Looking for CNC Mill Part I

[BennyLaird]

Thanks for the quick reply Cranky, can you advise me of any other ways to get up and going?

Is it a case or designing our own to suit locally sourced materials?

I guess the hard bit would be reinventing the wheel and learning by trial and error, a good thing in itself. Us modellers do seem to make what we need from some very obscure materials LOL.

Are there any other Aussies here in the same boat?

[BennyLaird]

Originally posted by uscra112
Trizza - get on eBay and you'll find a zillion of 'em. Also read WAY WAY back in this thread and you'll find sources that'll ship to you.

Do steppers motors rotate backward in the Southern Sphere?

No luck on Australian ebay, only found 3 small geared steppers that look like they are out of a plotter. I'll try and find other sources.....

[BennyLaird]

Hmmm well water does go down the sink the other way so guess steppers are the same, I just can't work out how you lot down in the northern hemisphere manage to stick to the floor though being upside down as you work???????????? I guess you spend a lot of time hanginf around???? LOL

[crankorgan]

Benny,
There is lots of info here! Go back through the thread. Threaded rod from other countries is mostly metric. I had a guy buy my plans from someone in Canada. He installed what he thought was a three turn per inch leadscrew. It was metric! He was trying to mill a circuit board that was in inches. He had me going in circles. Instead of using 1/4-20 threaded rod he got fancy. After dozens of Emails I figured out he had a metric leadscrew. I gave him the metric settings and the machine was fine! But it would not work in inches. A stepper has 200 steps per revolution. That works great with 20 turn per inch threaded rod. 10 turn per inch is also good. Other rods cause weird fractions per step. These fractions can cause errors!

John

[BennyLaird]

John,

It's a pain there are so many standards, you would think it would be in the worlds interest to standardise? Never happen though, here in Aust for example we had a different rail gauge for each state.

I am of the opinion it would be better to source parts from the states and go with a proven machine.

I am getting through the posts on this thread and finding the info as I go, just there are lots of pages... I started a mystery aircraft thread in Electric Scale models and it had passed the 100 pages and navigating that is hard work too.

In case anyone hasn't thanked you for your hard work bringing cost effective opportunities to us, then please accept my gratitude. However, my wife's thanks may not be forthcoming lol.

Benny

[crankorgan]

Benny,
With just some Roller Blade Bearings, aluminum angle, MDF and some odds and ends you can make a machine.

John

[limbo]

Originally posted by BennyLaird
John,

It's a pain there are so many standards, you would think it would be in the worlds interest to standardise?

A tag line I'll never forget:

We are going metric, inch by inch !

;)

John

[uscra112]

Why not a single world standard? Parochialism and competitive advantage. It's only been in the last 50 years or so that it even mattered. No "world economy" for manufactured goods before WW2. Before WW1 many American machine tool builders used their own thread pitches - it was just more convenient, and often driven by the threading machinery and tools they had on hand. We'd still have it, except in WW1 the US Gov't had to enforce a standard so that multiple companies could make the same parts and have 'em be interchangeable.

One of the points brought up 30 years ago when the push to make the USA go Metric began, was that the volume of engineering data (handbook data, strength-of-materials data, process control data, performance test data, part drawings, etc., that would have to be converted was so massive as to make it virtually impossible. Not to mention that billions of dollars worth of tools and manufacuring machinery would have been made unuseable overnight. I've lived in this world for 30 years and I absolutely agree. We crashed a Mars mission because somebody was using inch data in a metric calculation, or some such. If we had just lept in, that would have been multiplied a millionfold.

Having said that, I have to say it's getting better all the time. In 1968 I counted seven different thread standards on a single BSA motorcycle. Only one of them metric. It's gonna take another 30 years before the Imperial system will be as gone as the Whitworth standard is today. The US auto industry is now designing in metric, (I see the drawings all the time). But it took 'em years to get to it.

And of course the metric system was a bloody Frog invention, and why should we kowtow to them?

[BennyLaird]

It hasn't helped the French aircraft designers, the metric system is easy but why can't they design a half decent looking aircraft????

Having used both metric and imperial here in Aust, I do find metric the easiest. I was working out the size of my new house and forgot that everything was in links? For a while I thought the block was huge but came down to earth when I accually measured it. How long since any one has used links? and how many links in a chain????

Still looking for parts for a mill, I will have a go at my own design with what I can find but will base it heavily on Cranky's 7th Sojourn.

Cranky would you consider a general design manual or similar for us outside the states?

Can't wait to cut something, here.......

[crankorgan]

BennyLaird,
All the basics are here for free! I went back over the thread to make sure. This is the best thread for making a CNC machine anywhere on the net!!!

John

[BennyLaird]

Thanks John

I'm working my way through the pages and building a database LOL. I am trying to find an aluminium extrusion source locally with the off chance I'll find something close to your window channel.

I'm only up to page 29 though, pity work cuts down my browsing time, lol. Can't do much at home with all the packing and moving.

My son has seen possibilities to automate his room via the PC. He want's to have his speakers fold out from the ceiling possibly with a jackscrew system, lighting linked to his MP3's etc etc etc, he's doing IT at Uni as well as working for IBM. Hmmm wonder if there are any old steppers on the old IBM printers???

