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Re: How to Resolve a RPS State Error 0

Posted: Fri Mar 09, 2018 2:39 pm
by c2h6o
This is a follow-up to a long string on RPS errors. Since I did all the fixes last year, the system has run very well. After doing a fair amount of drilling, I lowered the unit for some disk sanding. Upon starting the unit up, I got the dreaded RPS error again. This time removed the back cowling and blew out all the saw dust from inside the housing, both in the vertical and horizontal configuration.

...and this fixed my problem, no RPS errors!!

Re: How to Resolve a RPS State Error 0

Posted: Fri Mar 09, 2018 11:17 pm
by BuckeyeDennis
Dang, after reading about this this problem here on and off for years, I might just have to drive an hour over to Dayton, and show them how a $6 magnetic encoder solution could eliminate the optical-encoder dust problem once and for all. Commercial off-the-shelf technology, and it worked great for a couple of military-vehicle systems I designed.

Re: How to Resolve a RPS State Error 0

Posted: Sat Mar 10, 2018 6:19 am
by algale
BuckeyeDennis wrote:Dang, after reading about this this problem here on and off for years, I might just have to drive an hour over to Dayton, and show them how a $6 magnetic encoder solution could eliminate the optical-encoder dust problem once and for all. Commercial off-the-shelf technology, and it worked great for a couple of military-vehicle systems I designed.
You might have to drive a little further -- like to New Zealand. Aren't the PowerPro DVR and electronics made by Teknatool?

Re: How to Resolve a RPS State Error 0

Posted: Sat Mar 10, 2018 9:01 am
by BuckeyeDennis
algale wrote:
BuckeyeDennis wrote:Dang, after reading about this this problem here on and off for years, I might just have to drive an hour over to Dayton, and show them how a $6 magnetic encoder solution could eliminate the optical-encoder dust problem once and for all. Commercial off-the-shelf technology, and it worked great for a couple of military-vehicle systems I designed.
You might have to drive a little further -- like to New Zealand. Aren't the PowerPro DVR and electronics made by Teknatool?
I do believe that you are correct. But if Shopsmith wanted the magnetic-encoder solution implemented, I’m sure they know who to talk to at Technatool.

Re: How to Resolve a RPS State Error 0

Posted: Sat Mar 10, 2018 9:53 pm
by everettdavis
I too am familiar with magnetic sensors and used hall-effect-processor sensors for years. I never saw them used in proximity of the magnetic fields of a motor.

I don't know how they would function in that application. Optical sensors can be affected by contamination getting in the path of the sensor.

Everett

Re: How to Resolve a RPS State Error 0

Posted: Sat Mar 10, 2018 10:03 pm
by reible
I have yet to see this error. I have two machines and so far so good.

One of the things I have noticed is that I see less dust in the inside of my machines. Now that could be just me. It is also true that for most tasks I use dust collection. This is especially true for sawing and sanding. I do limited dust collection while drilling but little dust is generated and my vacuum attention is more of clean up after.

I have to wonder if those seeing the errors are less dust collectors, ie don't have a hose hooked up and using it most of the time. Anyone what to comment?

Ed

Re: How to Resolve a RPS State Error 0

Posted: Sat Mar 10, 2018 10:45 pm
by BuckeyeDennis
everettdavis wrote:I too am familiar with magnetic sensors and used hall-effect-processor sensors for years. I never saw them used in proximity of the magnetic fields of a motor.

I don't know how they would function in that application. Optical sensors can be affected by contamination getting in the path of the sensor.

Everett
I used a 12-bit magnetic encoder IC for commutation and position/velocity feedback of a 1 hp rare-earth brushless DC motor design, with operating speeds up to 8000 RPM. A small magnet was pressed into a bore in the back end of the motor shaft. The sensor IC was mounted on-axis with the shaft, and sensed the magnetic field orientation. Internally, it did indeed have an array of Hall sensors, and all of the magic was done inside the IC. The system was 100% reliable through all the MIL-STD testing and field trials, including gun-shock testing of over 500g’s, IIRC.

Variations in the magnetic field can introduce small sensing errors, but in our case they were negligible. For the highest accuracy, the position errors can be calibrated, and computationally corrected by the sensor IC itself. I was greatly impressed with the device — especially given its low cost.

