magnets?

[Carl Watts]

Model D/E its always the cable on the pickup or the TACH socket is loose or cracked or the PM is set to the wrong version of rower.

Model B/C its usually the cable as well but a problem with the magnets is rare unless there is a lot of obvious corrosion on the rest of the rower and then it can be magnets. The sensor on these is easy to test, its just a 105 Ohm coil of wire you can check with a multimeter at the connector that plugs into the monitor.

[Mikeeboy]

Cheers guys gave it a good clean and put a washer to get it slightly closer to the fly wheel and jobs a goodun
thank you

[JaapvanE]

single donut shaped magnet that has 12 poles- 6 positive and 6 negative.

Presumably the circuitry reads 12 impulses per turn of the wheel.

It creates a sinoid-like pattern, with 6 peaks and 6 valleys per rotation. I have the gut feeling there is a full-bridge rectifier circuit in the detector/generator as the signal never goes to a negative voltage, which makes sense as the generator is also used for powering the PM5, which runs on DC (Carl knows a lot more about that part than I do).

There is some underlying pattern present as the alignment isn't perfect. As we see the same pattern on all RowErg's and we've tested it with different electric circuits on our side, we assume it is a deliberate design by C2 or an accepted production tolerance. I don't know how C2 actually processes it. In theory they could go all analog and have infinite accuracy in their force curve. They report 64 positions on their force curve via Bluetooth, but nobody outside C2 knows how they achieve that. With OpenRowingMonitor we typically look at crossing the 12V threshold (we do this as it can be done by cheap of-the-shelf electronics that can be inserted non-destructively and is electrically safe for both the machine and the Raspberry Pi) then you indeed get 6 impulses per rotation.

[JaapvanE]

Cheers guys gave it a good clean and put a washer to get it slightly closer to the fly wheel and jobs a goodun
thank you

Great to hear. Enjoy that machine. I hope you have as much fun as I had on the Model B.

[Mikeeboy]

Ik more teething problems, seems to be working to well just cracked out a 5k in 15 mins im usually about 21 mins, i cant work out what the problem could be,ie it either works or it doesn't,also if i get a pm 5 do you use the same cable?? sorry for .ore questions

[c2jonw]

seems to be working to well just cracked out a 5k in 15 mins im usually about 21 mins

that's weird. Are you getting consistent stroke value updates, ie, one update every stroke of a consistent value? Or hi-lo pairs and incorrect strokes per minute?
Maybe one magnet is still bad or the pickup is faulty.

[Mikeeboy]

consistant updates but very high stroke rates about 60 spm but then can settle down to what id normally row, starts of at 1.5 per 500m but then setles into 2.10 per 500 but the fluctuates again ???

[c2jonw]

likely missing or weak magnet(s) or pickup spacing or bad pickup. I'd order the magnets and pickup.

[Carl Watts]

Do you have a PM1 monitor or a PM2 monitor on it ?

You need to post what version of monitor you have on the rower.

[c2jonw]

Do you have a PM1 monitor or a PM2 monitor on it ?

good point, Carl. I assumed a PM1
https://www.concept2.com/service/monitors

[Mikeeboy]

yes its a pm1

[Carl Watts]

yes its a pm1

Very old monitor now.

These HAVE TO BE RESET correctly as per the instructions on the end of it every time you change the batteries or it will not work correctly.

The correct battery is not the common Alkaline A76, they require the Silver Oxide version which is 1.55V like the SR44 or 357 for better screen contrast.

[Mikeeboy]

Thanks carl, for all your advice, so batteries were the ones you said but changed them anyway still same result
weirdly
i rowed for 30 mins a 80 spm ( you would have thought it would be a lot less than 20spm if magnets are not working)
1.20 per 500m
and did only 5700 odd metres
by my reckoning my metres should be way higher i suppose cheapest thing to replace would be magnets? then pick up but i want a pm5 anyway so may go down that route
thanks again everybody

[Mikeeboy]

Also did the battery reset

[Carl Watts]

Magnets problem I would say, one of them is not working.

Replace all 3 of them its not that hard. To get three was pretty hard, I had to order like 40 on AliExpress or E-Bay they are as cheap as chips. They come in "Stick" you just feed them into the hole from the stick to keep the polarity all the same and swipe sideways to leave each one in the hole.

Put the leftovers on your fridge, note that's ON your fridge not in your fridge LOL