Connect stainless stell with aluminum profile

[brdf]

We are building a light detection system which works like a clock’s hand: an aluminum profile (the “hand”,shown in schematics) carrying detector assemply on its one end rotates around the other end; as the aluminum profile is quite long (2200L*40W*40H mm) and heavy (~10kg)， we will add a counter-weight to the other end of the hand to reduce the torque.The hand rotates around the center of the system through the inner part of a cross-roller bearing. The question is, is there any “off-the-shelf design" of a stainless steel “connection block” that connects the aluminum profile, the bearing and the counter-weight?

 

[MikeHalloran]

I don't recall seeing such a thing in the 80/20 catalog, but that was a long time ago.

Are the stresses so high that you need stainless steel?
I.e., if you have to make it a custom part, as I suspect, I'd look at an aluminum alloy billet.



Mike Halloran
Pembroke Pines, FL, USA

 

[brdf]

Mike,

We conjectured that a stainless steel would be a more reliable choice, but it will be up to the machinist who actually does the work. Thanks for your suggestions.

hz

 

[dinjin]

Curious as to why a cross roller bearing rather than a ball bearing.
I would assume the cross roller would have greater torque requirements.

 

[MikeHalloran]

Uh, brdf, you need to get an actual engineer onsite.
Learning everything the hard way gets expensive fast.




Mike Halloran
Pembroke Pines, FL, USA

 

[c0rd0bes]

to be fair it looks simple, I presume it is not motorised? you are simply rotating a balanced load at no speed

Get the machinist to mill you a block for the bearing and turn a spigot to connect both.

Also using aluminium and stainless steel together in un-ideal conditions can cause corrosion

 

[MikeHalloran]

Yeah, it looks simple, but I'm not convinced that brdf knows what a crossed roller bearing is, and leaving material selection up to a machinist is scary. He needs someone on site to look over the stuff he hasn't told us yet.





Mike Halloran
Pembroke Pines, FL, USA

 

[racookpe1978]

On the other hand, for a one-of, test or trial install - the machinist's boss will want to charge the original poster for as much as the machine shop can get away with. Or, he (the machine shop) will try to use whatever-he-can-grab-from-the-junkpile to save HIS shop money while charging the orignal poster as much as was on the original estimate.

I agree: If it is a light load, use a simple Al block: it is easier to machine all at one time.

 

[GregLocock]

Did you think of making the "hand" symmetrical then you don't need any fancy balance weight, just more of your extruded section?

If the crossed roller bearing (neat by the way) proves too spendy then you can probably do the job with an oversized deep ball bearing, or definitely with two taper roller bearings facing each other.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[MintJulep]

A little creativity with your framing system components and two of these: