Roswell Bob
Solar Enthusiast
Is 12psi the pressure we are trying to keep?
kgf is the same type of unit as lbf. Which for our purposes is the same as lb and kg.
300kgf is 660lbf. Cells are about 53.5 square inches on one side. So pressure is about 12psi. I can apply 12psi to 1 square inch with my thumb, so its not really a major load. In fact sufficient clamping force to prevent cell movement is probably at least 300lb unless some adhesive or rubber mat is involved.
is PSI the actual unit? Seems to me pounds should be the unit.I used these for my build. Cheap and easy to get. They have been easily handling the .200" of expansion my 8 cells have exhibited.
Its not odd for the application. Its a valve spring. The only thing that matters is pressure when the valve is open (compressed) and pressure when the valve is closed (still compressed but not as much as when the valve is open).
It is probably not PSI but in fact just straight up lbs. I missed the fact that it was in psi. Valve springs are application specific. The spring is made to go on a specific valve and the dimensions at closed are fixed so that spring on that valve has 125 lbs holding it closed. The open dimension can vary a bit based on the lift of the cam but not a whole lot so the open "pressure" is given for the stock cam. If you know the lift of the stock cam then you can calculate the spring rate and then the open "pressure" for a cam with more or less lift.Why would they be rated in PSI ..... for our use, we are going to have to figure out how to determine that actual spring pressure in Lbs or KG.
It isnt Melling, it is Orilly that hires people that have no idea what the data is that they are entering.Maybe @curiouscarbon would consider doing a little testing with his strain gauge ..... Just not sure I would trust that they meant to say lbs of force instead of PSI .... and is their spec really trustworthy if they don't know the difference?
hi!! thank you for your many engineering contributions that keep me on track. given the 280/300Ah cells vary approximately 0.5mm per cell over total State Of Charge curve, monitoring the Cell Wall Displacement seems valuable..Maybe @curiouscarbon would consider doing a little testing with his strain gauge ..... Just not sure I would trust that they meant to say lbs of force instead of PSI .... and is their spec really trustworthy if they don't know the difference?
Wow .... glad your on thisduring a test of a 1Kg rated load cell, with the same amplifier as to use with the 200Kg amplifier, the data signal resulted in a reliable discrimination of approximately 0.1 grams.
this was determined by comparing s reference object to a prevailing kitchen scale in grams, and by recording 30-60 seconds of samples at 320 samples per second, and taking the mean/average of the digital number reported each time, with that same reference object on the 1Kg load cell
this would linearly scale to a reliable discrimination margin of 20 grams with the 200Kg load cell
Yes. I measured them and came up with approximately 165 lbs/inch. I say approximately because my measuring "apparatus" was not exactly lab quality.Those look interesting .... the pressure rating is a little odd though. They rate at 125 PSI closed and 200 open. Did you do any measurements to determine for sure what the pressure was?
12psi is the target for the area we are concerned with, but the spec is 6 - 18psi for that area. We're not building furniture here. With a +/- 50% range, my crude measuring apparatus was sufficient for me.Is 12psi the pressure we are trying to keep?
Yeah, I think the units are a misprint. The marketing folks don't know the difference between a pound and a psi.is PSI the actual unit? Seems to me pounds should be the unit.
Valve Spring Rate
help.summitracing.com
OMG amazing characterization assembly!12psi is the target for the area we are concerned with, but the spec is 6 - 18psi for that area. We're not building furniture here. With a +/- 50% range, my crude measuring apparatus was sufficient for me.
Well, I did measure the amount of compression with my calibrated Mititoyo calipers to 3 decimal places... ????OMG amazing characterization assembly!
The Device Under Test acts in effect as a pumb bob!!! That is a Class 1 reference!
Great setup. Back in the day I’ve measured valve spring pressure using drill press and bathroom scales… Depth stop to measure open height etc.12psi is the target for the area we are concerned with, but the spec is 6 - 18psi for that area. We're not building furniture here. With a +/- 50% range, my crude measuring apparatus was sufficient for me.