spinning it with cord round the pulley and quickly closing the switch. but be careful.
When we first had the lathe the pictured motor was on it minus the capacitor. We used to start the lathe like that until we got the capacitor ( I don't know why we swapped to a different moto.) The one that's on there is a more recent acquisition)

(μ is in the character map)

 

[Vegable]

Hi Mike

Sorry I don't wish to seem to be ungrateful for your reply , but are you sure you have that right?

Wiki tends to suggest differently https://en.wikipedia.org/wiki/Motor_capacitor

It is possible according to this link, that mine may be a run capacitor and the values seem to be quite close as well , but of course I might be completely wrong.



Are you sure you are not getting mixed up with a interference suppressor?


Philip

Ah! Hmmm! I stand corrected. I've never heard of starter capacitors so I assumed! I should realise by now never to assume. Vic is most likely dead right. Apologies.
Retires to back of the shed muttering......
Mike

 

[Alfie168]

In case of failure to fix Lidl have a pillar drill on offer shortly for £50. Being branded Parkside it should have a three year guarantee, Chinese cheapie though it undoubtedly is....but I'd double check on that guarantee in case I'm wrong.

Tim

 

[rogerthebodger]

I have a 240v single phase bench type pillar drill, and I am in the middle of a project drilling stainless steel. It has suddenly started to run slow when first started up, and I wondered if this could be a capacitor problem?

The drill itself is an aged Tull Chinese type DIY drill ( I know its cheap ), but it has worked fine with light use for many years without any trouble and completed many small projects.
I have tried to look online for a replacement capacitor, should I need one, but seem unable to find one the same spec?

The original one is a CBB25 7Hf + or - 5%, 350Vac 50Hz, two soldered terminal cylinder type. The motor itself is a 1/4hp 1.23Amp @1330rpm 220v-50hz single phase. ( all info taken off the sides of the original parts)

If it is the capacitor and I do need one, does anybody have any suggestions where I might get one that would be suitable. Have tried Maplins as they do one which is 8Hf but they say it would not be suitable?

Would a replacement capacitor have to be exactly the same spec, or are there some tolerances which might be acceptable? I have read (rightly or wrongly) that the voltage can be exceeded as they are Max rated, but what about the Capacitance value ?

As you can probably tell electrics/electronics is not my strong point.

Any advice would be most welcome, as I need to finish the project in hand.


Cheers Philip

I would take the opportunity to up the power of the motor. I did this and it made all the difference to work speed and stopped damaging drills due to the machine stalling.

 

[GraemeS]

I have a 240v single phase bench type pillar drill, and I am in the middle of a project drilling stainless steel. It has suddenly started to run slow when first started up, and I wondered if this could be a capacitor problem?

The drill itself is an aged Tull Chinese type DIY drill ( I know its cheap ), but it has worked fine with light use for many years without any trouble and completed many small projects.
I have tried to look online for a replacement capacitor, should I need one, but seem unable to find one the same spec?

The original one is a CBB25 7Hf + or - 5%, 350Vac 50Hz, two soldered terminal cylinder type. The motor itself is a 1/4hp 1.23Amp @1330rpm 220v-50hz single phase. ( all info taken off the sides of the original parts)

If it is the capacitor and I do need one, does anybody have any suggestions where I might get one that would be suitable. Have tried Maplins as they do one which is 8Hf but they say it would not be suitable?

Would a replacement capacitor have to be exactly the same spec, or are there some tolerances which might be acceptable? I have read (rightly or wrongly) that the voltage can be exceeded as they are Max rated, but what about the Capacitance value ?

As you can probably tell electrics/electronics is not my strong point.

Any advice would be most welcome, as I need to finish the project in hand.


Cheers Philip

Your capacitor is almost certainly a run cap. 7μF is very low for a start cap. Usually the run caps would be rated at 450v in this country however being that yours is eastern anything is possible. If it is a run cap if there is no switch in the motor. I'd haply send you a 6 or 8μF FOC if you send me your details and you can try it.

Normally if the motor is partially burnt out it will run very hot and an acrid smell will be smelt if you open the terminal box. If the start and run windings have shorted the motor sometimes will try and start in either direction. So, not with standing testing it properly with meter and mega and the motor is running a bit slow it might well be worth trying a new cap.

Let me know if you want a cap.

Regards Graeme (Motor Rewinds is the game)

 

[xeitosaphil]

Your capacitor is almost certainly a run cap. 7μF is very low for a start cap. Usually the run caps would be rated at 450v in this country however being that yours is eastern anything is possible. If it is a run cap if there is no switch in the motor. I'd haply send you a 6 or 8μF FOC if you send me your details and you can try it.

Normally if the motor is partially burnt out it will run very hot and an acrid smell will be smelt if you open the terminal box. If the start and run windings have shorted the motor sometimes will try and start in either direction. So, not with standing testing it properly with meter and mega and the motor is running a bit slow it might well be worth trying a new cap.

Let me know if you want a cap.

Regards Graeme (Motor Rewinds is the game)

Your offer of the two capacitors to try is very generous thanks Graeme,

PM sent

Philip

 

[William_H]

I would start by checking if the motor runs at proper speed with the belt disconnected. If it still runs slow check that it spins by hand easily. It is possible that it is a bearing problem in either the motor or the drill spindle bearings. As said if it is a start capacitor that is bad then the motor (drill) can be started by manually spinning the drill and it will spin up to speed.
I am not at all familiar with a run capacitor but anything is likely. Induction motors I have come across only use a capacitor for starting.
Some induction motors have a centrifigal operated switch on one end of the shaft that switches out the start capacitor or start winding and conceivably if yours has one and the switch is shorted it could give similar effects.
Or perhaps it is just a bad "run capacitor". good luck olewill

 

[Lon nan Gruagach]

http://www.maplin.co.uk/p/8f-440v-motor-run-capacitor-rg64u is perfect replacement for the cap. The shop staff got it wrong. And at £4-99 a pop (maybe the wrong word) whats to lose?