stunthanger.com

Building Tips and technical articles. => Building techniques => Topic started by: MarcusCordeiro on September 04, 2012, 02:32:25 PM

Title: Sig Magnum
Post by: MarcusCordeiro on September 04, 2012, 02:32:25 PM
Hi all

Got  my Magnum today!!

Have always wanted to build one.
Will power it with one ST¨60.
Wondered if anyone had a tip or two for building it.
25 years in a box and still in great condition.
One thing for sure, replace the bellcrank for one 4" CF.
It's the double cored wings.
Any help will be welcomed.

Thanks

Marcus  H^^
Title: Re: Sig Magnum
Post by: Balsa Butcher on September 04, 2012, 05:10:45 PM
As far as the double cored wings go...cut a strip of foam (can be from the wing cradle or another project) and insert and glue it inside the rear cut-out, approximately centered. This will create a triple cored wing. It will maintain its airfoil shape better than a double cored wing as those wings tend to flatten out over time. 8)
Title: Re: Sig Magnum
Post by: MarcusCordeiro on September 05, 2012, 06:49:37 AM
Thanks guys. Yes, the wings... I'll cut it from the core that comes with it. That's good advice.
Anyway, the kit seems to be just like a regular building.
My concern is sheeting the wings. I'm not really sure about the glue..
What do you guys use for that?

Marcus
Title: Re: Sig Magnum
Post by: john e. holliday on September 05, 2012, 08:51:01 AM
Remember to leave the cores in place while sheeting the panels.   I would use the old tried and true epoxy method.  Slow cure of course.  Spread the epoxy as thin as you can with the credit card on the balsa sheets.   When you think it is thin enough go over it again.  Remember to have a flat surface to put the cradles on and most of all a flat plank on top with lots of weights.   Let set for more than 24 hour curing time.
Title: Re: Sig Magnum
Post by: MarcusCordeiro on September 06, 2012, 09:35:30 AM
Thanks John

Epoxi could be an option. The instruction booklet says Sig Core-Bond, but it's 25 years old...  LL~
I thought by now there could be something more up to date.
I could thin the epoxi using some alcohol and spread it with a brush, couldn't I?
That way I could keep it thin and save some weight.
I'll check what else I have available before I make my mind.

Marcus
Title: Re: Sig Magnum
Post by: Balsa Butcher on September 06, 2012, 03:07:51 PM
If you can find some Z-Poxy, that is the epoxy of choice for most. It is a finising resin as opposed to epoxy glue. Much thinner and can be spread out very thin. If you go to the tips section of Heman Lee's "Aeromaniacs" site you will find a link to a tutorial that Bob Hunt did on sheeting foam wings. I think you will find it very helpful. 8)
Title: Re: Sig Magnum
Post by: Bill Little on September 06, 2012, 03:33:55 PM
If you can find some Z-Poxy, that is the epoxy of choice for most. It is a finising resin as opposed to epoxy glue. Much thinner and can be spread out very thin. If you go to the tips section of Heman Lee's "Aeromaniacs" site you will find a link to a tutorial that Bob Hunt did on sheeting foam wings. I think you will find it very helpful. 8)

HI Pete,

Z-Poxy also comes in a 30 min. epoxy.  I made a mistake by buying the epoxy last time I needed some "Z-Poxy".   Same carton, bottles and all as far as I could tell.  (I wanted the finishing resin!)

BIG Bear
RNMM/AMM
Title: Re: Sig Magnum
Post by: MarcusCordeiro on September 06, 2012, 03:52:33 PM
Thanks people.
That's really good advice  H^^

Marcus
Title: Re: Sig Magnum
Post by: Jim Oliver on September 12, 2012, 09:49:33 PM
Marcus,

I would suggest that you carefully check the cores, bith wing and stab, to make sure that the cores are identical.  When I built my first Magnum, I found that the wing cores were different thickness. 

I didn't discover the problem until after the cores were sheeted and ready to join.  I was NOT pleased HB~>

Jim
Title: Re: Sig Magnum
Post by: MarcusCordeiro on September 13, 2012, 08:38:22 PM
Marcus,

I would suggest that you carefully check the cores, bith wing and stab, to make sure that the cores are identical.  When I built my first Magnum, I found that the wing cores were different thickness. 

