By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by CML

Converting C/L model to RC

All Topics | Latest Posts

Search for:  in Thread Title in  
alex nicol04/04/2020 11:42:03
avatar
359 forum posts
15 photos

there's a KK Spectre thread on here which triggered a couple of memories of my C/L days. I started to wonder if the Spectre could be scaled up to about 60" span and converted to R/C and if so is there anything I'd need to change?

my initial thought is the fuselage would need to have the distance from wing to tail increased. Is there a formula for this or do I just make it look right?

id be interested in any thoughts or opinions

thanks

Denis Watkins04/04/2020 12:07:38
4334 forum posts
104 photos

Ballpark numbers Alex, but has worked for me

screenshot_2020-04-04-12-01-58.jpg

Bob Cotsford04/04/2020 12:07:40
avatar
8390 forum posts
463 photos

There have been pull-out plans for a few conversions, the Marquis, Skystreak and Firebird come to mind. For the Spectre I think you could stretch the fuselage slightly, if I remember rightly you would be looking to make the tail moment at least 1 1/2 times the wing chord. Or build as is and use very small elevator movements.

I thought about the Mercury stunter, was it the Crusader? That probably wouldn't need scaling. Google tells me it was the Crusader and it had a 56" wingspan. That would make a nice sized model. Or what about a Spacehound? That was a stylish looking model.

David Davis04/04/2020 12:22:03
avatar
3685 forum posts
688 photos

There's a model called the Coy Lady which I've always admired. CL 727 in the old Aeromodeller listings. Stretch the fuselage a bit and it would make a good electric flight conversion with that slim fuselage. it's available as a download on The Outerzone. **LINK**

J D 804/04/2020 12:41:54
avatar
1447 forum posts
84 photos

One thing to watch for on CL designs is some had the inner wing of slightly greater span.

Bob Cotsford04/04/2020 13:15:38
avatar
8390 forum posts
463 photos
Posted by J D 8 on 04/04/2020 12:41:54:

One thing to watch for on CL designs is some had the inner wing of slightly greater span.

now that would make for an interesting model to watch someone else trying to flylaugh

Trevor04/04/2020 13:19:32
avatar
426 forum posts
57 photos

Probably best not to fit the usual folded up empty balsa cement tube to the r.h. wingtip either smiley

alex nicol04/04/2020 14:07:12
avatar
359 forum posts
15 photos

Thanks gents. much appreciated

the inboard wing length and tip weight would certainly make for some interesting flight characteristics

brokenenglish04/04/2020 14:13:08
avatar
551 forum posts
29 photos

Excellent plans already exist, at least for the Peacemaker, Phantom and Skystreak. All on Outerzone I think.

Peter Miller04/04/2020 14:19:59
avatar
10961 forum posts
1272 photos
10 articles

The Spectre would be nice in the size that it is, (very close to my The OHmen etc) The moment are could be a little longer as has been said,

David Davis04/04/2020 14:38:25
avatar
3685 forum posts
688 photos

The Nobler is also available as an r/c conversion.

**LINK**

alex nicol04/04/2020 15:51:02
avatar
359 forum posts
15 photos

There's a whole load of C/L stunt classics with really nice lines ..... no pun intended, that look like they'd adapt to a nice sport RC model. Another one I was always going to build and never quite got round to it is the Comodore ( plans on outerzone) it might even lend its self to EDF power who knows.

Anyways, thanks for all the excellent suggestions, looks like I've a lot of pondering to do

Andy Stephenson04/04/2020 16:47:02
138 forum posts
21 photos

CL models usually have zero dihedral to allow the control wires a straight run to the elevator bell-crank. If converting to one to R/C you might find significant adverse roll on application of rudder without adding a commensurate amount of dihedral to the wing.

A.

Erfolg04/04/2020 17:17:08
avatar
11714 forum posts
1309 photos

This is a scaled down conversion of a Nobler original by Georg Aldrich.

Why scaled down, because at the time of building there were limited range and numbers of brushless motors.

