Shopsmith Forums

I just got a new PowerPro at the beginning of December. As luck would have it, my old motor died just when I needed to get some projects done, so I bit the bullet and opted for a complete brand new headstock rather than trying to redo my old headstock and losing more time.

Overall, I am pretty happy with operation the new unit, but I do have a few concerns. The operation and expanded speed range are great, but the finish on my unit is about like 220 grit sandpaper. This is really disappointing and makes it a lot more difficult to keep the machine clean. I don't know if mine is abnormal or if this is just the way they come now. I bought my original machine back around 1985 and it still has a very durable glossy finish. It is a stippled kind of finish, but the paint is smooth and it is super easy to wipe off and keep clean. When I try to wipe off the new one however, it's like wiping down a piece of sandpaper.

So far, I only have one other major issue. That involves the heat produced by the new unit. I was working on a breadboard that I wanted to get done before Christmas and in order to attach the end pieces, I decided to use a sliding dovetail joint. To do this I was using a dovetail router bit and running the machine at 10000 rpm. When cutting the tails, I decided to feed the stock from the back of the machine with the bit cutting across the top of the stock. Since this was my first attempt at this kind of joint, I was taking my time and making many passes in order "sneak-up" on my final dimension. Naturally, being at the back of the machine< I could not see the display screen of the PowerPro. After about 45 minutes of operating I began to realize that something smelled like burning paint. I went around to the front and the display said "Inverter Heat", but it still seemed to be running fine. I put my hand on top of the headstock and was shocked by the amount of heat. I immediately shut it down. I then decided that I wanted to cool it down as soon as possible.--Without the machine running, there was no air flow and I could imagine the electronics was getting a bad roasting inside. I took off the access cover on the back of the headstock and taped my Shopsmith vacuum hose into the hole with some duct tape. After about a half hour of the vacuum pulling air through the headstock, the display went back to normal. Of course this being winter, my shop is relatively cold (less that 65 degrees). I could not imagine how I could operate when summer comes and the temp might get up to 100 degrees or more.

I know that heat is the biggest enemy of electronics and I really think there should be some kind of cooling fan for the headstock, so, I decided to mount a muffin fan on the access hole at the back of the machine. I got a good quality ball bearing fan and finally got it all mounted last night. The fan is rated at 41 cubic feet of air per minute if unrestricted. Considering the small amount of openings from which to draw the air and the resulting amount of restriction, I figure I might get 5 to 10 cubic feet flowing through per minute. I calculate the internal volume to be about .7 cubic feet, but about half of that space is occupied by the motor, inverter and all the other control electronics and all drive the parts and other various hardware. So, I'm guessing there is about .4 cubic feet of free internal space. If that's all true, the muffin should be changing all the air inside the headstock at least 12 times per minute. I am going to do some testing to get a better idea of the air flow.

I don't know if anyone else would be interested in doing this, but I can try to post some pictures, if they are.

Trubio, if you have not already done so, you need to discuss this with Shopsmith.

Trubio,

Diddo what Dusty said. I have had my PPro for over a year and it has not overheated. There is something amiss. I am sure SS can help.

Jack

Trubio, do I understand correctly that the PowerPro was operating continuously for 45 minutes at 10000 rpm?

Can a regular router operate at 10000 rpm continuously for 45 minutes without overheating? I've never put a router through that kind of workout, so I don't know what's normal.

Gary

greitz wrote:Trubio, do I understand correctly that the PowerPro was operating continuously for 45 minutes at 10000 rpm?

Can a regular router operate at 10000 rpm continuously for 45 minutes without overheating? I've never put a router through that kind of workout, so I don't know what's normal.

Gary

If you have a $3000 router - you better be able to operate it at that rpm for hours!!!:rolleyes:

If you had said the router bit was getting hot, I would not have been surprised. I have ruined router bits with too heavy a work load. Dumb but I have done it.

Please keep us informed as to the outcome of your communications with the mothershop. I am sure we all would like to know their response to your situation.
I have been operating machinery for fun and profit for over 40 years and also strongly believe that a $3,000 piece of high tech machinery better be able to run for 45 minutes with no problems.
Oh, and DUSTY, almost forgot to mention, I really like the new avatar!

