Rug Cutting Attachment for Shopbot?

[williams_architectural]

Is there an attachment I can get to cut irregular shaped rugs or carpet? Would a laser attachment work? I need to cut a few thousand with 1/4" radius in the corners.

William

[myxpykalix]

On the show "How it's made" it showed how carpets were made and they had a large slicing round knife that looked like a pizza pie cutter that was used to make cuts on the roll.

It looked very heavy and probably very sharp. Others have talked about using straightedge cutters similar to exacto knives to cut cardboard here.

[erik_f]

Make your pattern on the bot and then cut by hand?

[german]

you gona need this http://www.youtube.com/watch?v=bHeKgs058Lc

German.

[donclifton]

Here again is a tangent cutter I made and it will cut rug.

http://www.youtube.com/watch?v=8nYQaLgvvKI

[paul12617]

SB New Letter spring 2007 has a story about a rotary cutter used for cutting saddle blankets http://www.shopbottools.com/newsletters.htm

[knight_toolworks]

how hard is it to make that attachment?

[donclifton]

If your talking about mine its easy if you have a indexer you could turn it on its side. I don't know if shopbots software has the ability to do Tangent. The rotation of the bit is in the software it follows the contour of the cut. I use Mach3 which does tangents.
Thanks
Don

[myxpykalix]

Don i hadn't thought about using a indexer motor to turn the cutter but that would work I think. However wouldn't you have to change the cutting file (axis's) if you mounted the indexer in the Z axis?

[donclifton]

No,You don't change anything in the gcode file you just set that axis up as tangent and angular. It sets the head after each segment. I have made a shopbot clone and build my own gearheads and this is just one of those gearheads, kind of like shopbots indexers.
Thanks
Don

[donclifton]

Jack, You don't write code for the A axis like you would in a indexer. In mach and I don't know about Shopbot you just give it a path and the gearhead or indexer follows that path.
Thanks
Don

[myxpykalix]

I was trying to visualize holding a indexer with the head down and trying to visualize how the shaft would be turning to accomodate say a curve in a cut. I don't have any need to try to do this but it is interesting to think about. Yet another application and use for an indexer and more of a reason for shopbot to support it better. thanks

[donclifton]

The use of a tangent head leads to a lot of applications. to be able to cut with non rotory tools gives you a lot more options. I also have a video of a rotory blade cutting fabric on youtube.
Thanks
Don
http://www.youtube.com/watch?v=FQfIKaq3MZo

[myxpykalix]

that is very cool. That would make one heck of a cool pizza slicer!

[donclifton]

You could make every piece the same size.
Thanks
Don

[williams_architectural]

Very impressive video Donald thanks for the info.
Also thanks German, I'll check out the website.

I appreciate everyones responses

William

[donclifton]

anytime
Don

[williams_architectural]

German,
I just checked out their website and that's pretty cool.

Thanks

William

[williams_architectural]

Don,
Would you be able to make an attachment for me like yours?
Email me with a cost to attach to my shopbot.

Thanks,

William

[bill.young]

I've added the program that's used to convert the part files for cutting the saddle pads in the Spring 2007 newsletter article (http://www.shopbottools.com/arch/TheEdge07Spring.pdf) to ShopBot Labs. The download includes some documentation and pictures of cutters and stepper motor mounts and if you're a tinkerer might be used for cutting your rugs.

http://www.shopbottools.com/LabFiles/RotaryCutter.htm

The usual ShopBot Labs disclaimers apply...

Bill

[myxpykalix]

I used to "cut a rug" but that's an entirely different thing....

[steve_fedor]

Here's a nice set-up not sure of cost.

http://www.multicam.com/eng/Products/knifecutter.html

[williams_architectural]

thanks bill & steve for the info. I'll check those out. Also thanks for the laugh jack. I was wondering who was going to be the first to say that hehe! I never could cut a rug and apparently still can't because I'm asking you guys how to lol.

