[berin]

Tonight I'll be posting my current efferts on my contribution to the project. Current cost on my machine thus far is $48 including ALL parts. All motors have been scavanged few parts have been purchased. Most of the purchased parts are sheet metal and motion parts ect... I'll give a whole posting of images as well, to give an idea of construction steps.

[Big_Brian]

Originally posted by radio-op
Vacpress wrote on page 1 “... some sort of pic-driven H-bridge bipolar might be best in terms of ease of assembly and cost.. the hudle there is programming the chip..”
Embeddedtronic.com has a design for a 3A 55V chopper drive that might be useful.
Kfong has posted here many times and might be interested in helping with this idea. There are boards and programmed PICs for sale ($10 each), but I think the design is open source so the schm and source code could be included and a link to the web site for those that want the PCB.
Bill

I personally would offer programming of the pic chips for the price of the chips and the cost to send them to their destination. I have a great little pic programmer and would love to help in return for help. Open source is an excellent idea If everybody pitches in what resourses they have the end product cost us all less so everybody wins.

[chuckknigh]

$48 for your whole machine? That's quite good. Does that cost include the electronics, too, or just the mechanicals?

-- Chuck Knight

[berin]

that is every thing considering I've done a lot of scavaging from printers that I aquired. The majority of the cost came from construction cost on supplys. Its part of the reason I feel that alinment method of mine is such a good idea to add as an other option for designing cnc machine parts. I believe you've seen a part way construction image of the machine? tonight I with a @#$%@^# bit of luck may be able to post the images. I've been flat out for the past week so far, its driving me nuts!!!! Only time I can get on line is brake time at work.
Tonight I have to give a friend a ride to work after i get out (DUI, victom) Then food shopping and a few other things. I expect to get home with 1 hour befor bed time. Yippy! I might be able to post them then.

[satchid]

Dear designers (in the restricted treath).
I am new in designing CNC devices.
If I can sugest something while you design the router for the newbie, would you care to discus the different options of the major parts of the router? for exemple the different ways one could make liniar sliders, or how to make the cutting header. Then the home worker could, by folowing a different rout stil make his own design as a beginner without having to follow the general disign of the groups effort.
Thank you.
Satchid

[ynneb]

Satchid, From what I gather, you are suggesting that instead of making a fixed design, that it would be better to post different design principles, and then let the builder choose what parts they want to include?

I also feel this is the best method. Lots of small tutorials about different Z axis set ups for example, also linear bearing designs, etc.

[satchid]

Yes, but this is not excluding a working model.
I see it as follows:

A discussion of the different ways of doing it with sketches, then a vote could set the direction to go.

If we start with: moving gantry versus moving table or moving something else. A decent description with pros and contras of both systems, then a brief discussion in the group someone summarizes the discussion and then a vote between the posters could start the real making of the design.

After this we could start a discussion over the sliding mechanism, just simple Teflon sliding bushes, real rolling bearings, or lingniar bearings or other things. This would then also become voted and so on.

This way you have the active decision of the posters group instead of only one to make the decision.

You need only one or two persons to deside when to stop the discusion for the vote.

What do you all think?

[chuckknigh]

Well, if we want to, we can compartmentalize the design, so that it's just a collection of subassemblies. Let the ultimate decision be up the the builder, at the time of construction.

For example, screw drive. Making an axis move, whether it is a moving gantry, fixed bridge, or even a hexabot, is simply a matter of turning a screw, and making the nut move. This subassembly could be reused, for all different designs. The details, like whether the sliding parts are made from teflon or rolling bearing assemblies, is immaterial to making the axis move.

My current design ideas are leading me towards a fixed bridge design, upturned so it fits on my workbench more easily. The primary modifications to the basic design are going to be a reorientation of the "lower" bearing, and a counterweight for the Y axis, so the stepper doesn't have to fight gravity. Otherwise, it's just a traditional fixed bridge machine...no big deal.

The basic principles of design are pretty much fixed...it's just a matter of how you arrange the individual objects.

If any of you are programmers, it'd be like designing objects...reusable programming code that can be "dropped" into various configurations...same basic idea.

-- Chuck Knight

[High Seas]

Ohhh - Chuck, your comments sparked a flashback to "modular" programming in some ways.

I think you're right on target - modules or sub assemblys, "designed" to be scaled and adapted for the individual's specific use. Likewise the overall construct, moving table or gantry uses 90+ percent of the same components - just a different "point of view", so to speak.