I didn't discover the problem until after the cores were sheeted and ready to join.  I was NOT pleased HB~>

Jim

Thanks, that didn't cross my mind.
First thing tomorrow morning.
Just checked and all the parts are there.
Now, a little question popped in there, if I replace the stock 3" bellcrank for one 4", should I replace anything else or can I still use the stock horns?  #^

Marcus

Title: Re: Sig Magnum
Post by: john e. holliday on September 14, 2012, 08:27:58 AM
Use a little common sense here.  If you change one component, it will change the movements of the other components.   
Title: Re: Sig Magnum
Post by: MarcusCordeiro on September 14, 2012, 10:34:15 AM
Use a little common sense here.  If you change one component, it will change the movements of the other components.   

That's a sure thing John.
What I wanted to figure out was whether or not that would be a smart move.
I've been thinking about Tom Morris controls for this model.
Maybe that would be the smartest choice.


Marcus
Title: Re: Sig Magnum
Post by: Bill Little on September 14, 2012, 10:37:32 AM
That's a sure thing John.
What I wanted to figure out was whether or not that would be a smart move.
I've been thinking about Tom Morris controls for this model.
Maybe that would be the smartest choice.


Marcus

HI Marcus,

I would definitely strongly consider the Tom Morris controls.  Tell him want you need it for and he can give you a proper set up.

BIG Bear
RNMM/AMM
Title: Re: Sig Magnum
Post by: Pat on September 17, 2012, 08:07:05 PM
Marcus,

 I am building a Magnum right now. I sheeted my wings with water based contact cement and it worked like a charm. I used a foam brush so it made it easy to strip any excess cement off. I used a 3 inch bell crank with carbon fiber push rods and ball ends.

Pat
Title: Re: Sig Magnum
Post by: Rafael Gonzalez on September 18, 2012, 08:45:02 AM
Thanks guys. Yes, the wings... I'll cut it from the core that comes with it. That's good advice.
Anyway, the kit seems to be just like a regular building.
My concern is sheeting the wings. I'm not really sure about the glue..
What do you guys use for that?

Marcus

If you have not done the coring, the best available and lightest is Gorilla glue. Its a Poly glue that foams as it cures. It covers any valley or pore and forms a completely solid surface. Do all your prerequisite prep for the sheeting and when ready, spray the foam with a mist of water(Very, very light) wipe the foam with a dry cloth or towel just to make sure that there are no water spits from the mist. Poly uses moisture (humidity) as a catalyst. The wings will dry and be humid by the time you do the next step.

Get a squeegee and squeegee the gorilla glue on the skins to the point that there is a semi-flat shine on the balsa. Do the other skin and place on wing using the cradle. let it sit for 24-48 hrs. The glue is sandable much better than epoxy and 3 times lighter!!!

 H^^
Title: Re: Sig Magnum
Post by: john e. holliday on September 18, 2012, 09:11:39 AM
Make sure you have something in the cradle to protect it.  The Gorilla Glue will find every little pin hole and crack in the balsa sheeting no matter how thin you put it on the balsa sheet.   It comes alive when the moistened foam comes in contact and starts growing.   Also leave the cores in the foam wing as you will need to put lots of weights on the flat boards to keep the sheeting in contact with the foam until it cures.   24 hours minimum before removing the weights.   Goes the same if you use epoxy.   Wear goves and have plenty of rags as both glues are messy if you are like me.  Remember the flat surface determines how straight your wing will be when the glue is cured.
Title: Re: Sig Magnum
Post by: MarcusCordeiro on September 18, 2012, 10:34:41 AM
Thanks guys.
Every word of advice was very helpful, and now I have options to consider.
I'll start building in a couple of weeks, so I have some time to make up my mind.
In the mean time, I'll see about the controls.
I've checked the vendor's corner and Control Line Central seems to have Tom Morris's.
The 3" bellcrank looks so tiny for the ST 60...

Pat, mind if I ask what motor you're using for yours?

I'll keep you guys updated. H^^

Marcus
Title: Re: Sig Magnum
Post by: Rafael Gonzalez on September 18, 2012, 11:36:15 AM
Make sure you have something in the cradle to protect it.  The Gorilla Glue will find every little pin hole and crack in the balsa sheeting no matter how thin you put it on the balsa sheet.   It comes alive when the moistened foam comes in contact and starts growing.   Also leave the cores in the foam wing as you will need to put lots of weights on the flat boards to keep the sheeting in contact with the foam until it cures.   24 hours minimum before removing the weights.   Goes the same if you use epoxy.   Wear goves and have plenty of rags as both glues are messy if you are like me.  Remember the flat surface determines how straight your wing will be when the glue is cured.

