Monthly Archives: October 2014

NTN – 600 Hull Rigging – Part V

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.

Bracket Epoxy Mount

Plywood base was epoxied, and the whole assembly was clamped to hull bottom.

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NTN – 600 Hull Rigging – Part IV

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.

Servo Bracket Bare

Cut and milled from 2 mm thick 20 x 20 mm L-profile, the width is 53 mm.

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NTN – 600 Hull Rigging – Part III

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…

Rudder Complete

Final look of the rudder mechanics, with pushrod and rubber bellow.

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NTN – 600 Hull Rigging – Part II

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.

Hull Open Top

The battery fits nicely on the sides of the V. There’s enough clearance for the shaft to easily run under it.

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NTN – 600 Hull Rigging – Part I

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.


CNC props (38 mm and 35 mm) that require no sharpening or balancing. Their shaft holes (3 mm and 3.25 mm) from left to right) need to be enlarged to 4 mm.

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Proxxon MF 70 and LinuxCNC – Part VIII

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.

True Holes

Aimed for 6 mm holes, not bad at all.

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