making a 'flat' aluminum plate
making a 'flat' aluminum plate
(OP)
Hello all,
I have an application that requires an aluminum plate to be flat when mounted within a certain amount. It is approximately 70 inches x 18 inches x .50 inch. Taking out the deflection due to bending leaves me with an allowance for flatness of the plate of about .010 inch. In the past with stainless steel parts I have had problems when machining off the 'skin' on one or 2 sides and the part turned into a potatoe chip shape. Does anyone have any recommendations on machining/thermal processes to machine the part to required thickness and flatness?
Thanks,
Bob
I have an application that requires an aluminum plate to be flat when mounted within a certain amount. It is approximately 70 inches x 18 inches x .50 inch. Taking out the deflection due to bending leaves me with an allowance for flatness of the plate of about .010 inch. In the past with stainless steel parts I have had problems when machining off the 'skin' on one or 2 sides and the part turned into a potatoe chip shape. Does anyone have any recommendations on machining/thermal processes to machine the part to required thickness and flatness?
Thanks,
Bob





RE: making a 'flat' aluminum plate
RE: making a 'flat' aluminum plate
Interlakes Bases can give you a better tolerance and were nice people to work with.
http://www.alcoa.com/global/en/products/product.as...=
http://www.interlakesbases.com/productsindex.htm
I was about to forgot the best one..
http://www.tciprecision.com/index2.shtml
RE: making a 'flat' aluminum plate
As suggested, prefinished jig plate is your best bet. Thicker jig plate would be better yet.
I don't know what happened to your stainless parts, but cold working is part of the mill process for many aluminum tempers, especially in the 'high strength' alloys. If you take the skin off a cold- worked aluminum plate, you release some of the locked-in cold work strain that bestows apparent strength. The remaining strain should be _expected_ to warp the part, badly.
Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA
RE: making a 'flat' aluminum plate
Some aluminum alloys are more suceptible to machining induced distortion than others. Talk to a metalurgist at your supplier. The alloys marketed as "tooling plate" are usually the most dimensionally stable.
RE: making a 'flat' aluminum plate
Also your part could be mechanically straightened or flattened.
http://www.tciprecision.com/index2.shtml
RE: making a 'flat' aluminum plate
Standard mill thickness tolerance on the 18" width is +/- 0.023" while standard mill allowable deviation from flat for sawed or sheard plate is 0.1875 in any 6 feet longitudinal and 0.375 transverse.
On the other hand, I have never seen 1/2" plate any where near that bad. You'll ahve to measure it and get it ground as needed.
RE: making a 'flat' aluminum plate
http://www.designnews.com/article/CA270744.html
ProEpro
www.whitelightdesign.com
Pro/E FAQ www.whitelightdesign.com/servicestips.htm
RE: making a 'flat' aluminum plate
RE: making a 'flat' aluminum plate
The goal is reducing the delflections from unequal residual stresses after machining or chem-milling.
I don't have a lot of personal experience with this material, but have heard a lot of good things.
SuperStress
RE: making a 'flat' aluminum plate
The mounting sub-strate may boss the plate around. Depending upon the flatness of the sub-structure, the mount detail (2 inch diameter metal standoff?) and the number and location mounts, I'd anticipate I might have to shim to keep the plate neutral/flat at assembly. Or, even use the mounts to flatten/true the plate.
RE: making a 'flat' aluminum plate