Re: [CAD_CAM_EDM_DRO] Looking for Coupler

Most couplers are quite poor, actually.
Including the "almost good" industrial ones at 40-50$ and more each !

The problem is precision, under load, and wear.
A coupler is a mechanical engineering challenge. It is not easy.

The cheap ones will work, but will not be precise. For your use, it may
not matter.
The problem is , that the coupler should bend in two direcions (angular
x and z) but should not move vertically, and should not change length in
the x axis.
The best solution to this are the oldham style couplers, with 3 piece
construction, but they suffer from wear and usually bend under load.

Thats why they are expensive ... if your needs are for mderate power,
and around 1 degree resolution, the above may not be relevant or important.

You can get one type, well made, aluminium, from Peter Homann in
Australia at a decent price for the under 100W (ie stepper) territory.
Homanndesigns.
No affiliation etc. just a satisfied client. I have some and they are ok
for stepper/low precision use.

As an example, good couplers/precision motion requires repeatability in
the 0.1 degrees to 0.001 degree or one thousandths of a degree.
Timing belts work well for this use, upto about 0.01 degrees (for me).

>
>
> Hey I am new to this group, so Howdy.
>
> I am looking for a supplier of Couplers, I wish to couple to a Stepper
> motor a sprocket, so I am looking for 1/4 bore with 5/8 OD and about
> an inch long, I have seen them at about $12 each but cannot see why
> they woud cost more than a $ or 2.
>
> Thanks
> Ray
>