That's right Bill!  H^^ I forgot, I use wax paper in between the cores and the wings!!! And yes lots of weight! And a straight and trued surface...
Title: Re: Sig Magnum
Post by: Pat on September 19, 2012, 08:02:28 AM
Marcus,

I am leaning tword the evolution .61, this is a really nice engine that is basically the physical size of a .46 or so. If I don't use that I will be going with a Super Tiger G 51, that has been worked over by Randy smith. This will be the more expensive option I am sure.

Pat
Title: Re: Sig Magnum
Post by: MarcusCordeiro on September 19, 2012, 10:14:37 AM
Marcus,

I am leaning tword the evolution .61, this is a really nice engine that is basically the physical size of a .46 or so. If I don't use that I will be going with a Super Tiger G 51, that has been worked over by Randy smith. This will be the more expensive option I am sure.

Pat

Pat

I've heard good comments on the Evolution, though never had one.
I have a big stunter here, about 67 ounces, and it's hauled by one ST 51.
Very powerful and easy to handle. Mine is stock, so one by Randy... #^


Marcus
Title: Re: Sig Magnum
Post by: Pat on September 19, 2012, 11:17:21 AM
I plan on getting the plane almost complete, and then weighing it before making my final decision. But I do like the idea of the Evo .61. As a drag racer I subscribe to the "you can never have to much power" theory... LL~
Title: Re: Sig Magnum
Post by: Bill Little on September 19, 2012, 11:58:18 AM
Hi Pat,

I think either engine would be very close in performance.  The ST .51 is a strong stunt engine, especially set up correctly.  I have a NIB Evo .60 that I will test and probably fly in the "redone" SV-11.

Bill
Title: Re: Sig Magnum
Post by: Pat on September 19, 2012, 08:10:01 PM
Bill,
 It all goes back to the "No replacement for displacement" thought!
Title: Re: Sig Magnum
Post by: MarcusCordeiro on October 16, 2012, 07:02:24 AM
Well

I have started...



Title: Re: Sig Magnum
Post by: Airacobra on October 16, 2012, 06:00:24 PM
There is fellow in our club that has been using one of the Evo .61. The engine is in a Time Machine. Probably not the lightest plane as he will attest, but the Evo has no problem hauling that plane through the air. It seems to run a bit smoother than the ST 60 and starts very easy. Seems to me there is no way you could go wrong with the Evo. It has me wanting one as I write this.
Title: Re: Sig Magnum
Post by: MarcusCordeiro on October 16, 2012, 06:55:02 PM
There is fellow in our club that has been using one of the Evo .61. The engine is in a Time Machine. Probably not the lightest plane as he will attest, but the Evo has no problem hauling that plane through the air. It seems to run a bit smoother than the ST 60 and starts very easy. Seems to me there is no way you could go wrong with the Evo. It has me wanting one as I write this.

I agree totally. heard good results from the people who have been using it.


Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on October 21, 2012, 06:04:51 PM
I'm not a fast builder, but there's been a little progress.

 H^^

Marcus

Title: Re: Sig Magnum
Post by: MarcusCordeiro on October 23, 2012, 07:00:49 PM
Got the elevators almost finished.
While I wait for thr Z-POXY resin to arrive, let's advance whatever I can  H^^

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on October 26, 2012, 08:45:09 PM
The flaps. There've been numerous comments about sheeting those flaps...

Marcus
Title: Re: Sig Magnum
Post by: RC Storick on October 26, 2012, 10:04:00 PM
Heck I am not a fast builder anymore
Title: Re: Sig Magnum
Post by: billbyles on October 30, 2012, 07:08:41 PM
Heck I am not a fast builder anymore

Riiiigghhht, Robert...since you build at the speed of heat I'm surprised that you haven't found a way to spray on the finish while the wing is still in the jig!
Title: Re: Sig Magnum
Post by: MarcusCordeiro on October 30, 2012, 07:57:00 PM
A little more done...
Hope to have that nose done by the end of the weekend, there's a lot of carving to do n~

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on November 01, 2012, 06:43:49 PM
I'll have to work on the top block and think I'll go with a cockpit... Never liked it, but after seeing Derek's thread, I got motivated to do one.
I think a cockpit weakens the area 'cause you cut the top block.
Gotta find a nice pilot...


Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on November 04, 2012, 05:19:03 PM
I'm a man of my word...

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on November 06, 2012, 09:52:36 PM
Marcus,

Nice build so far. Looks like you know what you're doing.

Did you sheet those wings yet?

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on November 07, 2012, 03:11:29 AM
Charles

I'm about to. My local model shop got the resin, but it's not the ZPOXY, it's Brodak's, so I needed to check if it  would be ok to use it. It is, so next week I.ll be working on all the sheeting, there's the stab too, which I'll do first. Gotta finish the fuselage this week..

Marcus
Title: Re: Sig Magnum
Post by: RandySmith on November 07, 2012, 11:50:36 PM
Foam wings?  Wow. The one I built in 1974 was all balsa and at the time the biggest plane I had ever built.  Keep it light. H^^

They made an all balsa kit???  I would like to find one of those

Randy
Title: Re: Sig Magnum
Post by: Brett Buck on November 09, 2012, 07:22:53 PM
They made an all balsa kit???  I would like to find one of those

Randy

   I think Ty is confusing this with something else, I think the Magnum was first produced in the mid-80s, not 1974.

    Brett
Title: Re: Sig Magnum
Post by: MarcusCordeiro on November 10, 2012, 05:10:55 AM
   I think Ty is confusing this with something else, I think the Magnum was first produced in the mid-80s, not 1974.

    Brett

It was released in 1986, I have the FM issue...

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on November 21, 2012, 01:47:18 PM
I got the bottom fuse sheeting done. The cowl will get an exhaust for the hot air.
Gonna start sheeting...

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on November 25, 2012, 02:00:18 PM
I wish I could move faster with this bird...
Anyway, i got the stab sheeted. :D :D


Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on November 25, 2012, 07:41:22 PM
Marcus,

Looks good so far!! It's shaping up so keep up the pace!

I know absolutely nothing about the model you're building, but looks like you have it under control.

What did you wind up using for an adheasive to sheet with?

I did google to see what the model looks like.

It's a great looking model! Sig has their's painted in sky blue.

Ideas for color yet?

Charles

Title: Re: Sig Magnum
Post by: MarcusCordeiro on November 26, 2012, 01:51:29 AM
Charles

I used Brodak's Finish Resin. I couldn't get the ZPOXY, but it is said to be good too.
It was my first time sheeting foam, then later I'll get them out of the cradles and see the result.
I followed Bob Hunt's tutorial and it was kind of easy.
The resin is easy to spread and there's plenty of time to place the skin on the foam.
The wings to come soon...

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on November 26, 2012, 08:22:43 AM
Marcus,

This is not advice.   n~

I used to cut foam wings years ago. Sheeted plenty of them also.

Tried all kinds of adhesives. Near the end, when I had just about stopped doing foam wings, I found myself taking the skins and wings to my local Woodcraft Shop.

They would spray the surfaces with the glue they used, "commercial grade," for laminating Formica and veneers.

They never charged me because I would bring in coffee and donuts. Actually true.

These wings were sheeted exactly that way, in the 90's, and show no evidence of separation. Light too.

Worked for me on a bunch of foam wing cores.

This wing, the last of my foam wing models, and will be the last, is for an electric DF jet I'll eventually get around to completing. Eventually.  ;D

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on November 28, 2012, 03:20:45 AM
Charles

That's great advice. I sheeted the stab using finish resin and liked the result.
It was kind of easy to do. Just didn't like the fact that the stab cores were a little different from one another
and that made it a little difficult to get them aligned. I'm considering building a new stab, but a build up one
so I can get it straight.
That sucks...

Marcus
Title: Re: Sig Magnum
Post by: Jim Oliver on November 28, 2012, 05:23:57 AM
Marcus,

I would suggest that you carefully check the cores, bith wing and stab, to make sure that the cores are identical.  When I built my first Magnum, I found that the wing cores were different thickness. 

I didn't discover the problem until after the cores were sheeted and ready to join.  I was NOT pleased HB~>

Jim
Title: Re: Sig Magnum
Post by: MarcusCordeiro on November 28, 2012, 08:23:29 AM


Yeah... Dumb dumb here only checked the wing cores... HB~>
At least, the wings seem to be ok...

No biggie though...