[SkyPyro]

How much would a full 3 axis CNC mill/system end up costing, ready-to-mill? I would probably need it to cut about 45"x40"x12" stock, and being able to mill anything from balsa and foam to possibly soft metals. Would there be any cheap way, such as smaller dimensions or softer materials? Also, do you guys make your own circuits for it, or is there somewhere to buy them? What motor do you use for the spinning part? (Probably a name for it, but I don't know. The dremel part :p ) I haven't yet read this whole thread, but have been following it for the past few weeks, and plan to read it eventually.

Thanks,

Dan

[crankorgan]

SkyPyro,
How deep do you wand to cut into the 12" thick material? Most routers can only handle a 2" long bit. A 45" X
40" machine will need servo motors. I think you are looking at $1000 and higher. If you need to cut the 12" thick material deeper than 2" the machine will jump way up in price!


John

[SkyPyro]

Ok, two inches. What do you think would be better dimensions? Although cutting an entire profile from depron/bluecor would be nice, I could limit it just to cutting balsa "kits." Two inches would probably work fine for that. The other dimensions could go down, too. Exactly how cheap can I go and still be able to cut parts like that? IE, ribs, bulkheads, etc. I guess I wanted the tall dimensions for cowl molds, wheel pants, etc, but if it would cost me a lot more, then no thanks. Also, would I need to buy a 3D CAD program? What kind of CNC programs would I need? About all I have right now is the basic 2D stuff, not setup for engraving. You are talking to a real newb to CNC :p

Dan

[BennyLaird]

LOL Dan

Your in my boat, best bet is to start reading these pages fast....

[balsaman]

To cut ribs all you need is 2D cad and some shareware/freeware easily downloaded.

For cowl and canopy molds you would need 3D cad and expensive cam software.

That 40x45x12" machine would be $1000.00 just for the drive system. Really the 12" is the hard part to achieve mechanically. Imagine a router hanging 12" below the gantry. Now imagine the flex you would have to deal with unless built very heavily (steel!). Nevrmind the short bit limitations.

A realistic size is 12X24X3 or so. No more, and smaller is better for your first machine. How big those ribs going to be? 12" chord? Make it 13x13x2. Fuse sides are easy to cut on a bandsaw, and you only need two anyways. Even on a 13" square table you can cut a 16" rib from corner to corner.

Eric

[SkyPyro]

How much do you think the 13x13x2 would run? Should I want to upgrade later, could I rip the router and steppers out, and pay whatever for the new equipment? Also, will I have to be able to cut and bend a bunch of metal for this? I could pick up some angles and all from Home Depot, and cut some little stuff with my Dremel, but I couldn't make something like in Eric's avatar.

Benny- I accept my mission, I'll start later tommorow :p

Thanks again,

Dan

[balsaman]

The one in my avitar was all documented in this thread. It's made from MDF for a few hundred dollars (about 5). www.crankorgan.com has inexpensive machine plans made from hardware store parts.

Yes you can reuse many parts if you want a bigger machine later.

Eric

[Tree_Magnet]

Well i finally finished my version of Cranky's 7th Sojourn. finished the x axis tonight. I made my controller for my cnc foam cutter and another for my lahter/mill but this time i bought a controller. i bought the one from xylotech ( please excuse my spelling jeff) for the price ( even when you convert it to canadian) isn't much more than building one from scratch, and it's a chopper drive so no current limit resistors that heat up to a million degrees :D .
i should have it up and running early next week i still have a little tweeking to do. cranky's plans are pretty good and an easy way to get into the hobby.for now i will play but in the future i would like to go servo motors and linear bearings. hey balsaman any bearings and lead screws kicking around:) . i'll post pictures later

Tom

[PanzyPoof]

About Time it's almost been a year:D True you did build a CNC Foam Cutter from Scratch and Help build my CNC in that Year.
You ya know how to work that Digita Camera right... Show it off!!;)

[Hague]

Great thread guys, started getting all my "scrap" parts and pieces together. I have a budget of 100 dollars to work with, but I already have my motors and controllers and software working. I am using mostly alum parts that I bought at auctions over the years at the plant I work at, all the good stuff goes to scrap yard though. I will post a pic in a couple days. It will work similiar to 7th Sojourn, but I am using aluminum extrusions for the rails and structure.
Hague

[crankorgan]

Hague,
If you use aluminum extrusions for the rails, make sure the slides are plastic. Bearings are out! Don't forget the motor oil.

John

[balsaman]

Tom,

I gave away the parts I didn't need. There are now two home made cnc routers in the town of woodstock.

Eric

[Hague]

John, I assume you mean not to use bearing because of wear, on the ways. To tell you the truth this was my plan, I have some sweet 60 and 30mm bearings that I was going to use,but I may rethink that and use some delrin or pipe and bearings. Thanks for the heads up.
Hague

[crankorgan]

Hague,
The Slide needs to be softer than the Rail. When you use bearings, you want a steel rail. The fact the bearing turns makes it softer than the rail. Delrin in most cases is tougher than steel. People will argue this! But the best Hip and Knee are a type of Delrin plastic! Steel is a dinosaur! Paint cans are now plastic! The fastest airplanes are plastic.


John

[PanzyPoof]

79000 hits:)

[AirX]

If this thread gets tabled and a new one starts I want to get this one on archive as a guide.

