Sterling C-1 Monocoupe

Cant risk a crash, it's a plane built by dear ol dad it should be a show piece.

Beautiful plane! I would repair it and fly it gently if it was me

Super cool. Please post glamour shots when you get it repaired, well worth the effort as they're so nice looking just as a display model. There is a Waco hanging in a hobby shop in Pomona Valley in black and red dope, beautifully done too, a coat of fine dust over it with a new looking McCoy red head in it. I like those Sterling models a lot. I have the Monocoupe, Mr. Mulligan and Corsair kits though none are built.
Chris...

stuntflyr wrote:Super cool. Please post glamour shots when you get it repaired, well worth the effort as they're so nice looking just as a display model. There is a Waco hanging in a hobby shop in Pomona Valley in black and red dope, beautifully done too, a coat of fine dust over it with a new looking McCoy red head in it. I like those Sterling models a lot. I have the Monocoupe, Mr. Mulligan and Corsair kits though none are built.
Chris...  

Thanks Chris, I will make the repairs and check the beam-mounts to see if I can make an engine-swap. I have mixed emotions about flying the model. The OS .25 that's on it now is too light in the nose. None of my other older engines have mufflers and I have other airplanes that I'd like to try that OS engine on.. and not have to worry about noise.

If I choose to display the Monocoupe.. I may try to mount a McCoy RH .35 in it. I'll have to see how it fits/looks inside the red cowling.

I love the cabin designs. My Dad does too. I remember his 1960's C/L Sterling Waco having gloss-white plastic side-windows. Would that have been provided in the kit? He doped that model a cream-beige color with red trim. I have the McCoy RH .19 that was originally inside the spun-alum. cowling. The airplane is sadly 50 years gone.

Roddie, the engine in the plane currently with that muffler and Higley heavy hub is heavier than any engine designed for that plane. Most C-series kits were designed around a unmuffled Fox .35 which is in the 6.5-7 oz range. The lightning bolt redhead Mccoy is 7.05 oz and the Fp is 6.5 oz's without muffler. Enya .19 -VI 4006 is 5.70 in a control line version. Depending on your version Enya, some came ball raced.  The problem with these kits were that they only allowed a 2" bellcrank in them limiting the control throws and also making the control to the elevator very fast. If the undersized pushrod wire wasn't braced correctly inside the controls which was typically overlooked  this made them  just mushy. The kit wood was extremely poor and heavy. Much of the thickness sizes used in these kits were overdone and these planes were just heavy especially in the built up tail feathers. One of Sterling's lead draftsmen visited out club last fall and gave us a full tutorial about the how and why of most of these kits.  He's a very interesting person to talk to and he's currently making kits now. This gentleman was responsible for several Sterling designs including the S1-A Ringmaster. Ken

Ken Cook wrote:Roddie, the engine in the plane currently with that muffler and Higley heavy hub is heavier than any engine designed for that plane. Most C-series kits were designed around a unmuffled Fox .35 which is in the 6.5-7 oz range. The lightning bolt redhead Mccoy is 7.05 oz and the Fp is 6.5 oz's without muffler. Enya .19 -VI 4006 is 5.70 in a control line version. Depending on your version Enya, some came ball raced.  The problem with these kits were that they had 2" bellcranks in them limiting the control throws and also making the control to the elevator very fast. If the undersized pushrod wire wasn't braced correctly inside the controls which was typically overlooked  this made them  just mushy. The kit wood was extremely poor and heavy. Much of the thickness sizes used in these kits were overdone and these planes were just heavy. One of the Sterling's lead draftsmen visited out club last fall and gave us a full tutorial about the how and why of most of these kits.  He's a very interesting person to talk to and he's currently making kits now. This gentleman was responsible for several Sterling designs including the S1-A Ringmaster. Ken

Hi Ken, I guess if I ever decide to fly the Monocoupe, I may have to use a heavy-hub with any of my current engine options. Possibly my old Max III .29 @ 8.35oz. would be heavy enough without one? Any idea how the mounts compare between the .25 FP-S and the Max III .29? The old Max III has a 1.330" case-width, 1.600" hole-spacing l/r and .875" hole-spacing f/r.

This model has a 3" bell-crank installed.

It's pushrod is .062" m/w. My Dad always paid attention to having a good solid pushrod support in his models.

The lead-out guide concerns me actually. It just doesn't look very strong. Dad had also soldered his lead-out connections. I believe that you had mentioned this being a bad practice.    

