Powerpro problem-maybe?

[TomMckinney]

You can buy a new motor on ebay for almost the same price.

https://www.ebay.com/itm/333185254723

So a power supply should be less

[tucsonguy]

This is why I have a 110v computer fan and a HEPA filter system built into my headstock - to keep sawdust out and keep it cooled. So far not a speck of dust since I did it, and no problems. Sawdust buildup = heat build up = #1 killer of headstocks, PowerPro AND conventional.

[bainin]

Well- I started this post on March 21st.

The driver unit went off to Florida right when COVID started and languished there thru the summer.

I just received the drive unit back 7/12 , re-assembled and turned on. All seems OK again.

I didn't receive any detail information from SS on exactly what the problem was-I suspect they don't get that info from their FL affiliate.

After the 4 month hiatus-i seem to have lost 2 Tinnamen clips that hold the motor cover in place --argh. I even disassembled the unit a 2nd time to make sure they hadn't fallen inside the case..as I heard a jingle when i lifted the unit back onto the waytubes..but it turns out that was just the washers on the waytube lock mechanism (whatever that thing is called).


I had plans this summer for some shop time- now I'll have to double up to get back where I was.


b

[RFGuy]

How much did the repair cost? Unfortunate they didn't tell you what was wrong with it...

[bainin]

It was $365 including the shipping.

[dusty]

You can buy a new motor on ebay for almost the same price.

https://www.ebay.com/itm/333185254723

So a power supply should be less

Due Diligence: Be careful with this. The motor may be the same while the mounting mechanism may no be.

Power Pro Motor Mounts and Drive Pulley

Power Pro Motor Mounts.PNG (1.29 MiB) Viewed 8054 times

[edma194]

You can buy a new motor on ebay for almost the same price.

https://www.ebay.com/itm/333185254723

So a power supply should be less

Due Diligence: Be careful with this. The motor may be the same while the mounting mechanism may no be.

If you're replacing a broken motor then the original mounting blocks might fit the new motor. If you're lucky.

[JPG]

You can buy a new motor on ebay for almost the same price.

https://www.ebay.com/itm/333185254723

So a power supply should be less

RE: The chart extoling the virtues is mis leading. AC motors do not have brushes nor rotor windings either.

[adrianpglover]

This is what really gives me pause about ever buying a PowerPro headstock. If the power supply module replacement really is $572 from Shopsmith it seems like extreme price gouging to me (thought I saw a previous thread where someone posted that this module was only $350 previously from Shopsmith). Based on a couple of decades of experience in designing electronics, I can't imagine the raw components of the power supply module cost more than about $50-75 all totaled. Accounting for assembly and company overhead & profit, a price of around $200-250 would be more than generous for this module (IMHO). I would have to go through the BOM and price it out to be sure though. Given the fact that the PowerPro doesn't seem to be as reliable as the original headstock (based on posts I have seen here), I think it is unfortunate that Shopsmith is charging so much for replacement parts for it since many PowerPro users don't even get a decade of use out of it before repairs are needed. For me, a key advantage of the PowerPro is the ability to reverse and the lower RPM range for woodturning. If I get good enough at woodturning, I will likely purchase a Laguna REVO 18 | 36 lathe or similar rather than upgrade to the PowerPro.

I've been in the electronics industry for a little while now (probably less time than you), first at a small company where we assembled and tested our own boards in house and since the acquisition with a large company known by three letters and associated with the color blue. I specifically design, test, and spec out PSUs, batteries, and all manner of dc-dc and analog circuits. From what I've seen, sure, I can agree that the BOM cost of a power supply unit wouldn't be above $50 or so, for what goes on the board at least. If you are running extremely low volumes, like we were prior to the acquisition, then your PCB cost can get up to $75 pretty quickly. The real cost comes in if you're not using automated means (pick and place machines, reflow ovens, wave soldering, and the like) to assemble and test (ICT - in circuit testers, boundary scan, etc) and instead requiring skilled labor to do the job. If the testing is all manual and takes a lot of time to perform, then this can also increase your labor overhead. If then you also assume that you are outsourcing this (as you can tell by them sending the parts to Florida for testing and repair), there's another source of markup. If the company you have been outsourcing to has increased their charges to you since you started the design due to lower than expected quarterly/yearly volumes. The company they're contracting with may have also changed their tune since they originally developed the power supply unit and now may be asking for more money for it than they first were getting. Then there's the issue of fallout - if you have a design that fails spectacularly enough during testing that it can't be repaired, then you may have more scrap to factor in than the design should have. It could take a lot of engineering resources to redesign it to fix such issues, which may be either a personnel or monetary resource issue for either SS or the CM. BOM cost is one thing. The cost to deliver an assembled, tested, and working unit or sub unit is an entirely different thing.

I'm not trying to justify high costs for high profits, just trying to show that there are plausible reasons for such a high cost on this part. I do agree that I see a lot more posts about issues with the PP headstock than I would like to see. I also don't feel very comfortable with a design that the company feels it necessary to put language into the manual stating that if you are going to run it on a 220V circuit, then normal circuit breakers don't provide enough protection and you should hobble together your own separate OC protection device with 10 A fuses on each leg. That just seems so backward and leads me to believe that they have done some poor design (or possibly poor quality of design testing prior to mass marketing) work when it comes to device protection on their AC front end. It really makes me think that this unit should be run with a full blown power line conditioner to really baby the power circuit and make it last.

This is why I have a 110v computer fan and a HEPA filter system built into my headstock - to keep sawdust out and keep it cooled. So far not a speck of dust since I did it, and no problems. Sawdust buildup = heat build up = #1 killer of headstocks, PowerPro AND conventional.

I have not opened up my PP headstock since I got my Mk7 early this year, so I'm not sure what the interior looks like. I'd be interested in seeing pictures and a description of how you put a fan and filter on your unit. Got a link to a thread on your mod?

[JPG]

House circuit breakers are not intended to provide protection for an appliance(especially one that has a maximum load of <50 to <70 percent of circuit breaker rating). In the case of the 230v scenario that ratio is greater.

BTW the third party repairing/building the power supply is quite likely also the designer who surely has a chinese vendor doing assembly etc. Not sure re the relationship between Striatech and Nova.

Regardless of who designed the electronics, the Shopsmith design had severe physical limitations placed upon it to get it all inside the headstock(which had heat buildup problems with the reeves drive to begin with). I find it interesting that the Striatech product appears to be much smaller in an external package.

Yes the Shopsmith Power Pro is a small volume item. Yes the replacement costs seem excessive. Yes other replacement item costs seem excessive. Yes automobile replacement parts seem excessive. Yes ink jet printer replacement cartridges costs seem excessive. But I digress!!!