Mean Machine Build - for Aussie racing

[Scott T]

In between refurbishing my OM26, buying a new house (and selling mine), I've been working on a Mean Machine. Our club is racing cats/tunnels for the first time this year, under the AMPBA rules, which allow 4S lipo up to 600g.

Credit goes to Jay Turner for giving me advice while I was deciding which hull to build, as well as a few set up tips. Thanks Jay!

So, first up is the hull. Aeromarine seem a bit random in their carbon placement in the MM hulls. Another one in our club has carbon that goes right up past the hatch opening - mine is well short as seen in the first pic.

So I added a small piece where I thought the motor might end up, and covered the entire tunnel in very lightweight glass to smooth things out. I did manage to get a small gap between my carbon and the installed carbon, but turn out this doesn't matter due to my final motor placement.

[Scott T]

The hardware was installed next (Speedmaster). I offset the strut about 4mm to the right, as I do on all my hydros. The rudder was put on the right as per Jay's advice.

With the hardware on, I laid out all of the major components so I could get the CG right. The battery wires weren't long enough to put each 2S pack in a sponson, so they will sit on the tunnel floor, at the back of the boat. This meant the motor had to go a lot further forward than on most Mean Machine I have seen. So the motor has to sit almost flat to fit under the hatch. No problems, I don't mind running an s-bend shaft with flex drives.

[Scott T]

With the internal layout sorted, it was time to install the motor mount. I mixed up some MAS epoxy, with some fine glass fibres added. I wanted to thicken the mix slightly, so I would get a nice fillet around the fibreglass motor mount rails.

I roughed up the surfaced, and epoxied the mount in. I used a square to line up the motor mount with the strut. A drill bit in the flex coupler provides a goopd guide.

The next day the mount was done, and the epoxy had a nice fillet as I wanted. Should be more than strong enough. With the mount rails going over the gap in the carbon mat, there should be no problems in that area.

[Scott T]

The steering servo will go in the rear of the right sponson. Figuring out how to mount it was a pain - I like to be able to remove things easily in case they fail.

Mounting the servo upright just didn't work well with the steering rod location. So I mounted it on its side, similar to how Randy at BBY does his. Two big wooden blocks were epoxied into the hull, and the servo is bolted to a piece of aluminium angle. The angle is simply screwed to the wooden blocks from the top. I did open up the hatch opening a little to make access easier in this area.

The wooden blocks are shown in this pic, and the servo and bracket can be seen on the other side of the hull.

[DISAR]

Nice job. Keep going! what is your setup and what speed are you looking for?

[Scott T]

Thanks! I'm going to start with a Nemesis 8XL, Hacker 70 and 4S lipo. I have a Barra 125 being repaired, so that will go in when I get it back. Maybe a Neu 1515 sometime down the track, but I'm in no hurry for that.

Not sure what speeds I'll get, should easily be upper 40s.

[Scott T]

A bit more progress from late yesterday.

Stuffing tube was bent to shape and put in - not a fun job! I had to join two pieces of tubing as the only piece I had was just too short. No time to get to the hobby shop before the house move! I cut the slot with a Dremel, in approx the right spot.

The two holes in the side are for the safety loop. They still need to be drilled out to take 5.5mm females plugs. A plywood backing plate has been added behind there, and the plugs will be epoxied in place. The water cooling outlet is just visible on the opposite side of the boat.

[Scott T]

The stuffing tube was fitted and epoxied into place. Masking tape was used under the hull to give a flush finish with the epoxy. A piece of medium fibreglass mat reinforces the tube on the inside.

While I had the epoxy mixed, I also coated the servo mounting blocks and safety loop backing plate. I also added a 1/16" ply support for the stuffing tube. It looks lightweight, but I've used similar in other boats and never had a problem.

Next will be the aerial installation. There's not much deck space to use, so I'll have to have a look at some other MM builds to see what people have done. Not much time today though, it'S Australia Day, so beers and BBQ's await!

[bonewar]

Nice job mate , (clean) That motor mount looks the goods, and the hull looks wide, plenty of room for those lipos . Keep up the good work. Ive been interested in these hulls for a while now. I will be watching your build with interest. Thanks for the pics Bonewar

[tylerm]

So, first up is the hull. Aeromarine seem a bit random in their carbon placement

Aeromarine are a very random company, have found that out after seeing a few hulls and people i know purchasing them.

Good going on the build man, very good looking. Enjoy your Australia day as were enjoying Auckland annaversary day over here(although I still had to work)

Tyler.

[DISAR]

For the aerial position I have mine in the back corner as shown in the foto. However I had a bad exeprience with this antenna eventhough it looks very nice but I was very close to damage my boat because of lost signal.
http://www.offshoreelectrics.com/pro...?prod=gnd-whip

My favourite is this one:
http://www.offshoreelectrics.com/pro...=dh-bruline110
or a normal piece of tube with the antenna cable in it like in cars.

[JCAustralia]

Scott



Good job. Carbon fibre always look great

Could you comment on the quality of the aeromarine hull?

Thinking of getting the challenger hull when the exchange rate improve....

Happy Australia day.

JC

[Scott T]

For the aerial position I have mine in the back corner as shown in the foto.

Thanks, that's where I'm going to put it. Should work well. I'll just use a tube with the aerial up the middle.

JC, the gelcoat and glass is fine. Not up to H&M standards, but certainly good enough that you may not need paint. The join at the front of the sponsons was messy - lots of filler. But a mono should be better in that respect.

[JCAustralia]

Thanks Scott

Been hearing similar feedback on Aeromarine products lately....

Keep your great build.

Cheers

JC

[Eodman]

Hey Scott nice build ... question - did you consider mounting the batteries in the sponsons it might make a difference in race water not sure. With the weight further out you may be able to drive faster in corners again not sure but maybe Jay Turner can weight in on this!