[vacpress]

I have this desire to develop some or at least one of my device ideas into a set of "commercial plans" my plans will cost no more than $35, and will cost this because I want to offer a very nice set of full color plans, in binded book form. These would not be like what i have put up so far here. these would be step-by-step instructions with source lists, faqs, etc.

Full color means LOTS of pictures and illustrations. I am an "expert" industrial & graphic designer, and can produce plansets of a quality i have not seen yet.

I ask you : what should my first offering be?

Small Robot Arm - Total cost to build:$75-150

CNC Hot Wire Foam Cutter - Total cost to build:$75-300

CNC Foam Carver - Light weight rotary axis 3D carver: $100-300

Color CNC Gantry Printer - Plans $50.00 - Total cost :$100-300

Semi-Automatic Vacuum Forming Machine - Cost to build:200-500

Dont Bother?

[ger21]

Do you plan on actually building something, and thouroghly testing it to find any possible flaws, before you offer the plans?

[vacpress]

ger21- of course. most of these ideas are at least partially built allready.

i like the robot arm project, cuz i can include DXF files ready to be routed on "cheap CNC" machines. it could be a fun project for someone with a "lower echelon" CNC machine like an MDF router, etc... this is something all the projects would include. my $20 to 35 plansets would be similar to a real bound book, including a CD-ROM. these will cost me at least $5 each most likely, not counting for all that time spent supporting customers.

Ger21- i would probably put up a preliminary set or send them to some betatesters free.. regardless, the plans would document a build of an actual device, with a narrative form. supported by diagrams with dimensions, source-lists, schematics, PCB designs, etc.

the robot arm with a small computer controled clamp, could load PCBs in and out of a small mill all day.. maybe... probably.. if it had a neat registration system on the clamp system

whatever i decide to do first, I will do the hardpart of hunting down working "homebrew" sftware recomendations and at least for those allready listed, hardware. a 4th axis rotary for wood machines is another possible idea. the only plans i know of for a rotary table are no good.

if any of the "regulars" here were interested in building an idea as "betatesters" i would gladly send them all the materials I currently have, which is alot.. they would just have to keep a journal and take pictures of the build.. nothing to indepth..

anyone? please? it will give me motivation to actually finish one of these if some highly critical and sceptical engineer or machinist was giving me insight\insults.

i will add, those guessy prices dont include much for electronics. i will include full info on DIYing the electronics, but recomend commercial sources. there is a slimish link to an .RTF if the gantry printer thread that is what 2 pages of the intro to my plans would be like..

[Urgundiz]

What Plans Do we Want Cheaply?

PCB engraver, but is not in the poll..

[ger21]

I think what everyone here would want are both gantry, and moving table routers. There is really only one source for plans for under $100. If you could come up with plans for a 3 x 4 or 3 x 5 machine, that was easy to build, was fast (100ipm cutting speed), and inexpensive, and then throw on an optional 4th axis, people would be beating down you're door.

By far the busiest forum here is DIY wood routers. If you want to sell something, go to where the market is.

[alexg]

Originally posted by ger21
I think what everyone here would want are both gantry, and moving table routers. There is really only one source for plans for under $100. If you could come up with plans for a 3 x 4 or 3 x 5 machine, that was easy to build, was fast (100ipm cutting speed), and inexpensive, and then throw on an optional 4th axis, people would be beating down you're door.

By far the busiest forum here is DIY wood routers. If you want to sell something, go to where the market is.

I comptetely agree.. A gantry router that is easy to build with common tools....

[vacpress]

yes. i knew that.... i want to do something a little quirky. plus - i dont have the funds to build a 100ipm gantry cutter myself. i have very little $$. i cant even spend $300 at any one time to buy 80/20 parts. i end up using plain-ol 1.25x1.25 alum square tubing.. and acrylic... and lots of hardwarestore alum and steel extrusion.. i think the robot arm is an obvious winner at this point - cheap, fun, etc... a gantry table that does 100ipm is not offered in a $30 planset for good reason..

the robot plans would cost no more than $15-$20 - postpaid..... maybe $25 for europe if it costs that much more to ship there...

if .pdfs were not SOO easy to share. i would do a digital distro also. maybe if i made each set of instructions have a password that was the purchasers creditcard # they would be less inclined to "share" the plans...

if i had help on this beast, i would put it out free.but noone will ever help me. my friends think im crazy, and on the internet people are very selfish.. they just want to get what they want out of most forums.. my favorite is people who think their very first attempt to build a very complex mechtronic device like a cnc machine is gonna replace their dayjob..


you will never build a 100ipm CNC device with hardware store parts for linear actuation - at THE LEAST, you will need ball screw, toothed belt, rack and pinion, or other locomotion.. this is not cheap.. even toothed belts seem to be very pricey.. even 10tpi leadscrew would require 1000rpm for 100ipm. i would not expect any stepper system to be accurate at those speeds. maybe at 600-800rpm, with propper acceleration.

i cant believe a 1inch toothed belt pully is $50. but, hey. it is.