William

[benchmark]

My problem was that I needed to cut foam inserts for wooden boxes, I tried to cut them on the Shopbot but the heat buildup caused the backing glue and foam to stick to the cutter resulting in it tearing the foam. I looked at some of the vinyl cutters but found the only one able to cut the foam was £2500, so that was out.
Then, thanks to the ingenuity of Bill Young who wrote the Rotary cutter programme, it gave me the control of the cutter direction that I needed. Bill’s setup was designed for a rotary cutter, but because my foam parts have very tight radius corners I planned to use a knife blade.
I was able to use a spare drive on my PRS to give me a fourth axis for the cutter direction.
I made a temporary mount for the stepper motor out of birch plywood, just to make sure it would work, at some point I will remake this out of steel or aluminum. I mounted this in front of my “A” axis spindle.

7933

The blade holder was fabricated from odds and ends from the scrap box, this bolts onto the end of the stepper motor and fitted with a blade clamp to hold the cutting knife.

7934

I created my vectors in Aspire making sure they run clockwise, and then with the “Rotary Cutter” program I converted the Shopbot file into a Rotary part file.

I changed the setting in the Shopbot software with the information that came with the rotary cutter program , my first attempt was a complete success with the exception for a slight overcut on the internal and external corner, which I put down to the blade shape and the setting of the cutting angle. So far the project has cost me £3 for a packet of blades.

7935

At some point I need to make a few odd size cardboard boxes so this setup will sure come in handy.


A big thank you to Bill Young


Paul

[bill.young]

Hi Paul,

That's really neat...glad it helped you out. Let us know how the cardboard cutting turns out...

Bill

[dray]

Jack Jarvis: "I used to "cut a rug" but that's an entirely different thing...."

5 stars for timing and delivery! lol

[myxpykalix]

You know these young "whippersnappers" won't know what that means...you have to be an old fart to get it!

Bill Y,
I asked this in another thread and didn't understand the answer so let me ask so i can try to get it.
My assumption is that this is similar to the indexer conversion where the Y axis is converted to a B (or A) axis.

Taking Pauls part picture above, if i was to draw that out, I am drawing in X,Y,Z but then you run that resulting toolpath thru this "Rotary Cutter" program that converts (which) axis to (what) axis?

Also how is the Z axis compensated or set because cloth might not be as thick as foam or cardboard?
thanks

[benchmark]

Hi Jack,

Bill is the man to speak to, but I will have a go. You need 4 axis X,Y,Z and B, XYZ speak for themselves what the B axis does is turn the blade 360 degree's in the direction you are cutting in (allway clockwise). The Z axis is zero'd at the table, so the material thickness is ignored.

Paul

[bill.young]

Paul's absolutely right...the convertor basically just reads the file, calculates the angle between where the cutter is and where it's going, and outputs that to the B axis so that the blade is always lined up with the cut direction. If you're cutting with an angled blade then it also has to calculate a 3d move every time the bit is inserted or retracted.

I remember sitting in trig class many years ago thinking "I'll never need this"...little did I know!

Bill

[Brady Watson]

Thanks for putting in all the work to make this happen, Bill. While I don't have an immediate need for it at the moment, it's nice to know that the ability to do this is just a download away.

-B

[ted]

Hi Guys,

As Bill indicated, we have actually sold some of these cutters and we still have some in stock (ours will hold the wheel blades, not the exacto blades). We did not publicize it much because it seemed like the usefullness of the system really depended on the user making a very good match of the cutter, the hold down system, with the particular needs of the material and project being cut. Once you get a ShopBot set up for this, it works pretty well. But if you were making a tool just for cutting flexible materials or cardboard, then a ShopBot would be overkill ... so probably would not make sense to trick one out just for those purposes.

Do keep in mind that the systems being described here involve adding a 4th axis motor and driver, which involves some cost. For thin materials and vinyl, the drag knife now available from Widget Works does very well with a ShopBot (look at the bottom of our Products>Router/Spindle/Bit page for pix).

[NB. We expect that the new Vectric system for post-processors will allow making the rotary output more automatic for those who need it.]

Ted Hall, ShopBot

[knight_toolworks]

whats the cost? and do you think it can be changed for a straight blade? I may be cutting more cardboard and it may be a good investment.

[beacon14]

...new Vectric system for post-processors...

Excuse me? Did I miss something?

[benchmark]

Hey Ted,

That's a bit like fishing, David and I have taken the bait.

...new Vectric system for post-processors...

