Estimating wear of hard anodized aluminum
Estimating wear of hard anodized aluminum
(OP)
I originally posted this in the Tribology forum, but it seems pretty quiet over there...
We are designing a cheap and cheerful linear guidance assembly using a formed sheet metal carriage supported using dirt-cheap skatewheel bearings within a hard anodized aluminum extrusion.
A vertical load of approximately 20 pounds will be supported by two 18mm (OD) bearings acting as wheels and rolling along the extrusion. There will be a moment load on the carriage that will be taken by the same type of bearing mounted within a delrin disk.
There is some concern about the wear of the aluminum with hardened steel bearings running on it. Our equipment often goes into food plants (not in the food processing area, though) and it is felt that visible metal wear particles would be offensive to many of our customers.
Is there a way to calculate an estimated material wear of the aluminum based on rolling-contact point loads? I've done some Googling without success. Any help is appreciated.
We will be doing physical tests of a prototype, but I want to move more quickly than that would allow.
Thanks,
Dean
We are designing a cheap and cheerful linear guidance assembly using a formed sheet metal carriage supported using dirt-cheap skatewheel bearings within a hard anodized aluminum extrusion.
A vertical load of approximately 20 pounds will be supported by two 18mm (OD) bearings acting as wheels and rolling along the extrusion. There will be a moment load on the carriage that will be taken by the same type of bearing mounted within a delrin disk.
There is some concern about the wear of the aluminum with hardened steel bearings running on it. Our equipment often goes into food plants (not in the food processing area, though) and it is felt that visible metal wear particles would be offensive to many of our customers.
Is there a way to calculate an estimated material wear of the aluminum based on rolling-contact point loads? I've done some Googling without success. Any help is appreciated.
We will be doing physical tests of a prototype, but I want to move more quickly than that would allow.
Thanks,
Dean





RE: Estimating wear of hard anodized aluminum
RE: Estimating wear of hard anodized aluminum
In that case, with only a 20 pound load the thing will last pretty much forever.
RE: Estimating wear of hard anodized aluminum
RE: Estimating wear of hard anodized aluminum
run a test. It really sounds
like your are doing everything
on the cheap. The military has
used steel pinions running against
aluminum that was anodized.
Do not know if they will make
their information available to
you. Check out the turret bearings
used in many of the tanks.
RE: Estimating wear of hard anodized aluminum
RE: Estimating wear of hard anodized aluminum
While we aren't looking to design something "on the cheap" we are certainly looking to make it as inexpensive as possible. Given the low loading, low speed (it moves about 3/8" every 2-4 seconds) and low precision requirements of the guideway, we felt that we could make our own linear guide much more cost effectively than using the linear bearings and shaft than we use now.
Mint: due to space constraints we can't fit anything that large, but we do have a source for a similar bearing with a urethane "wheel" that we can consider if this doesn't work. The extrusion is a 4" x 2" aluminum C-channel with additional flanges, as below:
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| '
|
|
| ,
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Within this channel we need to fit a cylinder, wheels to support vertical, horizontal and moment loads. Plus the carriage will be nearly flush with the outer flanges. It will be a very tidy, clean and easy-to-assemble component, vastly superior in every respect to what it replaces.
diamond and rnd2: Personally, I'm not concerned. The people in the company that are concerned are non-engineers who don't appreciate how hard the anodized aluminum is, and how lightly loaded the application really is. The biggest naysayer just happens to have his own pet solution, so there is some not invented here going on.
Thanks for the ideas, guys.
Dean
RE: Estimating wear of hard anodized aluminum
The question is will the steel bearings stand up to rolling over the hard anodized aluminum? I read a report that hard anodized aluminum is the second strongest material next to Diamonds.
Tofflemire
RE: Estimating wear of hard anodized aluminum
RE: Estimating wear of hard anodized aluminum
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Estimating wear of hard anodized aluminum
cooperjer
Cooperjer
Mechanical Engineer