Floating Nut Design

[Barefooter]

Hey everyone. For anyone having trouble getting their leadscrew and nut to line up, here's something that worked for me. It's a 1/2" 13tpi nut spot-welded to a piece of 1/2" stainless rod I robbed from a printer. The other piece is a 1/2" pulley welded to a piece of angle. It gives you up/down, and left/right adjustability in motion with VERY little added backlash. You can leave it floating or lock it down with the hex set screws that are in it after you get your alignment right. The grantry mounted one is a shaft hub from a fan. Neither has anti-backlash nuts but that will come later. Sorry for the bad pic quality... camera phone

[solarchimesam]

Very interesting...I might try that out.
Thanks for sharing it too!

[Barefooter]

Originally Posted by solarchimesam Very interesting...I might try that out. Thanks for sharing it too!

You're welcome! I hope it works as good for you. The only downside I can see to this is allthread smaller than 1/2" might tend to whip if the nut is floating on a axis of 40" or greater.

[solarchimesam]

I have been getting better understanding why folks on the cnczone are sometimes very stern with rules on how do do it right. The one thing I have learned in last few weeks with my 2nd homebrew cnc router is the wip coming from the screw. So your idea is good for those that are making a homemade cnc and can't afford high prcied items starting out.

What got me was I that just bought a rolled screw (acme 10-8 with 2 turns) and had it spinning on a setup so I could turn the ends for some bearings. I could see this was acme was not that much better in the straightness as I assumed it would be, so once again this is where your design might be a great way to have a nut floating like that when it is going up and down the lead screw.

It is so amazing what people can come up with.

[Barefooter]

That was one of my big problems. A friend of mine brought me around 100 feet of allthread that was left over from a job that they finished. It was like pulling teeth to find a straight one. I really never did find one that was perfectly straight but after an hour or so of rolling it on the table and flexing it, it was close enough. My x axis chatters(but doesn't affect performance)... my y runs quite and smooth... and I didn't use the floating nut idea on my z axis. I've tested the machine up to speeds of 200ipm where before the floating nut, it would only get about 50-70ipm and cause the steppers to freeze.

BTW Solarchimesam, that glass etching looks great! It'll be a long time and another/better machine before I try that.

Take care

[solarchimesam]

Thank you thats nice of you to say.
I must admit I have lots of broken glass and busted bits to get to where I am with glass etching. You would be surprised though anyone could do it. My machine is no perfection at all it has bugs...that is why I am always looking for a way's to fix it..LOL.

I chuckled since I did same thing messing with all thread rod (hardware store).
I put it on a slow motorized spinning setup with a candle under it trying to get the dang thing to straighten out. Your right, you end up taking what you can get out of it and moving on. Live and learn right?

By the way I did the glass with low cost Ebay burnishing bits and a Bosch router...slow spindle RPMS and just touching the glass. I goofed once, an out of control Z burned a perfect "glowing" hole right through the glass once...hmmm I thought what a neat way to have the glass hangable...with premade holes.

As I work on finsihing this CNC I will stop, take breaks, sip coffee and check out the CNCZONE.

[bkukowski]

if anyone has bought john kleinbauer's plans, he has a pretty ingenious floating nut design (It is in his phoenix plans) I will be using it for my router. It requires pvc and or delrin or nylon.

[Barefooter]

Dang, and I thought I had an original idea! LOL

[Barefooter]

Here's a pen and paper test on my machine with the floating nut design. Looks tight enough other than the bleeding on the paper from that Sharpie which is distorting the resolution. Dancin nanner time!

[bkukowski]

barefooter, how do you convert text like that to gcode? also, what cam prog do you use?

[Barefooter]

Originally Posted by bkukowski barefooter, how do you convert text like that to gcode? also, what cam prog do you use?

Hey bkukowski,
I'm using Bobcad to do the text and Mach2 to run the gcode. So far I'm happy with both but I'm new to all of it. I used Bobart to do the Harley drawing.

Take care

[solarchimesam]

Barefooter.
Your work looks great!
I can see you already have the glass ability just looking at your work.
They have a swiveling diamond bit deal that you can use and it needs no spin...it is static in a mount but the cutter itself turns into the direction that X and Y are going. Anyway just another tid bit.

Keep us posted on the floating nut concept and how it is going.

I am finishing up a cnc router made with lots of unistrut and WOW it is working good. Just bought a FET-3 and fired it up for a test run.

Again...great to see your cnc pics!