[mdframe]

I'm new to the DIY CNC and just love reading through everyones posts. I know my following question has been asked hundreds of times here so please forgive me.

I was wondering what the consensus was on the lead screws and linear rails were for the 3 axis. The real acme screws are just so expensive. I am trying to make a usable bed of 48"x48". I hope my second one will be 4' x 8' which I have a need for now but I figured start small and move up. The polished rail are just so expensive as well.

I really appreciate everyones comments.

Thanks,

Matt

[foamcutter]

Check your local screw and bolt suppliers. Here I can get 5/8 acme with a lead accuracy of .005 per foot for about $5.00 a foot. The more accurate the lead accuracy the more money you spend. Depends on what you are wanting to achieve in accuracy. Good luck, post your progress and photos and keep asking questions. Ron

[mdframe]

Ron,

Thanks for the quick post. Unfortunately here in Richmond we have 3 metal manufacturers so they make sure no markets exist for small users. I even use to work for Reynolds Metals and I know they made sure to knock down the little guys. I have asked around but the best I can do is just plain threaded rod with very course threads. I wish I had your area as I would love to be able to get acme screw stock for $5/ft.

If you have any other suggestions I am very open to them.

I will keep calling and digging in the area to try and find that type of deal.

Thanks,

Matt

[InventIt]

Checkout Barn hill bolt. They have acme threaded rod 1/2" x 6' 10TPI for $2.80 foot.

http://www.barnhillbolt.com/acb26/Sh...drodleft%2Egif

[pminmo]

A number of people are using this stuff to build inexpensive machines:
http://www.use-enco.com/CGI/INSRIT?P...&PMPXNO=942694

to get the back lash down with these cheap nuts you have to use two in some antibacklash configuration.

http://www.use-enco.com/CGI/INSRIT?P...&PMPXNO=940474

[ger21]

I got mine here:

http://www.mscdirect.com/PDF.process...=451&Keyword=Y

Very good quality, too.

Gerry

[foamcutter]

Matt,
Someone else in another old post suggested using the acme thread out of old garage door openers. They said a lot of places that install new one would have old ones they would sell cheap or maybe give away. I have not tried this since when I called all the opener companys here they seem to have all gone to the landfill with their old junk just the week before. Day late and dollar short again. I don't have any idea of the lead accuracy of them either. Just a thought. Ron

[teilhardo]

I am new to DIY cnc'ing to and was thinking about building my own router. Can someone give me a basic list of what is needed?
I can list the following:
frame
spindle
stepper motors/servo motors
leadscrew
pillow block (what is this thing? I am not sure yet how it works)
linear rail or SSteel rods with linear bearings

Thanks,
Tei

[ger21]

A pillow block is basically just a bearing holder, usually for the round type of linear bearings. You basically have everything listed you need except the stepper drivers. There are a lot of simple routers here to give you ideas.

Gerry

[teilhardo]

Thanks, would you reccomend a DIY leadscrew assembly or one bought off of ebay?

[jcc3inc]

Gentlemen:

Here is a source of various leadscrews and nuts- I haven't used them but you can check:
Green Bay Manufacturing Co.
Box 56, Two Rivers, WI 54241
Ph. 920-793-2411
Fax 920-793-4848

They show a large range of acme screws and nuts, .375-12 to 2.0-4.

Regards,
Jack C.

[ger21]

Since most of the guys here make there own nuts with either allthread or acme, I'd go that route (preferably with acme). If you find it's not good enough for what you're doing, you can always upgrade later. I think it's cheaper than going the Ebay route anyway, from what I've seen there. What do you plan on doing with this router, anyway? Knowing that makes it easier to answer questions sometimes.

Gerry

[teilhardo]

What do you have to buy to make your own? Other than the leadscrew itself.

Just a nut with the right size threading? Or is there some other trick with the pillowblock/ballbearing assembly?

[ger21]

You make a tap out of a piece of the leadscrew and make the nut out of Delrin. See this thread:

http://www.cnczone.com/forums/showth...5&pagenumber=1

He shows the tap and you can see the nuts in some of the pictures.

Gerry

[teilhardo]

Thanks for the link, I'll start reading through the thread