Deadstik

My Feedback: (8)

John,

Are you going to use the limit switches to shut off the Dremel or to shut down the entire machine? Not that I know a lot about this, but I thought that if there was an error that most CNC programs would default to tool power off and go to home position? I used to be very involved in CNC programming 5 years ago and since I am now teaching nothing but Electrical Wiring Systems I've forgotten the elementary electronics/programming needed for this project. Are you planning on using steppers or servo drives? Inquiring minds want to know.. Thanks,

Dan

John Mason

My Feedback: (4)

The limit switches will stop the axis drives from tearing itself apart. I dont have plans for them to shut-off the motor due because the motor is not controlled by the computer. I will have to manually turned on or off. I'm going to be using steppers from Hobbycnc. There will an emergency stop button which I have plans to make shutoff everything.

dreadnaut

My Feedback: (5)

I might suggest a roller type limit switch. If the table is traveling at a high rate, it will need time to decelerate to a stop. Most of the CNC milling machines I have worked on had two limit switches at each end. The first was a ''warning' switch about an inch ahead of the final switch that would slow the table into a ''creep'' mode. When the table hits the final limit, it is going at a preset speed that, given a known rate of deceleration, allows it to be stoped at a presise spot. This prevents the loss of you 0,0 coordinates.

They use roller switches. I dont know if the switch shown will stop it in time to prevent damage.

John Mason

My Feedback: (4)

In my opinion the limit switches will be fine due to the fact that the feed rate is fairly slow. Heck the build articles I have seen on this particular machine have not incorporated any type of switch.

FLYBABY6

Limit switches are great! On my waterjets, if I'm moving it too fast towards its' limit and it slams into, it sucks. But hopefully you wont be moving to fast to cause damage to your machine there. One tip though conserning your axis's, Make sure all around table is clear of desbris and obstructions to snag the gantry and posibly pull it out of allignment. o/o would be lost and have to be reset, and further parts wont be cut out where you wanted.. Keep it up, great job.!

dreadnaut

My Feedback: (5)

You're probably right. For someone with a $100k machine tool who hires someone to operate it, a two swich scheme makes sense. I know I would be careful on a macine I owned.

John Mason

My Feedback: (4)

I am going to be careful but this is my first cnc machine and I am simply following what has been suggested in the building instructions. Plus with a feed rate of around 20-30" a minute I don't feel the stepped switch as you mentioned will be necessary. Plus I would have no idea about how to program one. I appreciate your concern and realize you have way more experience than I. If you see me going in the wrong direction please step in and correct me. Thanks!

In other news I received my dremel mount today. I had to drill 2 holes through the mount and z-axis slide plate and it was mounted. It came out pretty square to the base but It will do until the machine is operational so I can cut out a perfectly square z-axis slide plate.

Yuu

Please keep this info going, John. I really enjoy this. Thanks.

John Mason

My Feedback: (4)

After A few days off I got back to the router.
First step was to order the cnc kit from hobbycnc.com
It comes with the stepper motors
parts to assemble the circuit board
one gigantic capacitor
6ft serial cable
cooling fan
misc cable and heat shrink tubing

I opted to pay the extra $$ to get the 205 Oz/in torque motors. These things are heavy for their size.
the steppers were mounted and I have started to put extensions on all the wires while I am getting some really small solder.

John Mason

My Feedback: (4)

Well the driver board is finished. I was really dreading having to solder it all together but it was actually pretty simple and took about an hour.

TFF

Looks great! What does the third stepper move, and what language does it use?

John Mason

My Feedback: (4)

not sure which stepper you are referring to but it has z,y and x movement. It will run gcode

TFF

Pretty cool. I see a lot of these things use only X and Y so I am impressed.

dreadnaut

My Feedback: (5)

Keep it comming. I can't wait for details on the PC interface and software.

CliffordH

My Feedback: (9)

John,

I am watching your build with interest. I got plans for a CNC router from RockCliff and am making an enlarged version of that design. I am also using the stepper driver and stepper motors from HobbyCNC. I just finished building the other version of their driver board and am making the router assembly parts now.

Have you been looking at programs to run your router and programs to convert images other than CAD files to G-Code?

Cliff

John Mason

My Feedback: (4)

I am going to be using a program called mach 3 to run the machine. It is fairly easy to use and not too bad on the wallet.
To convert my .dxf files to g code i will use LazyCam a program made by the same company as mach3 .
As far as a program to vector image files such as scans from plans I have not decided on one just yet.

Xairflyer

My Feedback: (1)

Hi John

I built my machine about 3years ago and it has been cutting non stop since.
I mainly cut lexan for parts I make for full size ultralights, I have cut some ply formers, and some mdf but not much wood, had all these plans for cutting out a kit etc but never got round to it !

Have a lot experience now running the machine, I also use Dave's Hobbycnc board and it has been faultless from day one.

I draw in Autocad, convert the file with ACE, do a test run with CNC simulator and then use turboCNC to run the machine.

If I can be of any help just ask.

Vapor54

Hey Guys, I love this thread! Can more of you post what programs you are using to draw with and run the machines with? I am wanting to build a CNC router but have some doubts about being able to program it. I have a CNC foam cutter I built years ago and it works great, I use Hobby CNC board to run it and it is flawless! -Rick Fraley- Eaton, Ohio

Xairflyer

My Feedback: (1)

If you have been using a cnc foam cutter you already know most of it.

A 3 axis router is very similar, most people draw in autocad or similar program and then convert it to the gcode needed for the machine. I use ace converter which works well for me, only things I change from the code it supplies is maybe the plunge speed etc

I use turbocnc to run my hobbycnc board it works well and very easy to use, once you get the machine parameters set you noever look at it again.

Vapor54

Thanks for the reply. My latest foam cutter is built from 8020 materials and slide bearings from 8020-this works great on the foam cutter; whats your opinion on using it to build a router? Thanks again-rick

PS I just went & looked and autocad is what my son gave me a manual to read-it looks pretty tough to me! Is Delta CAD OK? It sure looks less complicated, maybe it isn't. I will keep reading autocad and see how far I can get.-rick

Xairflyer

My Feedback: (1)

If you read too much into it autocad can be mind blowing, best get a autocad for dummies style book or I bet there is a basic course on the internet somewhere.

You really only need to know the basics, drawing lines, circles etc.

Any other drawing package will work as well, so long as they are in a dxf format if you want to use a program like ace to convert them to gcode.

There is also some software, that combine the two, and also some that will autoput 3d images from graphics

John Mason

My Feedback: (4)

Well I have been slowly working on the router im glad to say it is almost done. I still need to mount the lead screws and finish the enclosure.

dhal22

looking good. i wondered how your project was coming along.

Deadstik

My Feedback: (8)

John,

Looks like you've been making excellent progress. Great to see all the other folks here on the forum giving it the watchful eye too. No substitute for experience. Now I've just got to get started on mine.

keep up the good work !!

Dan
Carolina Custom Aircraft

John Mason

My Feedback: (4)

Few more