Cal Club Autocross Forums

Just wondering if anyone has a good source that is relatively inexpensive.

There's actually a manufacturer in Chatsworth, I forget the name. But they run about $400 each.

I assume it's for suspension position? I have some ideas about building a home-brew one. I'm in Porter Ranch, email me if you're interested in working on it.

Most linear potentiometer's run $300 to $400. A cheaper, less accurate method is a string potentiometer, I have one if you want to borrow.

What data aquisition and sampling rate are you using?

Will Kalman wrote:There's actually a manufacturer in Chatsworth, I forget the name. But they run about $400 each.

I assume it's for suspension position? I have some ideas about building a home-brew one. I'm in Porter Ranch, email me if you're interested in working on it.

Yes it would be used as a shock sensor, I know Motec has them for $288.00 each. I will let you know as soon as we find out what direction we decide to go.

Tin Bui wrote:Most linear potentiometer's run $300 to $400. A cheaper, less accurate method is a string potentiometer, I have one if you want to borrow.

What data aquisition and sampling rate are you using?

I don't have a system yet, we used to have max q but that was pretty useless. I was interested in getting the chasecam data module but I'm afraid it would be similar to how the max q would have been, however the software does look more promising.

If I were to go in this direction, I would probably use a DL-1

I have a Traqmate which is nice because of the Display unit. Problem is sampling rate, fastest I believe is 40ms.

But I prefer the DL1. It would be good for your application because it has very quick sampling rate (good for suspension travel measurement). Software interface is not so great, but you get used to it.

We use the DL1 at work for not so critical data taking, we have higher grade DAQs for all other jobs. I recommend the DL1 for your application.

String potentiometers would probably not work due to reel inertia, air pulling at the string, and string slack at the frequencies seen in suspension movements.

I have a DL1 but I'm uncertain if the 100Hz sampling frequency will be fast enough. If it's not fast enough, I have an idea to build an oversampling front-end to the DL1.

Will Kalman wrote:String potentiometers would probably not work due to reel inertia, air pulling at the string, and string slack at the frequencies seen in suspension movements.

I have a DL1 but I'm uncertain if the 100Hz sampling frequency will be fast enough. If it's not fast enough, I have an idea to build an oversampling front-end to the DL1.

Dudes Toby has been working with on the suspension were saying they've been able to get useful suspension data with pots sampling as low as 60hz, but that's second hand, so I dunno. Certainly would lose a bit of the light vibration data.

Aaron Goldsmith wrote:Dude's Toby has been working with on the suspension were saying they've been able to get useful suspension data with pots sampling as low as 60hz, but that's second hand, so I dunno. Certainly would lose a bit of the light vibration data.

Toby's using string pots? Not sure if you're referencing sampling speed or string pot issues or both.

Will Kalman wrote:

Aaron Goldsmith wrote:Dude's Toby has been working with on the suspension were saying they've been able to get useful suspension data with pots sampling as low as 60hz, but that's second hand, so I dunno. Certainly would lose a bit of the light vibration data.

Toby's using string pots? Not sure if you're referencing sampling speed or string pot issues or both.

We're not using anything and I think those dudes are using Linear Pots.

Aaron Goldsmith wrote:

Will Kalman wrote:

Aaron Goldsmith wrote:Dude's Toby has been working with on the suspension were saying they've been able to get useful suspension data with pots sampling as low as 60hz, but that's second hand, so I dunno. Certainly would lose a bit of the light vibration data.

Toby's using string pots? Not sure if you're referencing sampling speed or string pot issues or both.

We're not using anything and I think those dudes are using Linear Pots.

I read your repsonse as "Dudes, Toby has been working..." LOL

Search on LVDT's too. The sensor operates and outputs AC voltage, but you can find some that have DC converters in them. LVDTs are more accurate, faster response and much, much longer life (no physical contact). Besides the AC, other down side is they error over temperature ranges.

Jay W

Jayson Woodruff wrote:Search on LVDT's too. The sensor operates and outputs AC voltage, but you can find some that have DC converters in them. LVDTs are more accurate, faster response and much, much longer life (no physical contact). Besides the AC, other down side is they error over temperature ranges.

Jay W

don't worry, after looking at LVDT's and finding out how much they cost, 400 bucks for linear pots will seem cheap.

my butt POTS are calibrated well enough

Jonathan Lugod wrote:my butt POTS are calibrated well enough

Um, that's not where you install them!

Jeff Wong wrote:Just wondering if anyone has a good source that is relatively inexpensive.

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