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on November 30, 2012, 09:28:47 AM
Dumb dumb HB~> HB~> is going to build a buildup estab...
No way to save the foam one.
Well, let's have some fun cutting some balsa.


Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on December 18, 2012, 06:50:59 AM
Back in action.
I'm sure I can get the sheeting on those wings done today.
By the way, what a poor cutting job Sig did with the wings... ''
And got started on the new stab...

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on December 19, 2012, 09:44:23 AM
Wings sheeted as per Bob Hunt's tutorial, Though I didn't have 200 pounds of weight, so had to satisfy myself with around 60...
The only way to get 200 lbs over those wings would be me sitting on top of them... LL~ LL~ LL~
For a first timer, I guess it is very good!!

Marcus
Title: Re: Sig Magnum
Post by: Bill Little on December 19, 2012, 11:12:13 AM
Everything is looking good so far, Marcus.  Good luck with the build and with the flying!

Bill
Title: Re: Sig Magnum
Post by: MarcusCordeiro on December 19, 2012, 12:30:18 PM
Everything is looking good so far, Marcus.  Good luck with the build and with the flying!

Bill

Thanks a lot Bill.  H^^

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on December 22, 2012, 01:41:55 PM
Spent all afternoon sanding...
Now, let's sheet everything.

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on December 22, 2012, 02:13:07 PM
Marcus,

Your third wing photo. Is that a drawn line or material on the edge?

Lookin good so far, you are progressing.  H^^

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on December 22, 2012, 03:17:31 PM
The stab is tappered, so I had to draw the lines to guide me sanding.
I liked the result so far, but I want to wait until it's fully finished to pop that champaigne %^@

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on December 23, 2012, 01:47:45 PM
Got the LE and TE shaped and boy, that TE wood was as hard as a rock!
Now comes the cntrol system thing.
I'd thought about a total overhauling, changing everything, but unfortunately I haven't been able to contact Mr. Tom Morris yet, then,
I think I'll stick to the kit stuff, just replace the pushrods for a Brodak adjustable ball link kit that In have here and that's OK.


Merry Christmas folks!! May the blessing of God be with everybody!!

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on December 23, 2012, 02:27:32 PM
Marcus,

Can you get a photo of the Brodak hardware?

I'm sure Tom will answer his phone on Monday. Monday is a working day.

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on December 31, 2012, 01:02:04 PM
Sharing time between 2 models is crazy, but vacation is only once a year.
I'll have the stab/elev assembled by tomorrow night.
Got some good 1/32 sheeting, no covering.

Happy new year!!

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on December 31, 2012, 01:09:11 PM
Sharing time between 2 models is crazy, but vacation is only once a year.I'll have the stab/elev assembled by tomorrow night.
Got some good 1/32 sheeting, no covering.Happy new year!!Marcus

Marcus,

Was 1/32" suggested instead of 1/16"?

I thought everyone was sheeting control surfaces with 1/16" ?

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on December 31, 2012, 03:01:03 PM
No, it was my choice.
The flaps, I think I'll go with 1/16 though.

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on December 31, 2012, 04:23:40 PM
No, it was my choice.
The flaps, I think I'll go with 1/16 though.Marcus

Marcus,

What did the plans call for?

Ya got plans?

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 01, 2013, 05:23:10 AM
Marcus,

What did the plans call for?

Ya got plans?

Charles

The plans ask covering with silkspan or monokote, but they flex too much, specially the flaps, so...

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 01, 2013, 04:56:58 PM
Yep, I did it! ;)

Marcus
Title: Re: Sig Magnum
Post by: RandySmith on January 01, 2013, 05:28:33 PM
Planking helps much with making them stiffer

Randy
Title: Re: Sig Magnum
Post by: Doug Moon on January 01, 2013, 07:36:20 PM
Spent all afternoon sanding...
Now, let's sheet everything.

Marcus

That is really nice work!!!!!!!
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 01, 2013, 11:18:29 PM
Planking helps much with making them stiffer

Randy

Yeah, that was the most common word of advice in previous Magnum topics I could find here in the forum.
But it's quite simple to see, as the flaps will flex and get a propeller shape with essy twisting them with your hands. ~^

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 01, 2013, 11:19:23 PM
That is really nice work!!!!!!!

Thank you Doug.