Eric B.

[Hague]

Hey Fellas, worked most of weekend on and off on my router table. I used some aluminum scrap I have been saving for most of it, luckily I did not sell it. The x axix is a positioning slide as is the Z, had to do a little bit of modification though as it was a 2 axis unit set up for pick and place operation. I need some hole saws, drills and taps from work, and another week or so and I should have some movement.
Hague

[limbo]

hey guys,

I would like to switch my spindle off during a G00 positioning move. Turbocnc will recognize M03 and M05 commands and switch a relay. The trouble is how to get these commands in a (big) G-code file. How do you guys do this? Is there a simple "find and replace" trick in a windows editor? You would have to replace a single line by two, as tcnc only accepts one G-or M word per line. Perhaps there is software that will convert dxf to G-code and add the m03 and m05 commands on the fly? If all neat solutions fail I would even consider a mechanical solution where the Z-axis trips a microswitch to switch the spindle on and off. Any ideas?


John

[SkyPyro]

John- sorry, can't help ya.

Anyone- Sorry if this is a stupid question coming from a stupid person, but is G code the same as NC code?

Dan

[uscra112]

G-code is the vernacular name for it. The originators of NC, back in the '50s, developed a code format that had groups starting with a letter followed by two digits. The G prefix defined axis-motion commands, (linear motion, linear interpolated motion circular motion), F designates a feedrate, X/Y/Z designates linear motion axes, A/B/C designated rotary axes, I/J/K designated vectors used for certain special purposes, M-codes call for miscellaneous stuff like on-off of coolant, spindle motor, etc.

These groups could be assembled into blocks. The NC could execute only one block at a time. Looking at the code, each block is a line. You cannot have more than one of a given prefix letter in any given block.

There is an industry-wide standard for G-code format and content known as EIA-RS-274. You can find tables and an explanation of the various codes on site -- http://desktopcnc.com/gandm.htm

Typical block: G00 Z4.000 M05 would be a Z-axis rapid move to 4.000 inches plus, and at the same time a spindle stop. (Assuming your controller software supports that M-code- it might not.)

The code is always expressed only using pure ASCII characters, which means you should use a pure-ASCII editor like MS EDIT or Notepad or Norton Edit. When you get to very large files, Notepad or MS EDIT choke, but MS Word will do it if you're careful to save the file in "text" format (.txt). I've used an old, old DOS editor called WordStar for many years. It's what I'm used to.

All such editors will have a "string search" in them. The trick is identifying the string that commands the Z-axis moves you want to find. If you're generating G-code from a software that interprets .dxf files, make a really short program that includes the moves you want, and study it in the editor. Once you recognize the group you want, you will know how to search for it in your big program.

DO NOT use "search-and-replace" when editing. It may prove the law of unintended consequences to you in a big way. Always make each insertion or modification manually, so you can see and double-check every single thing that gets changed.

Never DELETE any blocks until you're really experienced at this. I used to generate G-code punched tapes by hand, on a teletype machine, (yup!). I once or twice lost a block that commanded a Z-axis move to a clearance plane before a rapid-traverse move across the part. Try this with a 30HP machining center if you want an adrenaline rush!

In an ASCII editor, you can usually get a count of how many lines there are. Get a count BEFORE you start editing, and recheck the number afterward.

[balsaman]

I can't answer your question but turning your router off and on a hundred times per job may not be such a great idea. Hard on the router.

Are you using Ace converer?

Eric

[limbo]

Yes I use ace converter and I've been playing around with Deskam. Toolradius compensation is NICE!
Good point about wear of the router when switching it on and off all the time. I'm just too obsessed with noise I guess. But I'd like to stay friends with my neighbours. I have a new plan: A relais will switch the router on and off, but in the off-state a parallel resistor or something will keep the thing spinning on a relatively low RPM. The problem how to switch the relais is solved. I use a flipflop that has the Z-dir signal for DATA and the Z-step signal for CLOCK. This way, when the Z-axis is retracted the spindle will stop and while plunging the spindle will start. Oh yeah, don't use this for 3-D work :D , I only do 2.5D....

John

[balsaman]

A speed control on the router will help with the noise as well.

Eric

[Tiramisu]

Hello,

Has anybody had any experience using Ingus Drylin N trackslides? Not as beefy as THK guides but they look like they might do the job and not quite as expensive:

http://www.igus.com/drylin.htm

I was thinking of using them for my router project and any help would be appreciated.

Thanks

[uscra112]

I've used these in stuff for work. They will work just fine for a router. They don't like abrasive dust, so they should not be used for a router that cuts circuit board. For balsa and ply they'd be great. The rails are anodized aluminum, so they dent easily. Don't drop any heavy steel objects on 'em.

[MrChips]

Tiramisu
Here is a link where this type of bearings were used. Also a very good design.
http://members.aol.com/wjbzone/images/
Hager

[uscra112]

Sure is pretty, Mr. Chips, but you'd hafta already have a CNC machining center to make the parts!

[Tiramisu]

Thanks for the input on the Igus Rails. I wish I could make a nice aluminum setup like yours Chips but yeah..I would need a mill to make one!

Since I am only cutting 1/16 balsa and ply I think I will go with the cheap Igus slides..I think its gonna be about $200 bucks for all three axis. I already have the leadscrews and nuts so I think I can build this thing for around $400 since I can use the controller from my foam cutter.

