Air Pressure

tkhudson · Post by **tkhudson** » Sat Feb 06, 2010 1:29 pm

Had a wild idea this morning :
What would be the downfall on running a small air line to the headstock for purposes of creating positive pressure as a means of expelling dust and or preventing it from entering, due to air pressure that is exiting . Im thinking maybe 4 or 5 PSI.

Any thoughts?

robinson46176 · Post by **robinson46176** » Sat Feb 06, 2010 1:54 pm

tkhudson wrote:Had a wild idea this morning :
What would be the downfall on running a small air line to the headstock for purposes of creating positive pressure as a means of expelling dust and or preventing it from entering, due to air pressure that is exiting . Im thinking maybe 4 or 5 PSI.

Any thoughts?

Somewhere is a thread where I discussed the possibility of mounting a small blower with a small air cleaner element attached to it to the headstock to do just that and to keep the ambient temperature of the whole headstock down.
I just haven't gotten around to trying it yet. I personally think it would be a good move. I considered the air line but that is something else (hose) to mess with. plus the air compressor would run a lot. I think pressurizing the headstock would keep a lot of dust out.

beeg · Post by **beeg** » Sat Feb 06, 2010 1:58 pm

Sounds like a good idea. BUT my only thought is ya might be messing with the engineered airflow then?

a1gutterman · Post by **a1gutterman** » Sat Feb 06, 2010 2:16 pm

beeg wrote:Sounds like a good idea. BUT my only thought is ya might be messing with the engineered airflow then?

You really think that the air flow was engineered?

I am doubtful...
tkhudson, while I think it is a worthwhile idea, the airline might be a bit cumbersome.

tkhudson · Post by **tkhudson** » Sat Feb 06, 2010 2:27 pm

Im thinking probably no more than a 1/4 " tube going in with some quick connects of course should do the trick. I dont think it will really impact the compressor at less than 5 psi. I will give it a go once I get "the Green Money Pit" all assembled and copacetic

JPG · Post by **JPG** » Sat Feb 06, 2010 2:55 pm

a1gutterman wrote:You really think that the air flow was engineered? I am doubtful...
tkhudson, while I think it is a worthwhile idea, the airline might be a bit cumbersome.

I do not think the perforated sn plate, the 'fan' sheave and the motor pan vent were a freak of nature. They were 'engineered' with heat transfer in mind. Methinks the flow is in the vent plate, through the sheave area, down to the motor and fan sheave and out the bottom vent.

A 'simple' improvement would be to put a 'fan blade' on the middle shaft blowing into the vent plate(or use that large hole as a fan shroud). I believe the small holes in the vent/sn plate are to restrict the particle size of 'dust/debris'.

This would be 'automatic'(blows only while running).

tkhudson · Post by **tkhudson** » Sat Feb 06, 2010 5:34 pm

JPG40504 wrote:I do not think the perforated sn plate, the 'fan' sheave and the motor pan vent were a freak of nature. They were 'engineered' with heat transfer in mind. Methinks the flow is in the vent plate, through the sheave area, down to the motor and fan sheave and out the bottom vent.

A 'simple' improvement would be to put a 'fan blade' on the middle shaft blowing into the vent plate(or use that large hole as a fan shroud). I believe the small holes in the vent/sn plate are to restrict the particle size of 'dust/debris'.

This would be 'automatic'(blows only while running).

Sounds a little more sophisticated than my idea, but I like it. an old computer fan, a relay and a transformer. BUT if you are blowing air INTO the vent place FROM your dusty environment, you will need to pre-filter the air as well.

michaeltoc · Post by **michaeltoc** » Sat Feb 06, 2010 7:42 pm

It would probably work, but compressed air contains a lot of water vapor so you must use an air dryer.

Michael

charlese · Post by **charlese** » Sat Feb 06, 2010 8:10 pm

Can anyone tell us they have found accumulations of sawdust inside their headstocks? Since I've never found any, I am wondering why this concern exists.

robinson46176 · Post by **robinson46176** » Sat Feb 06, 2010 9:08 pm

charlese wrote:Can anyone tell us they have found accumulations of sawdust inside their headstocks? Since I've never found any, I am wondering why this concern exists.

Hi Chuck:
You are right, sawdust does not normally "accumulate" in the headstock in any quantity. Normally even up in drillpress mode if any accumulates it falls out the lower slot when lowered back down to horizontal. Even though it seldom accumulates any quantity the fine dust entering the headstock can mess up the centrifugal starting switch and can also build up in the motor as well as gumming up the speed control. I had considered slightly pressurizing the headstock with filtered air when I first started thinking about building a dedicated Shopsmith drillpress.
A vacuum port wouldn't be right because it would pull sawdust through the headstock and it would be impossible to filter all of the entry ports. Under slight pressure all openings would be exits and zero dust can enter. The unit I have planned will just be wired into the SS switch. The blower draw is quite minimal.
It should also lower headstock operating temperatures a little.