How to extend JGRO length and have a firm bed?

[matt888]

I'm going to extend the JGRO machine out an additional 20-30 inches so that it can cut 55-60" long pieces. I've seen posts on how to support the rails from sagging, but how do you keep the cutting bed from sagging in the middle at that length? With the gantry moving down the sides/bottom, it appears you can only support the cutting bed on each end... that's not going to work out well with it being 60" long!

Matt

[tajord]

Here's my 2 cents, i used part of this idea on my jgro though it doesn't show, i placed two lengths of angle iron on the undersides of the cutting bed to help support against sag, but my bed is just short of 60", but to get it to fit the length you require i'd advise a little bigger angle than what i used, which was 1 1/4", just take a look at the sketch below see if you get the idea, you probably will have to make your cutting bed support thicker than illustrated in the plans by jgro and adjust the whole base to suit, a little work there, but it should do the trick, good luck.

[matt888]

Good deal. I see what you did. Thanks! Now, for the supports you made to hold the longer pipes...

Did you cut 1" holes for all of the extra supports? I was trying to think of the best way to get exact duplicates of each support. In my mind, I figure I would cut all the rectangle pieces twice as wide, cut a 1" hole in the center, and then cut the whole piece in half.

[tajord]

Well i think if you drill your blocks then cut them in half you'll have to make sure that the 1.318" (i think, but personally i used a 32mm forstner bit i had laying around), not 1" holes, are perfectly centered, and the correct distance from the end, this i didn't do, what i did was set up a stop block on the drill press with one of the blocks to be drilled aligned to the position of the hole needed, drill, remove and do another till i got all i needed, easy.

P.S. Remember to clear any chips against the stop block and fence away after each block you drill, as this could make your holes be off.