View Full Version : 1020400W Gantry Frame Welding instructions

Sun 29 October 2006, 10:45
Some photos for reference and discussion when looking at drawing no. 10 20 400 W:


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

Wed 30 January 2008, 12:31
I should have mentioned this before now but a table saw makes an excellent platform for holding the gantry tubes in the same plane. Don't worry about getting splatter on it because you are only welding the very ends of the tube and they are far enough from the saw.

Sat 08 November 2008, 09:24
Yuri made this post in this thread (http://www.mechmate.com/forums/showthread.php?t=663)- go there to follow some comments

This is the distortion of my gantry :(.




Sat 05 February 2011, 02:21
Red These may help you !!




Sat 05 February 2011, 06:11
Cheers Tony,
Those are the clearest pictures on the site. Many thanks.
Just a question on the slotted gantry end support. I see this is diagonally opposite the end support that carries the cable chain. My reading of the plans was that it should be on the same side as the one carrying the cable chain. Why is it diagonally opposite?

Sat 05 February 2011, 08:36
Red, they are both on the same side, in Tony's first pic the rear tube is on the right of the picture (see the Y cable chain on the extreme right edge) and in the second pic the rear tube is on the left (just below the vinyl logo is the end of the Y cable chain support), same tube different ends.

Gerald D
Sat 05 February 2011, 09:14
The rear tube is the only tube carrying internal cables . . . . the slots are adjacent to that tube.

Sun 06 February 2011, 03:29
Thanks for all the help on this. I'm generally OK reading schematics, but just didn't seem to "get" this one. Next free day I'm tackling this.