When I went down to the workshop last night, the servo bracket was stable and the epoxy was cured. So, I shot a little video of the moving mechanism and converted into a GIF animation.
Yesterday, I finished the rudder mechanics. First, I coated the wooden base of the bracket with 20-minute epoxy (I didn’t get a new one, I used to cloudy old one, hoping it would not fail me) for more strength, and waterproofing. Then, I countersunk the holes for the brass screws on the aluminum part, before mounting it on the wooden base. Finally, I stabilized the servo on the bracket with the 3 mm stainless steel bolts. It was time to epoxy the whole thing at the bottom of the hull, close to the transom.
Today, I made a bracket for the rudder servo. I have seen (needlessly complicated) examples using L-profiles around the web, and since I have lots of aluminum L-profiles laying around, I decided to make use of one. I cut a 53 mm wide piece from a 20 x 20 mm L-profile, then I sawed and milled the gap for the servo. Finally I drilled 3 mm holes for the servo bolts, and 2.5 mm holes for the 6 x 2.2 mm brass screws for mounting the aluminum part to the plywood base.
Today, I drilled the hole (from 2 mm to 4 mm, 6 mm, and finally 7 mm) for the push-rod bellow (or boot), and epoxied the bellow into the hole. The new push-rod is an old bike wheel spoke, heated and buried into a plastic push-rod link. I later on sanded the crappy old rod for a shinier look. Here are some pictures from the workbench…
I got done with cleaning and rearranging the workshop yesterday, and finally started working on the hull. As you can see in the picture below, the 7.4 V 5800 mAh Li-Po (I will switch to a 3S if necessary) pack fits nicely in the hull, and the shaft can easily run under the pack.
I’m taking a break from the CNC Project, since I keep losing steps, and I’ll probably need to open, adjust, and clean the whole thing. I may even have to mill the gibs.
So, I started working on the NTN – 600 fiberglass (deep v) hull I got a while ago. I ordered a water cooled brushless motor (Turnigy AquaStar 2842-2800KV) and an ESC (HobbyKing 50A Boat ESC 4A UBEC), an adjustable stinger drive (55 mm – Black), an aluminum water cooling outlet, and a pair of turn fins last week from Hobby King. I’m waiting for their arrival. I already have various shafts and props, a good quality aluminum rudder with water intake, some servos, and some LiPo batteries (7.4V – 5800 mAh) in stock.
This last Thursday, I went ahead and got a second hand HP DC7700 (with KB and mouse, but without a monitor) for about $100, along with a cheap and suitable external video card (since LinuxCNC is supposed to fail with on-board video cards) with VGA, DVI, and HDMI outputs.
I installed LinuxCNC from a flash drive (the other one was too old to boot from USB!), and tested the on-board and the external video cards for latency. They were pretty similar, around 15000ns. But since my LCD monitor only has VGA, and I don’t want to take no chances, I use the external one. I use soft OpenGL drivers, and all is well. Good to use a 2GHz Core II Duo with 2GB RAM. No more flickering AXIS and late opening windows! I did a test cut, and all was fine.