I've actually seen these machines in person, they're used to cut boat sails. A small stepper rotates the blade holder.
http://www.carlsondesign.com/#Plotter_Cutters
The cutting heads look pretty simple. I don't think they make any oscillating cutters.
Hmm, I should get into that business, 30k for a simple track and cutter head. They are using belt for the drive system too, wonder what they used to glue it down to the rails?
I still don't like the idea of mounting a blade directly on the stepper shaft.
My design in almost done...don't tell my boss.
Ok, so here's my take on it.
Let me know what ya'll think...
P
That looks AWESOME, can i have your brain lol so when are we going to design it? here is a picture of what the picture framing CMC machine blades look like
except they slide in at a 45deg to do bevel cuts
MomentZ,
This project is interesting. Here's the information. It may help you.
http://www.cnczone.com/forums/showthread.php?t=26128
http://www.comagrav.com/oscillating_...ial_knife.html
http://www.carlsondesign.com/#Plotter_Cutters
I know the A-axis of mach3 can rotate the knife.
I am not sure what cam software is suitable for the tangential cnc machine.
What do you choose cam-software?
Mongkol
Mongkol, thanks for the links.
In the first link, ger21 says Mach3 will do tangential control only for G1 commands, but I think this has changed. I wrote a simple program to cut out a rectangle with rounded corners and it handled the G02 and G03 curves fine, although this was just a simulation since I don't have a tangential axis yet.
The Comagrave is a pretty nice machine. I think I could design in an oscillating tool holder by adding another through shaft that is keyed inside the main shaft. This would add a fair bit of complexity, but could be done.
Yes, to use tangential control, you install another motor driver as the 'A' axis. There's a button on the settings screen to put Mach3 into tangential control, and that's it. The 'A' will rotate according to the cutting path.
As far as software goes, Sheetcam would work fine. Just use zero offset paths and away you go. I think the trick is to get the cutting tip exactly on the 'A' axis rotation.
Overcutting isn't handled by Sheetcam as far as I know, so this would have to be drawn in as part of the .dxf.
I'm pretty pumped about building this little machine. I just finished a CNC rotary table a few months ago, and this will be very similar as far as components and control.
How many should I make? Is anyone interested in buying a completed unit or just the full set of plans?
Paul
Hi Paul that machine looks excellent but i think i will stick to trying to get a computerized mat cutter/router developed first and with the help of you guys out there i can already see it
I like the design, it looks well thought out.
A couple of random thoughts...
I wasn't sure the purpose of the pigtail (# 220) in your drawing. At first glance I thought it a spring to preload the blade but based on position am I correct in guessing that it is a strain relief for your cabling?
I'm not expert on bearing specs is DE,AC an angular contact bearing? Seems like a good idea here though probably not very imprtant for this application.
Is the oscillating motion a high frequency/low amplitude motion? I think I recall seeing something about 3,000 cycles and travel anywhere from 2-10 millimeters depending on the material being cut.
The knife blades used in these machines seem to be either thin xacto type blades or much heavier cylindrical sections with cutting edge machined on the end. Are these heavier blades used only for oscillating cutters, are they for machines intended to cut thicker or heavier materials, or is their no such correlation?
I think I recall reading someone having trouble using Mach's tangential support for cuts angled relative to Z. I guess this is needed in mat cutting to get a bevel cut. Apparently the Mach feature to lift Z at the correct angle didn't work corrctly, the blade was lifted straight up out of the bevel.
Sorry if all of these thoughts don't apply to your application or design. We have a couple people on this thread trying to do different things so I thought it useful to put these all together in one place.
I have found the website and cutter I was thinking of
http://www.thecmcdoctor.com/thecmcdoctor_blades.htm
It is a US company so someone there might be able to investigate if it is a mat cutting blade and if it will work on a CNC router.
Cheers
Peter
The ingenuity of idiots is unlimited.
http://www.youtube.com/user/cncnutz
got a call back from axyz, the tangential cutter as you know costs 16k WELL if you want the controller box aswell then it $35,000 with the cutter again YIKES,
there is money in CNC's
I saw this in one of the trade pubs covering the IWF show in Atlanta, an add-on oscillating cutter head for any CNC with tangential control.
http://www.benz-inc.com/products_woo...w=detail&ID=56
not much info there but check out the video at:The Reciprocating Knife Cutter - RCK1
is designed to add a new level of versatility to a "C"-axis equipped CNC machine. It utilizes a standard spoil board to hold material. During cutting with the oscillating knife cutter the spring-loaded floating ring ensures optimum contact of the material with the surface underneath. Similar to a jigsaw, very small radiuses can be cut.
The very high reciprocating speed of up to 6.000 strokes per minutes ensures very effective machining with high federate speeds.
The RCK1 is designed to cut cloth, fabric, leather, veneers, rubber, carpet, cork, vinyl, fiberglass matte, cardboard, linoleum and other similar products.
http://www.benz-inc.com/videos.php
scroll down in the list of videos until you see the one
titled "Benz Oscillating Knife Cutter"
That's looks NASA expensive. I'm sold on the spring loaded hemisphere hold down though...Gotta add that to my original design.
Should be able to start making the unit early next week. All this 'after work' work is getting in the way!
Paul
How to calibrate A Axis to get the angle using Mach3 Settings menu Steps Per Unit button? Im using gear reduction to get the perfect angle rotation.
This was posted to me on joes forum, it looks like a simple design with just a blade holder on the end of a stepper motor, i was also in a framing store today watching some matts getting cut on a computerized mat cutter, and the z axis comes down the you hear a "PSST" and it shoots the blade in on a 45deg angle, there is an air compressor hooked up to it so i guess there is an actuator that shoots the blade in and out, i got thinking and thought back to my car central locking days and wondered if you could use a single car locking magnetic actuator and when you give it some current and it fires out and then reverse it, like what your locks do on you car by going up and down, any thoughts on that?.still following closly and the good ideas here.
Don't know much about the topic.
http://www.smp-sign-systems.com/produkt ... ser_e.html
http://www.globalimaginginc.com/equipme ... ools.shtml
http://lumenlab.com/forums/index.php?showtopic=25903
This one looks very interesting and do-able :?:
It is for a 24 footer :!:
http://www.carlsondesign.com/#Fun_Shareware
You've got some incomplete URLs
Don't know much about the topic.
http://www.smp-sign-systems.com/produkt ... ser_e.html
http://www.globalimaginginc.com/equipme ... ools.shtml
Bob
"Bad decisions make good stories."
Moments, that sounds like the best idea yet for 45 deg cuts. It would take a little playing around to make sure the cuts all end up where you want them, but yeah, any way of extending and retracting the knife at an angle, independently of the motion control system, would be a decent solution. A small air cylinder hooked to a solenoid valve would probably be the easiest...
I could envision making that an addon that would attach to the output shaft of my tangential axis design.