Motor sparking

[JimM]

Hi all

I've recently rebuilt an old Atlas lathe, it all seems to have gone back together pretty nicely the only issue I have is with the motor.

When you switch it on it makes a rumbling noise and you can see it sparking inside through the vent holes - after 10secs or so it usually settles down to a more normal hum and the sparking stops. Other times it keeps rumbling/ sparking.

It must be something to do with the motor being under load because if you run it without the drive belt connected it, settles down after a second or 2.

Any ideas of what the problem might be and how to fix it or should I just get a new motor

Cheers

Jim

 

[Pete.]

Is it a single-phase motor? If it is then the centrifugal switch might be sticking a bit or the contactors burned. Why not remove the back plate and take a look inside?

 

[madkayaker]

could be a centrifugal switch or a capacitor issue take the back off the motor and take a picture. try a tin of air dust on the contacts

 

[shenion]

Yes, could be the switch or a bad start winding.

Which Altas do you have?I recently picked up a 12x36". Nice machines.

 

[JimM]

Hi Shenion

I've got the 10F, first lathe I've ever used so can't really comment on what it's like. First time I used it was yesterday ! Got a decent result with a piece of aluminium but my steel turning is going to take a bit of practice I think !


pete / madkayaker thanks for the suggestions 'll try and get the back of the motor later and have a look inside

Cheers

Jim

 

[rtbcomp]

Is it an induction motor or one with a commutator and brushes? (ie universal motor or an ancient repulsion motor)

 

[madkayaker]

could be mucky commutator good idea

 

[eil]

If its been standing a while try and run it with no load for a couple of hours to dry itself off, then try to swich it off and on a couple of times still with no load before hooking it up just to see if it will behave before taking it apart.

 

[shenion]

JimM, does it "click" and then stop sparking, you should also hear a similar click when it spins down.

That would be the centrifugal switch turning on/off. The switch could be cleaned. I would just find another motor off ebay. I picked up a relatively new 1/3HP for my 109 for $50. The old motor might have cracked insulation.

My 12x36 atlas has an old motor that shakes. The rotor is way out of balance. Been looking for a replacement.

If you haven't already, check out the atlas craftsman lathe yahoo group. Lots of good info there

 

[JimM]

Thanks for the info guys, had a look at the motor and to get inside it looks like a right pig of a job. The vent plates come off but the covers are held on by through rods front to back - think I'll just hunt out a replacement on the bay

Shenion - that's for the pointer, I'm already a member of the Atlas group - currently have query about spindle pulley axial movement if you have any ideas

Cheers

Jim

 

[madkayaker]

live with it a bit it might settle down.

 

[shenion]

JimM, post some pics of the 10F, I have never seen one. I hear they are almost the same as my 12x36.

Did reply to your spindle post on the atlas/craftsman group.

 

[Weldingartisan]

My pillar drill used to have a sticky centrifugal switch, used to start it by flicking the belt....... till I caught my finger OUCH!, then I took the end cap off the motor cleaned it, polished the contacts and hey presto W/A

 

[JimM]

Hi guys

Today I managed to source not 1 but 2 different motors, they're both rated at 1425 rpm but I'm not sure if one would be more suitable than the other.

The spec plates read

Motor 1
The British Thomson Houston Co
Type BKS 2408
HP 1/4
RPM 1425
Volts 200/210 (will this even work with 240v ??)
Cycles 50 Phase 1
Rating Continuous
Cat No D8722


Motor 2
Electromotors Ltd
Type BS2210
Ph 1 A 4.2
Hz 50 Wo 370
RPM 1425
Inc C1 b BS Frame B56Z
Rtg Int
Cat No D?2834

Not sure if a pic will help but they look like this



Apparently motor 1 is a 4 pole but don't know about motor 2.

Any suggestions of which would be the better for running the lathe or is there not a lot in it

Cheers

Jim

 

[Hitch]

Ive got one in my garage that looks identicle to the left one, its an ond Metropolitan Vickers... they merged with BTHco in 1928 (wikipedia)

I think our motors are antique!!

 

[rtbcomp]

I had a British thomson Houston Motor on my Skip Compressor http://www.mig-welding.co.uk/forum/showthread.php?t=8692 It was a "Repulsion Motor" it had a commutator but was nevertheless an induction motor!

I offerred it to a museum but they didn't want it.

I'd use the newer one, the insulation on the older one may be getting a bit iffy!

 

[shenion]

Motor 1 says continuous duty while 2 is intermittent. Both look to be 4-pole as they are 1425 RPM.

I'd check the wiring. The one on my lathe has cloth covered wire so I am preplacing it rather than rewire it (it has other problems.)

I'd b tempted to try the second as it is bigger and probably 1/2 HP. The first at 1/4HP is probably a bit small for a lathe but given its age, it probably is underrated by todays standards.