Hi,

Just a thought here about routing sliding dovetails, longer ones especially. It is very hard to clear the chips on these cuts. You can not do the normal take three/four passes as dovetail bits do not work that way. What you can do is use a straight bit that is the same or smaller size then the top of the dovetail and make either one or two passes to come up just a little under the depth of the dovetail bit. This way the dovetail bit has a lot less material to remove and normally will clear the chips way better.

There is a lot of heat build up on the bit and from the description I think the router bit could well have expired at some point. Best check that as well.

Now as far as the shopsmith, I would hope that they have more than a visual message letting you know when the machine is over heating, I'd hope they would shut it down before any real damage is done. I have no knowledge if this is the case or not. It is covered by shopsmith at this point so I might think about calling them and telling them you want to send it in for testing, they would I think send a loaner so you can keep working.

Ed

Thanks to everyone for all your responses.

I will try to contact Shopsmith tomorrow to see what they say. I'm not expecting them to let me talk to anyone who would really know what the story is and I really don't want to pay nearly $100 to send it back just so they can take a look at it and tell me there is nothing wrong. I may be wrong. --Maybe they'll let me talk to someone who is really knowledgeable and he may tell I have a problem.

To tell the truth, I never suspected that there was anything wrong with my machine. I have opened it up and taken a look and everything appears fine and moves freely. I just think that the machine needs better ventilation. When you look inside , you see a lot of aluminum heat sink material. That, of course, is there to pull heat away from the motor and electronics, but the heat needs to then be taken out of the housing and there is no provision to do that.

I was operating it for a long period of time. It may have been more that 45 minutes. It's hard to remember, because I did it in several stages. I cut the slots in each of the end pieces first and then I worked on the tails. And I did first rough-out the slots, by the way, with a saw blade.

It was after I had been working a long time on the tails that the machine got hot. There was never any great stress placed on the bit and I'm sure it did not over-heat, because I was taking a lot of light passes-- not trying to plow through. Cutting the tails was where I spent a long time, because I had never done this kind of a joint before and I didn't want to cut off too much and mess things up.

When I installed the new unit, I read all the directions and there was never any mention or precautions about running at high speed for long periods of time, but I think that was the problem. I never gave it a second thought and just expected that the machine should be designed to do what it is supposed to. I have gone through the manual again and there is no mention of anything about "inverter heat". It seems like it would be nice to explain i's meaning in the manual. It also seems like it would have been relatively simple (and smart) to put an alarm on the machine to alert the operator to any problem.

By the way, calculating from the dimensions of the pulleys, the motor is turning at about 5500 rpm when the machine is set to 10000 rpm.

Hello and welcome to the Forum!

I have not used my PowerPro at the highest speeds for any extended length of time, but I expect we'll soon hear from member charlese who has done so successfully.

As properly noted above, Shopsmith is the authority on what's normal. My own 2-cent comment is that having done a PowerPro DIY installation, I found the alignment of the belts to be influential on the ability of the machine to achieve and maintain top-end speed. If I didn't have them just right, it fought to pull that fast.

Regarding the paint finish, yeah, all the new stuff from SS is rougher-finished. I don't have a problem with that, but I don't know how to duplicate it if I do touchup painting. I primarily use a vacuum rather than a cloth to clean my equipment.

I think you have been given, and will act on, the best advice I could give concerning your heat issue.

I have run my PowerPro for a steady 6 hours, but at much lower speeds with no heating. The warmest part of my headstock is on the side having the drive belts.

One issue I had after my entire PowerPro was re-built at the factory, was the idler shaft would keep slipping into the case through the eccentric. When I received the unit from the factory, the idler shaft was pushed into eccentric so the inside bearing was just barley being held by the eccentric. After re-positioning the shaft and adjusting the belt tension, used the machine. Even though the belts were both vertically aligned and properly tensioned, the shaft would slowly creep toward the center and the inside bearing would be partly exposed. Finally, after getting disgusted with this condition, I tightened the ears down more than I thought was wise, all the time holding my breath the ears would not break. It has been holding it's position for several weeks of use and seems set. My thought is the hole/ears that hold the eccentric had become stretched and needed repositioned.

I bring this up because during the slippage period, there was also an occasional hot rubber smell. No heat other than normal, but the smell was there. After aligning the idler shaft in the eccentric, any smell has disappeared.