What's that all about ?

[tmerrill]

This comment was in the beta release notes a couple of weeks ago. Must be part of it, but there may be more.

Quote:

Toolpath preview for Rotary Indexer (to enable, set display to 5 axes in [VD] then click Indexer Preview box in Preview Mode)
- displays toolpaths only, no cut simulation
- "RotaryWrapper" program included to turn flat 3D file into a cylindrical file for indexer
(C:\Program Files\ShopBot\ShopBot 3\RotaryWrapper.exe)

End Quote

The beta notes can be found here:

http://www.shopbottools.com/beta_notes.htm

Tim

[williams_architectural]

Ted,
It seems to me that shopbot with that type of cutter would be usefull in a lot of small upholstry shops who are still cutting by patterns.

Paul, Thanks for the photos of the attachment. That looks great and I am going to build one.Do you still have the designs? If mine doesn't work out I can always turn it into a bird house lol.

Bill, Thanks for helping him because now he's helped me with what it's supposed to look like. Now I just have to figure out the B axis.

Thanks everyone for your posts and keep me posted.

[williams_architectural]

Would anyone be interested in explaining step by step on how the fourth axis works. I literally mean telling me where to point and click my way through the steps. Kinda like one of those instructional books for dummies. We'll call it "Shopbotting for Dummies" with lots and lots of pictures lol. Sounds like it could be a real book. Just remember that I came up with the name and idea so my portion of the profits will need to go to:
William Moore
8690 Fm 13 W
Henderson, Tx 75654

[benchmark]

William,

The "Rug Cutter for Dummies" has allready been written by Bill Young, it has all the information you need, you can download it here http://www.shopbottools.com/LabFiles/RotaryCutter.htm . If you need my cad files for the stepper holder, just let me know... I don't think it would be any use as a bird house it has too many windows.



Paul

[myxpykalix]

William,
I started a post with some example pics for you with a simple explaination that i will add to later on or you can email me with questions and i can try to help.
http://www.talkshopbot.com/forum/messages/312/39249.html?1235843336
(you can't miss it)

[williams_architectural]

Thanks Paul & Jack for this information. Confidence is high that I will get it now. I'm looking forward to getting this going. This forum is like going to shopbot college and you have all of these wise professors at your disposal.

Thanks guys

[denver]

Hello,

I'm looking into the possibility of cutting floor mats for entrances. The mats are basically carpet with a rubber-like backing. The work involves cutting parts from various colors to make patterns that form logos, lettering, etc. All the pieces get assembled and glued to another backing layer.

Is my understanding correct that the stepper for the cutting tool always rotates clockwise? If I'm cutting something like the letter "C", won't it have to turn counterclockwise for the concave part?

Thanks,

Denver

[myxpykalix]

No Denver you are incorrect. The stepper motor will run clockwise and counterclockwise.

[denver]

Thanks Jack, I'm glad I was wrong about that one. I was concerned that this wasn't going to work after all. And I see from the documentation for the rotary cutter software that you can specify angles beyond which the cutter lifts up. That was another concern. Sounds like all I have to do now is cobble up a mount for the stepper in place of the spindle, and some kind of holder for the blade.

Thanks again,

Denver

[knight_toolworks]

to cut 90 degree corners I just make straight lines that overlap. since I have to rotate my knife by hand I make the start points all on the same end. I cut x and y separately.
I have been cutting cardboard displays this way now I plan all the cuts so they all go in the same direction and separate them it works ok.

[denver]

I finally got all the pieces I needed, and the time, to try this. Everything works fine as long as I stick to simple shapes like circles and squares. But when I try something a bit more complicated I run into an odd problem. It appears as if the B axis gets lost, and suddenly the knife is going sideways.

Here's the drawing I'm using:


7936 (23.0 k)

The circles and rectangles are fine, and the letters in the middle start out ok, but when it starts cutting the inside curve of the "C" the B axis gets lost.

After I stop the file, and set B back to 0, the blade is no longer lined up with the Y axis like it was when I started. Here's a copy of the part file for just the letters:


7937 (38.8 k)

I'm having a hard time thinking of what might be going wrong here, so any ideas would be welcome.

Thanks,

Denver