I have a question regarding sag. I am hoping the rails will get rid of the sag as my X axis cutting table is going to be 18x40" (so I can cut two standard 6x36 balsa sheets). I am using a 56" leadscrew on the X. Should I use three tracks for a board that long? I was planning on using 3/4" MDF but that might sag under its own weight. I guess I could use some sort of beefy metal brace to keep it rigid. Any help on the type of material to use on this would appreciated.

It actually might be a better idea to just cut the Y down to about 8" of total travel and use the Igus slides to support a gantry instead of a moving table..then I can make sure the table is flat by using like two 1x1x48 aluminum square bars to support the MDF table. That should work..I think..

Thanks,

MM

[MrChips]

The link I sent you of the all alum. CNC isn't mine, I just pulled it off of the internet, because it used the same bearings.
40" is a long span for MDF and it would sag. Would have to be reinforced with alum as you suggested.
I'm building a MDF machine also, It's copied after this one with the exception of my Y axis will have linerar bearings.

http://chuckknight.bravehost.com/router/router.html

If it works out then I'll use it to make the alum parts of a better machine. Just want to try all the hardware and software to see it all works together before I put a lot of time and money into a better machine. I baught two 7/8" supported rails with 4 bearings use for $10.

Regared
Hager

[Tiramisu]

I went ahead and ordered up the Igus slides..I got all three axis for $150 bucks. I also snagged the aluminum bars for $40 on ebay. I spent another $50 on molex connectors and an enclosure for the controller from Mouser. The leadscrews and nuts where about $120. The costs are mounting but I figured on spending $500 easy.

Chips..I probably could have saved a ton of dough by using the pipe type design you are following. I am sure it works just as good as these slides..oh well.

[MrChips]

You'r one version ahead of me.
Which Igus slides and leadscrews did you order?

[Tiramisu]

Chips,

I ordered the Drylin N types. I got two 46" tracks of N27 for the X, two 15" N27 for the Y, and two small N17 tracks for the Z. The leadscrews and nuts I got from cnclinx.com. I got two 1/2" leadscrews, a 56" and 36", and 3/8" 20" one. I will have to cut two of them down since I am now making my machine smaller. They come already cut down on the ends to accept a 1/4" Vexta shaft. The leadnuts are nice beefy brass ones.

Hopefully this stuff will work as this is all new to me and I am kinda winging it..

[MrChips]

Most of us are winging it. Just read a lot and profit from other's mistakes.
What do you plan to use your CNC for, are you interested in R/C's?
Hager

[Tiramisu]

Hagar,

I bought the CNC foamcutter and router stuff to build sailplane kits. I was also thinking of using the router to make foam plugs for glass molds. I might have to get more Z travel in order to do that..hmm

[MrChips]

Here is a person that made a foam cutting machine.
http://www.8linx.com/cnc/day1.htm
Hager

[Tiramisu]

Hagar,

I bought a kit for one from foamlinx.com. I didnt know much about it when I bought it but I could have built it for half what I paid for it after seeing how it works etc..

[BennyLaird]

Does anyone know where I can get kits cut either with cutter or laser in the Melbourne Vic Australia area?

email me at lairds@iprimus.com.au if you can help as my ezone access has been cut from work sighhhhh

Thanks

Benny

[MrChips]

Tiramisu,
What progress have you made?
I'm still struggling with designs, and materials. Haven’t found a good Z axis linear bearing so I’m going with the roller blade and pipe solution. Picked up a 16” X 18” piece of ½” alum today at the junk yard for $11, they sell it for 65 cents a pound. Been collecting alum when I find usable pieces for my alum machine.
Am in correspondence with Xylotex as I don’t want to buy their three driver board. I want to buy three of their single drivers and control the axis with them. Don’t want to replace all three drivers if one dies. They say it’s possible, but didn’t tell me how it is to be wired up. In looking at the two schematics I have a pretty good idea but not sure, want the information from a person that has first hand information.

Hager

[Tiramisu]

Hager,

Not much progress this week but I collected more parts. I got a plastic enclosure for my controller along with a bunch of Molex connectors to wire up the steppers. I got them both from Mouser. I also bought three new Vexta steppers for $65..not a bad price. I should be finished with my garage remodel in the next week then I can start cutting out the MDF and get rolling...

[MrChips]

Tiramisu,
Thanks for the update.
Have you decided which driver you will use?

[Tiramisu]

Hagar,

I am using the same driver/controller that came with my foamcutter. It is a 4 axis version made by cnclinx.com. As far as software goes I have not figured that out yet but I guess TurboCNC is a good place to start..

[MrChips]

Tiramisu,
I was looking a foam cutter and their example cutting wings. Does the right and left attachment point of the hot wire move independently in the X axis and the Y axis?
If it didn't you could only cut straight lines? Or am I missing something?
Is the software different for foam cutting?
Seems like I see a lot of French involvement in foam cutting.
Hager

[Tiramisu]

Hagar,

Yes..each side of the foam cutter moves independently so you can cut tapers etc. It uses two steppers on each side. The software is the one written by Gilles Muller (spelled something like that) which is all that is available as far as I know.

