Exchange magnets

[c2jonw]

That's probably why Concept 2 changed the flywheel for the Model D & E. I'm assuming the same flywheel is also used on the skierg & bike erg.

No, the main reason for the magnet change was to generate power for the PM5- which the three small rare earth magnets could not do. The molded 12 pole donut magnet serves the dual purpose of power generation and sensing flywheel speed. And yes, the same flywheel/magnet setup is used on all current C2 ergs.

[RicardoRQ]

The work is done!
The magnets that I bought are smaller than de original. I didn't need redrill the holes. I putted two magnets per hole.
First I attached the magnets with eletrical tape to test. Worked well. So I glued the magnets with epoxy adhesive applied on both sides.
I took care to put all the magnet sets in the same polarity as the originals.

[faach1]

The work is done!
The magnets that I bought are smaller than de original. I didn't need redrill the holes. I putted two magnets per hole.
First I attached the magnets with eletrical tape to test. Worked well. So I glued the magnets with epoxy adhesive applied on both sides.
I took care to put all the magnet sets in the same polarity as the originals.

Nice Ricardo! All the best.

[c2jonw]

That's great! Good Job.

[mict450]

The work is done!
The magnets that I bought are smaller than de original. I didn't need redrill the holes. I putted two magnets per hole.
First I attached the magnets with eletrical tape to test. Worked well. So I glued the magnets with epoxy adhesive applied on both sides.
I took care to put all the magnet sets in the same polarity as the originals.

All right Ricardo! Well done!! Did you have to replace all the magnets?

General question for the experts: Won't magnets exposed to high heat from powder coating, become demagnetised? And if all three no longer functioned as magnets, would the PM even power up?

[bornnslippy]

Im having to replace my 3 magnets also and was wondering do the magnets have to be s facing towards the sensor

Thanks

[mict450]

Im having to replace my 3 magnets also and was wondering do the magnets have to be s facing towards the sensor

Thanks

You've already ruled out the sensor & the PM? No expert, but my understanding (thanks Google)
is the S pole faces the sensor.

So how do you reckon which pole is which? Are they labeled? Or do you need to use a compass to figure which is which?

Another question for the experts: if all 3 magnets had the N Pole towards the sensor, would the PM work? If it worked, would you register some crazy world record splits or would you be slower than your 80 year old Granny?

[bornnslippy]

Yes i ruled out its not the sensor or the Monitor

I pushed the 3 magnets through a bit and the monitor comes to life

So ive ordered some new magnets to replace the old ones as one has crumbled

Ive read u can tell which is s or n on a magnet with a compass but i havent tried yet

If anyone elese knows ayother method to tell which is n or s i would love to know

Yes i also read that the magnets need to face s towards the sensor but just wanted to make sure



Thanks

[mict450]

Yes i ruled out its not the sensor or the Monitor

I pushed the 3 magnets through a bit and the monitor comes to life

So ive ordered some new magnets to replace the old ones as one has crumbled

Ive read u can tell which is s or n on a magnet with a compass but i havent tried yet

If anyone elese knows ayother method to tell which is n or s i would love to know

Yes i also read that the magnets need to face s towards the sensor but just wanted to make sure

My SWAG would be, compass N pole should face S pole on magnet, ala opposites attract, like repell.

[Carl Watts]

If you cannot get the small 3/32 inch imperial magnets (2.4mm) then re-drill the holes for 3mm diameter x 4mm long Neodymium magnets. I used a decent quality, brand new 3mm drill and you need to keep it square to the flywheel. The old hole makes it pretty impossible to stuff it up.

If you have a scope you can connect it to the lead and see the pulses. The amplitude and frequency changes depending on the pace. The correct magnet orientation gives to a positive going pulse first then it goes negative and back to zero and it looks a bit like an ECG pulse. The amplitude gets to 0.4 to 0.6V peak.

Actually not sure if it makes that much of a difference as long as all the magnets face the same way, cannot remember but if at least one of the original magnets is okay you can use that to get the new ones correct. Your new magnet should be attracted to the old magnet (easier from memory to detect a repel so then flip the magnet), keep it facing that way and push it through from that same side. You can just buy a whole stick of these all joined together really cheaply. They actually self centralize and hold themselves in the holes, however I used a bit of Loctite.

Pretty easy to test the rower before you finally Loctite or superglue the the magnets in.

[mict450]

If you have a scope you can connect it to the lead and see the pulses. The amplitude and frequency changes depending on the pace. The correct magnet orientation gives to a positive going pulse first then it goes negative and back to zero and it looks a bit like an ECG pulse. The amplitude gets to 0.4 to 0.6V peak.

By my understanding, if you want a positive waveform first & then a negative deflection, then the S pole should be facing the sensor. N = negative. Ergo S is the positive pole.

I'm not an expert. Electrical engineers' comments are welcomed. I am open to being corrected.

[Citroen]

By my understanding, if you want a positive waveform first & then a negative deflection, then the S pole should be facing the sensor. N = negative. Ergo S is the positive pole.

I'm not an expert. Electrical [sic] engineers' comments are welcomed. I am open to being corrected.

I'm fairly sure folks who work on 400,000V systems probably aren't the electronics engineers you're thinking of.

https://www.electronics-tutorials.ws/el ... ffect.html

All three magnets must be the same way round. The polarity N versus S of the magnets is important for the induced current in the Hall Effect sensor (regardless of whether it's a purely analog sensor or an analog sensor with a comparitor that makes it a digital sensor).

[bornnslippy]

Just a quick question what would happen if u only had 2 magnets facing the correct way and 1 was the wrong way round?

Just curious

[mict450]

I'm fairly sure folks who work on 400,000V systems probably aren't the electronics engineers you're thinking of.

https://www.electronics-tutorials.ws/el ... ffect.html

All three magnets must be the same way round. The polarity N versus S of the magnets is important for the induced current in the Hall Effect sensor (regardless of whether it's a purely analog sensor or an analog sensor with a comparitor that makes it a digital sensor).

Thank you for correcting me, Dougie, re: electrical vs electronic.

I understand that the three magnets must face the same way. In the article you referenced, S is facing the Hall sensor. So I'm assuming that that is the correct orientation. Is this correct or maybe it doesn't matter, just so long as all three face the same way?

[mict450]

Just a quick question what would happen if u only had 2 magnets facing the correct way and 1 was the wrong way round?

Just curious

My guess is your splits, watts, speed, force would be slower, lower. Unchanged would be stroke count, drag factor & drive length.