I'm thinking that's what the McMaster spec sheets have done. Still... be nice to have a compression modulus, too. Though I can probably derive that from the ILD/PSI spec...
-Kurt On Thu, Sep 2, 2010 at 1:31 PM, David Cummings <[email protected]> wrote: > I think you're on track. And yes,I would concur that sample size would > change things from here: http://www.pfa.org/jifsg/jifsgs4.html > "It is also necessary to report the entire sample size. Sample size, > in addition to thickness, can drastically influence IFD readings." > > But you could just convert to PSI and have a uniform measure across > the board, right? > > -Dave > > On Thu, Sep 2, 2010 at 12:37 PM, Kurt Nolte <[email protected]> wrote: >> So... if I have a PSI (25%) deflection value of, say, 4... that would >> be a minimum ILD of 96 (4 pounds/square inch * 24 square inch minimum >> sample size), if I'm understanding correctly? >> >> The Foambymail quote seems to be saying they use a big foot (50 in^2) >> on a possibly much smaller sample (24 in^2); it would seem that ILD >> would thus depend on the sample size... >> >> -Kurt >> >> >> On Thu, Sep 2, 2010 at 10:21 AM, David Cummings >> <[email protected]> wrote: >>> From the foambymail website: >>> >>> ILD: Indentation Load Deflection - A measure of the load-bearing >>> capacity of foam. ILD is generally measured as the force (in pounds) >>> required to compress a 50 square-inch circular indentor foot into a >>> 4-inch thick foam sample no smaller than 24-inches square to a stated >>> percentage of the foam's initial height. Common ILD values are >>> generated at 75% of initial height. >>> >>> -Dave >>> >>> On Wed, Sep 1, 2010 at 11:06 PM, Kurt Nolte <[email protected]> >>> wrote: >>>> That's just it, man. I'm reading through McMaster's spec sheets for >>>> their closed cell polyethylene foam. The densities seem to cap out at >>>> 5 (with 2.3 and lower being more common) and a "PSI (% deflection)" >>>> spec instead of an ILD. I get a tensile strength, and occasionally a >>>> stretch limit range, but no compression modulus... I'm rather >>>> disappointed, this time around. >>>> >>>> I've used McMaster numerous times before, usually I get a lot more of >>>> the info I need than I am this time. >>>> >>>> -Kurt >>>> >>>> >>>> >>>> On Wed, Sep 1, 2010 at 10:45 PM, Allen Thomas <[email protected]> >>>> wrote: >>>>> Mcmaster carr sells practically everythin including any foam you could >>>>> want and the have spec charts to help you figure out what you want if >>>>> you don't know. >>>>> >>>>> On 9/1/10, Joey Kelley <[email protected]> wrote: >>>>>> I'm with Kyle on that one.... >>>>>> I had mine redone by a local guy, trying to start a name for >>>>>> himself in the upholstery business - it looks less like a 80s Honda >>>>>> seat now, more like an ATV, but I actually prefer it, looks cleaner. >>>>>> -Joey >>>>>> >>>>>> On Wed, Sep 1, 2010 at 8:58 PM, Kyle Munz <[email protected]> wrote: >>>>>>> Um, that's way over my "cut up the couch and steal the foam" level. :) >>>>>>> >>>>>>> -Kyle >>>>>>> >>>>>>> >>>>>>> On Wed, Sep 1, 2010 at 7:00 PM, Kurt Nolte <[email protected]> >>>>>>> wrote: >>>>>>>> >>>>>>>> So, let me bounce some stuff off you guys, since the specs listed on >>>>>>>> the DIYmotorcycleseat.com site don't seem to be standard with the >>>>>>>> suppliers I'm looking at. >>>>>>>> >>>>>>>> Since neither of my foam inserts are really in any decent shape to put >>>>>>>> back on the bike (lots of dry rotting and cracking), I'm looking to >>>>>>>> use one of them as a basic shape guide and just making something new. >>>>>>>> DIYms suggests a high density polyethylene closed cell foam as a base >>>>>>>> layer, but I'm not finding much info on the ILD and compression >>>>>>>> modulus specs on supplier websites. >>>>>>>> >>>>>>>> I do have specs for "PSI (% deflection)" which seems to be how much >>>>>>>> PSI (usually 4-9) it takes to hit (usually 25%) a certain compression. >>>>>>>> I don't know if this is comparable to ILD; anyone here know? Anyone >>>>>>>> here a materials engineer? >>>>>>>> >>>>>>>> Thanks! >>>>>>>> -Kurt >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Nighthawk Motorcycle Lovers!" group. >> To post to this group, send email to [email protected]. >> To unsubscribe from this group, send email to >> [email protected]. >> For more options, visit this group at >> http://groups.google.com/group/nighthawk_lovers?hl=en. >> >> > > -- > You received this message because you are subscribed to the Google Groups > "Nighthawk Motorcycle Lovers!" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/nighthawk_lovers?hl=en. > > -- You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en.
