My 1st homebrew CNC.

[Kammo1]

Ok guys just have a quick one for you all. I have some 8mm threaded rod at the moment which I will be using for the machine to drive the X Y and Z axis as I have had it given to me for free so why not use it for the time being. I came up with an idea for the leadscrew nuts and that was to take a large washer which has a hole so that the 8mm threaded rod can pass through and then epoxying a 8mm nut to it and then when this is dried and firm thread it onto the threaded rod and then glue another nut on the top but just tightening it so it takes out the backlash and believe it or not there is very little if no play in it at all. I have made 2 so far and have fitted it to the Z axis and the Y axis but have ran out of some epoxy to make one for the X axis. So my question is to you all is what are you guys using that is better than this and works without any problems ?? Also I would like to eventually upgrade to some Trapezoidal leadscrews maybe some 1/2 10 which seems the most popular leadscrew that everyone is using but again I am a bit green on this issue so any help would be great and also other than Marchant Dice where is the best place to order this and what would the cost per meter be ?? sorry for all the questions guys. Laz.

[Smiler]

Delrin nuts. Doesn't Lee make/sell them? Very easy to make yourself I would have thought, lump 'o delrin, 6.5mm drill, M8 tap.

I think by using M8 nuts and preloading them in the way you are doing will lead to wear on either the nuts or screw and quickly too. When using threads in this way, you really need to have the nuts to be of softer material than the thread. I think you will find the most likely scenario will be that your leadscrew will seize and scrap both the screw and the nut even with lube, BTW, don't even think of trying it with Stainless nuts/screws.

Make some delrin nuts!:p

That's what I'd do anyway, no doubt I'll get shot down now by everyone who's done it your way for years:D

Jeff.