Tuesday, 5 May 2009

More development....

...and more errors!
Bending over the tops of the pins holding the springs worked well. The trick was to make the bend-point somewhat higher than the spring. However, I have had to remove one of the washers between MDF layers because two left the pivot arm wobbly from side to side. If only I could find a washer with a 5 mm hole but bigger outer diameter....

Also, on trying out my sliding x-stage, the nuts of the pivot arm holding the PTFE disks hit the base board either side. I shall have to cut away another 2 cm each side. Even then, I shall have to put the whole assembly on feet so that the ends of the screws don't touch the ground.

The locations and the design of the pivot arms works, basically, but there is currently more friction than I would like, and it's not to do with the lack of PTFE slider, unfortunately. I don't know if the friction is too great for the motor or for smooth movement, though, so I shall work on it some more to see if there is something simple I can tweak, but otherwise I shall leave it until it goes motive to find out whether it matters.
On that front, the stepper motors arrived today.


  1. Large outer diameter washers are called "penny washers" and are readily available on eBay, etc.

  2. I didn't know that. That's handy to know.

  3. Thanks Nophead - I have now found that ScrewFix do penny washers, but they're not filed/found under "washers", no, they're under bolts!
    I'll have to go get some (ScrewFix is just up the road walking).