Checkout foamlinx.com and look at the pictures which should help you figure out how it works...pretty simple device really.

[shim]

Hi,
Just found out this discussion by chance. Can any one post a picture of a window channel. Thought they use the same material to build window around the world.

Anyway I have decided to purchase the Phoenix plans and the Piker board from Cranky althought I live outside the US as I don't think there is any thing simpler and cheaper to get started than Cranky's plans. Well at least that's what he has me convinced after browsing his website for months.

Am now trying to get someone help from a freind in the US or Canada to acquire the plans form Cranky as a relative in Canada has decided not to get involved in case I got scammed.

I am surprised to learn that no one outside the US or Canada has build one of Cranky plans.

Cheers.
shim

[djmrozinski]

Hello,

If you are looking for foam cutter software, check out my website. I am very close to releasing a program that drives a 4 axis cutter via the parallel port that can cut wings or other general shapes. The demo is online and can be downloaded. Let me know what you think.

Dave
www.foamwork.net

[Bez]

Hi Shim,

John shows the channel in the plans.
I'm building the Phoenix, and have the piker board.
Your freind in Canada might be able to get the channel for you.
Maybe you should look at his designs that don't use the channel.

Bez

[shim]

Benz,
Thanks for the advise on the channel.

Not much info on John's work except what he has on his web site. They don't tell much about the different machines he has, but after much pondering, sleepless nights and some guess work I've decided to try the Phoneix. He doesn't reply his email with much enthuiasm either. (Sorry John)

I just started reading this forum so I think I'll have a long way before I catch up so hopefully when my purchase do fall through I hope I've made the right choice.

Anyway I plan to use it for cutting RC stuffs and basically to learn more about CNC.

Let me know how your Phoenix goes. How did you go about deciding which machine to get?

Cheers.

[crankorgan]

Shim,
I answer 200 or more Email per day. I have to keep them short. I have no time for people who want me to help them choose a machine. People from other than the US and Canada. People wanting free stuff. People who want me to design stuff for them or explain something that has nothing to do with what I sell. Go back through the messages here before you say I lack enthusiam. Start at the beginning and read! The questions you are asking have been answered here before.

Cranky

[uscra112]

Shim - he ain't called cranky for nothin'.

Be nice to him - he's contributed an AWFUL lot to these threads. . . !

[crankorgan]

Hey,
Talk is cheap! Try this side for a week or better yet try building instead of talking.

Cranky

[shim]

Hi John aka Cranky,

Don't get too worked up. You're busy man, I know.

Yes sir, I'm reading from page 1. Currently at page 10 or so and taking notes too.

Don't blow your horns if you think my questions are silly. Just don't reply. I'm sure some kind and willing folks out there will take pity and post a reply. Will try to hold my questions till I've read all the thread.

Cheers. Stay cool.

:D

-shim

[xairflyer]

Hi Cranky,

I have been transfixed to this thread since I found it a couple of nights ago.
Any from what I've read, I will be going with your format as I like the way you think.

I am at page 24 and think I have to now make a start.

I want to be able to cut balsa/ply and polycarbonate(lexan)
Also like the idea of pcb work.

Which one of your machines would you think most suitable.
I like the layout of the 7th soujourn.

You say on your site that you will only send out plans to the US ? I am in Ireland and would love to build one.

Can you help, Please ?

Seamus

[PanzyPoof]

Cranky:) Let me get this one for ya!

xairflyer:) The main reason Cranky won't sell overseas is the Alum Channel is not availible there. Only in North America .
So you will find simulare products but the game is to stick with the Plans ... hense Plans.
But as you continue to read You will see others that have based there machines on a simular style useing availibe materials.
A little more study and you'll see where to begin.

I had a Small breakdown The Flex shaft on my Dremal :( Out of the game for 2 weeks but now have replacement.

[uscra112]

More accurately put - the aluminum channel Cranky drew his machines up for is made by North American mills to USA standards and dimensions, and anything you get anywhere else will be metric, and not quite the same. It's a nightmare I live with - we build German-designed equipment here in the States, and vice versa, and it drives us nuts. A 1" plate is 25.4mm, and there ain't any 25.4mm stock to be had in Germany, so they take 30mm plate and mill it down, at horrendous expense. They send us a drawing for a part calling for 30mm raw material thickness, and we have to start with stock that's 1 1/4" thick and mill it down .068" to get 30mm. You get the idea.

[xairflyer]

The aluminium channels won't be a problem as I have access to all types of extrutions and can fabricate whatever parts I need.

I build aluminium frame aircraft for a living.

I mainly want to start from a blueprint rather than figuring out everything as I go, and then asking you guys stupid questions every day.

[FlycastSeven]

This question may already been addressed, but do the controller boards need programming?

thanks,
George

[uscra112]

Generally no. They take in signals from the computer and apply current to the motors according to some internal algorithm. There is "programming", because they'll inevitably have a microprocessor in there somewhere, but the firmware will be fixed from the factory.

Not to say that some high-end controllers wouldn't have programming to allow customizing of things like accel-decel rates, current limits, and whatnot, but low-cost ones we use generally won't have that kind of sophistication.

[xairflyer]

I would like to build something like crankys routezilla, it dos'nt seem to contain this aluminium extrution.

