SIG Magnum 2-Piece

[Ian Hewitt]

Hi Stunthangar,

I am looking to put together a SIG Magnum - after a long pause - but am running out of hangar space..  ..and my car may be a bit marginal too.

I think that making the foam wing removable might be a solution and have been looking at design solutions. I think that the Super Hawk by Bill Draper (who used to be in my club - Nottm) might work but am concerned that the slim fuselage on the Magnum might be over stressed. I am wondering whether extending the ply doublers and using carbon veil might be sufficient to beef things up.

The Super Hawk wing fitting is hopefully shown as attached. I was not going to use the centre bolt through the bellcrank as the wing is already assembled - I will look to include ply reinforcement above and below the bellcrank pivot located in the upper fuselage and below the wing.

The Super Hawk fuselage is of similar proportions to the Magnum and proved to be very durable in practice over many years.

Does this sound viable - or is there some negative experience that I need to factor in?

Also I am hoping to use a recently acquired Stalker 60 RE in the model and wondered whether the standard wing mounted gear is going to be useable with a 13" wooden prop - there looks to be sufficient clearance on the plan.

Many thanks in advance

Ian
Nottm, UK

[Dennis Toth]

You can do the Magnum as a take-a-part I have built two this way using Paul Walker's Impact approach. Just make new 1/16" plywood doubler that runs to the trailing edge former. The trick with take-a-part is to keep things aligned as you build. also match the mount formers; drill the mounting holes and secure the blind nuts before you start assembling the fuse and wing mount pieces. Do the final sanding and shaping of the mount formers after you have all the mount bolts and blind nuts in and bolted together (this insures that it matches later on). To get the final wing position, use the foam cartels to support the wing on a level building table, check the fit of the fuse to the formers (you can build the fuse but don't glue in the mount formers until you are ready to do the final alignment). With the wing level and at zero angle, fit the fuse and all the mount formers, tag glue the fuse side former from the front with Titebond (do not use CA as it will wick through and glue the wing side mount former to the fuse side former). As that dries do a final check on alignment (check that the fuse top is parallel to the wing centerline). At this point you can tack glue the wing side formers while all are bolted together. Once these are dry you can do the stab mount while everything is secure at zero/zero. After all is glue is dry/cured carefully unbolt and lift off the fuse & stab. Now you can use CA on the joints and reinforce with a strip of 3/4oz fiberglass and epoxy. Now build the rest of the ship.

Best,   DennisT

[Ian Hewitt]

Many thanks Dennis,

I will try to make good use of your advice.

I note that Paul Walker's impressive Impact design uses a very different location scheme for the wing than than of Bill Draper and other designs published on this side of the pond. I think I prefer the UK system which appear sto offer better accessibility - but I realise that this might not work with a pipe tunnel to navigate as per the Impact.

It is encouraging to note that you have successfully built and flown two take-apart Magnums and your insights around building in alignment will no doubt be valuable.

I think that I am going to mount the undercarraige in the fuselage as per the Magnum Plus - mostly because the wing is almost complete (bought that way).

It occurred to me this morning that a clubmate has a take apart model of similar size to the Magnum with a foam wing and fuselage mounted undercarraige - so I will look to get some more local advice at our next club meeting on Monday.

Thanks again

Ian
Nottm, UK

[Dennis Toth]

Ian,
I am interested in seeing the method you guys use over there. I live in western North Carolina and may be the only control line flyer for hundreds of miles (there is a big group in Huntersville but that's two hours away) so I like to build take-a-parts for easier transport. If you have a plan or website, you could post that would be great.

On the Magnum, I did mine with fuse mounted gear, basically added a 1/4" cross former to the fuse section over the wing. To clear the pipe, I added around 3/4" extra depth to the bottom of the fuse and use 1/64"ply to line the tunnel and molded 1/16 balsa for the bottom block. The gear fits over the straight part of the pipe so it was a nice clean fit. If you are doing electric, you will not need to add the extra fuse depth and still can do the fuse mount block on the bottom of the wing fuse section.

Best,   DennisT

[Ian Hewitt]

Hi Dennis,

Here is a link to the Superhawk plan on outerzone.

https://outerzone.co.uk/plan_details.asp?ID=9818

The first take apart model was Nimrod 5 by Jim Mannal  also on outerzone.

I guess that I am lucky having a local club with a few active control liners. However just about the only time we fly stunt together is at our annual Aerobatics  contest..

Ian
Nottm, UK

[doug coursey]

Ian,
I am interested in seeing the method you guys use over there. I live in western North Carolina and may be the only control line flyer for hundreds of miles (there is a big group in Huntersville but that's two hours away) so I like to build take-a-parts for easier transport. If you have a plan or website, you could post that would be great.

On the Magnum, I did mine with fuse mounted gear, basically added a 1/4" cross former to the fuse section over the wing. To clear the pipe, I added around 3/4" extra depth to the bottom of the fuse and use 1/64"ply to line the tunnel and molded 1/16 balsa for the bottom block. The gear fits over the straight part of the pipe so it was a nice clean fit. If you are doing electric, you will not need to add the extra fuse depth and still can do the fuse mount block on the bottom of the wing fuse section.

Best,   DennisT

HOW DO YOU CONNECT THE PUSROD TO THE FLAP HORN FOR EASY DISCONNECT

[Lauri Malila]

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[Dennis Toth]

Too keep the rod in place and connected I have used the "L" rod approach with a washer soldered to the inside as a stop and a wheel collar out side for extra security. Make sure the bend is 90 degrees to avoid it wanting to slide around and have the wheel collar end pointing to the outboard side to keep it being push against the horn as you fly.

Best,   DennisT

[Ian Hewitt]

Just stumbled upon an article by Glen Alison in the March 1978 Aeromodeller.

This diagram help clarify the detachable flap horn fixing - though the refinements by Dennis are noted.

I have enough to go on now - many thanks for the input. Just wish my workshop was warmer..

Ian
Nottm