Some aspects were redesigned by necessity.

A major fault is the rudder is pretty useless.

Could do with UC, there is not enough room for UC, mostly down to size of model and the Lipo.

Another limitation is that the fuz is highly tapered, which means that apart from right at the front, there is little room.

If I were to make another it would be much bigger, to free up space, for equipment.

Apart from the negatives, it still is flown, handles generally well, no real stall. You just have to accept it originally was designed to go round in circles. Not designed to specifically roll, knife edge, nor necessarily go fast (more a single speed, what ever it was doing).

Erfolg04/04/2020 17:24:08
avatar
11714 forum posts
1309 photos

I have a Spectre, which I had thought of refurbishing.

The more I looked at it, the more it became apparent, I would have to start from scratch. The panels are odd lengths. One side is full of Plasticine. The body would have to be opened up to get rid of the coupled elevator and flaps. The fuel tank is built in of wedge type. Plus the model is in a sorry state. Apart from these issues, I have lost the drawing.

alex nicol04/04/2020 17:52:29
avatar
359 forum posts
15 photos

I think you may be right. Mine ended up in a similar state (dead stick in the middle of a wing over) the useable bits were harvested and the remainder cremated and assisted with a good squirt of diesel fuel.

Peter Miller04/04/2020 18:14:16
avatar
10961 forum posts
1272 photos
10 articles

The Spectre had a horribly weak spot where tehflap connector caame through the fuselage sides just below the rear of the open cockpit.

I have even seen one snap in mid air,

WE learned to put a ply doubler in that area,

Not so much a problem with a radio version but I would have a doubler from the firewall back to behind the wing anyway

Erfolg04/04/2020 18:26:01
avatar
11714 forum posts
1309 photos

A typical type of design limitation with respect to RC use is the flap, which we would want as an aileron. Outboard they often are quite narrow, compared to the root. This reflects that the actuation is a one piece torque rod type of wire, actuating at the root. The arrangement is the opposite of having the principal area at the tip for an aileron.

The body tends to narrow in the middle as there is only the bell crank there, it does not need to be wider. The narrowness helps with the tracking, in conjunction with a rudder often set to turn the model out of the circle, to help in maintaining line tension in the cross wind part of the circle.

Possibly team racers offer a better CL to RC model, as the rules as I remember them had a minium cross section. Although the latter mono wheel types look nothing like a full size racing plane.

Malcolm Fisher04/04/2020 19:59:03
avatar
641 forum posts
7 photos

I converted a Crusader to R/C sometime in the 1980s. Modified the flaps from being coupled with elevator to make them act as ailerons. Initially they weren't very good being very narrow near the tips. Added extensions at the tips to make them wider ad this improved things enormously. Also had to remove part of the inboard C/L wing to even things as far as the wings were concerned. Flew well and could turn very tight loops as I found on one flight when it was coming towards me and getting a bit low. Somehow I had managed to get it inverted without realising and was very surprised when on pulling a lot of up elevator it did a half loop downwards before flying away from me - a bicycle clips moment.

Sadly it was among other models, engines and radio gear which were stolen from my shed.

Malcolm

PatMc04/04/2020 22:56:38
avatar
4386 forum posts
527 photos
Posted by Andy Stephenson on 04/04/2020 16:47:02:

CL models usually have zero dihedral to allow the control wires a straight run to the elevator bell-crank. If converting to one to R/C you might find significant adverse roll on application of rudder without adding a commensurate amount of dihedral to the wing.

A.

Care to explain why ?

All Topics | Latest Posts

Please login to post a reply.

Latest Forum Posts
Support Our Partners
CML
Sussex Model Centre
Slec
electricwingman 2017
Sarik
Advertise With Us
Latest "For Sale" Ads
Has home isolation prompted you to start trad' building?
Q: The effects of Coronavirus

 Yes - for the first time
 Yes - but Ive bashed balsa before
 No - Ive existing projects on the bench
 No - Im strictly an ARTF person

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E!