[FlycastSeven]

Originally posted by uscra112
Generally no. They take in signals from the computer and apply current to the motors according to some internal algorithm. There is "programming", because they'll inevitably have a microprocessor in there somewhere, but the firmware will be fixed from the factory.

Not to say that some high-end controllers wouldn't have programming to allow customizing of things like accel-decel rates, current limits, and whatnot, but low-cost ones we use generally won't have that kind of sophistication.

Thanks. I appreciate your help!

George

[BennyLaird]

I'm building up a cutter down here in Melbourne. I have the electronics, steppers and software and a lot of ideas. I love to try one of Crankies designs but not available down here. Can anyone put me onto some plans for something about 4' X 2' and able to cut balsa and ply with enough accuracy to produce kits?

Please email me at james.laird@defence.gov.au as I have no access to this site due to it being deemed a chat site by the network nazi's.

Thanks

[Trizza]

Benny,
Where did you end up getting your steppers, and how much were they?

[vintage1]

HEY!!!

I found a reference to this in unsenet - uk.d-i-y

Wonder if its any good?

http://www.milinst.com/robotics/robotics.htm#axis

[balsaman]

I know someone who built that machine. It makes for a very bad unit. It also uses proprietary software and hardware interface.

Eric

[vintage1]

Ok. Thanls for the tip. Won't be one in my Xmas stocking then :)

[BennyLaird]

Originally posted by Trizza
Benny,
Where did you end up getting your steppers, and how much were they?

I bought the whole package in order to get up and going. Just need to make up the hardware

now.http://www.lowcostcncretrofits.com/

[FlycastSeven]

I'm wondering what it would take to mill aluminum in a 3D fashion. Is there any way that I could do that cheaply? If I'm asking this question in the wrong place, feel free to redirect me. I want to be able to engrave textured surfaces out of a block of aluminum, for a plaque. I would appreciate any advice.

Thanks,
George

[uscra112]

People do engraving in aluminum with these machines, but that's very shallow cuts that don't remove much metal. If you need to cut down deep (say 1/2") to make your plaque, it's iffy. A strong router of the kind we see here might do it, save that the bearing life will be short. When I was in the airplane machine-tool biz, we used to mill aluminum with a 1" diameter cutter at 40,000 RPM, to give you an idea. With a 1/8" diameter cutter an RPM of 100,000 will not be out of line. Thing is, if you're removing significant amounts of metal, this has to be done wet - aluminum cut dry will pack up the cutter flutes in a jiffy. In the auto industry where I now work this means a garden-hose-size flood of soluble oil, which when it hits the cutter makes a fog that goes everywhere. In the airplane machines they often use "mist lube" which means spraying the cutter with a fog of air and soluble oil, and again it goes everywhere. They use massive vacuums to draw it (and the chips) off to meet OSHA air quality standards.

One useful thing to know is that different alloys cut very differently. If I had to do this dry, I'd use a block of 2024 alloy, which makes a nice crispy chip, almost like brass, and probably wouldn't gum up the cutter if you kept a steady blast of plain compressed air on it. 7075 is a second choice. The common 6061-T6 is a distant third. There is no fourth.

Have you given any thought to casting this plaque? There's a number of web sites that describe the tools and the methods. It's not all that hard. Aluminum melts at a low enough temperature that you can easily do the melt over charcoal with a hair-dryer for forced-air draft. One guy even melts pop cans to get his aluminum.

[gjahnke]

I recently built a CNC mill (last week) mostly to cut PC boards with. I already had a commercial model that works fine but it is a little big to fire up every time I want a board etched. A few thoughts for you guys who are just getting started as far as finding cheap/free materials goes.

First off, buy a set of crankys plans. I didn't, and should have. I used roller blade bearings and pipe for my linear bearings (saw this on another discussion thread) . I didn't realise that the plans for this were crankys until reading this thread. I took a little different approach, though, and made the bearings go completely around the pipe. I got my bearings form a couple of pairs of roller blades I picked up at a garage sale for a quarter each.

I built my table and supports from some old cabinet doors that I pulled out of a dumpster on a building site. They are laminate grade MDF, which means they are meant to be covered with a laminate. Theya re courser grained than the standard MDF (which is cabinet grade) but the resin they use to bond it is waterproof. The doors I got measure 3' x 2.5' and have a while formica inside and a nice wood grain laminate on the outside.

My step motors came from a local computer shop. I went in and explained to the uy what I wanted and walked out with 7 dead printers for free. The old tractor feed dot matrix printers yielded the best steppers. I built my controllers using Aleggro's UCN5804 step drivers. I used their "request sample" button and got 8 of them for free. You guys who are buying controllers should really look into building your own. I took a look at some of the ones available on the web and for themost part you are paying $300 or more for $25 worth of part (that is if you buy everything) and 2 hours worth of assembly time (assuming you are using a blank proto board and running wires for your connections). With a board design like cranky offers on his site, you should be able to populate the board and get it all soldered up in about an hour. There is nothing to it, soldering is easy. I built a model plane one time (think I will give it another go) and if you can do that, populating and soldering up a circuit board is a walk i the park. Lokk at it this way, if you screw it up, you have blown a little money, but you can screw up a WHOLE BUNCH of homeade boards for what you pay for a single commercial unit. The other advantage to building your own is that you learn something new and you will be able to fix your own board when it fries (the commercial ones will fry eventually too, not a whole lot of built in redundancies or protection from the ones I saw).

