Gerald_D
Sun 29 October 2006, 10:45
Some photos for reference and discussion when looking at drawing no. 10 20 400 W:
http://www.mechmate.com/Forum/messages/9/1837.jpg
http://www.mechmate.com/Forum/messages/9/1835.jpg
The notes on the drawing state:
1. Lay the two Cross Member Tubes 01 20 440 D across a firm workbench with the DRILLED HOLES AT THE BOTTOM. Clamp the tubes to the bench with 4 large g-clamps. (Construction starts upside down)
2. Using an accurate spirit level, framing square, shims and the sub-weldments 10 20 450 W as distance gauges, get the tubes very precisely in position BEFORE any welding is done. They must be level, parallel and square to each other. Use the framing square from one tube over to the other to get the ends in line. Keep within 1mm tolerance.
3. Put in TACK welds (small!) in the following sequence: A1, B1, C1, D1, A2, B2, C2, D2, A3, B3, C3, D3.
4. Un-clamp gantry from bench, gently turn it over, re-clamp and check square/parallel/level again. This is the last chance to correct "propellor twist". Here (http://www.mechmate.com/forums/showthread.php?t=663) is a method for correcting a twisted gantry.
5. Lay full welds 40mm long in pos. 4 where the (now) top of the cross member meets 01 20 456 B. The rail lies over this position and the weld must be ground flat down to be flush with the top of the cross-members. Keep to the ABCD sequence hereafter. . . . . .
6. Lay welds 15mm long from opposite pos. 1 up to the tip of the gusset (marked as 5). Same size weld at pos. 6 . Un-clamp and turn gantry over.
7. Join welds 1 and 5 together. Join welds 2 & 3 together.
8. Turn gantry on its edge and do 20mm welds opposite pos. 6
http://www.mechmate.com/Forum/messages/9/1837.jpg
http://www.mechmate.com/Forum/messages/9/1835.jpg
The notes on the drawing state:
1. Lay the two Cross Member Tubes 01 20 440 D across a firm workbench with the DRILLED HOLES AT THE BOTTOM. Clamp the tubes to the bench with 4 large g-clamps. (Construction starts upside down)
2. Using an accurate spirit level, framing square, shims and the sub-weldments 10 20 450 W as distance gauges, get the tubes very precisely in position BEFORE any welding is done. They must be level, parallel and square to each other. Use the framing square from one tube over to the other to get the ends in line. Keep within 1mm tolerance.
3. Put in TACK welds (small!) in the following sequence: A1, B1, C1, D1, A2, B2, C2, D2, A3, B3, C3, D3.
4. Un-clamp gantry from bench, gently turn it over, re-clamp and check square/parallel/level again. This is the last chance to correct "propellor twist". Here (http://www.mechmate.com/forums/showthread.php?t=663) is a method for correcting a twisted gantry.
5. Lay full welds 40mm long in pos. 4 where the (now) top of the cross member meets 01 20 456 B. The rail lies over this position and the weld must be ground flat down to be flush with the top of the cross-members. Keep to the ABCD sequence hereafter. . . . . .
6. Lay welds 15mm long from opposite pos. 1 up to the tip of the gusset (marked as 5). Same size weld at pos. 6 . Un-clamp and turn gantry over.
7. Join welds 1 and 5 together. Join welds 2 & 3 together.
8. Turn gantry on its edge and do 20mm welds opposite pos. 6