Marcus
Title: Re: Sig Magnum
Post by: Bill Little on January 02, 2013, 11:36:08 AM
Hi Marcus,

You should have a really good flying model when finished!  As everyone has said, sheeting the controls really helps.

Bill
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 02, 2013, 12:20:18 PM
Hi Marcus,

You should have a really good flying model when finished!  As everyone has said, sheeting the controls really helps.

Bill

Thanks Bill.

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 03, 2013, 10:34:32 AM
Something very important was to make a poor man's triple core, so no collapsing wings on thhis bird...

Marcus
Title: Re: Sig Magnum
Post by: Bill Little on January 03, 2013, 01:24:48 PM
Great idea, Marcus!  It only has to help.

Bill
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 03, 2013, 01:51:43 PM
You know Bill

I ran a search here to see past Magnum topics and 3 things were everywhere:

-Sheet the flaps

-Make it a triple core

-Reinforce the fuselage at the wing area

Great advice! H^^

Now, let me work on those pushrods...
Wanna have this ship in one piece ASAP.
Need room o0n the bench for my Thundergazer...

Marcus
Title: Re: Sig Magnum
Post by: Bill Little on January 03, 2013, 02:41:37 PM
Hi Marcus,

Many years ago we (Aaron and I) built a Magnum from plans.  We had a triple cored wing and used sheet stock for all the control surfaces.  It flew really well , but two things happened.  One, the finish went South very quickly, and Two, we had just stared using tuned pipes and out Magnum was not set up for a pipe.  It has been waiting on a new finish for many years.  I hope to get it redone once I get the projects now underway completed.  Not sure what engine I will use, I have ST G.51s that run great plus an OS .45FSR and an Evo .60.  Either way, I hope to get it finished and finally put a number of flights on it.  As it sits, it has maybe 2 dozen flights.

Keep on going with yours!
Bill
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 03, 2013, 04:26:18 PM
Bill

I hope it doesn"t take us too long to see that ship flying again!!
I'm using brodak's pushrod on this bird.
It's the only mod in the control system actually.

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on January 04, 2013, 11:44:59 AM
Marcus,

That Brodak pushrod. Does it arrive just as in the photo?

Do you cut it to length and add the ends? Brodak sells the ball links?

4-40?

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 04, 2013, 12:22:40 PM
Charles

You have to glue the ends and cut to lenght, but no biggie.
I'm pretty sure it's 4-40.
About the ball links, I think so, gotta check in the site...

About to enter home straight with this bird...

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on January 04, 2013, 02:07:16 PM
Marcus,

Thanks for that info.

Is that horn a Brodak part also?

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 04, 2013, 03:50:41 PM
The horn is the one from the kit.
Got the stab in place...

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on January 04, 2013, 09:07:24 PM
Marcus,

Looking good, that sheeted stab makes it!

I think I'll do that.

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 06, 2013, 02:41:48 PM
With a little effort, I'll have this bird in one piece by the end of the week... #^ #^ :)! VD~

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on January 06, 2013, 06:58:09 PM
Marcus,

Nice job squaring off the joining of your wing halves.

Epoxy?

Fiberglass cloth for the center section?

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 06, 2013, 10:17:09 PM
I used the cradles, had to shim a little, but the wing is straight.
Used slow curing epoxi and yes, I'll reinforce that joint with some fiberglass.


Marcus
Title: Re: Sig Magnum
Post by: Jim Oliver on January 07, 2013, 03:33:19 PM
Marcus,

FYI, I have had two of the threaded links break right where the threads start (or stop, depending on your point of view!).  I suspect vibration was the problem, but it happened on two different models.

One of the threaded couplers was steel, one was titanium.
Jim
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 07, 2013, 05:27:58 PM
Gee, titanium!! I guess that's bad luck...

Marcus
Title: Re: Sig Magnum
Post by: RandySmith on January 07, 2013, 07:36:52 PM
With a little effort, I'll have this bird in one piece by the end of the week... #^ #^ :)! VD~

Marcus

What glue did you use to attach the sheeting?
Randy
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 08, 2013, 03:26:24 AM
Randy

I'm assuming you're talking about the stab/elev, so for that I used medium viscosity CA, as I will for the flaps.
You cannot compare how much stiffer they are now. I'm seriously considering using 1/16 for the flaps, because they are very flexible, much more than the tail feathers, so a thicker sheeting might be more appropriated.
By the way, what CF landing gear of those you sell would best fit on this ship, if you don't mind me asking? I want to order but not sure of which one.
Let me know and I'll place my order.
I'm having second thoughts about using the wing mounted gear...

