Power Pro headstock cooling

[reible]

Heat is a major killer of electronics. I have already lost a power supply. It would seem to me that drawing more air through the Headstock with a regular "blow out" maintenance regimen is far better than than burning up $500 power supplies and controllers. I am going to look into this. I get overheat errors when routing/shaping constantly. With SS not protecting the customer from the internal failures of these units beyond 2 years, a little extra maintenance is worth doing.

JMHO

It is too bad we don't really know the issue of what happened to your power supply, was it heat related or??? There can and are a lot of reasons for power supply failure. As an example early on in the PC days we were having power supply failures regularly. Once we dug into the issues we found that almost all of them had to do with large components that were solder in place with no mechanical support. The repairs were a matter of securing the part and re-soldering. Was there heat present, yes, was the failure totally due to the heat, no. Like wise the power supply in the powerpro may have some like issues and just providing added cooling will not solve them.

It is unlikely that one can simply blow the dust away from all the places it might collect while in use and who knows where it goes once you add a fan.

This is really a lot more complex an issue then most people are aware. Back in my working days we did a lot of modeling and testing of electronics. The preference was to use natural flow when possible but when the heat density got too high we had to resort to added air flow and trying to do circuit board layouts to allow the air to move with out stagnate areas over heat sources.

I have no idea what powerpro parts are likely to fail but capacitors are always a high failure item. Getting high temp rated caps were always an issue back in the day, no idea how it is now. If you have a heat source that feeds the heat to the cap and it is on the eddies of that part with a fan blowing things could get worse.

Just adding a fan is unlikely going to be the golden egg solution.

I have to admit I do very little routing on the powerpro or shopsmith for that matter. I have plenty of routers to use and do. For me the whole top end is a waste, if they were to offer a 100 rpm to 8,000 rpm I would have preferred it. I did do some routing today on the shopsmith, but only at low speed which worked fine, and I only did it that time due to a reuse of the setup I had from a drilling operation.....

If you are a heavy router user it would seem a lot cheaper to buy a couple of routers then worry about running the shopsmith at high speed if you are worried about repair costs to the shopsmith. I know shopsmith decided to market it as a router but if anything was a mistake that probably was.

Anyway just wanted to make sure people know that a fan is not necessary the solution and could even make things worse.

Ed

[Hobbyman2]

JMO thinking out loud here , in the radio world heat sinks and fans, and some times both are used to transfer heat from the finals , just wondering if there would be any practicality to mounting the boards to the bottom interior and adding a external heat sink on the external bottom of the headstock , might not need a fan ? might not be worth the design effort .

[rjent]

JMO thinking out loud here , in the radio world heat sinks and fans, and some times both are used to transfer heat from the finals , just wondering if there would be any practicality to mounting the boards to the bottom interior and adding a external heat sink on the external bottom of the headstock , might not need a fan ? might not be worth the design effort .

The problem is that every square inch of space is taken up. They really struggled getting it all in there and there is only one place for the motor and power supply to go (this is coming from the head engineer Jim McCann). If they could have redesigned the headstock, I don't think this problem would be as severe or even a problem, but it is what it is. It is all well and good about the concern of drawing dust into the headstock, but the real fact remains that it does run hot, it has no true ventilation so it is a design flaw. A flaw that seemingly they are not going to address. I am going to try (in time, as I am busy right now) to work up a ventilation system.

One thought is to draw air through the access port like the OP has had success with, but have a filter of some kind on the PTO grill (just a thought).

The headstock is pretty easy to work on and quite easy to blow/vacuum out. My opinion is something is better than nothing. I worked with high tech equipment for 40 years. Heat kills electronics ....

JMHO

[BuckeyeDennis]

JMO thinking out loud here , in the radio world heat sinks and fans, and some times both are used to transfer heat from the finals , just wondering if there would be any practicality to mounting the boards to the bottom interior and adding a external heat sink on the external bottom of the headstock , might not need a fan ? might not be worth the design effort .

The problem is that every square inch of space is taken up. They really struggled getting it all in there and there is only one place for the motor and power supply to go (this is coming from the head engineer Jim McCann). If they could have redesigned the headstock, I don't think this problem would be as severe or even a problem, but it is what it is. It is all well and good about the concern of drawing dust into the headstock, but the real fact remains that it does run hot, it has no true ventilation so it is a design flaw. A flaw that seemingly they are not going to address. I am going to try (in time, as I am busy right now) to work up a ventilation system.

One thought is to draw air through the access port like the OP has had success with, but have a filter of some kind on the PTO grill (just a thought).

The headstock is pretty easy to work on and quite easy to blow/vacuum out. My opinion is something is better than nothing. I worked with high tech equipment for 40 years. Heat kills electronics ....

