Powered by Invision Power Board


Forum Rules Forum Rules (Please read before posting)
  Reply to this topicStart new topicStart Poll

> 90 Degree Shaft Coupling - Spring? Wire Rope?
ingre_dients
Posted: August 24, 2009 04:57 am
Reply to this postQuote Post


Newbie
**

Group: Members+
Posts: 19
Member No.: 25,822
Joined: August 23, 2009




Hi,

I'm new to the forum but saw this section and thought I'd post a Q here.

Does anyone know what the smallest, simplest way is to transmit a shaft rotation 90 degrees is?

Bevel gears are sort of out of the question for me I think b/c of price and having to position them, etc.

I've made many spring couplings, but I've had trouble with the springs forming a curvature after time (and hence a very wobbly.. result). THe springs however were hand made and heat-treated in a toaster oven - so they probably weren't done right!

But I've never messed with wire rope, o-ring cord, or anything like that - if there are any ideas, I'd be happy to hear. Or, if someone knows something about these springs that I don't.

Just for reference, I have been using a 1/16" shaft turning with a friction-fit spring around it made from something like .016 spring wire.

I know they make some fancy wire rope couplings that are expensive, and I'm not sure how they are made, but I've only seen them long - like 6 inches or something, where I'm looking for something shorter, much more light-duty, less expensive, and that I could possibly make my darn self.
PMEmail Poster
Top
MacFromOK
Posted: August 24, 2009 07:11 am
Reply to this postQuote Post


Forum Addict ++
*******

Group: Spamminator Taskforce
Posts: 14,142
Member No.: 5,314
Joined: June 04, 2006




Depending on the load, a rubber wheel (or one with a rubber tire/o-ring/etc.) running on the flat surface of a rotating disc should make a decent 90 friction drive in a small area.

If desired, you could even change the drive ratio by setting the rubber wheel nearer/farther from the disc center.

Also, a round (or pointed) edge on the rubber wheel will heat (and wear) less, as the surface speed of the disc changes with diameter, and you want to span as little of this variance as possible with the rubber wheel.

Something like this perhaps (a bit smaller disc/wheel could be used).
CODE

       _
      | |
      | | Disc
      | |
      | |
 _____| |_
 _____| |_|
      | |         Rubber
      | |       _ wheel
      | | _____|_|_____
      | |<_____________>
      |_|      | |
               | |
               | |


Just a thought.

Knowing more about the load and application would probably help. beer.gif


--------------------
Mac *

"Basic research is what I'm doing when I don't know what I'm doing." [Wernher Von Braun]

* is not responsible for errors, consequential damage, or... anything.
PMEmail Poster
Top
Sch3mat1c
Posted: August 24, 2009 01:19 pm
Reply to this postQuote Post


Forum Addict ++
Group Icon

Group: Moderators
Posts: 19,554
Member No.: 73
Joined: July 24, 2002




Two CVs?


--------------------
Answering questions is a tricky subject to practice. Not due to the difficulty of formulating or locating answers, but due to the human inability of asking the right questions; a skill that, were one to possess, would put them in the "answering" category.
PMEmail PosterUsers Website
Top
tekwiz
Posted: August 24, 2009 07:45 pm
Reply to this postQuote Post


Forum Addict ++
Group Icon

Group: Moderators
Posts: 28,711
Member No.: 5,746
Joined: July 24, 2006




For very small apps, you basically have 2 choices; A flex shaft, like a speedometer cable, or bevel gears. The flex shaft will require much more space, as there are severe limits on the minimum radius it can assume. Look around, as there are bevel gears made in virtually any size you could possibly want. cool.gif

BTW: Price need not be an issue, as you can likely scrounge something that has suitable gears in it. Positioning need not be an issue either, as you have to position the shafts at 90 anyway.


--------------------
Trouble rather the tiger in his lair, than the sage among his books.
For to you, kings & armies are things mighty & enduring.
To him, mere toys of the moment, to be overturned at the flick of a finger.

Fortuna favet fortibus.
PMEmail Poster
Top
ChipUser
Posted: August 24, 2009 11:40 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Trusted Members
Posts: 2,406
Member No.: 15,445
Joined: May 30, 2008




If the spacing between the two shafts is not critical, how about using dial-cord like pulleys & belt arrangement? You will need about 4 pulleys. Two of the pulleys will be oriented in a direction that is at 90 deg to the pulleys on the shaft and in parallel. The remaining two pulleys will be mounted on the shafts. Hope I haven't confused you with my description.
PMEmail Poster
Top
ingre_dients
Posted: August 26, 2009 04:47 am
Reply to this postQuote Post


Newbie
**

Group: Members+
Posts: 19
Member No.: 25,822
Joined: August 23, 2009




Thank you all very much for the replies and sorry about this late reply.

Those are great designs. I really like the rubber roller with disk in the diagram that you posted MacFromOK. I would never have thought of that. I think thats a great idea because of the simplicity and because of the range of speed.

Thanks for giving me more confidence on the bevel gear idea too tekwiz, maybe they are something to try as well if I could get a housing that is minimal enough. I've never really used gears very much, only lots and lots of pulleys, but I will give it a try.

I think I may know what you mean about the dial-cord pulley system Chipuser. I've used a lot of pulleys but have never tried that, and it seems a little complicated but also within my range of ability.

Thanks a lot for the comments, being new to the forum I'm totally amazed at the knowledge here and would like to be able to contribute soon and keep the ideas moving.
PMEmail Poster
Top
tekwiz
Posted: August 26, 2009 06:45 pm
Reply to this postQuote Post


Forum Addict ++
Group Icon

Group: Moderators
Posts: 28,711
Member No.: 5,746
Joined: July 24, 2006




Unless you are running at high speeds for extended times, you may not need a housing at all. wink.gif


--------------------
Trouble rather the tiger in his lair, than the sage among his books.
For to you, kings & armies are things mighty & enduring.
To him, mere toys of the moment, to be overturned at the flick of a finger.

Fortuna favet fortibus.
PMEmail Poster
Top
BlueVanACD2005
Posted: August 26, 2009 10:37 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Cleanup Taskforce
Posts: 2,230
Member No.: 4,841
Joined: April 16, 2006




I think he means something between the gears as opposed to an enclosure type thing? I sort of picture a small peice of angle metal with two 90 degree shafts through it...

-Spenser
PMEmail PosterUsers WebsiteYahoo
Top
0 User(s) are reading this topic (0 Guests and 0 Anonymous Users)
0 Members:

Topic Options Reply to this topicStart new topicStart Poll

 


:: support us ::




ElectronicsSkin by DutchDork & The-Force