This page shows some of the tools and fixtures that I use in the Sailplane Fab Shop (my basement).
Two heavy duty fireproof doors serve as the work surfaces, they were obtained from a office building demolition job and weigh about 80 pounds each. What helps a lot in keeping the place ready to go, is lots of electrical outlets. There are outlets every 6 feet, and receptacle expanders so cords are not crossing the workbench. Fluorescent lights provide most of the illumination, and the desk lamp can also be used to heat epoxy for faster curing. Can you spot the main tools: bandsaw, cordless drill (yellow), scrollsaw, Dremel, rolling chair, assortment of files and knives, cutting board, epoxy (West System dispensers), paper towels, phone (which always rings as you mix the five minute epoxy).
For doing extreme weight control on the DLG's and the serious balsa planes, nothing beats the MyWeigh iBalance 201. This digital scale is accurate to 0.01 grams and can handle up to 200 grams. The main use is for mixing small batches of epoxy, but doing tail surfaces under 6 grams, you need the accuracy.
What's not shown is the vacuum bag system mounted on the left wall, the pool table, which is used for alignment, and this neat device:
It's a Craftsman belt sander lying on it's side, with a small table at 90 degrees to the belt. The sander has a dust bag and variable speed, it can be used for squaring off stock, rounding corners, trimming fiberglass, you name it. The fixture is made from 3/4" pine and the belt is inset 3/4" below the work table. The sander is lying in a cutout that fits the frame and holds it stationary. If you have a belt sander around, I highly recommend that you build one.
I found the sander to be so useful, that I decided to get a more serious sander for even more jobs. Large format sanders can be used for sanding in angles on dihedral joints, tapering tail surfaces and shaping of taper angles on foam blocks prior to cutting the airfoils.
This sander has a 4" belt and a 8" disc. Mounting the sander on the end of the work surface in that custom jig gives the flexibility to do this:
The sander can be laid on its side with the belt perpendicular to the table. Now the root ribs, long stock, and foam blocks can be precision sanded to compound angles. Absolutely perfect for sanding in dihedral joints in wings with a 14" root chord. The adjustable taper jig allows you to set the sanding angle for any wing LE taper. Power sanders are right behind band saws as a tool which becomes indispensable.
This is my foam cutting jig which is the the garage because of the fumes that get generated. The Charles River RC website has plans for the foam cutter. I built the cutting bows from 3/4" oak and the wire is 0.020 single strand stainless steel fishing leader. Clean the wire before each cut. Cabela's sporting goods sells a lifetime supply for $10.00. The templates are made from Formica (counter top laminate) which does not heat sink the wire.
A power supply was made from a dimmer switch and a 12 Volt AC transformer. No I will not tell you how to do this since a wrong connection can kill you. I looked at the amperage ratings of doorbell transformers and decided to use a transformer made for halogen lights (12V and 15 A). The bargain bin of the hardware store had one with the ratings on the label. Before using your bow, put a voltmeter on the leads to make sure you don't have over 12 VAC at the terminals. To cut normal foam it takes only 5 VAC and 5 amps, not enough to kill you anyway.
The little guide pulleys are heavy duty patio door rollers that are screwed into the 2X2 edge, they are pre-grooved to keep the pull string aligned. I would definitely use kevlar pull-pull cord for the strings since stretch on the lines of different length can lead to an inaccurate pull. I've had success on blue foam with 15 oz of weight on the arm, Hi-D 60 Dow foam needs more than 3 pounds of arm weight. Experiment since foam is cheap.
I've also found that the Hi-D 60 Dow foam MUST be skinned (1/4") top and bottom to get good results. After skinning, put the surface 1/4" thick sheet next to the block it was just cut from, and it will be at least 0.5 % shorter (1/16" per foot). This is what causes the curl when the block is cut, and skinning relieves the stress from the extruded surface compression. After skinning, never a problem with core warpage.
With the 40" bow, 75% power will burn the foam. The bow hangs from the ceiling so you get a wide arc when cutting. Once you get the blanks cut out and set up, it can cut a core in 2 minutes, and it's kind of fun to watch. The bow is made from 3/4" X 2" oak and is hinged on the bar ends. A simple turnbuckle using SS braided wire adjusts the tension.1/4" music wire is used for the wire pegs, and they have a small groove filed into the tip for the cutting wire. Any bow you choose should be springy enough to maintain tension as the wire heats up. Note the on/off switch on the bow, very useful when positioning for the start of the cut. Wear safety glasses when cutting cores, I've never had a cutting wire snap yet, but it only takes once! The styrene fumes remind me of the days when I melted plastic models during elementary school.
The computer is used to plot out the airfoils, and the sander shapes the templates.
For the impatient, or a really hard epoxy cure, this is my hotbox made from 1" foam sheeting lined with foil. The edges are sealed with cheap weather stripping. Heat is provided from two 100 watt light bulbs connected to a dimmer switch. Full power to get up to temperature and then about 1/2 power to maintain 50 to 60 degrees C. This will accelerates the slow West System epoxy to a 2 hour cure and is required for the MGS epoxy which I now use for structural parts. This allows you to do two glue operations in one day, a great time saver.
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