Saw Dyno

[Adirondackstihl]

Interesting logo

 

[malk315]

Interesting logo

Hey Jeremy-

In case you missed the paragraph about that in the first post see:

"Jeremy -- when putting the web interface together I used the two idiots logo and was hoping you'd be OK with it on there. If you would rather us not use that logo I will replace it with something else just say so. My apologies for this appearing w/o you seeing it first. Just say the word if you'd rather it not be on there no worries at all."

I wanted you to see it on there and be happy to remove it if you prefer it not be there.

 

[Adirondackstihl]

I get royalties right?

I think it's cool!
I got a pic or two of it yesterday.

 

[malk315]

I get royalties right?

I think it's cool!
I got a pic or two of it yesterday.

We'll make sure you get a "kickback" or two...
Figuring wouldn't get any financial gain from this... like dumping dollars into CAD.

I'm a yutz for not PM'ing you a screenshot which I meant to do when I first made the web interface a week or two ago.
The orange font with white and black (Stihl or husky looking) was screaming for that two idiots logo up there...
Bill and I are the two idiots for this thing.

Anyway -- thanks... STILL bummed I didn't make the NY GTG this year.
Who knows -- next year maybe we can bring a complete one of these setup to take data runs quick.

 

[Adirondackstihl]

We'll make sure you get a "kickback" or two...
Figuring wouldn't get any financial gain from this... like dumping dollars into CAD.

I'm a yutz for not PM'ing you a screenshot which I meant to do when I first made the web interface a week or two ago.
The orange font with white and black (Stihl or husky looking) was screaming for that two idiots logo up there...
Bill and I are the two idiots for this thing.

Anyway -- thanks... STILL bummed I didn't make the NY GTG this year.
Who knows -- next year maybe we can bring a complete one of these setup to take data runs quick.

The font used is Coop Light if you wanna be official

 

[Danders]

Excellent work guys. I'm still trying to get my head around how this thing works. I think of horsepower as simply a function of torque and rpm, but the graphs kind of indicate some sort of disconnect there. It looks like the operator controls the resistance that the engine sees with the brake lever so that's likely it. You can spin the thing without applying resistance, and have no torque to measure. This is a cool setup - hat's off to all of you involved.

 

[Moparmyway]

WOW
I'm speechless
AWESOME!!!!!!

 

[Definitive Dave]

Two things
I want one and
I really want one
Amazing
Knowing is greater than guessing!!!

 

[drf256]

Two things
I want one and
I really want one
Amazing
Knowing is greater than guessing!!!

I want one with a Solo Twin mounted to it sitting on a NIB 090.

Dear Santa....

 

[malk315]

Excellent work guys. I'm still trying to get my head around how this thing works. I think of horsepower as simply a function of torque and rpm, but the graphs kind of indicate some sort of disconnect there. It looks like the operator controls the resistance that the engine sees with the brake lever so that's likely it. You can spin the thing without applying resistance, and have no torque to measure. This is a cool setup - hat's off to all of you involved.

You got it.

The caliper could just spin around if not attached to torque arm which pushes on the load cell. Bill has a couple of stops to catch the arm in case the load cell ever broke.

In the videos the torque reading stays around zero when piss reving and no brake active. Even better with latest mechanical setup.


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[stihl_head1982]

Wow...just...WOW....oh can I say WOW!

 

[Lootbug]

Wow, most impressive! Looking forward to seeing some numbers. Now all we need is a way to measure how effective a chain is and we're all set .

 

[Jose A.S.T.S.]

@malk315 awesome work man wow be able to tell guys what they really have rubber meets the data!!!! Talk about being able to fibe tune wow saws with potential to run like top fuel dragster wicked sweet. I would of never been able to put something like that together in a hundred yrs bro hats off genious!!!

 

[jmssaws]

Where does the line start?
I've been trying to get a couple saws dyno'd for a year.

This is kool,good work fellas

 

[olyman]

mm needs one of these for his shop..........

 

[malk315]

mm needs one of these for his shop..........

If we get it where it needs to be, I want to make sure Randy has one!

 

[paragonbuilder]

Y'all realize that when we get hard data, and realize that this is all pointless, Randy and the others that rely on porting for their bread and butter, are going to be out of a job...[emoji33]
He has been warning us that it's just a fad...


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[srcarr52]

Here is the curve estimate graph with the RPMs on the horizontal for a run of Bill's 372 -- this was before the first mechanical clean up of the load cell bouncing around. We went from like a 2 to 4 foot-lb. variance to only about 1 ft-lb variance. Combine that if needed with a decimation filter and I think we can get there:

Signal noise is a common problem with a friction brake, there is not enough damping in the brake response. This is why most dynos are hydro (water brake or oil pump) or electromagnetic, I hope you guys are able to clean up the signal noise with a low pass filter to where you can have reproducible results.

 

[paragonbuilder]

Signal noise is a common problem with a friction brake, there is not enough damping in the brake response. This is why most dynos are hydro (water brake or oil pump) or electromagnetic, I hope you guys are able to clean up the signal noise with a low pass filter to where you can have reproducible results.

Where were you a few months ago? Lol! We are learning as we go. Maybe Eric can clean it up? If not we may be back to a hydraulic system.
We had discussed doing a thread from the beginning but thought it would be too many opinions and people bugging us about it.
Pros and cons to everything...

I think we are in a pretty good place with it now.

 

[malk315]

Signal noise is a common problem with a friction brake, there is not enough damping in the brake response. This is why most dynos are hydro (water brake or oil pump) or electromagnetic, I hope you guys are able to clean up the signal noise with a low pass filter to where you can have reproducible results.

Yes -- that's what we're seeing. Next run I'm going to try sampling the load cell 10x more often and using 1/10th of each sample (decimation filter) to get it more under control. Bill already did a mechanical change that appears to have improved from a 2 to 4 ft-lb swath to a 1 ft-lb swath with the latest run.

If we do change to some other method for the power to push on a load cell that is smoother, the electronics can work the same -- so that's good for what I'm working on.

My day job involves linear synchronous motors and of course I've shared with some of the fellow nerds here the dyno project.
We were looking at eddy current brakes -- those would be ideal since there is no contact, should be perfect smooth power transition.
Some that go on exercise bikes are cheap -- one we looked at has a sort of cable to put the brake in a position that makes the eddy currents happen and create the braking force... with no friction contact.

Always open for ideas -- that's how we've gotten this far! Thanks.