nonmagnetic/electrically nonconductive/low outgassing
nonmagnetic/electrically nonconductive/low outgassing
(OP)
Hi,
I was looking for the right materials for a rack/pinion design to open a door. Here are some constraints.
Temp=160F
Pressure=10^-6Torr
all parts must be low outgassing, nonmagnetic and electrically nonconductive.
I thought of using aluminum for the door/rack/pinion since it is nonmagnetic. I then planned on using a class II anodize on the aluminum to make it nonconductive. However the anodizing will cause high outgassing which is not allowed. I am unsure exactly what other nonmetals would work under these conditions. I do know of nylon gears, however I understand nylon becomes brittle at high temperatures.
Any suggestions would be GREATLY appreciated.
Frank
I was looking for the right materials for a rack/pinion design to open a door. Here are some constraints.
Temp=160F
Pressure=10^-6Torr
all parts must be low outgassing, nonmagnetic and electrically nonconductive.
I thought of using aluminum for the door/rack/pinion since it is nonmagnetic. I then planned on using a class II anodize on the aluminum to make it nonconductive. However the anodizing will cause high outgassing which is not allowed. I am unsure exactly what other nonmetals would work under these conditions. I do know of nylon gears, however I understand nylon becomes brittle at high temperatures.
Any suggestions would be GREATLY appreciated.
Frank





RE: nonmagnetic/electrically nonconductive/low outgassing
Can you "bake out" your parts after production, hold at 200F and subject to the low pressure for a few days?
nick
RE: nonmagnetic/electrically nonconductive/low outgassing
Maui
RE: nonmagnetic/electrically nonconductive/low outgassing
RE: nonmagnetic/electrically nonconductive/low outgassing
Do you know what that would cost and what companies can do that? I was thinking of using Delrin, though I am unsure if it can handle the low pressure. I am almost positive it is low outgassing.
RE: nonmagnetic/electrically nonconductive/low outgassing
RE: nonmagnetic/electrically nonconductive/low outgassing
RE: nonmagnetic/electrically nonconductive/low outgassing
RE: nonmagnetic/electrically nonconductive/low outgassing
Or Pyrofolite , easy to machine, then baked hard
123cat
RE: nonmagnetic/electrically nonconductive/low outgassing
123Cat
RE: nonmagnetic/electrically nonconductive/low outgassing
RE: nonmagnetic/electrically nonconductive/low outgassing
RE: nonmagnetic/electrically nonconductive/low outgassing
RE: nonmagnetic/electrically nonconductive/low outgassing
RE: nonmagnetic/electrically nonconductive/low outgassing
RE: nonmagnetic/electrically nonconductive/low outgassing
RE: nonmagnetic/electrically nonconductive/low outgassing
RE: nonmagnetic/electrically nonconductive/low outgassing
Agree with choice of either 304 SS or an Al alloy. EN plating would provide wear & galling resistance.
Advise getting more competitive bids on the EN plating. If no masking and an easy-to-plate substrate (i.e., not free-machining leaded crap), 0.001" of mid-phos EN runs $0.10/sq. inch in my area. [However, your job would be a minimum lot charge of $75]. Surcharges for lengths more than 5 ft and for baking (advisable for gearing).
Lots of machine shops are looking for work. $2000 is outrageous unless there is some geometry I don't understand. What do you mean by a 3/8" high x 6 ft long gear (or is this the rack?).
RE: nonmagnetic/electrically nonconductive/low outgassing
RE: nonmagnetic/electrically nonconductive/low outgassing
the cheap/quick anodizing processes produce a thick and porous film, but the modern solutions leave a uniform hard film that is abs. okay.
304 ss is non-magnetic until you machine it otherwise cold work.
you can reduce the need for non conductive materials if you incorporate insulating bushings or washers in your design