Has anyone figured out a good technique for building the practice field elements, specifically the scoring platforms? The 16-degree angles in hardboard are nearly impossible to cut on the table saw in our shop, especially if you like having all your fingers when you’re done.
We cut blocks of wood with the 16 degree angle with a miter saw instead. you could stack the blocks together. We found the HDPE plenty strong and spaced out the blocks.
We managed to quickly, but roughly, build a scoring platform with two (2) sheets of half-inch plywood (at least twenty inches wide, length is up to you), two (2) two by fours, a protractor, and a reciprocating saw.
The edges of the plywood were marked with the protractor (sixteen degrees (16°) for contact with the floor), and the plywood was clamped to a table. A reciprocating saw was used to cut the angle. Extending lines down and perpendicular to the angle were drawn to help keep the saw in line, roughly.
This method was used for both of the long-angled edges and the short-angled edge. Laying your flat sheet of plywood (half-inch thick, twenty inches wide, and your desired length) on top of the two by fours allowed us to have the top of the scoring platform two inches above the ground. Duct tape was used to “attach” the edges to the center piece, but alternate methods are recommended for long term use.
A video of our robot driving over the scoring platform will be posted soon for reference.
We made a jig that held the hardboard (or the plywood tops) at the 16 degree angle. This worked, except that the uneven pressure on the blade caused it to deflect so we couldn’t get a cut as deep as we wanted. If we tried to over compensate, the blade would dig in too deep by deflecting the other direction.
When cutting the plywood tops for the platforms, we clamped a 2 x 4 to the center to keep the plywood straight.
We have a nice SawStop table saw with a huge fence, so the vertical 16 degree angle cuts worked out OK. We had two grown-ups hold the wood for that cut.
Totally off topic, but where are people buying HDPE? We have some polycarb but I understand that HDPE can be bought much cheaper.
Are there good local options for buying it in bulk or do you rely on a large-scale provider and then wait for shipping.
A very effective method for cutting sharp angles on the hard board is to tape the hardboard to a larger piece of lumber (2x4 or 4x4) with a GOOD QUALITY double sided tape. Like this: http://www.woodcraft.com/Product/15D25/Double-faced-Tape-1-x-36-Yds.aspx.
Set your blade to 16deg make several small passes until you have the right depth of cut. Gently remove hardboard, use a butter knife to slide between the pieces.
Does anyone know how tall the scoring platform floor is from the ground to the platform floor?
It’s 2". Full specifications are on page 8 of the game manual.
We were able to fairly easily cut the angle by attaching the board that needed the angle to on of our steps while the step was standing on end. We then clamped a fence to the top of the up turned step for the appropriate off set for the angle. You then set a circular saw to 16 degrees from the vertical and you run it along the attached piece with another part of the step supporting the saw and giving it an even surface to run along. See attached photos. This was suggested by our swiggity swaggity mentor Sr. Verde.
We bought our HDPE here: http://www.usplastic.com/catalog/item.aspx?sku=42585 ordered and received in 3 days!
Is that HDPE smooth texture or “orange-peel” texture? The tote chute calls for smooth, while the scoring platform calls for orange-peel. We decided to cover our scoring platforms with some leftover Regolith that we still have in our shop; the texture feels pretty similar.
We got the smooth. Did not know they were different textures? Where did you find that info at?
Depending on how the ramp is being made it may be a lot easier to use trigonometry for building the ramp. You wouldn’t actually have to cut a 16 degree angle as long as you make all the lengths of the pieces correct. Think of the side of the ramp as a triangle. The shortest side being 2" The Hypotenuse being the sloping piece 7.215" The third side using geometry is 6.84…". Using these and making a right angle on one side will automatically give you the desired angles by default. As long as the FRC field drawings are accurate and to scale of course. I"ll try to make up some quick sketches if needed.
Has anyone found a good supplier for the “orange peel” texture.
My plastics supplier told me that orange peel, cutting board, & textured were all the same. The actually texture may differ from manufacture to manufacture. Best bet is to look up local plastic suppliers & get a quote. Price per sheet will depend on quantity ordered. It takes 7 4’x8’ sheets to do four scoring platforms.
We were lucky to have a company in town, Laminated Plastics, donate a 4’x8’ sheet.