increase adjustment block hole size?

[forgetcolor]

In my reading over the last many months I seem to recall someone suggesting that increasing the hole in the adjustment blocks over the jgro spec was a useful modification. The idea was that it would provide more opportunity for adjustment. But I've been trying to find that thread via search and can't.

Does anyone recall or have a recommendation on this? The plans call for a 1.5" diam. hole on the Y adjustment block.

[Northboy]

Originally Posted by forgetcolor In my reading over the last many months I seem to recall someone suggesting that increasing the hole in the adjustment blocks over the jgro spec was a useful modification. The idea was that it would provide more opportunity for adjustment. But I've been trying to find that thread via search and can't. Does anyone recall or have a recommendation on this? The plans call for a 1.5" diam. hole on the Y adjustment block.

If you are accurate with your layout the 1/4 inch or so clearance is lots. The main secret I found is to clamp your two end plates together and drill them together so they stay square to each other. I would however definitely recommend making your blocks out of something other than mdf if you can, as it is difficult to tap it well. I threw out several mdf blocks before buying some aluminum and making them from that instead.There are some pics of my ongoing build here if you want to check it out.
http://www.cnczone.com/forums/showthread.php?t=76277

Northboy

[forgetcolor]

Awesome, thanks for the info and the links to your build. I like the black. I'm considering a dark gray for mine, but I'll have to add black to the consider list.

I was planning to clamp my pieces together, although I'm not sure if my drill press has that much travel. Will have to see. I'm planning to make my adjustment blocks out of delrin. I just went ahead and ordered a 3/4" thick 12" x 12" sheet. I'm using nuts from dumpstercnc, so the delrin is almost exclusively for the adjustment blocks.

[Northboy]

Originally Posted by forgetcolor Awesome, thanks for the info and the links to your build. I like the black. I'm considering a dark gray for mine, but I'll have to add black to the consider list. I was planning to clamp my pieces together, although I'm not sure if my drill press has that much travel. Will have to see. I'm planning to make my adjustment blocks out of delrin. I just went ahead and ordered a 3/4" thick 12" x 12" sheet. I'm using nuts from dumpstercnc, so the delrin is almost exclusively for the adjustment blocks.

If you can't drill through with the press, you will at least be able to start them to get the layout right, then use a drill guide to keep the hole square. I bought a cheapo for 10$ that works okay for using a handdrill fairly accurately.

The delrin should be good for the blocks, it's good stuff. I used aluminum for mine because a friend had some and I made them in his shop. The dumpster nuts are great, consider using his couplers as well, they are nice pieces and considering how long it would take to make them yourself not near as accurately a great bargain.

Northboy

[BobF]

If you use mdf, put super glue in the hole. after you tap it put super glue in the threads. After it drys run a tap through again. It will make the threads stand up to a lot more wear and tear.
If you have it, use the thin super glue.

[tbenefi33]

Becarefull with MDF its spits easy with small part here a pic of the split problem I was having I'm swaping to hdpe or delrin.

[forgetcolor]

yeah, i'm using delrin for my adjustment blocks cause of that.

i tried superglue in the threads of a test piece. i must have tried to thread it too quick, cause my tap came out all gunked up and it was just a mess. i only waited a few hours.

[BobF]

Originally Posted by forgetcolor yeah, i'm using delrin for my adjustment blocks cause of that. i tried superglue in the threads of a test piece. i must have tried to thread it too quick, cause my tap came out all gunked up and it was just a mess. i only waited a few hours.

It certainly should have been dry by then. Never had this problem.
Delrin, HPDE, or aluminum shoud work fine.
Some of the mailorder woodworking stores sell HPDE off cuts by the pound.
http://www.leevalley.com/wood/page.a...455,43831&ap=1

[MrWild]

When tapping MDF and using superglue, you tap the untreated hole first. AAfter it is tapped, you add the superglue. It will swell the hole a bit, so you retap (chase) the hole and there are no problems with massive amounts of glue stuck to the tap.

[mlabruyere]

Originally Posted by BobF It certainly should have been dry by then. Never had this problem. Delrin, HPDE, or aluminum shoud work fine. Some of the mailorder woodworking stores sell HPDE off cuts by the pound. http://www.leevalley.com/wood/page.a...455,43831&ap=1

Thanks! I ordered 6 pounds from them!