PowerPro idler shaft misalignment

[edma194]

I bought a used Mark 7 minus the table system. This was purchased at auction by someone, don't know what was done with before, likely nothing was done by the guys I bought it from. There were clear issues right away with the headstock, I could feel and hear a bearing problem and with a sanding disk mounted I was getting the banging problem noted in other threads. The power switch had also been replaced with a plain black one.

Serial# 03-30-11 PowerPro version v9.02xa05 2010

My plan was to switch out the drive sleeve assembly and quill to make sure they weren't the issue but as soon as I took a good look at the belts and the idler shaft I could see there was another issue. The idler shaft was clearly askew, and it had pushed out along with through the eccentric bushing toward the back. The screw and washer that hold back the bushing were doing nothing because the hole for the screw was not drill and tapped very deeply, or else there a broken off screw in there, so the washer was almost 1/4" away from the casting allowing the whole assembly to move around. The bushing and idler shaft were jammed into the casting an angle and took considerable work to get them out. The bearings on the idler shaft didn't turn as smoothly as they ought to and one was dry. Out of the casting the idler shaft didn't fit well in the bushing, nor the bushing in the casting.

Somebody had worked on this headstock and done an awful job. Some of the heat sink fins on the power supply were bent in one corner also.

So I purchased a new idler shaft and installed that in a spare eccentric. I loaded up the hold down screw with washers so it reaches the eccentric. I'm not sure how to take care of it without drilling and tapping a wider hole. It all fit back together easily. But the banging continues. To rule out other possibilities I swapped out the drive sleeve and quill with no improvement.

So now it's time to see if Shopsmith has any help to offer.

Gotta say that double tilt might not get much use from me ordinarily but it's great to have when working on a headstock.

[edma194]

I should have mentioned that I checked the fan and pulley screws right off the bat and nothing was loose, but after working on it and testing it I'll check those again before I close it all up.

[oldnavy]

Did you follow the belt balancing proceedure? I just completed my new DIY Power Pro install and the balance proceedure is very simple. A few degree of rotation of the enccentric make a huge difference.

[edma194]

Yes, belts are balanced now. This is my 2nd PowerPro so I've been through that before. I saw some note about the belt tension being an issue but this one tuned up just fine. It runs quite smoothly up to max speed until I put the sanding disk on (not at full speed).

Speaking of belts, initially the bottom belt (motor to idler shaft) was very loose compared to the upper belt. I believe excess tension on the top had pulled the poorly installed idler shaft and bushing to be pull askew while it was running.

[edma194]

Contacted Shopsmith customer service. As expected they sent a stock letter listing their support services. I suppose I'll take a chance talking to their engineers for $1+ per minute but they promise very little for that money, I don't need help finding parts, documentation or getting started. I won't be happy if they tell me they don't after it cost me $20 to ask the first question.

There must be someone there who will want to help me resolve this problem and can do that, just hope it doesn't take long to get to that person quickly.

[edma194]

So, previously I had replaced the idler and eccentric assembly, and tried swapping out the drive sleeve and quill to check for an issue there but the problem persisted. The motor and belts are now well aligned and tensioned properly, the pulley and fan screws are secure but I haven't glued them in with Locktite yet. I think I forgot to mention up to now the clicking sound that happens at power up before the keypad begins beeping. It's a few light thunks or clicks right at start up, all in just a second or less, but not something my other PowerPro does. I can't feel or see anything happening in the motor when the clicking occurs.

Yesterday I spent a little time on the phone with Sue Powell, an engineer at Shopsmith. We went over the basics again but there was nothing more to look at. She could hear the problem over the phone and says it sounds like the loose pulley issue but the set screw is quite tight. I also played the odd clicking sound and that isn't normal according to Sue. It's possibly a sound inside the motor from the fan if it is still actually loose inside.

There isn't more they can do without getting the headstock in their hands but I still have options. First, I have to check every way possible for something loose in that fan. If that doesn't help I have a second PowerPro and I can swap modules between them to narrow down the problem. The power supply and motor are expensive to replace, but I suppose there's some chance an identifiable problem could be fixed. And if it's the keypad then it's not that expensive to replace. I'll swap the motors first, they have to come out to get at the rest of the parts anyway.

[DLB]

A data point to get while you are swapping - Does it make the abnormal 'odd clicking sound' with the motor belt off? Does it make it at one, some, or all speeds? If it does it with the belt off, that will make the other swapping go easier and faster, just run the motor un-mounted. Having been down that road, it is fairly easy but kind of tedious to swap those parts. Per the DIY manual, and I'm paraphrasing, its okay to run the system outside of the headstock. I did it that way too, but I did add a ground jumper between the motor and power supply when I ran it on a bench since the power supply chassis was ungrounded otherwise.

Just checked to make sure I'm up to date... My Power Supply has been on order since late March. Several weeks ago I ordered something else and asked them to put it on the same order to save shipping and was told it could be months to get the power supply.

- David

[edma194]

I was told the backlog would clear out eventually, but they were non-committal. I'm not sure I did check for the clicks with the belt off, that should be the first step. Yeah, it is a bit tedious taking the parts in and out, but I'm getting kind of used to it. If I don't find anything here I'll make a shorty to hold it and maybe put the headstock from my 510 on the new base for the time being. If it's just the power supply or just the motor I guess it will be worth it to replace one or the other, not sure I'd spend all the bucks on the two most expensive components.

[wurlitzerwilly]

I bought a used Mark 7 minus the table system. This was purchased at auction by someone, don't know what was done with before, likely nothing was done by the guys I bought it from. There were clear issues right away with the headstock, I could feel and hear a bearing problem and with a sanding disk mounted I was getting the banging problem noted in other threads. The power switch had also been replaced with a plain black one.

FWIW when I converted my original headstock to Power Pro, some years ago, it was supplied with a black toggle switch to replace the original one with the removable lever. I don't think your black power switch is a bodge or a mistake.

[edma194]

I bought a used Mark 7 minus the table system. This was purchased at auction by someone, don't know what was done with before, likely nothing was done by the guys I bought it from. There were clear issues right away with the headstock, I could feel and hear a bearing problem and with a sanding disk mounted I was getting the banging problem noted in other threads. The power switch had also been replaced with a plain black one.

FWIW when I converted my original headstock to Power Pro, some years ago, it was supplied with a black toggle switch to replace the original one with the removable lever. I don't think your black power switch is a bodge or a mistake.

That's interesting. According to the sticker this was a Mark 7 not an upgrade, but it's possible they ran out of the red switches for a little while or it got switched for any number of reasons. I'm about to try swapping parts between my two PowerPro headstocks to isolate the problem. More on that later.