Finally used my vacuum table to cut the balsa parts for my current RC glider project. 1mm downcut, 1250 mm/min, 30krpm. Vacuum generated by side channel blower. Great fun - no need for holding tabs! Using a compressed wood thermal isolation board as a sacrifice board and to distribute the suction.
…glider is not my own design, but digitized from a magazine plan.
Stefan
Nice work!
Those parts have a pretty small surface area, I would not have guessed the vacuum would have enough to hold on to. Having no tabs to deal with must be real nice!
I love this. I miss the kit days. All of the old manufacturers are gone Goldber/Lanier/Sig/GWS/Dalton/Carden
The ARF’s have really taken the soul out of the hobby.
That looks familiar.
I’ll be starting one soon too.
That’s great! I did a search but a very large variety of boards came back. Can you share details of what you used?
I bought the board in Canada. It was a full sheet and I cut it up, stuffed it into my suitcase and took it to Germany. Here it seems I can only order a huge palette for delivery - still searching for a local source of single ‘Holzfaserdämmplatte’.
I’ll try to find/remember the exact english name of the stuff. It comes in various thicknesses, is very airy and lightweight - much more airy and lighter than MDF. Mine is appx 12 mm thick. Here is a picture:
In the US, wood fiber insulation is starting to be used more in green construction.
An example:
I never thought of using this material for a vacuum table. Interesting application for it.
Ok, funny. Searching the Rona catalog on my phone doesn’t find the board - had to check on a PC.
Here is a picture of the product page:
Even Hornbach has them in 8 to 18mm in 2mm steps.
They sound a lot better for a vacuum table than MDF! Great idea.
…seems like you can order them into the market. Wonder if they’d do this for a single plate.
They usually do.
I’m close to start cutting 3mm birch plywood for a 2m Super Cub, and I’m really interested in your vacuum table setup. Can You give more info about it, please?
Sure 
Took some pictures tonight. Hope this is helpful. The design can certainly be improved, but I am very happy with the performance so far. Improvement suggestions at the bottom.
I was trying to get a flat design, so took two birch plywood boards and CNCed grooves and throughholes. Length of the board was choosen to fit a full length balsa board (100 mm x 1000 mm) The board overhangs the LR table, so that I can connect the vacuum hose without having to cut a hole in the table:
CAD and gcode generated in FreeCAD:
The spoilboard was discussed further up. It is pretty beaten by now. I think it can be surfaced, but haven’t tried yet. During cutting I covered the areas that are not covered by balsa boards to reduce air leakages (scrap pieces of paper, foil along the edges of the wood fibre board).
The side channel blower I’m using to suck the vacuum (1.1 kW). This has been a good investment (was using the vacuum cleaner before, but always felt sorry for the poor thing…)
Connection of the vacuum hose with a printed adaptor:
The snake-grooves. The idea was that the suction channel structure doesn’t transfer through the wood fibre plate as much as on a regular grid…probably overthinking:
I used a downcut bit from Sorotec for the cutting. It pushes the balsa dust down and helps reduce air leakages. Apart from balsa I also cut birch plywood with the same bit on the vacuum table - no problem.
Improvement suggestions:
Central suction from middle of the board to more evenly distribute the vacuum. Currently noteably higher suction at the hose connection side of the board. requires a hole in the LR table.
Increase cross section of longitudinal channels to more evenly distribute vacuum.
Have some kind of alignment along the board to put balsa boards against.
Maybe try a smaller tool diameter: 0.6…0.4 mm?
…do share some pictures of your Piper cutting progress.
Stefan
Wow, what a detailed explanation!! thank You very much!!
Your vacuum table seems great!
I’m thinking about using a venturi with compressed air to create the vacuum (I don’t what to spend too much on new equipment). But first I want to try with the “old” painter tape + CA metod, maybe it will work ok for this project. The vacuum table it’s a must have if You cut balsa most of the time.