My cutting head is a Rotozip. If you want to use a rotozip, you will need to tighten up the spindle bearing. Luckily the slop is between the bearing and the case, not the bearing and the spindle. Take the unit apart by twisting the metal collar counter clockwise while pulling. Remove the handle. Remove the 7 philips head screws from the casing and separate the casing. Find the nuts for the handle that fell apart when you pulled the casing apart (check under the table). Remove the motor from the casing being careful not to slide it around too much (or it will slip past the brushes and you will have to press them back to get it back in place, not a big deal if it happens, use 2 small screwdrivers). The bearing that is the problem is the front one. The rear bearing has a rubber cap on it that keeps it tight. Wrap the front bearing ONCE with electrical tape. Trim off the excess. Installation is the reverse of removal. You will probably have to go back and replace the electrical tape periodically, but that's no big deal (I'm thinking about once every 5000 hours of operation).

The rotozip has a nifty collar where you can mount it to your Z axis (just don't put the metal collar back on, you won't need it if you build a collar out of MDF wit a couple of wingnuts and tighten it down good).

I am using linux to run the machine. A lot of people shy away from linux EMC because it is more complicated to set up. Learn to use it. It is every bit as good as the $2500 software that runs my big machine (in fact, I installed the linux software on that machine also) and it is FREE. There is also some nifty stuff available for the linux package that saves you some BIG bucks (like a build it yourself for under $5 digitizer that plugs into your PC's joystick port that actually does a really good job).

So far, I have cut about 20 circuit boards (I have been cutting boards for other guys for $5 each, they supply the board layout file and the blank board), made a copy of a toy car (had to try out the digitizer) and machined a block of aluminum down to a sliver of aluminum (just to see if I could do it). If you want to machine aluminum, you have to install a lubricating assembely (think windshield washer pump and aquarium tubing). You also have to run the machine pretty slow for aluminum.

I then went and got a sheet of 4'x8' foam an inch thick (they sell this at your local lumber yard) and built a case to enclose the whole thing in out of some more of my scavanged doors and a bug piece of plexi glass I had left over from another project. i lined the case with the foam. It quited the machine down enough that I can drown it out with a radio without going deaf.

I think my total outlay for the machine (if you don't count the roto zip and the computer, which I already had) was about $25. My pipe came from a bulding site where they were installing gas, my MDF was free, my bearings were 50 cents, there was about $10 worth of nuts, bolts and screws, and the rest of the stuff came form a local recycler. My electronic parts and pieces (besides the motor controll IC's which were free samples) came out of other electronics, most of which I pick up off the curb on trash days when I see something interesting. If you are going to try to salvage electronic components, though, you really need to invest in a desoldering iron (they sell them at radio shack. They look like soldering irons with funny ends and a red rubber ball attached). If you just try to desolder with a regular iron and a pair of pliars, you will burn up your components 9 times out of 10.

Overall, I am pretty happy with the new machine. It does what it was built to do, which is cut circuit boards, and as a bonus it cuts wood and aluminum reasonably well.

Also, I saw earlier in this thread (now it more like a rope, haha) where somebody had cut a bunch of gears out of MDF and made a really nice looking clock. Are there plans available for that? I would like to try my hand at that. It looked GREAT. Good job!

[gjahnke]

Correction, the metal collar on the rotozip turns COUNTER clockwise to get it off.

Also, I saw a bunch of threads where people were talking about using delrin and other types of plastic in their machine. Where do you guys get this stuff? The closest I could come to any of this is plexi glass.

[GenesisCreation]

Very inspiring story gjahnke. I will get a set of cranky's plans. Do you have any pictures of your unit? I would love to take a look at it.

Thanks for sharing your experience. I've wanted to build one of these for a while but have had a big case of "Fear of the Unknown". Just have to step out there and give it a try.:)

[xairflyer]

Gjahnke Do you have any pictures of your machine, I'm sure the group would like to see them.

This is what it is all about, the more I read the more I believe people should build a simple machine with small'ish motors and a simple driver board like the ones from www.kitsrus.com (kit no. K179) that are very cheap, or the piker.

Then after you have a machine up and running, build another one with all the things you don't have in the first.

[crankorgan]

gjahnke,
Best price for Delrin is Ebay. Buy a 1/2" or 5/8" thick slab.
This works best for drive nuts.

Cranky

[gjahnke]

Thanks, cranky. I used to live in kansas city and there was a place there that sold plastics. They had a defect and cut bin and for $10 you could fill a grocery bag from the bin. Now I live in a small town and there is nothing like that around here. I will be purchasing a set of plans from you. Looking further back over this thread, more than a few of the things I did on my machine were rip-off from your plans. Sorry, nobody gave credit in the pictures I had seen so I didn't know. It is going to be a couple of months, though. I am a self employed computer programmer and liast week I broke my right hand pretty badly (which pretty much means I am an unemployed computer programmer until the cast comes off).

There will be pictures forthcomin in about 2 weeks. I have a sony mavica digital camera and the floppy drive has gone bad. I ordered a new one, but it will not be here for a couple of weeks. If I can borrow a camera before that, though, I will!

