Source for shock absorbers

[RobS]

Hey Mark, how about the gas struts that hold open most car trunk lids and such? These are available as replacements in a variety of sizes at most auto stores. You'll get some additional spring rate in one direction but should get the damping you want in both directions. Pretty cheap too /w3tcompact/icons/smile.gif

 

[MChalkley]

RobS - That's the sort of thing that would work, but so far all the ones I've looked at are way too long. Maybe I haven't hit on the right source yet, though. I'll keep looking.

 

[RobS]

I can't tell you where Mark, but I know I've seen fairly short gas struts somewhere. Most modern office chairs have one inside for the heighth adjustment (though with an closeable valve). Maybe a call to Steelcase would net a supplier name /w3tcompact/icons/smile.gif

 

[ddl]

in a mechancal system, the shock is resistance or a mechancal resistor, springs are the capacitor and the mass of the body that you are trying to smooth out is the Mass or inductance. Since it is your body that you are trying to smooth out you body is the mass. So the RLC product is the time constant and 5 time constants the movement should stop. If you want a soft stop, you under damp the RLC, if you want a harder ride you over damp.

Dan L

 

[Egon]

Comfortal seats:
Perhaps try implement dealers that sell large agricultural tractors [Doesn't matter what color] or places that supply the big truck seats [ truck repair shops] If need be you may have to purchase an entire unit which would be pricey but the cost of a new back is also quite pricy. A tired back does not make for finishing work.

After bouncing around on my B7100 for 4 or 5 hours I can barely walk.

Egon

 

[Charlie_Iliff]

ddl
I know teachers who have worked years figuring how to explain electricity in mechanical terms. Now I see they had it backward.

 

[MChalkley]

Well, I spent most of yesterday visiting half a dozen truck parts places, several heavy equipment outfits, 4 ag/compact tractor dealers, and 3 different auto parts chains. Nobody had anything that even remotely resembles what I need. I ended up buying a gas-charged strut that's the right length, but is way too stiff for my needs, I think. We'll see.

I think my only choice is going to be to find a manufacturer of these things and match up something, or buy a whole new seat. I found a company, called Enidine I think, that makes exactly what I'm looking for. They call it a "rate controller", and it's adjustable for different compression and tension settings. Unfortunately, they make them too big and too small, or close to the right size with completely wrong ends. So, I may have to buy something close, cut the ends off, and weld the correct ones back on. So much for the warranty...

 

[Von]

Mark, Did you check any bike shops yet? I think you might be surprised at what you find. The rear shocks on mountian bikes are about the size that you are talking about. I rent out my carrage house to a bike shop and they have all different kinds of them. Or do a search on line and see what you find.

 

[MChalkley]

Von - Do you mean motor bike or pedal bike? I tried one small motorcycle shop, thinking that's what you meant, but they didn't have anything close.

 

[Von]

Mark, Pedal bike. Not motorcycle.

 

[Von]

Mark,Here is a site that might be of help to you. I don't know how to make it a link but here is the address. http://www.mtbreview.com/reviews/rear_shock/

 

[MikePA]

<A target="_blank" HREF=http://www.mtbreview.com/reviews/rear_shock/>Here's the link.</A>

 

[MChalkley]

Von - There's some pretty interesting stuff in the bike shock world, alright. I had no idea. It's been a long time since I did any serious bike riding.

I looked at about 6 different shock manufacturer sites, but none of them tell you the dimensions of the shocks. They all mention that they make the best there is, of course, but they only say which bikes they fit, which doesn't help me much. So, I printed off the phone numbers for the ones that seemed to have the widest range, and I'll call them Monday. Thanks for the lead!

 

[bgott]

What big city are you close to? I tried punching " truck parts eastern virginia" into google and came up dry. From your posts it sounds like you get around some, when you're going out of town hit the yellow pages from where you're going. Try a Mack or Peterbilt dealer. If they don't have it they can direct you to an independent.

 

[MChalkley]

bgott - I'm about halfway between Richmond and Norfolk, with Richmond being a lot easier to get to and get around in traffic-wise.

I went to Richmond and looked at Peterbuilt, Volvo and independent truck parts dealers. One of them let me go back in the warehouse and showed me everything they had - they had a couple dozen different shocks, but there was nothing even close.

 

[ddl]

I have been tring to figure out if your cpmment was postive or not, but as I tell my students, everything follows the rules of physics wheather in the mechcanial system or the electrical system or even the fuild system. The biggest problem with a lot of physics classes is that they treat all systems seperate instead of looking at chararistics of a system such as force, which is wieght in mechcanical, voltage in the electrical or temp change in the heat. This is fun talking about this. Oh by the way, the tuned supension of a car is just a tuned MCR circuit just like a tuned electrical circuit.

Dan L

 

[bgott]

Any room for an air bag?

 

[MChalkley]

bgott - Yeah, I think so. Do air bags have a controlled release valve?

 

[MarkV]

Mark,

<font color=blue> Do air bags have a controlled release valve?</font color=blue>

Sure they do! Don’t you remember the ones you put under someone’s seat cushion to get that funny noise a certain body function makes?/w3tcompact/icons/blush.gif

MarkV

 

[MChalkley]

MarkV - That wouldn't be much different from what I've got now, at least from the sound of it. Those rubber stops at the bottom of the seat travel are pretty brutal...