Thanks a lot

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on January 08, 2013, 06:07:07 AM
Marcus,

Joining your wing halves?

Myself and R/C pattern guys always used 6" of fiberglass cloth.

Probably more than needed, but when feathered, you couldn't tell it was there.

Will you use 6" of cloth at your wing center?

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 08, 2013, 06:12:11 AM
Marcus,

Joining your wing halves?

Myself and R/C pattern guys always used 6" of fiberglass cloth.

Probably more than needed, but when feathered, you couldn't tell it was there.

Will you use 6" of cloth at your wing center?

Charles


Now I might, I have to go to the store to buy the cloth, but your idea seems good...
The one that came with the kit is only 1"... n1

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on January 08, 2013, 11:22:09 AM
Marcus,

Please, I'm not saying that 6" was a "good idea."

It's just the way some of us did it, or at least with pattern ships. I learned from others.

Much of it was sanded and remember, ALL the wings had airfoils that tapered in thickness.

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 13, 2013, 06:53:04 PM
Did the weight box.

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on January 14, 2013, 08:51:55 AM
Marcus,

Looks like most builders use balsa for the weight box lid top.

I can toss my 1/8" ply lid and go with thin ply and then balsa.

Gives me a recessed screw like yours.

Thanks for posting those photos, I just caught it.   :!

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 14, 2013, 09:09:09 AM
I used some scrap 1/16 ply to make the box.
Balsa on the lid is much easier to sand.
The wing tip is almost finished, have yet to round it a little...
Gonna work on the leadouts now.

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 14, 2013, 12:15:42 PM
The lead out.
I thought it was better to make a kind of box and glue it to a "half rib", and then glue the assembly to the wing.
I guess it's stronger and I'm sure it's aligned...
Now, to the wing tip block and Dremel on!

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 14, 2013, 01:14:54 PM
I love it when a plan comes together!!

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 14, 2013, 06:42:30 PM
Just a little more and the wing will be done!! #^ #^

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 15, 2013, 01:33:48 PM
Apart from the fiberglass cloth reinforcement at the certer joint, wing finished...
I wish I had a scale here, it seems light enough.
Anyway, by tomorrow this time, fuselage and wing will be joined as one piece, hopefully #^ ;)

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on January 15, 2013, 02:46:23 PM
Marcus,

You're the Feature Film!

I go here first. I shouldn't, but I do.   ;D

You have your weight box lid on top?

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 15, 2013, 04:16:11 PM
Yeah, decided to do it a little unusual ;)

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 15, 2013, 06:32:32 PM
I was thinking about a fuselage mounted LG, but decided to use the one that comes with the kit.

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 16, 2013, 10:25:53 AM
LG OK, joint reinforcement OK, used 2" cloth.
Now let's put the fuselage and the wing together... S?P

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 16, 2013, 12:09:36 PM
So, I got to weight the wing, with flaps and everything 680 gr/ 23.98oz.
Now I ask, is it good, bad??

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 16, 2013, 02:01:30 PM
Damn! Missed by a few minutes...
It's one piece!


Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on January 16, 2013, 06:29:05 PM
Marcus,

Looking really good.

Seems like you do a bit each day, correct?

My schedule won't permit that.

What? You got two models going?

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 16, 2013, 07:07:17 PM
Charles

I'm on vacation, and it's been raining a lot, so I've been doing a lot of building.
Yes, I'm working on 2 models.
Hopefully, the Magnum will go to finishing very soon.
Needed to take advantage of the free time.
Next Monday, back o work HB~> LL~

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 17, 2013, 04:07:16 PM
A little more... Couldn't build as much as wanted today, but will have this building finished by the weekend....  S?P

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on January 17, 2013, 04:24:24 PM
Marcus,

Did I miss something or are you slacking.   ;D  LL~

I did check your entire build, photos and all, so???    LL~ LL~

I don't see your secrete method of cutting hing pockets and attaching control surfaces?

I could have missed it?

Did I! Did I!

That photo, those flaps look really really tight!

CA, Epoxy, pinned, your method?

Charles

Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 17, 2013, 05:33:48 PM
I use the regular dubro hinge slotter, and I always pin my hinges.
I konw some people like to attach the flaps and elevators after painting, but I have a phobia about it, so I drill a small hole and put a toothpich through it with medium viscosity CA.
Never had a problem.

