Powerpro problem-maybe?

[RFGuy]

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.

Adrian,

Thanks. I was just speculating based on my experience. The reality is that none of us really know Shopsmith's supply chain, or at least no one has posted about it here yet. There are lots of reasons for why the PowerPro modules might be more expensive and you stated some good reasons for it. I believe what we do know is that Shopsmith didn't design or build any of the PowerPro internals. A company called StriaTech did that. So presumably the PowerPro version of Striatech's motor is a special licensed version that Shopsmith purchases for Shopsmith only, e.g. the power supply module and control/display module are custom just for Shopsmith. Since StriaTech is the OEM and because they sell their own line of DVR motors for DIY use or for their NOVA line of tools or to sell to Rikon tools, we know that StriaTech has all of the volume manufacturing from these such that you can buy an entire DVR motor with power supply and controls for around $500 total. So, let's contrast that to Shopsmith charging over $2k for the equivalent, or a power supply module repair/replacement going for $350-500 from them. Of course the PowerPro for $2k also includes a full new headstock, so maybe not a 100% fair comparison, but hopefully you see my point. I am not saying that Shopsmith shouldn't charge a fair price to cover their costs and a reasonable profit, but when I hear of it costing close to $500 to replace just one module on the PowerPro it certainly gives me pause for considering to purchase it.

I haven't read the PowerPro manual, but with regard to doing inline fuses in addition to the circuit breakers that isn't an uncommon practice particularly for more sensitive electrical equipment. I wouldn't think less of the PowerPro because they recommend inline fuses on 240V in addition to the circuit breakers. The circuit breaker is there to primarily protect the wiring in the house in the case of an overload. Inline fuses are for the sole purpose of protecting the equipment connected to that circuit.

[dusty]

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!!!

No doubt there is a Chinese connection. When isn't there one?

https://www.teknatool.com/about/

[adrianpglover]

All very good points. I just haven't seen a device that required fuses in addition to the circuit breakers unless it also had the position for those fuses internal to itself. I guess what I meant is that it's not so much that it isn't an acceptable way to design the unit, it just seems a little less professional than what you would expect in designs when autoranging power supplies have been in mainstream operation for more than 2 decades now. Then again, the only 220V devices that I get much exposure to are normal household appliances, power tools that really are just a motor connected to the wiring by some type of switch, magswitch, or other protection device, or equipment at work that is hard wired and professionally installed so I wasn't involved with it or the systems that we design or the test equipment we use, which all has auto-ranging PSUs with either a C13 or C19 plug on it. It just seems interesting to me that they would have adopted an approach that required an external box to be created to power the device. I haven't done the switchover to 220V for my SS yet. If I were to do it, I would want to do it in a way that I could easily and quickly switch back and forth, i.e. use a C19 or similar type connector that denotes both 220V or 110V operation. For now I use it in my shop, but in cases where I may need to send longer boards through it or the planer attachment I've thought about wheeling it to the garage bays and running it on 110V there to run it.

[JPG]

"Due Diligence"?

pp vs stritech mouint.jpg (192.68 KiB) Viewed 6841 times

[edma194]

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 agree. I designed and manufactured electronic equipment and these costs while high, are not really exhorbitant for the small volume production of Shopsmiths and related devices. Without this kind of price structure Shopsmith might not be able to keep operating, and it appears their resources are strained already these days.

I wish the cost wasn't so high, right now I'm trying to work out a motor for my Delta bandsaw. A variable speed motor like that would be fantastic, there's even a 1HP version on eBay right now for considerably less, but still too rich for my tastes right now.

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?

Seconding this request. I suppose a box fan can be mounted on the outside of the belt cover where the nameplate is.

[RFGuy]

I agree. I designed and manufactured electronic equipment and these costs while high, are not really exhorbitant for the small volume production of Shopsmiths and related devices. Without this kind of price structure Shopsmith might not be able to keep operating, and it appears their resources are strained already these days.

Remember Shopsmith doesn't manufacture these. StriaTech (parent company Teknatool) does. They have significant enough volume to sell the entire DVR motor, PSU and controls for around $500 to individual customers (retail). Shopsmith should be able to leverage StriaTech's economy of scale and sell these parts cheaper IMHO since I am sure there is some commonality between their other DVR product lines and the one they sell to Shopsmith.

[edma194]

I agree. I designed and manufactured electronic equipment and these costs while high, are not really exhorbitant for the small volume production of Shopsmiths and related devices. Without this kind of price structure Shopsmith might not be able to keep operating, and it appears their resources are strained already these days.

Remember Shopsmith doesn't manufacture these. StriaTech (parent company Teknatool) does. They have significant enough volume to sell the entire DVR motor, PSU and controls for around $500 to individual customers (retail). Shopsmith should be able to leverage StriaTech's economy of scale and sell these parts cheaper IMHO since I am sure there is some commonality between their other DVR product lines and the one they sell to Shopsmith.

That just increases the price though. The price you'll see for the motor and controller on Amazon isn't typical retail pricing, it's about what Shopsmith will have to pay, then they'll have to multiply that cost to cover their own operating costs and to make a profit. If they can get the motor, custom mounting hardware, custom controller, and a power supply that fits in the headstock for $500 then they're going to need just that part of a Power Pro head or upgrade to sell for $1500 retail.

[Mrzip]

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 would like to install a computer fan and HEPA filter to my units. Can you post how to do this?