[ger21]

Have a look at this thread here

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

Using steppers and acme rod, he's tested it at well over 150ipm.

I never said anything about hardware store parts. You have to expect to spend a little bit of money (maybe more than a little) to get that kind of speed. But, you can get multiple start acme leadscrews for relatively cheap. I bought 6ft lengths of 2start, 8tpi for about $22 each. I noticed yesterday that you cna get 400+ oz-in Nema23 Vexta's for $150. You'll most likely need Geckos, as well. Of course the problem always lies with the linear bearings. From the trial assembly I did on my router (not yet finished), I think I'll get good results with my rollerblade bearing interpretation. You can see that here:
http://www.cnczone.com/forums/showth...r+first+router
I'm hoping I can see at least 100ipm rapids or more. Time will tell. Even with motors and XYlotex drivers, I'll should end up at around $1000. For another $500, I could substitute THK type bearings. Maybe the B-W dualvee system on the longer axis if affordable THK's aren't available on Ebay. I think a $1500 3ft x 4 ft machine is attainable. And $35 plans would probably sell like crazy. But, I understand your position, I was just making a suggestion.

i would not expect any stepper system to be accurate at those speeds. maybe at 600-800rpm, with propper acceleration.

Why not? Shopbots can supposedly cut at 120ipm, rapid at twice that, with 300+ oz-in steppers. The Shopbot's limits in my opinion are the somewhat flimsy construction. Which they seem to be addressing with a new version (although it's $2000 more). Wer'e talking wood routers here, not precision metalworking mills.

[vacpress]

ger21-we will see how my current project goes. its a 1000-1500 36x36x6. i will likely try to add a 4th axis on the Z, so it can easily be upped to 5. each extra rotary costing like $200... i am looking at cheap $100 imported 4" rotary tables for the rotary axis joints. with fast servos, those might be the elbow joints for a full size robot arm concept i am working on..


homebrew robot arm, to go with your homebrew 6-axis. silly me

oh - whats 2 start acme rod?

[vacpress]

Ok.

i have come to a conclusion - i am going to do the robot arm plans this week, and put them up for free.

i am going to begin developing a set of plans for $35 to build a $1500 gantry machine. the required tools are going to be a drill press, band\scroll saw, set of taps, some way to cut square aluminum tubing.

i am considering producing a set of plexiglass drill templates that may be an additional product. all very cheap.

this will not be a project that relys on linear bearings from THK. it will use some sort of rollerblade bearings.

i like square aluminum tube. its economical and easy to work with, and easy to find localy and from online sources. its not t-slot extrusion, but its much cheaper.

stay tuned for the robot arm plans, free, i need to get the hobby servos to finish the thing..

should i make it a project that requires a small CNC mill and includes machine ready DXF files of the parts?

[ESjaavik]

Sell the plans really cheap. Don't allow copying (to keep rights), but don't enforce anything. This will contribute making them popular. A low price will also mean many just buy the plans to browse them without having committed to building. Or just to pick ideas from them.

Then incorporate some parts that are not very easy to make for everyone. Make these parts yourself, and sell them together with plans. These should of course be parts that needs to be somewhat complex because this makes it a better product. One obvious example is brackets that makes the product more rigid. From what I see on the net, that is the most repeated shortcut. Obvious examples are mills where little or no concern is made about what happens when cutting forces and rapid move of masses are applied to the construction. If you make a design that incorporate well thought out distribution of forces and masses, I'll be one of your customers rather than going through the tedious process of designing one myself.

I take your comments as a bait for starting a joint project here on CNCzone.com? OK, I take the bait with hook line and sinker if the project is a small CNC mill.

With the wealth of resources here, this could be both fun and educating.
VacPress, you obviously are a master 3D draftsman. And I've seen other postings around here that shows great knowledge ranging from demanding users to analytic problem solvers.

So isn't it just opening a forum on Open Source CNC Mill then? :-)
The software can be found over at www.linuxcnc.org, but there is no hardware.

[vacpress]

ESjaavik - that is essentially what i was suggesting in the "opesource cnc" thread i started. i really enjoy producing technical documentation, and was looking for a chance to work on the production and presentating art for some ideas beyond my technical abilities alone.. i can do PCB design, 3DCAD stuff, etc. and graphic design pretty well - thats my living and education, what i cant do is design a great motor driver, or a really well designed "engineered" mechanical device. I just have experience and common sense. No theoretical math background. THe deepest I go is my continued research on inverse kinematics for Robot Arms and Digitizing Arms.

