Radial mounted engine + profile fuselage

[Angelo Smyth]

I'm thinking of building a profile stunter that features a radially mounted engine (in this case a OS .40 LA). I've included a picture of the type of mount I'm considering. But I just can't get my head around how to mount the fuel tank for this particular situation....or even which one would be effective. Part of me says "You don't see too many of these around....for a reason", but another part of me says "Why not?". I did a quick and dirty search on the subject here, but thought it might be better to ask my question directly. Although I'm new-ish to the hobby, I'm thinking this had to have been done before. So, which tanks worked for a radial-mount engine with a profile fuselage, how mounted, etc.? Pictures would help. And as always, thanks in advance for your time!

[Dan McEntee]

   Angelo;
   Search out the forum here for threads on Ted Fancher's Imitation. It was a construction article in Model Aviation several years ago, and if you don't have the magazine, you can find it in the AMA archives. It was designed for an R/C mount and the article is typical Ted Fancher, very complete and descriptive. Mike Griffin did a kit run of the airplane last year and maybe you can find some one that wants to sell theirs.
 
   Type at you later,
  Dan  McEntee

[ericrule]

A couple of years ago when I owned RSM Distribution I worked with Mike Griffin and Ted Fancher to produce kits of Ted's Imitation. We used a plywood radial mount that worked exceedingly well. The standard profile fuel tank was mounted in the fuselage behind the engine mount.
If you are interested in a 46 size profile model give Mike Griffin a call and I am sure he will be happy to sell you one.

[Fred Quedenfeld jr]

This link should help
https://stunthanger.com/smf/nostalgia-30/ted-fancher-imitation-45714/msg475789/#msg475789

[FLOYD CARTER]

Having done this years ago, I recommend also installing straight hardwood braces from the outer edges of the firewall (engine mount) back to at least the wing main spar(s). I used pieces of 1/2" x 5/8"  motor mount stock.

[Dave Hull]

And keep in mind that the resulting plane may not meet the local definition of a "profile" should you choose to enter a profile-only contest.

The Divot

[Angelo Smyth]

This link should help
https://stunthanger.com/smf/nostalgia-30/ted-fancher-imitation-45714/msg475789/#msg475789

That was helpful - thank you!

[Angelo Smyth]

And keep in mind that the resulting plane may not meet the local definition of a "profile" should you choose to enter a profile-only contest.

The Divot

No worries here - doing this for my own pleasure. But it is something for me to keep in the back of my mind.

[Angelo Smyth]

Having done this years ago, I recommend also installing straight hardwood braces from the outer edges of the firewall (engine mount) back to at least the wing main spar(s). I used pieces of 1/2" x 5/8"  motor mount stock.

I was think along the same lines - I just got stuck thinking about how to integrate all that along with a fuel tank. Wasn't sure if the tank should be embedded into the fuselage, or simply attached onto it. The Fancher article shows the tank embedded into the fuselage.

[Angelo Smyth]

   Angelo;
   Search out the forum here for threads on Ted Fancher's Imitation. It was a construction article in Model Aviation several years ago, and if you don't have the magazine, you can find it in the AMA archives. It was designed for an R/C mount and the article is typical Ted Fancher, very complete and descriptive. Mike Griffin did a kit run of the airplane last year and maybe you can find some one that wants to sell theirs.
 
   Type at you later,
  Dan  McEntee

Thanks for pushing me in the right direction - I was able to pull up both articles in the AMA archives. Loads of information way beyond what I was seeking - but all good stuff! Seeing the publish date on that (Sep / Oct 1979).....makes me wish I had gotten much more serious in this much earlier, though I was only a kid back then! I waited a few decades too long!

[Mike Griffin]

Hi Angelo,

Before I released the Imitation kit in November of 2017,  I had several consultations with Ted Fancher to make sure we had everything as it should be before I released the kit for sale.  I actually built two Imitations, one from the original plan years ago and then one from my kit and they both flew like a dream. 

Just wanted to add a couple of things to the previous comments that have been made.  When you attach the 1/4" plywood "firewall" to which the radial mount attaches, make sure you drill for and install the three 1/4" dowell pins as shown on the plan.  Running motor mount stock back to the leading edge of the wing would in my opinion be overkill and since the tank is recessed through the balsa block to the core of the fuselage, this might create more problems than it would solve. 

As far as the questionability if it would be allowed in a profile event, I have never had that arise as an issue.  There are other designs that use the balsa blocks on the front of the fuselage that make the fuselage at that point thicker than 3/4" of an inch and the Coyote by Dick Mathis is the one that comes to mind.  It has been years since I flew in a contest so I guess the prudent thing to do would be to check ahead of time with the contest director if you are going to enter the model in a profile event. 

As far as an engine, I had OS LA.46 on both of the ones I built and they fly wonderfully with that for power. 

In any case, if you decide to build the Imitation you will certainly enjoy flying it as it is a tried and true design from a great designer, Ted Fancher.

Mike Griffin

[mike londke]

Samuel's Stuntbot build here. Designed by a friend using Dave Brown RC mount.   https://stunthanger.com/smf/index.php?action=dlattach;topic=49015.0;attach=287181;image

[Brent Williams]

Follow the Imitation nose construction method and there will be no problems.  Ted got it right 40+ years ago.

[Angelo Smyth]

Follow the Imitation nose construction method and there will be no problems.  Ted got it right 40+ years ago.

Cool. That's the clearest view I've seen thus far - thanks!

[Steve Helmick]

The last Imitation I've seen was Bob Duncan's, which had a very standard profile slab nose with only an Aero Tiger .36. It appeared to fly very well...but the Aero Tiger is an exceptional engine that is highly prized and hard to come by!  Steve

[FLOYD CARTER]

And keep in mind that the resulting plane may not meet the local definition of a "profile" should you choose to enter a profile-only contest.

The Divot

Imagine four hardwood "posts" extending from the 4 corners of firewall  on an angle  and embedded into the fuselage at the main spar location, Nothing "solid" here, so I don't think it would be counted as any violation of profile rules.

[Steve Berry]

Not exactly the same thing, but you may also want to check Al Rabe's Mustunt I. Profile with upright engine mount, tank directly behind the engine (just like on a full fuse ship). On the original it was a platform of 1/4" balsa X 2 for a 1/2" thickness. I think later on he changed it to 1/8" 5-ply with 3/8" sq. maple mounts glued on - basically a crutch. Very strong and lightweight.

Steve

[Bootlegger]

 Where can those R/C mounts be found?  Thanks

[Brent Williams]

Where can those R/C mounts be found?  Thanks

They are readily available.  Just search for "Dave Brown mounts".

[Mike Griffin]

Here is the link to Ohio Superstar website.  They have the mounts.

http://www.ohio-superstar.com/dave-brown-product-line/fiber-filled-motor-mounts

Mike