Hey Glort and all!
Played round with the scfm again today, interesting things indeed...
Remade the spindle from a bit of what I think is EN8 bar stock...tough as nails, a bitch to machine cleanly, and a bastard to tap threads in... Reason: the previous spindle was made up from some free cutting steel I had laying around, it was a 'concept' mock up to test with... it served its purpose but started to run out of true around to 10 000 rpm mark and caused a bit of vibration... The new shaft with the old bowl runs nicely up till around the 18 or 19000 rpm mark, but then the bearings start to complain a bit and I have to back it down to about 17500 to 18000 rpm area to keep things reasonably happy... The bottom spindle bearing is the bugbear, I remember dropping it whilst I was assembling it... it might have dimpled the raceway...
I ran some gunk through the beast, 2 x 5l cans of wmo individually... the first was from a petrol engine service, the second was from a diesel engine oil change.
Markedly different behaviors and markedly different results... The petrol wmo, after 3 passes, thinned with 500ml of diesel after the first pass, ended up slightly darker than honey, kind of like when you do an oil change on the car, nip it round the block to test drive it, get home and check the oil...that sort of colour, not new, but just recently changed... The diesel wmo after 3 passes, also thinned with about 500ml or maybe a bit more, remained very dark, but not a 'dirty' dark as in stained skin black, but considerably darker than the petrol wmo. Of interest too, was the tailings left after each run. The petrol tailings were easy to clean and more oily/greasy than the diesel. The diesel, was almost rubbery,sticky, latexy, perished rubber band type snot that needed more scraping than wiping to remove....
It seems like the limiting factor on the rpm is going to be the wallet, last check, the ultra high rpm bearings were quite exy!
Tomorrows plan.... put some covers over the pulleys and belts, then rev the cr@p out of it properly and see if I can trash it! .... Any bets as to the frag rpm of a cast and machined Ali bowl, 10mm wall thickness and 95mm od?
Lets find out!
Keep it spinning...REALLY FAST!
Cheers
Ed
PS... scfm=scary candy floss machine!