How do I mount my delrin nut? Inexpensively.

[arthernan]

Hello anyone!!!

I read enougth on nuts to convince myself of this. The most cost-effective way for me to minimize back-slash on my CNC Router proyect is to make my own acme tap out of a piece of acme screw, and make delrin nuts out of delrin rod.

A foot of rod will cost me about $20 with shipping.

And now that I have come to this conclusion, the issue at hand is how do I mount it?? Well I thougth I could just get a 2"x2"x2" piece of solid Delrin until I saw the prices. $200+!!! So that, went out the window. I thougth maybe a pillow bearing, but how would I keep the nut from spining??.

I have checked the price of a solid piece of aluminum to hold the nut, a 2" thick to hold a nut of the same length, of course I would need to make the hole for the nut and screws to attach it. The aluminum is about $27 a foot, no ship. But an angle with a .25" wall is about $7 a foot. Then I thougth to avoid using wood, I could buy a flanged bearing, screw it to an angle and tap the bearing to put a mini screw in to hold the nut.

Am I making any sense? I did search for an answer here but I could not find it.

[SORCHEROR]

i sell plastic acme nuts that have a mounting flange on the with two clearance holes,which are slotted for alignment,i usually recomend two for each axis with a spring between for backlash,i sell the nuts for $7 each,you cant find them cheaper anywhere
that ive seen,any if interested i will gladley post a pic or two,these are 1/2-10 single start,i can also provide 5/8

[leggazoid]

http://www.dumpstercnc.com/

Maybe this is useful info?

[arthernan]

OK, I looked at the dumpstercnc link and I may upgrade to these later. $20 dollars of delrin is a close to a fourth of the $78 for 3 dumpsternuts. I don't want to sound cheap, but my list of materials is close to $500.

My problem remains how to mount them inexpensively. I may do a lot of research and remember my physics classes. But I am still a newbie. Any help will be greatly appreciated!

SORCHEROR your offer does sound appealing. Could you please post a pic?

[sonex128]

Yes please post pics. I am trying to figure this out now. Can't quite afford the dumpstercnc ones right now.

Brian

[MrWild]

why are you asking this question? You need a lathe in order to do a nut properly, and a tap of some sort which can be a chunk of the Acme rod you will be using. If you are planning on using all thread as your lead screw... Well you could use glue. No I jest. But in order to do a good job on the nuts, drill them on center, etc. you should use a lathe. Once you are using a lathe, it is a simple matter to thread the outer diameter (OD) of one end and then thread the nit into a plate. All this is so much work you'd be better off buying the cheap $7 nuts.

I'm wondering why you paid so much for your plastic. I bought a box of 2.5"dia. off cuts and paid $25 with shipping for so much Delrin plastic it will last me years. Sure it's a gay pink color, but I call my machine a she so it works out. On a cheap cheap cheap all thread lead screw machine, your mounting plates could be MDFB that have the mating threads hardened with a thin super glue (cyano-acrilate). But then you have the added costs of the glue.

My advice is toss the chunk of plastic in a box and label the box, failed attempts at being cheap. Buy the $7 nuts and be done with the head ache.

[doorknob]

There is a thread on a different forum that may be relevant to this one - see http://bbs.homeshopmachinist.net/showthread.php?t=43645 "Making Acetal leadscrew nuts the easy way" - it describes and illustrates a method for using acetal copolymer or Delrin, an acme leadscrew, and a heat gun to create acme nuts (and half nuts) that closely conform to the leadscrew threads. A lathe is required to bore an ID into the acetal material ahead of molding the threads, as well as to turn down the OD after making the nuts. There is some discussion of mounting techniques in that thread.

[Dean448]

I'm using a 1/2" 10 5 start acme lead screw and also asked if there isn't a cheaper way to get anti-backlash nuts. What I came up with and its been working flawlessly for ten months is two part pourable plastic. The plastic is poured while everything is mounted on the machine. Advantages are no machinging, perfect match to the lead screw, perfect alignment, I have not been able to preceive any backlash, very strong, could also pour and cut resulting in a split nut design, Doesn't ingest debris because there is clearance between the nut and screw. The only disadvantages (which might also be present in a delrin system) repeated motion of a heavy Z axis tends to heat the surface up and I occationally put a lubricant on the lead screw to eliminate a dry squeal sound.

[roy_okc]

Originally Posted by Dean448 I'm using a 1/2" 10 5 start acme lead screw and also asked if there isn't a cheaper way to get anti-backlash nuts. What I came up with and its been working flawlessly for ten months is two part pourable plastic.

Dean,

What brand is this pourable plastic? Do you have a link?

Thanks,
Roy

[trevis1st]

You might try polytek.com.

[Dean448]

www.alumilite.com

I used white for the x-y axis and tried Vac 50 for the z axis to draw some heat out. Either would work for all. If you give this a try I'd use a heat gun to warm the screw then spray on a light coat of silicon. The spray acts as a release and the heat allows it to cure without bubbles forming. If it doesn't turn out for some reason then just drill it out and pour it again. For your information my nuts are all poured to 1" long based on a 2:1 length to diameter. I expected to see some wear by now and have to pour it again but the nuts are all still tight.

Dean

[ger21]

Here's how I did mine, but I turned it on a wood lathe.
http://www.cnczone.com/forums/showpo...&postcount=117