Here I’ve added the 1/8 inch square strips and the window trim, then I shot the thing with some light brown primer.
I’ve been doing some experiments with the CNC router, trying to cut styrene. I’ve messed up and melted a sheet or two but now I think I’m getting the hang of it. I’m working on a standard N&W depot, this one is at Winfall, VA. I found the pic on the Virginia Tech Photo Archive.
Anyhow, what I have found is that styrene needs to be cut with a slow RPM and a decent inches per minute feed rate. I’m using a 1/32 inch bit at 7500 RPM and a 25 IPM feed rate. You also have to cut shallow, anything more than say .030 or so will start the dreaded melt. So I do three passes to get through 1/8 inch styrene (.125 inches). This produces a big shower of nice plastic chips or ‘saw dust’. This is what you want to see.
I wired up my yellow critter with a control widget, a Turnigy 20A ESC and a 4.8v 2300mah nimh battery pack. Works quite well. I did have to add a relay to reverse the motor but that’s already supported by the software, it’s what I use in my RS3.
A pic from the video, out on the track at Gilbert Virginia.
Just can see the Xbee in the cab. The battery is in the engine compartment along with the Turnigy ESC. The relay to toggle the motor direction is also in the cab but you can’t see it from here.
The development platform for my Dash 9 whenever I get around to it. A close shot of the control board with the Xbee. This is the same control board in the Critter. There is just enough room (I think) in the critter to put in micro servos for the couplers but I have not gotten there yet…
And here is the critter with the handheld controller.
This is my newest critter design. A freelance sort of fantasy vehicle but it came out pretty good and was fun to build. A couple of 3D peoples and some resin cast details thrown in for good measure. Everything is cut out on the CNC machine except the fuel tank which is a piece of PVC pipe. (I cut those on the band saw). Anythow, I am planning on possibly selling these as kits or at least making the plans available, not sure how that’s going to work out quite yet…
Finally got the basics together with a coat of primer. Some 1/29 People standing in front. Need some glass in the windows and an interior, some shingles on the roof and other details but the basic shell is coming off the router pretty well now. Still needs some tweaking to get a good solid production run but it’s coming together nicely.
Man, my o-flute-upcut carbide bit does some clean work on .125 inch styrene! This is the design from a few posts down, cut out with the CNC. A waterproof R/C servo provides the automation. The arm has one super magnet, the wheel on the servo has two. The idea here is that you can throw the lever manually to control a turnout but that it also remains at all times under control of the computer.
That’s the plan anyhow. The magnets are those little really powerful ones. They act like a ‘clutch’ in this situation. So far it works on the bench but the real world is another story, I’m not quite there yet. I need to install them on my three turnouts and stick them out in the cold rain for some testing.
So here ya have it, front, side and support of a building I’m working on. All the window and door openings look rough but will be filled with resin castings. There seems to be a sort of ‘black art’ to selecting the right bit for the right material and then getting the feedrate right as well. I’m closer to figuring it out I guess.