Massive sheet of parts...

[harryball]

I finished it and ran my first cut today. It was 98% successful. I need to do a few tweaks and I missed one tool path on a group of 6 parts. All in all... IT WORKED!

I did the layout in VCarve Pro using Corel X3 a couple of times to do some creative distribution and measuring. There are 60 long side parts, 60 small roof brace parts and 30 roof panels. This makes enough parts for 30 of our bat house DIY kits. The challenge was creating and efficient as possible toolpath to minimize time. The entire cut was 62 minutes! Keep in mind, each of those long and small parts has a 1/4" deep dado on each side that was cut as well.

I used a grid like cutting strategy so the bit only cut once between each part. I extensively used the VCPro 3D tabbing feature which worked great.

VCPro is a powerful tool and it can do more than just carve signs. I'd have to say the most painful part was the lack of a block copy and a few more measuring tools.

Take a look...



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This is the VCPro preview

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Robert

[ken]

Robert,

Nice work...did you use a vacuum to hold the parts down or tabs? How thick was the plywood? We cut a lot of HDPE parts out that are only an 1 1/2" wide by 48" long and each parts has several 1/4" holes in them. I fill up a whole sheet (4' x 8') of 9/16" thick HDPE with them so the yeild is very high. We are currently using screws to secure them but are considering installing a Roots 15HP vacuum but I'm still not sure they'll hold.

Anyhow, it looks like you did a great job above and I always find your post informative.

[harryball]

I used a combination of vac and screws. I start by placing the sheet and using a twin fein hold down. 1/8" pilot holes are drilled for all the roof panels and I take the opportunity to mark about a dozen safe hold down screw locations. When I load the 1/4" bit and start the cutting process I put screws at the 4 corners and one screw half way down each side and end... so 8 screws around the perimeter. This is done while the machine is cutting dados which do not go all the way through. NOTE: I do not challenge the machine while placing screws, I work on opposite ends of the table from the gantry. I'm in no rush to place all the screws.

I had the screws in place well before any cut thrus occurred. I let the fein system run the entire time. The vac gauge stayed above 3" Hg until about 2/3 of the cut thrus were done. This is where the extra hold down locations come into play. I looked at the sheet to see if I noticed any areas trying to raise. My plan was to pause and install additional screws if/where needed. I didn't need to.

I'm running 1/2" ACX plywood so it's very consistent and flat. All of the parts are tabbed in with a 3D tab on each end. By far I’m thrilled with the results. This product, more so than any other we currently make, is bot dependant. Without the bot I would have no way to produce these kits. The kits (photo’d in a previous show and tell) primarily sell to schools for kids workshops. We conduct our own workshops as well. I’m behind on filling orders at the moment.

I was running with a density of 4 kits per sheet. I have a layout of a single kit on a ¼” sheet that I was running with offset. There wasn’t a great deal of waste and the overall average cutting time was only slightly longer. I now get 4.3 kits per sheet on average and save about 1 minute per kit in machine time even after adding a custom logo on the bat face. HOWEVER… I now get all my small parts up front which require some clean up and additional cuts like the 25 degree bevel cut on top of each long side and the 40 degree split cut on the roof panels. I can clean up all the parts and make all my cuts while babysitting the next 6 sheets of large front and back parts which take about 45 minute each. That is part of what I was after, more efficient use of MY time. When running 4 per sheet I would finish the 4 kits and be standing there watching the bot cut the next four unable to do anything until it finished. I started this morning at 10AM with files I’d never ran before and at 5PM I had 30 kits clean and ready to sell. I stayed busy, the bat bot stayed busy, we had a good day.

Robert

[beacon14]

Robert I like the way you think. Now what are you going to do with the 5 square inches of scrap leftover from the 7 Sheets of material you just cut up? I'm still shaking my head in amazement.

[ken]

We typically cut four or five of these sheets daily. Once we get our other machine running we’ll more than double that capacity. Since these parts are currently being held down with screws it presents a considerable workload for the operator. I would like to figure out a way to use a vacuum hold-down even it meant using a combination of tabs and vacuum, a template or just a few screws.

In case you’re interested we manufacture non-metallic industrial machine guarding. Our product(s) can be viewed at www.uniguardmgc.com (http://www.uniguardmgc.com).




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[ken]

My appologies but that picture above is of a 4ft x 8ft sheet of HDPE stacked with parts. The actual picture is only half the width...uploading images are a little tricky

[harryball]

David, I store my scrap all chipped up in the barrel under my dust collector. :-) I should take a picture of the waste that comes off the bot for some of my projects. For my regular bat house runs there are a few 1/4" strips and that's about it.

Ken, you're thinking along the right lines. I run vac only on all my retail projects except two. My goal was to have as little setup time and interaction as possible. When I finish this sheet of parts I quickly pull it from the table and run the table cleaning vac pass, toss on the next sheet which is all vac hold down and start the machine. Then I start processing parts. By the time the second sheet (first sheet of large parts) is complete I've removed all the tabbed parts, cleaned up the mess and had a cup of hot tea.

I then repeat that method. I finished processing all my parts with bevel cuts and so on about the time the 4th large part sheet finished up. During the next 2 sheet I cleaned up the shop, did some maintenance and drank some more hot tea.

By combining vac and screw hold down and alternating high labor and low labor sheet loads I can keep my time more in sync with the bat bot. Your products may lend itself to a similar approach. It took me a while to realize... all the parts for a single project don't have to be all on the same sheet at the same time. So instead of 7 medium maintenance sheets (small parts contained on each) to get 28 kits I now run one high maintenance sheet followed by 6 low maintenance sheets to get 30 kits.

I'm a one man, one woman, one son and one daughter shop so I strive to keep things efficient. I want to defer hiring and actually purchase another bot as soon as production warrants.

Robert

[harryball]

Ken... since you are running HDPE and your material doesn't have knots or divit like plywood... you MIGHT be able to run a full vac hold down using a mask sheet.

I think Brady Watson perfected this method. I heard about it from Bill Palumbo (both bright guys) during the Atlanta Camp.

The idea is to create a sheet between your cut sheet and the vac table leaving only openings underneath parts that need to remain fixed. To improve the seal use sealant tape around the openings.

Go search the main forums or ask in the tips and techniques forum and I'm sure someone will spill all the specs on it.

Robert