Thread: Homemade CNC Router

Rod,
The 8mm althread whips a little but can be damped down by sort of wedging delrin under the long thread at the edge of the gantry base I have considered spring loading something in this position. when I say wedge I mean just slightly put pressure on the thread at this point. I think Jgro calls it an anti-whipping Block.
The 8mm Thread fits inside the Skate-bearings nicely as they are 8mm also.
The software is not a problem as usually there is a constant for each machine which is the no of Pulses per rev of the stepper motor and the pitch of the thread. For 8mm this is 200 (steps per rev) X 8 (pulses per step) / 1.25 ( 1.25 threads per mm) = 1280 pulses per mm.
I was recently in the states and prior to going ove had a friend order from ENCO.com a 6' fengt and a 3' length with 8 nuts and shipping to his house in phoenix for $30.00 US. It is probably prohibitive to have it shipped here but you could ask.
Iam still using the Allthread with 116 OZ motors.
My build log is

http://www.cnczone.com/forums/showth...4&page=1&pp=15

and being added to all the time.

Good luck
Brian

Brian
Your CNC router is top stuff and thanks for the link to your build. I will go back and read your thread in detail later tonight.

I am following loosly the Jgro router but more in concept than design. I have decided on a much more complex bearing arrangement and with a steel base and alunimium gantry.

I built a the same bearing carriage as Jgro many years ago on a sliding table for a benchsaw. I have given it much thought over the years and have come up with what I think is a better design.

My problem with the pipe design is that there is a lot of sideways load on the bearings. There is also only a small contact area between ther bearing and the pipe. The result is that you eventually wear a track in the pipe. I know that the simple solution is to rotate the pipe but these factors have steered me away from his design. I am in no way knocking it as there are plenty of examples like your router where it works.

I spent most of Sunday cutting and threading and I have a couple more weekends of the same before I will have anything to show. I should start a build log on the CNC Zone.

Brian
I had to go out so I have only just read your CNC post. You are adventurous with the electronics and I wouldn't even contemplate building a board from scratch. All round top effort.

Rod

The silly thing is I'm a radio technician by trade and could have built my own gear for a fraction of the cost still it's nice to have it all plug and play.

DELRIN!!!!!!

Where can I get some? I searched all over the web and then bought some cutting boards hoping they would do a similar job.

Benny,
I used Cutting board too. but when I wanted thicker I used HDPE 20mm about 1/4 of a m3 for $30 from a plastics supply place.

OK, it's dear but it's buddy good. Used it on the long axis adjuster blocks as I was sik of repairing striped thread.

Hope this helps
Brian

Brian is right on the money with HDPE as Delrin is expensive. If you want to enquire try here:
http://www.solutions.dupont.com.au/
or
http://www.dotmar.com.au/products/ac...cetal_main.htm

I have been searching for cutting boards but all I can find is very thin ones. Does anyone know where you can get thicker ones?

Brian why was the thread stripping? Was it because you were using steel nuts? This is important because I am going to use two steel nuts in my anti-backlash design.

What will you blokes use your CNC set-ups for when they are finished?

I'm just curious.

For thicker cutting boards go to a shop that specialises in chef gear. There's one in adelaide I know of called Macmonts.

Craig
For me it is the challenge of getting it to work first. The combination of computer, electronics and fabrication has been too good to resist. These are very versatile units and capable of high accuracy depending on how it is built. They can used on lots of materials such as wood, glass (engraving only), foam, aluminium, plastics and anything else of that type of hardness. Example I have seen of finished work are signs both engraved and cut out solids, engraving or routing patterns or routing out solid shapes.
Sometimes the owners make their second units by cutting the pieces on their first machine.

Harry
Thanks for the tip.

Originally Posted by rodm

For me it is the challenge of getting it to work first. The combination of computer, electronics and fabrication has been too good to resist.

So, would you use one for repetitive work? How does the software interract with the board driving the router? You'd have different patterns/designs etc. So how do you distinguish between what you want to cut and what you don't.

(Also curious)

Cheers,
Keith

Keith
Repetitive patterns are where this unit will excel.
To give an overview you draw it in a software package that can save it in a dxf extension. This is an industry standard the same a txt or jpg. This drawing is then converted to gcode by software which is a series of commands that are sent through the parallel port of a computer to a driver board that controls the motors. This really is very similar to an ink jet printer or plotter excect a router or dremil is the end tool.
So basically if you can draw it you can make it.

However cnc controlled machines are used for one off jobs where absolute precision is needed such as in the medical field using lasers etc instead of routers.

Mine was originally to cut out Scale model kits of WWI aircraft, however I have found there is not the market for them that I had hoped. Many just buy them complete from Taiwan rather than build. Pity as they are electric powered and fun to fly. (see the Pic.) Kits are available for the EIII if anyone is interested, lol.)

My new intention is to use the first to make a better one from aluminium and eventually gear up to a 8' x 4' which I can do contract work with. There is a lot of demand out there.

Imagine producing carved artwork in door panels with the family crest in 3D.

While repetitive it also allows the accuracy to take a computer image and bring it to life.

Also lots of trim pieces could be made, would love to do a fancy pattern for the varanda woodwork etc.

Rod.
No I was stripping out the thread in the pipe adjustment blocks.

My uses are not determined yet but custom signs for homes or bars may be a good start. I hope to post a picture of something of interest maybe tonight if I finish it.

Yes rod it will be identified.

brian