Another chainsaw dyno...

[wcorey]

Certainly appears that there's separation on the edge of the pad where it's highlighted.



Unfortunately looks like the pad itself is pulled up and not just the wire from the pad, generally that's not good, but hard to tell on this pic.
Try to clean up around the connection as much as possible and touch it gently with as small a soldering iron tip as you can find. Make sure the wire is held in place so it doesn't spring up when the solder melts. Try to heat it as little as possible to just melt the solder, in and out quick, don't want to melt into the cell.
And not too hot on the soldering iron, like 6-7 hundred, not 8. If it's not temp controlled, try touching some flux core solder to it and if the flux really sizzles/smokes, try unplugging it and see how long it takes before the solder wire won't melt. Use that unplugged window of time to do the connection.
You might get lucky and it reconnects.

Does seem odd that it only uses 3 wires...

 

[Red97]

Certainly appears that there's separation on the edge of the pad where it's highlighted.

View attachment 248365

Unfortunately looks like the pad itself is pulled up and not just the wire from the pad, generally that's not good, but hard to tell on this pic.
Try to clean up around the connection as much as possible and touch it gently with as small a soldering iron tip as you can find. Make sure the wire is held in place so it doesn't spring up when the solder melts. Try to heat it as little as possible to just melt the solder, in and out quick, don't want to melt into the cell.
And not too hot on the soldering iron, like 6-7 hundred, not 8. If it's not temp controlled, try touching some flux core solder to it and if the flux really sizzles/smokes, try unplugging it and see how long it takes before the solder wire won't melt. Use that unplugged window of time to do the connection.
You might get lucky and it reconnects.

Does seem odd that it only uses 3 wires...

Thank you, I will take a better look in the am.

The white wire seemed to be pulled out if the silicone the most. Must be a vibration thing. As the cable has 2 holders on the arm, and a cover to protect the wires from a bit. Although it appears the ground wire is missing.

 

[Billy Currie]

You may need to recalibrate thehe strain gauges after you reinstall them. Hopefully there's a trim pot or something and you did not have to send it back for calibration.

 

[Sawrain]

Certainly appears that there's separation on the edge of the pad where it's highlighted.

View attachment 248365

Unfortunately looks like the pad itself is pulled up and not just the wire from the pad, generally that's not good, but hard to tell on this pic.

That would explain why pushing down on it gives a plausible reading.

Curios if the unused solder pad actually links to another when you are looking at it.

 

[Red97]

You may need to recalibrate thehe strain gauges after you reinstall them. Hopefully there's a trim pot or something and you did not have to send it back for calibration.

Believe the new ones will be calibrated.. everyone on the fb group says they still fix/sell this style.

 

[N8TE]

It does act as if it is lifted, or sprung...

It's most likely toast then. But you could try and super glue it back down, then wrap it tight with black electrical tape, while the glue sets.

 

[srcarr52]

This little doohicky is the problem.
View attachment 248320
I'll get the 5 successful runs graphed. Had some strong performers.

Think I'm going to have to ban one builder from the dyno everything he touches try's to break the dyno.

I can’t quite make out the internal loops of the strain gauges but I think that is a half bridge setup. One side strain gauge is in plane with the strain, the other is out of plane for temperature correction.

The resistance from the center wire to either side should be within a few percent. If not it’s screwed.
As you apply load one side from the center wire should change resistance and the other should not.

The idea of this is voltage is applied to an outside wire, ground on the other side and the center is measured. Change in the material length due to temperature should not change the center wire voltage since both strain gauges are equally changed. Change in material length (strain) due to load will change only the in plane strain gauge resistance and thus the center wire voltage.

 

[huskihl]

What he said^

 

[Cobby08]

Duct tape don’t stick to dyno’s very good....

That means you aren't using enough.

 

[Red97]

I can’t quite make out the internal loops of the strain gauges but I think that is a half bridge setup. One side strain gauge is in plane with the strain, the other is out of plane for temperature correction.

The resistance from the center wire to either side should be within a few percent. If not it’s screwed.
As you apply load one side from the center wire should change resistance and the other should not.

The idea of this is voltage is applied to an outside wire, ground on the other side and the center is measured. Change in the material length due to temperature should not change the center wire voltage since both strain gauges are equally changed. Change in material length (strain) due to load will change only the in plane strain gauge resistance and thus the center wire voltage.

Yep 3 wire half bridge.

Just called tech line.

He has to check the stock of a new arm. Said 2 weeks+ on repair.

May bite the bullet and do both. Be nice to have a spare handy.

Sounds like vibrations the killer... have some truing up to do on the jackshaft assembly...

 

[BonScott46]

Any graphs from yesterdays runs?

 

[cuinrearview]

Any graphs from yesterdays runs?

Dammit he's having a crisis here and that's all you think about!?!??











+1

 

[Red97]

Xs461 vs xs500i for those who may be in the fence of wanting to buy a 500i

 

[RI Chevy]

Wow. Very similar!!! Interesting

 

[srcarr52]

View attachment 248492

Xs461 vs xs500i for those who may be in the fence of wanting to buy a 500i

That's the beauty of fuel injection over a carb.

 

[Red97]

Dammit he's having a crisis here and that's all you think about!?!??











+1

Part ordered... should ship Monday. Once it arrives I'll send the broken one in for repair. Shouldn't have to worry about this issue again...

 

[Cobby08]

View attachment 248492

Xs461 vs xs500i for those who may be in the fence of wanting to buy a 500i

Me wonders which parameter table makes the changes at 11,250 to make that curve do that. Ignition or injection?

 

[usmcbuckwild]

View attachment 248492

Xs461 vs xs500i for those who may be in the fence of wanting to buy a 500i

that is an interesting graph. Do you think that dip in the 500i would be smoother if given more time for the onboard computer to make adjustments? I realize it should be almost instantaneous adjustment but just sheer curiosity.

 

[Bigmac]

I am going to guess it’s timing, that’s how my banshee reacts on the dyno when I pull timing after peak hp

 

[huskyboy]

Appears like the 461 has it beat in hp/torque slightly from 8000-9000ish. Probably equals a slightly torquier feeling saw in the wood when lugged. Makes sense with the stroke on both saws. Although I’m sure you have to have the 461 tuned optimally to reproduce those results... whether as the 500i is always tuned. It will be more consistent.