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on January 17, 2013, 06:07:52 PM
Marcus,

I do the exact same thing. I drill from underneath and don't drill through the top.

I was thinking of getting lazy and not pinning.

Guys don't pin anymore.

I read that.   n~

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 17, 2013, 06:51:21 PM
I can't go without pinning... Lost a ship once, my first 35 sized ship, 'cause I didn't... :X
I sanded the flaps and elevators LE to 45º and that's all.

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on January 17, 2013, 07:13:48 PM
Marcus,

Great close-ups! I used to know how to do that, the photo that is.  ;D
 
See where the hinge widens at the hinge pin. I trim more TE material and recess the hinge hinge pin area 50%. Same to the flap.

That's how we did it with R/C pattern ships. Not just me.

You gonna do that?

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 18, 2013, 04:09:16 AM
I do like this...

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on January 18, 2013, 05:09:59 AM
Marcus,

Thanks for that photo, but it's hard to see that, the angle?

Do you cut them like I mentioned, for the hinge pin recess?

I've been working on The LOSER. Got up at 4:00 AM. I'm trying to catch up to your build but you're way ahead. Will you sleep next month?

Hey! Been thinking about colors or a scheem for your Magnum? To soon for that?

I think about that each and every day.

I have to come up with a great scheem, make up for the terrible building.  ;D 

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 18, 2013, 08:26:44 AM
Almost there...
Just a few more tweaks #^ #^ n~ :)! H^^

Marcus
Title: Re: Sig Magnum
Post by: john e. holliday on January 18, 2013, 08:30:12 AM
T too do not glue my pinned hinge in place.   I have done it in the past using epoxy,  Elmers and silicone glue.   The silicone took the most work.   As far as notching for hinge barrel I have a peice of brass tubing I scrape along the slot until deep as I want it.   I use bamboo skewers from the home cooking department.   The drill bit I use makes for snug fit.   After drilling and inserting the skewer a drop of CA both sides.   Then I use a flush cut micro saw to trim them down.   Sand paper does the rest.   I do all hinges on one surface first before doing the other, like the flap/elevator.    
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 18, 2013, 01:58:51 PM
Well, I guess building is finished.
Few things to do in the tank compartment, but no biggie.
Will install the engine, etc, to weight the model at the club this weekend and post a pic of it H^^

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 18, 2013, 03:58:42 PM
So, this is what I got.

Marcus
Title: Re: Sig Magnum
Post by: john e. holliday on January 19, 2013, 10:00:13 AM
Now don't do like the old man and rush the finish.   That is looking great.
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 19, 2013, 01:52:39 PM
Now don't do like the old man and rush the finish.   That is looking great.

Thanks John.
I won't rush...

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on January 19, 2013, 02:16:40 PM
Marcus,

Looks really nice, great job, kudos!

Charles
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 19, 2013, 02:20:44 PM
Thank you Charles.

Marcus
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 20, 2013, 10:55:49 AM
So, took it to the club and the scale showed 44oz, with engine, tank, wheels, etc...
There's some sanding now and then I'll think about how I'll finish this ship.
Any suggestions?? I'm thinking about having it monokoted by a local expert.
Painting is an option, but I guess it would add some "love handles"... LL~ LL~

Marcus
Title: Re: Sig Magnum
Post by: john e. holliday on January 20, 2013, 02:00:55 PM
Monokote it yourself,  it take practice and patience,  more onth patience end of it.   Otherwise go with Poly-span and dope.   A search will yield a lot of ways of doing the finish. 
Title: Re: Sig Magnum
Post by: MarcusCordeiro on January 20, 2013, 02:49:31 PM
So, going to start another thread at the finishing board, building is over.

Marcus
Title: Re: Sig Magnum
Post by: Avaiojet on January 20, 2013, 03:00:15 PM
So, going to start another thread at the finishing board, building is over.Marcus

Marcus,

This is a sad note, a fine Thread coming to an end.   :'(

I'll be looking forward to your "Finishing" thread, whatever material you select!

Charles
Title: Re: Sig Magnum
Post by: john e. holliday on January 21, 2013, 08:59:58 AM
Waht sad about finishng???   Should dbe celebrating another plane going to be finished and in the air soon.  I will be over there watching.