PM940 Spindle

[fritts]

Recently tore down my spindle on the PM940 to do a belt drive retrofit. Running at 3200 rpm was unbearably loud plus I was wanting to check bearing preload and condition after a maybe 20 hrs of runtime. I was appalled by how much foreign material was in the lube. From small machining chips, rtv chunks, paint and other what appears to be sand from the casting process. The spindle I tore down was not much better. Plenty of debris in the upper and lower taper roller bearing. Most from the inside of the spindle where the casting slag was not removed. The spindle nut was loose which may have attributed to my surface finish defects. The grease had coagulated as well. Bearings to my surprise appear to be ok after cleaning. I removed as much scale as I could from interior of the spindle and then sealed the surface. I repacked bearings with Kluber grease and reset the spindle nut torque. Will have to check temps as it is slightly tighter than before. Hoping to have all my hub adapters and plates done by next week to get it run in. In hindsight though I highly suggest people review the spindle/gearbox sooner than later in case of damage.

On other item is I really would like to get a BT30 spindle. The current spindle is a 75mm diameter setup. I have gotten a quote from KAMI in Germany for the 75mm BT30 spindle in the FKM350. All appearance seem to be that this FKM350 mill is the same gearbox setup as the PM940. Anyone tried this spindle? I was quoted $230 shipped which I think is very reasonable but don't know the quality to know for sure. Also anyone else interested in one of these spindles? I believe they are the same ones that MTW has brought in before?

Thanks
Ryan

 

[cut2cut]

I too experienced the horror of debris in the "stock" PM940 spindle. I soon replaced the bearings with higher rated ones and converted to a belt drive ( my gears were noisy straight away ). But ultimately I've made my own head and installed a chinese belt driven BT30 spindle as well as a high speed ATC spindle motor ( BT30 as well ). If I had found a drop in replacement spindle, as you have, I'd surely have tried it, at that price especially. I hope you can update everyone on it, very cool if it drops right in and has decent runout. What rpm is it rated for ?

Cheers,

Jake

 

[7milesup]

Recently tore down my spindle on the PM940 to do a belt drive retrofit. Running at 3200 rpm was unbearably loud plus I was wanting to check bearing preload and condition after a maybe 20 hrs of runtime. I was appalled by how much foreign material was in the lube. From small machining chips, rtv chunks, paint and other what appears to be sand from the casting process. The spindle I tore down was not much better. Plenty of debris in the upper and lower taper roller bearing. Most from the inside of the spindle where the casting slag was not removed. The spindle nut was loose which may have attributed to my surface finish defects. The grease had coagulated as well. Bearings to my surprise appear to be ok after cleaning. I removed as much scale as I could from interior of the spindle and then sealed the surface. I repacked bearings with Kluber grease and reset the spindle nut torque. Will have to check temps as it is slightly tighter than before. Hoping to have all my hub adapters and plates done by next week to get it run in. In hindsight though I highly suggest people review the spindle/gearbox sooner than later in case of damage.

On other item is I really would like to get a BT30 spindle. The current spindle is a 75mm diameter setup. I have gotten a quote from KAMI in Germany for the 75mm BT30 spindle in the FKM350. All appearance seem to be that this FKM350 mill is the same gearbox setup as the PM940. Anyone tried this spindle? I was quoted $230 shipped which I think is very reasonable but don't know the quality to know for sure. Also anyone else interested in one of these spindles? I believe they are the same ones that MTW has brought in before?

Thanks
Ryan

Hi Ryan.
Could you put links to the equipment or suppliers you are referencing. I have an 833T mill and am looking to convert to CNC. I have no idea who KAMI from Germany is, and my google search turned up basically nothing.
Thanks.

 

[fritts]

Kami Machine Tools. What I believe to be the PM940 clone the FKM 350 is here.

KAMI Werkzeugmaschinen

KAMI Maschinen - Ihr Partner für Industrie, Handwerk und Hobby.

www.kami-maschinen.de

 

[fritts]

I too experienced the horror of debris in the "stock" PM940 spindle. I soon replaced the bearings with higher rated ones and converted to a belt drive ( my gears were noisy straight away ). But ultimately I've made my own head and installed a chinese belt driven BT30 spindle as well as a high speed ATC spindle motor ( BT30 as well ). If I had found a drop in replacement spindle, as you have, I'd surely have tried it, at that price especially. I hope you can update everyone on it, very cool if it drops right in and has decent runout. What rpm is it rated for ?

Cheers,

Jake

I'm assuming its the same rating as the stock PM940. Which means move to AC bearing or repack tapers for max 5k.

 

[Janderso]

That's ridiculous.
Most hobby guys who buy these lathes don't have the desire or know how to tear into a spindle to replace the bearings.
I can understand the need after hearing the story about chips, sand from the casting, paint etc. =no excuse.
I guess the Precision Mathews products made in Taiwan are assembled with more care. I know they have better quality bearings.
It seems many of us replace bearings in the headstock way before they should be needed on these Asian lathes.
My 50 year old Clausing Colchester has the original bearings.
I bet many of you have older lathes with the original bearings.

 

[Jim F]

That's ridiculous.
Most hobby guys who buy these lathes don't have the desire or know how to tear into a spindle to replace the bearings.
I can understand the need after hearing the story about chips, sand from the casting, paint etc. =no excuse.
I guess the Precision Mathews products made in Taiwan are assembled with more care. I know they have better quality bearings.
It seems many of us replace bearings in the headstock way before they should be needed on these Asian lathes.
My 50 year old Clausing Colchester has the original bearings.
I bet many of you have older lathes with the original bearings.

I have a SB9, so no bearings, but the full stack of shims are in the clamps and I have no movement on the spindle.
Lathe was made in 1947.

 

[Janderso]

That's ridiculous.
Most hobby guys who buy these lathes don't have the desire or know how to tear into a spindle to replace the bearings.
I can understand the need after hearing the story about chips, sand from the casting, paint etc. =no excuse.
I guess the Precision Mathews products made in Taiwan are assembled with more care. I know they have better quality bearings.
It seems many of us replace bearings in the headstock way before they should be needed on these Asian lathes.
My 50 year old Clausing Colchester has the original bearings.
I bet many of you have older lathes with the original bearings.

I have a SB9, so no bearings, but the full stack of shims are in the clamps and I have no movement on the spindle.
Lathe was made in 1947.

My 1941 South Bend 13 had cast iron bearings with several shims remaining.
I think that's a testament to quality.

 

[fritts]

PM940 is a mill not a lathe. I have no experience with PMs lathes.

 

[Jim F]

PM940 is a mill not a lathe. I have no experience with PMs lathes.

Does not matter, it is a quality thing, I doubt a SB mill or shaper from that time frame would be any different.