Shigley's Mechanical Engineering Design (5th, 9th and 10th editions) say "set removal should not be used when springs are subject to fatigue". It provides no explanation.
I am working on a helical compression spring and this confuses me. The residual stresses created by presetting should...
You might look into something called DiamonDyze. I have no experience with it and hence can not endorse it. Not sure if the base coating is decorative or hard anodize. Probably not available in China.
This is where I read about it:
http://www.pfonline.com/articles/diamondyze-in-the-rough
I would consider an EN (electroless nickel). It is hard and "lubricious". You will have to determine the best phosphorus content. I think the biggest risk would be the coating tearing off starting at a flaw in the coating. But in my opinion it would be worth a try. I don't know how the cost...
And what exactly are you trying to say Mr. Locock? Just say it.
Factory specs:
front toe: +/- .12"
front camber: -0 deg 5'
rear toe: +/- .12"
rear camber: -0 deg 55"
I took the car back to the alignment shop. They poked and prodded and checked the alignment. Couldn't find anything wrong...
I was mistaken about tire size. The size on the door placard is 185/70R14. The tires on the car are 195/70R14.
My alignment is (or was a month ago) front toe +.0625" with 0 camber both sides, caster is +3 deg/+3.5 deg. Rear toe is 0, rear camber is -.5 deg both sides.
It seems to be...
The door placard says 32 psi front, 30 psi rear. By my simple calculation, this means 1.7 psi lower tire pressure (a 185 should be 5% narrower than a 195). The diameters should be very close.
Ciba, it will take me some time to translate and digest your information, but I appreciate it. I am...
I was trying to make a long story short, but here are the details.
The vehicle is a 1995 Subaru Legacy. My reward in life for 25 years of being an engineer. I purchased it with 104k on it, it now has 175k miles on it. The tires are 195/70R14. The standard tire size is 185/75R14, so they are...
I have handling problems which I am convinced are related to my tires. I get an incredible amount of steering feedback, tramlining & sensitivity to any groove or rut in the road, a pull to one side depending on the camber of the road, some bump steer, and in spite of the tendency to wander, it...
"Like Dissolves Like". It makes sense that this general solubility rule applies to solids too, and hence there will be more inherent adhesion between two identical polymers then there will be between two dissimilar materials. In addition, PTFE does not have very good wear resistance. I spite...
Looking for a good book on Tribology. Many advances are being made, so I want something published within the last couple of years. I am interested in sliding performance, not rolling performance, and lubrication. Looking for both theory and practical information. Any recomendations?
How...
The product claiming 1% compression set is Cytec RN-3039. While I have not performed compression set, creep, or rebound tests on this material, we did make a prototype part and this material has amazing rebound for a urethane. Unfortunately other properties do not quite meet our requirements...
What about casting urethane between the two metal pieces? Does this thing need to be dissasembled? If not, you could bond them together when casting. A primer is likely required to achieve an acceptable bond to metal.
Regardless of the disassembly issue, many urethanes are easy to work with...
It depends on many factors, but I think a cloth reinforced panel with Vf = 50% and low voids should be in the 7-8 ksi range. I seen up to 12 ksi with epoxy/glass uni-broadgoods and generally vinylester has similar properties to an epoxy at room temp.
You want fibers in this resin, right?
Thanks Polym3. I have found a thermoset urethane which claims 1% compression set (maybe too good to be true?), so I will give it a try.
Creep and compression set are the same thing in my book. I don't have a good feel for why thermoset urethanes generally have such poor compression set...
I am looking for an elastomer of approximately 70A hardness which exhibits very low creep. I am currently using a thermoset urethane. While testing is not complete, preliminary results do not look good.
What type(s) of elastomers typically exhibit the best creep performance?
The...
I'm a little rusty here, but if volume fraction fibers = .5, then (.5 x 12,000 ksi + .5 x 400 ksi) = 800 ksi. So using a resin of modulus 400 ksi and a vf = .5 you should be good to go.
I'm not sure what Greg is proposing, but I suspect this is a reiteration of his suggestion. Vibration is a killer on tracked vehicles, and two roadwheels connected to a single structure with the structure able to pivot freely should be an effective defense if the two road wheels are spaced out...
Can anyone give me an allowable fatigue stress for 3/8" diameter titanium spring wire? I need 4 million cycles of life, which I am assuming is near the endurance limit.
I am trying to design a helical round wire spring which acts as both a torsional and compression spring. I am using the Von...