JMHO

I’ve designed power electronics for CNC machines, industrial applications, and heavy vehicles, and I agree with all the points made thus far in this thread. On the temperature issue, I’ve designed electronics for reliable operation in 100C (212F) ambient temperatures — you just have to specify the right components and do the component-life analysis carefully. If designed with relatively inexpensive automotive-grade components, if you can touch it without burning your fingers, it’s probably cool enough. It’s quite possible, but by no means certain, that Nova has the over-temperature alarm threshold set low enough that component life will not be unduly affected.

On the other hand, not being able to run a PowerPro continuously for normal woodworking functions strikes me as a definite design shortcoming.

Forced-air cooling is usually one of the easiest and cheapest ways to dissipate heat. But we all know that dust is a problem in the PowerPro headstock, so any forced-air solution that either blows or sucks more dusty ambient air into the headstock is likely to cause more problems than it solves. You can buy snap-on air filters for cooling fans, which would be a big help, but now you’ve introduced a filter-cleaning maintenance issue.

If I was bound and determined to cool a PowerPro, but didn’t want to get into significant redesign, here’s what I’d do.
1. Put an air-hose adapter on the headstock, just like the OP is doing.
2. Get a small wet/dry vac, and install a HEPA cannister filter in it. Also install a dust bag in the vac, so that the HEPA filter won’t get dirty for a long, long time.
3. Run a clean air hose from the exhaust port of the vac to the PP headstock.

Now you are maintaining positive pressure inside the headstock with clean filtered air, so no outside dust is going to get in. The airflow volume through the headstock depends on how leaky it is, but the OP’s experiment indicates that it’s enough to be helpful.

One caveat — if the headstock is sealed up too tightly, airflow will be low, and that vac will start to act like an airstream preheater. So some testing is needed.

[rat1932]

I want to thank all for the responses to my post. Looks like a lot of us share the same problem.

Heat: When the overheat message came on, I grabbed for the first thing I could think of to move the hot air out of the headstock; open up the inspection port on the rear of the headstock and insert my small shop vacuum hose in to get the air moving within the headstock. By the way, my main dust control equipment is a cyclone separator, connected at that time to the plainer, and the shop vacuum has a small cyclone separator with a HEPA filter inside the vacuum. I used an IR thermometer to check the outside temp of the headstock and the top left headstock temp was 120 degrees F. The only heat generators in that area are the bearings and the drive belt. I'm sure there are more heat generators inside. They are all sealed up inside the headstock with no real way to control their effect on inside temp.

Dust: To control dust buildup inside the headstock, air needs to be blown into the headstock to pressurize it, not to try to draw a vacuum in the headstock to move air over heat generators (and dust). That air should be as clean as possible. Pressurizing keeps dust from entering the headstock through all the seams and holes that are there.

These are my thoughts, must run now, so share yours and lets do some designing.

Bob

[Hobbyman2]

I would be a little concerned about humidity or static ,,in some areas of the country when you are dealing with air, you could be getting into a lot more then meets the eye.

Seems like a fan on one of the pulleys blowing air through a few holes into a shroud covering the external heat sink on the bottom of the headstock would be more then good , the headstock or a cover for the bottom would need a few changes . JMO

[dusty]

This is interesting. We (and I include myself) have offered solutions and we don't even know what the real problem is!! We know a couple end symptoms (fault indicators) and that is all.

Having had experience as an Environmental Test Engineer I know that this could be a very difficult problem to solve.

[davebodner]

As a non-PP user, my impression is that PP overheating occurs only when usage creeps over the line from typical hobbyist use toward professional use. Perhaps any modifications should be reversible so that the PP is configured as intended during the 90%(?) time it's not overstressed. That would minimize concerns over introducing dust into the headstock.

Or maybe the easiest thing is to take a break from time-to-time, and give the Power Pro a break as well.

[Ed in Tampa]

If you remember Bill Mayo was very concerned about heat in the Power Pro from his experimentation with DC motors, he had learned how adversely heat effected things.
He conceptualized putting a muffin fan in the housing using a filter on the intake to capture most of the dust.

To the best of my knowledge Bill never went much past the conception stage as he seemed to have little interest in the Power Pro. He was too busy trying to perfect the original.

[EliWalton]

I have not been able to find authoritative answers for the following:

1. Is the PP cooling air intake filtered?
2. Are the PP electronics all shielded from dust and contaminants?
3. What is the maximum operating temperature specified by OEM TeknaTool/StriaTech?
4. What are the SS PP operating temperature test results?
5. What is the OEM Teknatool/StriaTech MTBFDesign Spec for Motor and Electronics in SS application?
6. What is the PP actual failure rate experienced by SS over the past 10 years?

Given the anecdotes shared in this forum, it would be great to know these facts before taking the PP plunge!

Ely