It's good to see that he installed a 3" bellcrank. The cable through the aluminum bellcrank would be questionable as these like to saw through the bellcrank or through the cable. I've seen it happen both ways and in little to no time. I also fly one done like this which seems to defy all others and to date is still going good at least until it does fail which usually makes for a spectacular wreck. Sterling also used plywood which was poplar laminated. I've recognized that this ply over the course of time likes to delaminate. I've pulled the bellcrank screw right through it. All of this of course is speculation. A good pull test and one which flexes the arms of the Perfect bellcrank will tell you if this model should be flown. It either holds up or your bellcrank comes out the side of the plane. I wouldn't be concerned with the leadout guide of it's glued in well. Soldering lead out terminations is not a good thing, however that's how it was done back then. Time is the killer here as flux works it's way into the strands of cable and deteriorates it. It also makes a hard point in the cable where the strands fail rapid just outside of the termination.

I don't fly or use any of the OS MAX steelfins other than a .15 I have so I can't comment on them. The ones I've seen seem to chug along pretty well. I personally would use the engine in it currently. The repairs required on that plane could be done in a afternoon. I would fly it but that's just me. I don't get too attached to something like this and if it does get wrecked I fix it.

The 36 inch wingspan 1948 Sterling Kit C-1 Monocoupe was a very early Sterling entry if not the first kit.
http://www.outerzone.co.uk/plan_details.asp?ID=5097


Then, model engines had less power and were heavier, especially the ignition types, hence the .19 - .35 range of engines. Roddie's father used Monokote, which tends to add weight to the model (versus silkspan and doping, which provided a lighter finish) contributing to tail heaviness. It still is a very nice plastic covering job, if not the best. Plus, it could be that the wood used was also heavy.

The OS Max .25FP-S is an overkill for this size of plane. With the smaller wingspan, an OS Max .15FP-S or Testors McCoy .19 Red Head would be a better choice, IMO, or one could under prop the .25, put prop on backwards and run the .25 very rich, or put it on longer lines. (I like the longer lines better. )

I think once repaired, it will make a fine sport flier and one to be admired.
It sure is a purdy plane.

Wow I missed this topic somehow , Roddie the plane at least is in good hands now and can be appreciated again and that means a lot . Fix it up take the engine out and check it out , run it // I think your Dad would be proud to see you have it and fly as it was intended . I believe you would re-feel the joy also . Just my thoughts. Eric

getback wrote:Wow I missed this topic somehow , Roddie the plane at least is in good hands now and can be appreciated again and that means a lot . Fix it up take the engine out and check it out , run it // I think your Dad would be proud to see you have it and fly as it was intended . I believe you would re-feel the joy also . Just my thoughts. Eric  

Hey Eric, it's currently hanging above the cloths dryer..  a constant reminder for my wife..

But seriously.. it should be flown; as-built.. and in his presence.. at least one time. He came to my 1st band gig of the year last night.. but we won't see each other today. He's coming up on 80 yrs. and his health isn't too good. My Uncle would appreciate seeing it fly too. He and my Dad flew together in the early 60's. They live 5 miles from each other. There's a good chance, that if we all wore black suits and dark sunglasses.. we could probably pull-off flying it where they used to fly together.

I have some structural concerns with the model. As you can see in previous photos.. the outboard wing-strut came off. It didn't "break off".. but it needs re-gluing. Structurally; it doesn't look like the butt-joints provide much shear-strength at the wing attachment point. A rough landing would surely break them.. or at least break them loose.

The fin/rudder is loose to the stab.. flopping by stretched monokote. I pinned the fin/rudder on my Rare-Bear with two toothpicks.. using a drill in a pin-vise to make the holes. The toothpicks I cut to approx. 3/4"L. and installed the butt-end in the fin.. leaving the pointed end to punch-mark the locations to drill the fuse. The pointed ends guide the pins into the fuse-holes.. and really strengthens the fin.. once glued-in.



The Monocoupe's  fin..



Dad used DuBro pin-hinges on the elevator. Tedious work.. I've used the small size on several 1/2A models. Now would be a good time with these tail-feathers off, to run an iron over those wrinkles using the edge of a table for support.

Roddie, it is great that your father is still alive and as a tribute to him, I'm sure you'll figure out what repairs are necessary to ensure sufficient strength yet retain the character he had in the plane as he built it. Those struts are probably more for decoration than they are for structural strength. You may have to do some covering removal, but with closely matched up color films and touch up paint, I'm sure you'll do it justice.

If you're doing 3 second laps at 50 feet, I'm sure you'll figure out by repropping / reverse propping / longer lines have very successful flights to get that down to 4.5 to 5 seconds including a couple simple stunts just to show the old gal off.

Those OS FP-S engines are good reliable engines.