Twin SGX

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XtremeRcBoats

Well-Known Member
Joined
Jan 31, 2002
Messages
1,215
Last year i bought an unbuilt twin SGX from a guy in the Netherlands. Only thing he did was some carbon fibre in the engine and fueltank bay. From Jon Thibodeau i bought 2 new Mac84, so now i can finally start building. Will probably need some help, they don't run twins overhere.

This is how i got it:

Resize_of_P1000590.JPG


2 Mac84's:

s.jpg


I started with the mounts. Unfortunately because the guy put in the carbon fibre, i can't see the holes for the enginemounts in the middle. The mounts came numbered, i assume the order is 1 - 4 from left to right? That will give me some idea where to find the holes.

mounts1.jpg


Thanks,
 
In the centre rail there are four holes on the same plane as the outer ones. You should be able to run your finger and feel where the carbon wants to fall in the holes. The boat also looks like a twin SGX2 going buy the rear wings.
 
In the centre rail there are four holes on the same plane as the outer ones. You should be able to run your finger and feel where the carbon wants to fall in the holes. The boat also looks like a twin SGX2 going buy the rear wings.
Hi Paul,

thanks for the reply, found the holes. What is the difference between the twin SGX and SGX2, newer version?

I tried the engine mounts, but doesn't seem to fit and need almost all the spacers from both sets to fit one engine. Am I missing something?

mount0.jpg


mount1.jpg


I also wanted to mount the rudder. The manual has 2 ways (page 4 of the SGX Manual 3/16" of the right side or alined to the right side of the hull.

rudder1.jpg


I don't it's possible to mount if off the side because of the holes (used the rearplate of the rudder to illustrate). What do you think?

rudder2.jpg


Thanks for the help.
 
The major difference between the boats is the rear wings and rear sponsons. Are you sure it is a twin 80 boat looks a bit big and going buy the picture of the cowl I think it is a twin 90 boat. Email cmdi and get them to send you over some more spacers.
 
Hi Paul first install strut mount then touch side between mount and rudder mount ( put rudder's "L"angle flash end side wood and make sure degree 90 ) if you not sure so contact at email: [email protected] will show pictures of my SGX twins Hope to help Cheers Allan ;)
 
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Hi Paul first install strut mount then touch side between mount and rudder mount ( put rudder's "L"angle flash end side wood and make sure degree 90 ) if you not sure so contact at email: [email protected] will show pictures of my SGX twins Hope to help Cheers Allan ;)
Paul, i think it's a 90 twin, the guy intended to power it with cmb hr91's. I was too late buy buy the engines so only bought the hull. I'll send Andy an email.

Allan, thanks for your help. Send you an email. BTW the mac45 i bought from you is still running great!
 
I don't it's possible to mount if off the side because of the holes (used the rearplate of the rudder to illustrate). What do you think?
rudder2.jpg


Thanks for the help.
Why is there an enormous hole cut out of the rear radio box bulked????????? :eek: :eek: :eek: :eek:

Water cooled radio equipment? :huh:

-Buck-
 
So you finally started Paul, god luck and you know if you need some maching work stop by.
 
Buck is right. You need to apply a new doubler to the large rectangular hole in the radio box rear bulkhead. The transom should not be used for the radio box bulkead because of the strut and rudder mounting. No way to keep it waterproof with all the holes and vibration. This is an easy fix with some plywood and reinforcement cloth in the bait box. You should reinforce the transom with CF or kevlar anyway.
 
I don't it's possible to mount if off the side because of the holes (used the rearplate of the rudder to illustrate). What do you think?
rudder2.jpg


Thanks for the help.
Why is there an enormous hole cut out of the rear radio box bulked????????? :eek: :eek: :eek: :eek:

Water cooled radio equipment? :huh:

-Buck-

Put the rudder bracket to the far right so that it is flush with the triangle block that is under the wing.

If you don't put it all the way to the right you will end up chasing the needles FOREVER , because any

kind if rudder movement will change the water flow to the right prop, continuously changing the load on that prop.
 
I don't it's possible to mount if off the side because of the holes (used the rearplate of the rudder to illustrate). What do you think?
rudder2.jpg


Thanks for the help.
Why is there an enormous hole cut out of the rear radio box bulked????????? :eek: :eek: :eek: :eek:

Water cooled radio equipment? :huh:

-Buck-

Put the rudder bracket to the far right so that it is flush with the triangle block that is under the wing.

If you don't put it all the way to the right you will end up chasing the needles FOREVER , because any

kind if rudder movement will change the water flow to the right prop, continuously changing the load on that prop.
I wish when you sent me my twin 90 boat you guys would have included the instructions and the extra kit for the rudder brackets would have probably saved me a lot of heart ache chasing water pick up problems with my twin. Now I have major work to fix this issue with my boat.
 
Thanks for all the answers so far.

Buck, Jon, i got the hull this way and was wondering myself why the big hole was there. Maybe to put the steeringcable through :D I'll reinforce it and will also do the transom.

Andy, thanks for the info, now I know how to mount it. Another question, the guy intended to run it with cmb91 HRs (They were already sold before i could buy them) But i think the motormounts were setup (with the spacers) for that engine. Am I correct that the spacers and screws for mac84's for this hull are a lot bigger?

Juul, thanks for the offer, i'll probably step by soon.
 
It's been a while but finally working on the twin again.

Got the engines in, put the rudder on,put the servo's in and added the watercooling tube.

normal_waterinlet.jpg


normal_rcbox1.jpg


Where do you put your 3rd needle? looking for a good location. I want to put the 2 needles inline and was thinking somewhere in the middle of the hull but there is not much space (see pic below)

normal_3rd_neelde.jpg


What is a good pipe length to start with? (mac84's with parabolics) so that i can determine the pipe mounts.

Larger versions of the pictures can be found in my gallery

Thanks,
 
Glad to see your back on the twin build.

Here is the first set up I used. It worked okay but was a tubing nightmare!

This what I ended up with before the boat was sold. Worked good and was a little cleaner set up.

-Buck-
 
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Glad to see your back on the twin build.

Here is the first set up I used. It worked okay but was a tubing nightmare!

gallery_1167_287_18041.jpg


This what I ended up with before the boat was sold. Worked good and was a little cleaner set up.

gallery_1167_287_2485.jpg


-Buck-
Thanks for the pictures Buck, that helps a lot, i was already thinking the same. I'll keep you updated.

Paul
 
Well after a couple of years I'm finally back to this project and this time I want to finish it. Last few years I had to built other (racing)boats, got married and moved to a new house. And since we don't have a twin class overhere, this is just a play boat.

I built everything in the boat and now at the painting stage. Here are some pictures:

Twin1.jpg


Primer coating:

Twin4~0.jpg


Twin6.jpg


Al pictures can be found in my gallery:

http://gallery.intlw...s.php?album=868
 
Beautiful twin Paul!..and with 84's it should be a rocket for sure!!..good luck with the rest of the build.

Elias
 
Paul,

I envy you nice boat!!!!!!!!!!!! I love the MAC 84.... Good luck with the build and keep us posted....

Regards,

Jose
 
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