I can do amazing things(i hope) with a "knowledgebase" of design data. things to make a design cheaper, lighter, stronger, etc. I really just like to make things look good though, and for plans, i would want them to be very illustrative and photographic. I bought plans from John Kleinbauer, and while they were a usefull design aid, they were the ugliest POS i ever spent $35 to own on paper. Who the hell does he think he is? Thats what i dont want to see. So silly..

BTW I allready started an "opensource CNC" discussion - your thought parallels mine exactly. I will hunt down the link.
Here:

http://www.cnczone.com/forums/showth...ght=opensource

hopefully that works!

[mvaughn]

Originally posted by vacpress

oh - whats 2 start acme rod?

Correct me if I'm wrong guys.

Think of a lead screw as a spiral wrapped concentricly around a shaft. 1 start would be a single spiral making up the screw. 2 start screws are 2 alternating spirals wrapped around the shaft. Also, works for 3 start and 4 start....

[berin]

You know Esjaavik brings up a good point. When these plans are finished and confirmed a success. They could be sold at non-profit levels, on a CD containing every thing from cad drawings to free full/demo cad software. Um cnc control software with gcode, small videos with classes and demo’s of HOW-TO’s. Enough to cover cost and shipping and assist with the cost of domain and servers. Or free download, just not in an ISO form to make a CD. But rather all in raw form posted on the server in a presentable manner.

Also I move to make a statement, I believe it would be wise for us all to agree on one type or other for the DRIVE train. We basically have 3 options, standard threaded rod, ball bearing rod’s. or the other kind with the DEEP channel which I cant remember what its called. Belt drive has a tendency to shudder on the small scale. Wire drive stretches because it has to be pulled so tight. And geared track makes for a lot of noise (jitter) and low resolution. So it boils down to price when you really think about it. The standard threaded rod works great but its subject to wear, requires more Turk to turn and a lot of thin oil lube. But cost’s a little over a dollar for 3 feet. There turns per inch vary but, I’ve found them to be between 16-32 turns per inch. Average is 20-24 turns per inch, on the steal rods but they’re always an even number of turns per inch ALWAYS.

Ball bearing rods are not cheap and often don’t offer as many turns per inch. The outstanding factor though is the loss of friction and higher degree of accuracy per step and foot pounds to friction is almost non existent. A standard threaded rod has about +/- 1-2/64’s, as well as it increases over time and wear.
http://cnczone.com/forums/attachment...=&postid=31296 In this image the top axis is my Y-axis, the entire top Y-axis for every thing including motor (motor was salvaged) was under $10. My design as is gives about 6oz of force at 12v, but 20oz of force at 30v with out loosing any steps. The x and y axis are driven by the same piece of threaded rod cut in half.

I’ve given it much though, but the easiest way to entice people to try the cnc construction, would be the ultimate in simple design uni-polar driver circuit. 4 npn’s 4 resisters, a few traces or better yet an overhead view of a solder to protoboard with wires. A how to on testing it with two 1.5v batteries in series (3v minus the 4resisters) and a PC at/psu or any powers supply 12v. 5v would be better to use for safty but, not all motors will turn at that ratting. After the testing phase is proven working. A simple setup to the parallel port (5 wires 4 for step 1 to ground) and single dos program to make the motor live, and add start stop speed up and down (a counting feature comes to mind as well to help find what the motor can do). LED’s would be good to add for debugging but that’s what the battery is for.

Did I mention I can type 133words a min.

[joecnc2006]

i thought you measure the inch on a rod then just count the rings for the number of turns? mine has 13 in one inch, does not match the even number you mentioned. maybe this is not the right place to post and can be moved?

[Heavy D]

I would be very interested in the robot arm project......

[JFettig]

I was actually thinking about building a robotic arm myself, although the one I was dreaming up would have been a 6 axis robotic arm like those ones they use in factories(except really small). The major expence is the driver board for the motors, and the problem could be controlling it. Some sort of program would have to be made to controll the motion of it, the motion wouldnt be quite the same as if it was controlled by mach2 or something.

Jon

[chris69randy]

hi

i would love to see some plans for a CNC gantry Fabric Cutter as i would love to make custom car seats for my car and maybe sell aswell, if you make the plans let me know.

thanks and keep up the good work

[an0n]

Hm, I am interested in a EDM power supply... perferably a digital one....

[traveler]

Hmmmmmmm, I've used a ton of 1/2" X 12 tpi and 5/8" X 11 tpi threaded rod. joe2000che is measuring things correctly