As far as buygin a cheap kit or building your own motor controller, you definatly should, especially when guys like cranky are offering pre-etched boards (laying out and etching the board is the hardest part). You will save literally hundreds of dollars going that route!

[crankorgan]

gjahnke,
Lots of people using my ideas. I don't mind if they mention me from time to time. Some people are still mocking roller blade bearings. With gas pipe or drill rod you can't beat the price. I made CNC cheap and I like seeing people perfboard a controller now and then.

Cranky

[uscra112]

gjahnke - I've used the white plastic cutting boards you get at Wally World as a source for erzatz Delrin. I think they're probably a dense polyethylene.

[gjahnke]

The roller blade bearing worked great. I added a little to the design and surrounded the pipe w/ the bearings (so there is a bearing on all four sides). I was concerned about the x axis lifting the gantry vertically. I don't know if the extra support was really needed, but I figured that as long as I had the bearings and the angle, I may as well go ahead and do it.

I like your design on routzilla w/ the removable/replacable cutting table and the MDF support between the bearings. It looks like that would give excellent support to the gantry. The machine I built doesn't have either feature and I am a little worried about my gantry loosening up in time. I feel a redesign coming on.

I also saw a thread on here about using shop-vac as a hold down. I used an old kirby for my big machine (the old ones ith the cast casing) and drilled some holes in the vacume chamber to allow air to flow past the motor. Works pretty good, and I found the kirby in the trash somewhere so it was free :-)

After looking over this whole thread (and it took a while) I want to reiterate my previous suggestion that you order a set of crankys plans. He has a lot of stuff worked out already that will save you hours of misery.

Oh, and build your own controller. It is not that hard and what you will learn about putting together circuits will serve you well later (think building your own RC controls)

[Tiramisu]

Has anybody used their router to cut foam? I thought about designing a sailplane fuse in CAD and having the router make a perfect plug instead of shaping by hand. I guess I would have to cut a left and right side and glue it together since no 4th axis. I might have to increase my Z axis another inch or so to do this..hmm..

Any input would be appeciated. Thanks.

[xairflyer]

I did come accross a site but cant remember where (been searching all morning) but the guy had built a machine to cut out foam plugs for model jets.

This link has some foam wing cutting machines.

http://www.8linx.com/cnc/day6.htm

[xairflyer]

Hi,

I posted this on CNCzone as well but just in case some of you are not on there I thought it would be of some use.

Have you guys came across the range of kits by www.kitsrus.com in the US.

They sell a unipolar stepper (K179) and a bipolar stepper (K158) kit very cheap.

The single axis unipolar version is effectivly a cmos type of the piker except it uses fets and the complete kit pcb components and all is only £9.95 in the UK.

Kitsrus dont sell direct but I checked up thier US resellers and one company is selling the same kit for $9.95 three boards $29.85 has to be good for a starter machine.
All you need is some power resistors and a bit of wiring and your away.

They also sell a kit using the 5804 driver IC which could easily be used as well.

[gjahnke]

I have used my big machine to cut foam for casting aluminum and it does it just fine.

To cut foam for your sailplane, you would most likely end up needing a 5th axis, too. A 3 axis machine is mostly for 2.5d modeling, a 4th axis will allow limited 3D, but for complex shapes, you really need a 5th axis.

[xairflyer]

Got a K179 and K158 kit in the post today excellent quality PCB.

The Bipolar version comes with opto-isolated inputs as well not bad for £12.95

[BennyLaird]

John, I've been out sussing out bits for my own design cutter. Based on what you have suggested here and your site. I'm just a bit unsure of the layout of the pipe and how the bearing ride on it to eliminate side play. Anywhere I can see a pic or diagram. I'd love your plan but I'm in Australia.

Benny

[crankorgan]

Benny,
The pipe and roller blade bearings is all here. What will you use to replace the aluminum channel?

Cranky

[shim]

Hi all,

Finally finished reading all 93 pages of the thread. Such a vast info on CNC building here.

Hey Wallyh & AirX what happened to the Morph you are building. Hope you can share how your building is coming along.

I gathered and from picture posted here and on Cranky site, this is the only Cranky's design that DOES NOT use aluminum channels.

Cranky, can the Morph with a knife cut circle on vanila (1/16"hard board) paper or is a dremel with a router bit still preferable.

Cheers.

-shim

[BennyLaird]

I've been looking at hardware shops etc with no luck. The only window channel I can find looks nothing like yours.

I may use pipes instead?

[BennyLaird]

Which pages are the pipe and bearings? LOL I get lost in this thread...

[BennyLaird]

OK I found them, nice and simple Cranky. Just like me, lol. OK I'll start acquiring bits and pieces.

I just realised that it's so easy to see at your site. I was making things complex in my mind.

[BennyLaird]

My steppers are 130 oz, is this enough for a table of say 36" X 18" using 1/4" threaded rod?

[Jerry Dotson]

130 oz torque is plenty. I built a router with 20X48 travel and 118 oz in. Works fine. I use a Dremel for router and 1/8 shank .050 or .0312 diameter carbide router bits purchased from:

http://www.drilltechnology.com/drilltec.html

I made a vacuum table... works but need more volume of vacuum. When cutting a series of ribs from a sheet you have to cover some of the cuts up or it will let the part move. Have a picture below. It was taken before vacuum table was completed