Evening all you night Ewoks - This evening I detailed the Frame model. Took 4 goes to get it to target stiffness. I scaled down the Tee model a bit then had to creep up again in some dims. It's stats with an 50mm thick Al table:
X 23 Y 19 and Z 36N/um. If I run a 50mm steel table it becomes X 26 Y 22 and Z 37. As usual a steel table makes a big delta. I'll put in the 3rd table rail to see how that goes as well.
My main concern is that the table rails travel across two parts. All parts are less then 54kg so a little more tuning and holes should get the parts to <50kg but at the mo I'm happy. So another attempt at shrinking it a bit and then to the motion parts. Will try to use 60mm servos but 80mm maybe to go...
The base is 120mm thick and the Tee base was 130mm which would get the Y over the line with the alloy table. Its still 400x400x400 travel. Wednesday I can rearrange the workshop as the floor resin will be hard then I can do some casting tests at last... Peter
addition - starlog 3567853-001.234
Completing the discussion on motor sizing and ballscrew whirling and buckling.. The top speed of the servo is 3000rpm (can go faster but V happy there) Calculation via Hiwin formula says the 16mm shaft whirls at 3764rpm <3000rpm so all good there. The max force of a 2.39Nm motor and 5mm pitch screw is 275kgf. The buckling of a 800mm 16mm screw is 880kgf so all good there as well. So Dia16mm screws are OK Jose.. Peter