Method to Save Spoil Board?

[Bob Eustace]

Gerald there is a guy south of you that used to regularly post that swears by 1/8 dense cardboard. Have been meaning to try this for yonks. Of course Andrew uses the disposable MDF method so that obviously works. Since I have Andrews roller idea on the Buddy I can get away with the onion skin without breaking through method then using the 3/16 Amana trim cutter. Very, very, pleased with this method.

[gerryv]

Thanks Bob, it's hard to even suggest a potentially helpful change to a paradigm sometimes eh :-)

[davidp]

Hi All,

I am with Wayne, 18mm MDF skinned both sides and throw it away when it gets to around 6 mm thick. I always cut into the spoilboard 0.5 mm and depending upon the work on the table I level the spoilboard by removing .25 mm when needed. Last week we used up three spoilboards. It is a cost of the job, just like bits, electricity, and depreciation and certainly cheaper than a part moving while being cut and having to be recut.

Work out the economics. One sheet of 18 mm MDF $24.75, 60 to 100 sheets cut per spoilboard equals at worst $0.41 cents per sheet cut. To recut one part : re-toolpath, say 5 minutes @ $1.75 per minute, re cut the part 1 minute @ $2.10, you are already up to almost $11, and you haven't included extra material and all the other associated time and costs of loading and unloading the table etc.

I understand that for most, running the ShopBot is not about making money and your time is your time, but it is still false economy. You would be better spent using the extra time with your family.

My 2 cents worth.

David

[cowboy1296]

I cant even remember what this material is called but you use it to make your custom gaskets. It comes in sheets of about 5"x5" and I bought it at Ace Hardware. Its about .05 thick. I cut it up in smaller pieces and position them under the work piece. Of course this wont work for a vacuum but it works fine for a clamping system I use a 15 dollar caliper to measure the thickness of my work piece so on occasion I still cut into the sacrifice board but only a little.

[Jerome]

I tried the 1/8 inch mdf over my trupan spoilboard and find it works very well. I cut mine into 2' x 4' pieces. That allows me to replace only the sections that need replacing and I can sand both sides on a wide belt sander before using it. I am using 2 Fein vacs so I have plenty of vacumn.

Jerome

[dlcw]

I use 1/8" MDF surfaced both sides as a sacrificial board when cutting large numbers of sheets of material. This has a couple advantages:

1. NO loss of vacuum since the sacrificial board is so thin
2. I can cut about 4 to 6 sheets per side of the 1/8" MDF so it goes a long way
3. When the main material has been cut, I built an "outfeed" table for my bot that I simply push the sacrificial board and the main material on to for parts processing. I then load up another 1/8" sheet and the main material and it's being cut while I'm separating that previous sheet.

Adds an additional 2 to 3 sheets an hour using this method. Plus I don't have to resurface my spoilboard. I make enough 1/8" sacrificial boards up for the job using the 4 to 6 sheets per side rule and things hum along very nicely. Of course, the 1/8" MDF and time to surface it are included in the price of the overall project.

[gerryv]

Really appreciate everyones input on this. I'd not seen discussions about "thin" often replaced, sacrificial boards before but I'm not surprised that the insight is coming from some serious pro's. Thanks much, I suspect others will benefit from this knowledge.