Flex Couplings

[drk]

Hi,

Can anyone suggest some good sources for flex-couplings.

Thanks



Dev

[phantomcow2]

Well you can use Helical beam couplings, which will run you 20-30 each frm McMaster Carr.
THerse also Lovejoy type, 2 hubs and a spider. These are very economical, i got enough for 3 axes for a cnc mill for the cost of one helical beam coupling. THey allow for good misalignment, and seem to have no detectable backlash.
McMaster Carr all the way though.
ALso, SDP-SI has couplings too i believe, they ship pretty fast

[widgitmaster]

http://www.use-enco.com/CGI/INPDFF?P...&PARTPG=INLMK3

https://reidecom.reidtool.com/xephr/...T_WITH_ID=4214

http://www1.mscdirect.com/CGI/NNPDFF...6&PMT4TP=*LTIP

http://www.herbach.com/Merchant2/mer...t_Code=MEC-002

http://www.robotmarketplace.com/mark...echanical.html

http://www.surplussales.com/ShaftHar...ShaftH-10.html


Here is a wide variety of designs and prices!
Eric

[drk]

wow,
long list,

thanks guys

[ahren]

I highly recommend the lovejoy couplings from Enco. You order them as 3 parts, the two chaft connections and the spider in the middle. The shaft connectors are only $1.94, and the spider is $1.27, so your total cost is just over $5 a coupling. You can get different size couplings for each side, which is great -- I bought a 3/8" to fit my motor shaft, and a 1/2" to couple directly to my 1/2-10 ACME rod. The couplings are steel, even though they are listed as plastic, and the spider is a rugged buna material.

If you can get together a list of stuff you need, enco constantly sends out codes for free shipping for orders over $50. If you're going with the ACME rod approach, this is a great source for that as well. www.use-enco.com.

[loves80z]

I don't think the spider type are zero backlash. I don't know what U are using them for though.

[ahren]

The spider in these couplings fits tightly in between the two halves. You are correct that some backlash may occur if this material compresses during movement. However, I think for most hobby machines, these may be good enough. We use these sorts of couplers (although not these exact ones) on belt drive pick and place robots here, and achieve backlash of less than .001". Granted, there isn't a cutting load on these machines, so take that with a grain of salt.

I'll have some more info when I finish my machine, which is imminent. Once I'm done, maybe I'll start a project log.

[phantomcow2]

they are not zero backlash, but have very little. Nothing that cant be compensated using software in my opinion

[widgitmaster]

With all the machinery I have used or repaired in my lifetime, I have always thought the flex couplings were to be used to correct slight misalignemnt of the motor shaft to the screw shaft end. That all backlash in the screw would be controled by the end support bearings!
The remaining backlash would be from the nut!

If the screw were to be mounted directly to the motor, there is an anti-backlash coupling designed specifically fo that!

Eric

[phantomcow2]

Well yea you can get helical beam couplings which look nice and have zero backlash, but they are expensive. If I had gone for helical beam couplings it would have cost almost 80 dollars i believe, it did not even cost me 20 to go with lovejoy couplings. FOr such a difference in cost I can live with .001 of backlash, which can easily be compensated.

[sendkeys]

mcmaster has one for 20-25 bucks the hexil type where i got mine from. Ended up being about the same price when you start adding in the cost of a 3 part system.