If I use 1/2" lead screw and my motors have 1/4" shaft -

Where can I get couplings to allow my motor fit to end of lead screw? Or is that not possible? Links would be helpful - thanks

Many thanks!@

Check out DumpsterCNC (http://dumpstercnc.com) .

Chris

Am I missing something? I looked there and do not see where I can go from 1/2" to 1/4"...... I am not 100% sure.

Thanks...

you can always get one 1/2" coupler, and one 1/4 coupler with a lovejoy connector from mcmaster carr, that always works. But if you are using acme thread, the 1/2 coupler will not fit great onto the threads. Dumpster's bad ass couplers are threaded acme on one side and 1/4 on the other. he has several thread options to choose from. Got mine today and they fit great. That way I don't have to machine down the acme thread to fit a 1/4 coupler. Plus they are pretty cheap too.

What does it mean when it says ACME thread vice some other thread?

Thanks

What Dumpster has done is made a split-coupling that clamps on the 1/2-10 acme thread, and also has a 1/4" dia hole to clamp on the motor shaft.

This is great for those who are unable to have the ends of their leadscrews turned in a lathe!
However, I would recommend drilling a small cross-hole and pressing a split roll pin through the shaft and coupling to ensure it does not slip or come loose!

you can always get one 1/2" coupler, and one 1/4 coupler with a lovejoy connector from mcmaster carr, that always works. But if you are using acme thread, the 1/2 coupler will not fit great onto the threads. Dumpster's bad ass couplers are threaded acme on one side and 1/4 on the other. he has several thread options to choose from. Got mine today and they fit great. That way I don't have to machine down the acme thread to fit a 1/4 coupler. Plus they are pretty cheap too.

What is the lovejoy connector? Have a link?

What is the lovejoy connector? Have a link?
www.mcmaster.com page 1077, called spider couplings. LoveJoy is the manufacturer.

Thanks - they look perfect.

Is this a good price for lead screw?
EBay Auction # 230018828843

http://cgi.ebay.com/48-1-2-10-ACME-Leadscrew-W-Delrin-Nut-for-CNC-Router_W0QQitemZ230018828843QQihZ013QQcategoryZ57122QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Yes, thats my friends eBay page! He is making all my stuff now, I could not keep up with the demand from ebay!

By the way, this screw has turned ends, and you will need a coupling to go from 1/4 to 1/4
It will also require bearing blocks for the ends!
Eric

mcmaster carr has a good price on acme screws too, then you could use dumpsters nuts, those things are slick

just looked at the link. That is probably better than my idea. I bought some from premachine for my z axis. I also bought motor mounts from them too. I am a big fan of their work.

Nice - Thanks

I think I will get the 1/2-10 screw rods from ENCO. Really cheap. Then get the couplers from dumpstercnc -
Looking at his backlash lead nuts and threaded clamps..... Not sure if there are better/cheaper solutions for those.

What is a really inexpensive solution for linear bearings and guide rods?

Thanks

you can go the route of skate bearings and angle or iron pipe. I sucked at making those, so I bought thk rails, worth every penny. I also tried the 80/20 system, didn;t like it much

Sorry for all the questions but - Skate bearings? that would be a cheap solution.
What is the 80/20 system? And what is thk?

THK Linear motion systems (http://www.thk.co.uk/EN/index.asp?OID=80&test=1)

Thanks - Book marked it.

Have more of an idea of what I need now. I greatly appreciate everyone's help. On dumpsterscnc web page it says
Add Flange Option -
http://www.dumpstercnc.com/leadnuts_flanges.html

Why do I need a Flange and how do I know which to get? Thanks again.

The flange provides a way to attach the nut to your carriage, and you get which ever one best fits your machine.

Thanks again -
Man there are so many options/decisions and a lot of the are WAY EXPENSIVE!

It is amazing. Now need to find cheap source for plastic. For now will use wood for this because I have some. But would like to make it out of something that won't be effected by moister or something like that.

Thanks

You have to select plastics carefully. Most plastics have a much lower Young's modulus than MDF or wood, some even 10 or more times lower. Deflection is directly proportional to Young's modulus, so with the wrong plastic you could have 10 times the deflection compared to the same machine in wood. You can always coat the wood with epoxy or something else to protect it from moisture.

You have to select plastics carefully. Most plastics have a much lower Young's modulus than MDF or wood, some even 10 or more times lower. Deflection is directly proportional to Young's modulus, so with the wrong plastic you could have 10 times the deflection compared to the same machine in wood. You can always coat the wood with epoxy or something else to protect it from moisture.


Thanks - Just always think of wood warping with heat and moister.

For now I ordered 3 of these ACME Couplings:
http://www.dumpstercnc.com/acme_couplers.html

And these ACME 1/2-10 threaded rods:
http://www.use-enco.com/CGI/INSRIT?PARTPG=INSRAR2&PMAKA=408-0220&PMPXNO=942694

I have 3 stepper motors and drivers coming with PC hookup. Now will be building the router table.

I have seen some DIY plans use a dremel tool. What is better and has very high RPM's - still staying inexpensive?

Thanks -

Skate bearings are rollerblade or skate board bearings. I would reccomend using the search feature on this forum, it will answer your questions better than I could. Search for 80/20, and thk rails. THen look at the jgro section, they do a good job of using skate bearings and pipe.

StudySession,

I coated both sides of my MDF gantry walls with cheap Formica from the depot using yellow glue. It really really stiffens up the wood, is a moisture barrier, looks pretty good, and you don’t have to paint. It is easy to do. There are pictures and such in the build log section.

I would advise a variable speed router. You should be able to get one for about the same price as a dremel, and it will do so much more. Sometimes you want low RPMs. Get one with a half inch collet if you can.

Steve

i think the main thing to worry about with mdf is properly sealing the wood (if you can call it wood) in order to keep moisture out. Wood + moisture = movement, warpage, etc. Some of the machines made from MDF on here are bad ass. Some guys just use clear poly or acrylic to seal the mdf.

Clear poly? Can I get that at Home Depot?

Thanks for all the advice. I have the motors, controllers and pc interface. The threaded rods and couplings and threaded guides.

Now need -
Router instead of my dremel
Metal rods and guides for the rods

My place has a lot of moister in the air. I run dehumidifier up and down stairs. 55 pints each and have to empty every day or two. If this clear poly works - then that would be cheaper solution.

I should have been more clear. Polyurethane is available at almost any hardware store. I would get a few spray cans, and use about 3 coats to make sure you have completely sealed the wood. MDF will really soak it up. Make sure the surface is clean and dust free.

Is there anything wrong with using aluminum or steel tubing from the Home Depot instead of solid rods? I need to save some money.

EDIT: I have some 10 & 12mm milling bits. What router can I get that will allow me to use them in my DIY routing table? Thanks

I did a search on " diy router" and came up with MANY results. Not an easy thing to search to see what people are using. I want a low cost solution. I have a nice dremel but see a lot of people post saying "Don't use the dremel, use a router."

Anyway - Trying to figure it out.

like i said. searh the fourms here for the following:
"linear slides" " skate bearings" "thk rails" "80/20 bearings"

do individual searches on the forums, not google. DIY cnc router is way too vague for here. After all, that was this forum is all about.

I want to know what router they use instead of dremel.... So I was searching for it. Not sure what else to call it.

oh, i misunderstood. There are several ways to go with respest to a spindle. I am using a porter cable 690 (i think) with mounts made by K2. You can also use laminate trimmers that are a good midpoint between routers and dremels.