The trick is getting all the bits "scaled" or integrated together. That's where some experience can save a penny or 2! Cheers - let's all keep thinking and corresponding! Cheers - Jim

[chuckknigh]

It would definitely help new builders understand the way that each module fits together. And you're right about the commonality of parts between the designs -- it's simply a matter of which part you make move. The table, or the gantry?

The down side is that with an object oriented approach, it'd be less a set of plans, and more of a textbook.

The bottom line is that not everyone WANTS to understand how a tool works...they just want to build it, and/or use it.

I've found that my own desire to intuitively understand every aspect of a design is not shared by everyone. :-( A shame, really, because that level of understanding is required, if you want to make improvements!

-- Chuck Knight

[Patrick2by4]

It's interesting that you mentioned modularizing the different components. I was thinking along the same line for my cnc router that I building. I plan on making the y axis its own complete subassembly or modular axis that can be moved as a complete unit. Since one of the design problems of raising the y axis high from the x axis base is the introducion of flexing to the gantry, it occurred to me to make the y-axis movable so that it is close to the x-axis when I want to do aluminum routing and high off the x-axis when I want to router a 10" columns (on a 4th axis). Making the entire y axis assembly (complete with main beam, motor, ball screw and z-axis) movable on the two side supports of the gantry makes for a more flexible and accurate machine. And it isn't all that hard to do nor does it add significant amounts of weight to the gantry.
Benny asked my if I wanted to make my machine open source and I mentioned it would be fine (I'll make my millions elsewhere When I finish my machine, I'll donate its design and my notes to the open source community. It can be improved upon and refined by the millions of cnc'ers out there. (I may even incorporate some of the improvements on the original!)

[berin]

Very sarry for my tardiness, but you know how the summer months can be when you’re a busy person. Here they are the latest images of my $30 cnc machine so far.
The top left picture just gives an general overview of layout. The picture on the right show's the base/x axis drive setup. The bottem left picture give a nearly compleat picture of the machine minus the Z axis on the wooden arch.

[mikegaylor]

Dear Hack,

I was reading your article on Cheap CNC plans.

I have written a three axis free CNC program . The software controls all the step and direction outputs from the LPT (printer) port. It will run on Windows 95,98,XP ect. It comes in two parts the routoutcnc viewer and the manager. The viewer handles the conversion and the manager does the control with the LPT port. I would be great full of any feedback that you might give.(documentation not completely finished but the program works like a dream) The link below will take you to the installation file. Download and install.

www.routoutcnc.co.uk/routoutcnc.exe

The file currently has a thirty day trial period but I will gladly provide you and any other members free licence number if you would like to use the software.

PS This is not trial ware I am offering the full software for this project. If you or any other members need a hand setting it up then please let me know.

If your interested have a look at my Homemade CNC engraver / router on cnczone on:

http://cnczone.com/gallery/showgalle...00/ppuser/3940


Yours Faithfully

Mike Gaylor

Email : [email protected]

[pminmo]

Mike,
How fast of a processor is needed?

Phil

[pminmo]

Mike or anyone,
As I'm turning out boards in different configurations, it sure would be nice to have a simple test program. Something I can monitor parallel port inputs, set outputs, send a pulse train to an output. Graphical interface would be really nice.
Any ideas?

Phil

[mikegaylor]

Mike,
How fast of a processor is needed?

Phil

To be honest i'm not sure as the slowest PC I'v tried it on is a P3 450 Mhz.

But I would think that it will opperate fine with a slower processor I just don't have a slower PC to use it with.

If you try it let me know the outcome.

Also if you need any help setting it up, either email me on:

[email protected] or phone +44(0)1269 841230 (UK)

Regards

Mike

[mikegaylor]

Phil

To send Pulse trains to the port you can use my software. If you want just to monitor and send bit by bit then you can use the port monitor attached to this post. This was not written by me but is very good for initial debugging of wiring etc.

Regards

Mike

[chronon1]

I can help do some CAD work 2d / 3d ..(better with 2d)
could provide some site sources for steppers .

i'm kinda tired so i cant think of anything else at the moment.

[mikeschn]

I've been looking for the results of the open source CNC Router design. I've not been able to find it. Can anyone point me in the right direction?

Thanks,

Mike...

[Bear]

Hello All,
Seems to me what is needed would be, computer to controller to motors.
Start small,explain producedure, from computer to controller,
from controller to motors,stepper & servo, one system each. Then if
you want a bigger machine you would know needs expanding.
For me at least, I think thats why I spend so much time here.before I
under stand one thing the subject goes off on some related details,
interesting, but I loose my train (caboose) of thought.
Bear