Power Pro headstock cooling

[edma194]

And a question: I went the DIY route, so my motor pan has a number of holes with no obvious utility, other than improved convection cooling. I'm wondering if those holes are present on the 'new headstock' version PPs. Specifically, I'm talking about the motor vent from the AC motor, the motor mounting holes, and the original power cord hole. If some, but not all, are present, please specify. Thanks.

- David

I have a couple of screw holes open in the motor pan from my conversion of a Greenie headstock. Oddly, there was a Goldie motor pan on it, but a motor replacement had been done in that headstock by someone.

In the belt cover there is the perforated nameplate, those holes probably get clogged quite easily.

The PowerPro motor incorporates a fan directing air mainly straight back from the motor. I think a vent is needed directly behind the motor so the hot air is getting out. Additional forced air through the access hole is a great idea, if you have an access hole, not cutting one was a mistake on my part. Maybe it's possible to remove the nameplate on the belt cover and mount a fan blade and housing on the aux spindle blowing air in to maintain overall positive pressure.

I don't see running this thing at high speed for long periods of time though. I think an outlet in the belt cover behind the motor will be a good start though. I could just drill a lot of holes for that, possibly adding a shroud to help direct the motor fan output.

[DLB]

The main reason I asked that: While it's not a forced-air cooled design like the conventional headstock, the PowerPro fan will cause some air movement in and out of the headstock. My assessment is that the primary air 'inlet' is the hole where the cord entered the motor pan prior to the upgrade. But, I would think it is unlikely that a new Mark 7 or new PowerPro headstock includes that hole. Similar comment for the other motor pan holes, each of which has a use unique to the conventional motor.

- David

[edma194]

The main reason I asked that: While it's not a forced-air cooled design like the conventional headstock, the PowerPro fan will cause some air movement in and out of the headstock. My assessment is that the primary air 'inlet' is the hole where the cord entered the motor pan prior to the upgrade. But, I would think it is unlikely that a new Mark 7 or new PowerPro headstock includes that hole. Similar comment for the other motor pan holes, each of which has a use unique to the conventional motor.

- David

In addition to those holes, and the belt cover vent and gaps around the spindles, the way tubes have thin spaces for incoming air at 4 places. I think these are very susceptible to picking up dust, so positive pressure would be a great benefit and turn all those holes into outlets.

I've never met a factory made PowerPro so now you have me wondering if those have additional inlet or outlet holes.

[stephen_a._draper]

I received this response from Sue Powell at Shopsmith yesterday in response to my machine shutting down after 20 minutes running at 10,000 RPM.

"Working the machine too long and too hard the machine will lose power as it starts to overheat to protect itself. Then it will completely shut off.
Below is the running times before overheating.
Shaping and routing 20 to 30 minmax
Sawing,Planing and Jointer 1 hour max.
Heavy turning, stock removal, heavy cuts 1 hr.
Let machine cool down. Remove belt cover, open access plate to allow air to circulate.
  Let cool down overnight.  
 
 
The speed of the power pro many vary up to 10% of the speed setting."

[HopefulSSer]

So worst case run it 20 minutes then it has to cool overnight? Pretty poor duty cycle...

[DLB]

I received this response from Sue Powell at Shopsmith yesterday in response to my machine shutting down after 20 minutes running at 10,000 RPM.

"Working the machine too long and too hard the machine will lose power as it starts to overheat to protect itself. Then it will completely shut off.
Below is the running times before overheating.
Shaping and routing 20 to 30 minmax
Sawing,Planing and Jointer 1 hour max.
Heavy turning, stock removal, heavy cuts 1 hr.
Let machine cool down. Remove belt cover, open access plate to allow air to circulate.
  Let cool down overnight.  
 
 
The speed of the power pro many vary up to 10% of the speed setting."

Your machine appears to be a Gen 2, is that correct? If yes, did it shut down by triggering the thermal disconnect (unique to Gen 2) which removes all power? Or did it auto detect a hot condition at the heat sink, give you an over-temp message, and maybe slow down to reduce thermal load (common, IIUC, between generations)? I presume we can tell the difference depending on whether the display goes blank when the over-temp occurs.

IMO running the machine as a router or a shaper for 20 minutes should be considered neither too hard nor too long. That's not very long for operations where you may have a stack of material and be making multiple passes since numerous cutters recommend a 1/8" max depth of cut. But I understand the limitation and don't use the PowerPro for these operations.

- David

[stephen_a._draper]

It auto detected a hot condition at the heat sink, slowed down gradually until it stopped. Display was still lit and power still on. Jim McCann also sent me this response:

"This is normal for this fully enclosed Headstock with the more powerful, higher rpm PowerPro motor.
We feel most project components can be completed within this timeframe that Customer Service sent you."

"Sue Powell just told me you called her and left a message asking if the belt could be too tight, causing the machine to heat up and shut down after 15-minutes.
The answer is yes, the belt could be too tight… BUT loosening the belt will only get you an additional 5-minutes or so at 10,000 rpm… even at no-load.
Too loose a belt will cause the belt to slip at lower speeds.
I’m sorry that this is not the answer you are looking for, but this is one of the limits of capabilities with this machine. Everything has limits.

Jim McCann
Engineering, Quality & Customer Repair
Shopsmith LP"

[jsburger]

I know this is not what we want to hear. However, it does appear that Customer Service is talking internally to the right people to get the correct answer and not just winging it. That is a good thing.

[stephen_a._draper]

I view all of this as a POSITIVE CHANGE. Nick Cupps is making good progress in changing how Shopsmith operates. He is forthright and honest in dealing directly with issues that need to be addressed. The previous ownership was not willing to do that. Having current accurate information is essential for owners to make good decisions on how to best use their Shopsmith for a project. No machine can do everything, and I am glad for all of the things the Shopsmith PowerPro can do that the conventional AC motor cannot. Shopsmith is a Woodworking System, not just a tool. There is no other Woodworking System out there that can compare in terms of both versatility and accuracy for the money you spend.

[JPG]

Particularly the versatility thing!