Drive Hub question

JPG · Post by **JPG** » Wed Jan 30, 2013 1:28 pm

IMHO the touting of the hub as a heat sink is over stated for two reasons.

1) Such wishful thinking is a very recent phenomenon. Nothing was mentioned 60 yrs ago about that.

2) I have never seen anything in print either.

The heat sink 'need' only comes up when a hot shaft is questioned.

The heat is generated by either bad bearings or poor alignment of the belts(s), more likely both.

Last but not least, do not touch shafts.

Some heat is to be expected with rubber running over steel pulleys.

The interior of the headstock itself gets quite 'warm' itself.

Much ado about 'normal'!:rolleyes:

A dust free motor will help more than a hub(greater air flow out the headstock).

dusty · Post by **dusty** » Wed Jan 30, 2013 2:24 pm

JPG40504 wrote:IMHO the touting of the hub as a heat sink is over stated for two reasons.

1) Such wishful thinking is a very recent phenomenon. Nothing was mentioned 60 yrs ago about that.

2) I have never seen anything in print either.

The heat sink 'need' only comes up when a hot shaft is questioned.

The heat is generated by either bad bearings or poor alignment of the belts(s), more likely both.

Last but not least, do not touch shafts.

Some heat is to be expected with rubber running over steel pulleys.

The interior of the headstock itself gets quite 'warm' itself.

Much ado about 'normal'!:rolleyes:

A dust free motor will help more than a hub(greater air flow out the headstock).

I don't know about 60 years ago but when I purchased my first Mark V I was told by the person (from Woodcraft) who came to the house to set it up that I should try to keep hubs attached to the shafts. He told me that doing so helped to dissipate the heat generated by the shafts (especially the drive shaft). I have, therefore, never run for an extended period of time without hubs being mounted.

JPG · Post by **JPG** » Wed Jan 30, 2013 2:37 pm

dusty wrote:I don't know about 60 years ago but when I purchased my first Mark V I was told by the person (from Woodcraft) who came to the house to set it up that I should try to keep hubs attached to the shafts. He told me that doing so helped to dissipate the heat generated by the shafts (especially the drive shaft). I have, therefore, never run for an extended period of time without hubs being mounted.

The person (from Monkey Ward) who came to my house 50 years ago did not.

Maybe the Magna American stuff runs cooler.

Naw!

Sorta like piddlin in de bath water to warm it methinks.

However I also have never run without them except when doing weird non-recommended anyway stuff.

P.S. If'n ya really need to heat sink the shaft, use an aluminum sanding disk. They have built in 'fan blades'!

peterm · Post by **peterm** » Wed Jan 30, 2013 3:47 pm

The first place I saw referring to hubs as heat sinks was here:
http://www.shopsmith.com/ownersite/prod ... e_1_10.pdf
The last page has a caution:
[ATTACH]20132[/ATTACH]
I knew I saw it somewhere and after browsing my collection of old SS docs on my computer for about an hour (a pleasant hour), finally tried Google, which found it in seconds!:o Since I leave the hub on all the time, I have no idea how "necessary" it is.

dusty · Post by **dusty** » Wed Jan 30, 2013 3:52 pm

Thanks, Peter. That makes it official. I'm going to leave the hubs in place just like I was told.

JPG · Post by **JPG** » Thu Jan 31, 2013 12:40 am

dusty wrote:Thanks, Peter. That makes it official. I'm going to leave the hubs in place just like I was told.

So am I(but not for cooling purposes).

I put this in the same category as some other pieces of 'wisdom' from SS Inc. that 'differs' from previous 'producers'.

I remain skeptical!;)

P.S. That verbage is not included in my 1986 vintage manual.

reible · Post by **reible** » Thu Jan 31, 2013 1:00 am

I keep mine on too but only cause it is a good place to keep them.

I have seen and heard the heat sink statement, I don't believe it is valid. If I was still working I'd bring home a data logger and some thermocouples and give it a test.

So by way of testing now a days it would be quite simple, non contact thermometer and a test plan. Run the machine 10 minutes with them on, measure/record, 10 minutes with them off, measure/record, 10 more minutes with them on etc for say a half hour or more. Present your result here and prove I'm wrong.

A word of warning I might just go get the $25 HF thermometer and check your results if I am shown to be wrong. That would just to keep you and me honest.

Ed