Hey there! New here and looking to build my first frame and eat up my Maslow. This last design that has wheels, the frame width is smaller, which would better suit my space, but I’d like to make the top arm fold down at the edges of the frame. Are there any designs with a folding top arm that still maintains the rigidity needed?
I have not seen any designs with folding arms. I would expect that it would be
very hard to make the hinge points rigid enough. I would say that slinding arms
are more likely to be rigid enough than hinged ones. Remember that movement of
the ends will translate in up to double that error in sled position.
David Lang
The tricky thing about that is that the arms experience quite a bit of force on them as the router cuts and the force is not constant so if they have any flex in them the cuts won’t be as accurate as you would want them to be.
I’m building a steel frame which will be hinged to a wall and swing out when used. It’s 1-1/2" square tube 0.060 wall thickness. Side and bottom extensions are 1/8"-1-1/2 X 2-1/2" angle which will have slots that will allow the extensions to be set flush with whatever thickness sheet is being cut. I’m planning on about 4" wide wood on the side extensions and 6" or so on bottom. There will be 3/4" waste board on the 4x8 frame with no metal fasteners in the sheet. There will be vertical strips glued to the back of the sheet which in turn will be bolted to the vertical square tube sides. I was inspired by @MeticulousMaynard in the area of the upper beam except instead of unistrut, I created a slip joint with 1-1/4" inner and 1-1/2" outer sleeve with a set bolt arrangement on each of the 3 arms. The inner arm is longer to support the cables and that was also a knock off from the super maslow design. It has a 12’ shaft to motor shaft spacing and 30" from top of the sheet to the motor centerlines.
The frame will hang from a wall at the top of the frame and this point will be a hinge for angling it out on bottom. There will be adjustable struts at the bottom to get various angles. These will be a quick pin type. The slack side of chain will have para cord that will go to a pulley and run up the wall to another pulley with counterweight. Yes, I have a tall ceiling in my garage.
Total cost of what you see was $190 at a steel supply company. Tube steel consist of (3) -24’ long 1-1/2" tubes, (1) 1-1/2 x 2-1/2" 20’ angle and a 4’ 1-1/4" tube. I used a porta-band saw to cut everything but could have used a cut-off wheel on a grinder or even a sawsall with a metal blade. Welds were made with a MIG welder with E70S-6 .023" solid core wire at 18.5 volts and 320 ipm wire speed and 75/25 ar/co2 mixed gas.
I have about 6 hours total in the frame at this point. The adjustable extensions (laying on sides and bottom) should take me about an hour to slot and install the adjustable bolts. Probably another hour for the hinges and adjustable braces. It’s not a beginner project unless you have some fabrication and welding experience. If you’re interested I can post more pictures as I progress.
Jerry
6 Likes
Please do, that sounds like a very solid frame design (in both meanings of the
term)
David Lang