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View Full Version : Working with Precision Steel Shaft from McMaster (Round rails for linear motion)



Fasttrack
08-26-2014, 03:27 PM
Looking at buying some of below material from McMaster-Carr. I was wondering if anyone has worked with this stuff in the past. Can you cut it to length? Add more holes for mounting? Etc? They say it is a hardened steel shaft with an aluminum support. It isn't clear to me how the two are held together. I was thinking I could cut it to length using a thin abrasive wheel to get through the steel and then a bandsaw on the aluminum. What says the braintrust?

http://www.mcmaster.com/#59585k83/=tg8t4z

Paul Alciatore
08-26-2014, 03:59 PM
Grainger has a similar product, at a higher price, of course. Perhaps you could see one at a local Grainger store.

http://www.grainger.com/search?gclid=CjwKEAjw4PCfBRCz966N9pvJ4GASJAAEdM_KU mtb4wSn8zOTRYfFtyZLhsZ33BoW_PQMS2elsXvp7xoCwIrw_wc B&searchQuery=Shaft+Support+Rail&cm_mmc=PPC:+Google+Main+4-_-Power%20Transmission%3ELinear%20Motion-_-Linear%20Shafting%20and%20Support%20Rails%3EShaft% 20Support%20Rail%3EBroad-_-Shaft%20Support%20Rail&ef_id=UyZSpAAABZN4jSgR:20140826194620:s

Most such products are held together with screws from the bottom. Look carefully at this.

http://www.thomsonlinear.com/downloads/bearings_guides/RoundRail_LinearGuides_Components_cten.pdf

And, NO I haven't used any in my designs due to the cost. I have used products with these rails in them; expensive products. I would think that the aluminum base would be easy to machine if you want to add more holes for mounting. I would not count on adding more holes in the steel rail. And if you need shorter lengths, I would order them that way so that there would be sufficient screws holding the rail to the base at the right places.

Rosco-P
08-26-2014, 04:23 PM
Try: http://www.thomsonlinear.com/website/com/eng/products/linear_guides/linear_ball_bushing_bearings.php

for tech advice.

Bob Fisher
08-26-2014, 04:42 PM
You can cut it like you said, but I doubt you can drill and tap it. That stuff is like Rc 60. Bob.

Fasttrack
08-26-2014, 05:18 PM
Just to clarify, I was talking about adding holes to the mount. McMaster said it was aluminum but I wanted to be sure. Thanks for the link to Thomson Linear. I will check them out!

Spin Doctor
08-26-2014, 07:25 PM
The rails are case hardend. Use carbide to break through the case and drill and tap normally. Just make sure the top of the hole is equal to or larger than the tap size

dian
08-27-2014, 11:01 AM
how does steel and aluminum work together in this? is that glued, screwed?

QSIMDO
08-27-2014, 11:09 AM
http://www.mcmaster.com/#catalog/120/1095/=tgo5oy

projectnut
08-27-2014, 12:44 PM
We used Thompson shafting for lots of linear motion applications. As mentioned the aluminum support is bolted to the shaft. The rod is case hardened to about .030". If you need to tap additional holes in the shaft you can usually break through the hardening with a center punch. Then just drill and tap as you normally would. In extreme cases we just used a carbide drill.

David Powell
08-27-2014, 12:55 PM
We used Thompson shafting for lots of linear motion applications. As mentioned the aluminum support is bolted to the shaft. The rod is case hardened to about .030". If you need to tap additional holes in the shaft you can usually break through the hardening with a center punch. Then just drill and tap as you normally would. In extreme cases we just used a carbide drill.

Thompson shafting is hardened to about 30 -40 thous deep. Once you are through that it is fairly soft( Annealed 4140 comes to mind as being similar to machine). IF the shafting has been cut by grinding all the way through the cut ends will be hardened.I used to grind a groove round through the case hardening and cut with a hand hacksaw. Hope this hint helps. David Powell.

Rustybolt
08-27-2014, 01:19 PM
It's the same as Thompson shafting. You need an abrasive cut off wheel to cut it to length. I use a cut off wheel in a 41/2 inch angle grinder. You can cut through the case with a grinding wheel and then drill it and tap it. For a through hole you'll have to grind away both sides. You can mill it or drill it with carbide tooling.
if you're going to tap it just make sure you grind or mill away all the case. Otherwise broken taps and tears.