Re: How to Resolve a RPS State Error 0

Posted: Sun Mar 11, 2018 1:20 am
by everettdavis
Knowing what you do of the DVR design, could it be retrofitted or would it have to be totally engineered?

I wonder how many if any of the DVR patents involve the present sensor designs.

Do you own any patents that could be licensed to Teknatool?

I am working on a PowerPro & NOVA/Teknatool folder on my Google Drive. Nothing there yet, but NOVA side will have some things there soon. They are different but experience the same error codes.

I will add another post here later with some preliminary notes about it and the link etc. for folks who want to browse that info and tech notes.

Everett

Re: How to Resolve a RPS State Error 0

Posted: Sun Mar 11, 2018 3:58 am
by everettdavis
I know there are a number of threads for the PowerPro RPS where errors are discussed, and that some folks think it is a Shopsmith engineering issue they can resolve internally.

If it were a Mark V A.O. Smith centrifugal motor start switch I would ask if they still thought it to be a Shopsmith engineering issue they can resolve internally.

The answer is obvious for the A.O. Smith example: the motor was made by A.O. Smith external to Shopsmith.

The answer may not appear as obvious for the PowerPro DVR motor example using DVR Motor made by a company Teknatool International Limited in Auckland, New Zealand even though they have a Teknatool USA Inc. in St. Petersburg, FL.

The NOVA DVR Galaxi 1644, DVR 2024 and DVR Voyager all use the same technology as the Shopsmith PowerPro DVR Mark 7 although the frame end-bells vary in design.

Yes it is the same Nova that makes the Nova Chucks that fit Shopsmith and other lathes, including their own.

You guessed it, the NOVA lathes are also from time to time experiencing the same problems with RPS Errors of their own, just like Shopsmith.

Teknatool DOES NOT SUPPORT SHOPSMITH DIRECTLY - Don’t bother trying to get them to answer Shopsmith Questions, however, very much of what they write in support of the various NOVA Lathes that exhibit EXACTLY the same errors, and there is relevancy in knowing what they say.

The end bells and other housing variances exist, but they are similar, and have the same functions. Disassemble at your own Shopsmith Warranty Peril. If Shopsmith tells you to…. You are ok. If you are out of warranty, you are ok.

Teknatool is pretty specific with some of their support bulletins. Here is what they say:


RPS0 means the connection is open from the 5 pin ribbon cable on the board to the sensor board.

The cable is usually zip tied to the sensor board so that connection is not like a problem, just the one on the board.

RPS1 means something obstructing the optics (dusty).

RPS State Error relates directly to the sensor.

The "Low Voltage" error is typically caused by very simple problems, e.g. loose wire connection.

How to fix clicking noise and “Low Voltage” message – see PDF for relevancy; Two methods – one will eliminate the “Low Voltage” allowing it to run; the second eliminates both issues (Again NOVA)

You can find a number of the Teknatool service PDF’s in My Google Drive under the Future PowerPro folder in a Nova Teknatool sub folder. http://www.shopsmith.com/ss_forum/viewt ... 00#p185690

Once I find, or we create Shopsmith photos that are illustrative of the same areas inside, we can create some documentation to go in the PowerPro side.

I am going to Dayton for a week in May and meeting with folks on a completely unrelated project but I will see what I can find out when I am there.

Again, these are not Shopsmith documents, but when you look at the nature of the errors they also are throwing, the causal issues are essentially identical.

Everett

Re: How to Resolve a RPS State Error 0

Posted: Sun Mar 11, 2018 8:05 am
by dusty
I just finished reading through all of your posts (and links) regarding the RPS errors. As usual, you have done a phenomenal job of bringing these vital references together. I do hope all of the Power Pro owners will take time to read these.

However, I can't help but wonder why Shopsmith does not post something similar with specific information (pictures and links) that relates to the Shopsmith application. I understand warranty issues but ....

Failure to resolve issues similar to these in a timely manner can only hurt the PowerPro's reputation.

As an individual who has dealt with design and performance issues of this type, on a professional level, I have a strong opinion. It is my opinion that the PowerPro is packaged too tightly in the Mark V headstock. A mechanical redesign of that housing may be in order.

Band aides only work for a short while.