Paul Jefferies

Flying fullsize is not necessarily more difficult than flying models but it is different. The "feedback" is completely different and there is a lot more to take account of, particularly your speed, height and engine parameters. These things have to be constantly monitored as well as looking out of the window and enjoying it! There is absolutely no reason why any reasonably competent model flyer should not be able to fly a 2 seat Cessna but he couldn't just jump in and blast off without any instruction......... Or at least, I wouldn't want to be in the other seat!

Should you want to try two pack (polyurethane) varnish, it is readily available in yacht chandleries....... though I haven't tried it on top of cellulose. It ain't cheap though. Paul

You have certainly achieved your aim of making it look sinister, I too will be interested to hear how it flies....... The only time I tried a canard, it was a very different type of design, more like a powered glider. It was the best part of 30 years ago now but as far as I remember, the C of G needed to be much further back than I had guestimated but I did eventually get it to fly. It was stooging around quite sedately when it suddenly looped violently without any initiation from me! The thing about canards is that they are inherently unstable in pitch........ In a conventional (stable) layout, the tailplane has a downforce on it which opposes the nose down pitching moment of the wing as the speed increases. Being an aerodynamic force, AS the speed increases this downforce also increases which pulls the nose up and in turn stops the speed increasing further........... This gives stability in pitch. In the case of a canard, both the wing and foreplane are lifting, so in an upset, you have to be sure that the foreplane will not "take over" and cause such and increase in pitch that it loops! Unfortunately other things came along and I never did persue that layout but I think the C of G needs to be fairly well back so that there is not much load on the foreplane........ Mine had a lifting section on the foreplane and it was definitely lifting too much! Do let us know how you get on and where the C of G ends up.......   Paul Edited By Paul Jefferies on 26/01/2014 09:51:48

It does sound as though it is overheating, perhaps it is just not run in yet. Some engines can take several hours running before they are properly run in. You say you have run it on the bench....... For how long? In the air it will unload and reach higher revs and probably higher temperatures than on the bench. Try some more bench running and after an hour or two, if all seems well, reduce the size of the prop in order to increase the revs/temperature....... and of course go back to the bigger prop when you put it back in the model. Paul

Alan thanks for taking the time to reply. Yes I think you are right that it will be safer to continue using only castor based fuel, probably in my more modern engines as well. I have no problem with castor based fuel other than the gumming up problem if the engine is not used and I am told that synthetics are somewhat cleaner........ ie. less goo to be cleaned off the model after flying. Perhaps I need to find a good "afterrun" to squirt into the engine which will prevent it from gumming up...... any suggestions? Paul

No, I didn't deglaze it because I thought it is an old engine and the glazing must compensate for some of the wear. The ring appears to be free so I tried it and it runs well so on the basis of "If it ain't broke don't fix it" I decided to leave it. Should I deglaze it?

Alan, many thanks for that. I had a feeling that there might be something like that but I couldn't remember what it was! So is it only engines with cast iron pistons that should not be run on synthetics? I have a venerable OS40FSR which was badly gummed up. That has an alloy piston with a ring and I have freed it and put new bearings in. It still runs well on castor fuel, would it be safe to use a synthetic based fuel in that?

I am getting back into the hobby after a long layoff and have been digging out some of my old engines. Having stripped and de-gummed them they seem to be ok but I would like to prevent the gumming up happening again. I understand that fuels that use synthetic oil are must better in this respect but could there be any problems in using synthetic oil in old engines which have previously been run on castor based fuel? Paul

Thanks chaps, it looks as though he's buying the beer

Does anybody remember Tony Lunt? He now lives in the States, is still model flying but is currently over here and has been staying with me for a few days. We have been drooling over a number of old plans, including the Mustfire. The plan I have shows a conventional wing structure but Tony is adamant that the one he built in the 60's had a diagonal wing rib structure. I am not (quite) senior enough to argue with confidence but.......... Does anybody know if the original Mustfire had diagonal wing ribs?...... There is a beer in the balance here! Edited By Paul Jefferies on 30/12/2013 14:52:46

Thanks everybody for taking the time to reply........ I was afraid you might say that but I thought there was no harm in asking....... I was kinda hoping that somebody might have already done the same thing and found it to be OK. As you said Steve, MK were very good props and I have several of them but the risk is just too great. I also have some of the really lovely OPS wooden props (12x6). They seem fine and I think it should be safe enough to use them...... provided of course that they haven't got woodworm! Or do people think I should chuck them too?  I will have a look at the XJF etc that you suggest.   Paul Edited By Paul Jefferies on 28/12/2013 14:08:32 Edited By Paul Jefferies on 28/12/2013 14:10:15 Edited By Paul Jefferies on 28/12/2013 14:11:15

Following on from my question about the strength of the glue on old models, I started the refurbishment today with the engine and started that by removing the propeller.... Over the years I tried quite a lot of propellers in an effort to find which gave the best performance/noise combination. The particular prop in question is an MK Glass prop which I think is some kind of glass reinforced nylon and I have several of these as well as the more usual grey glass/nylon props and many wooden props. Most of these are between 25 - 30 years old and like the model, have been stored in the loft for much of that time experiencing the usual extremes of temperature that happen in your average loft. Has anybody used such old propellers? Will they be safe to use? Edited By Paul Jefferies on 27/12/2013 22:56:07

Many thanks for your comments and suggestions all. I had more or less accepted that this model would never fly again but you have at least prompted me to have a closer look at it and yes, I will have a go at refurbishing it. I have invested in a 2.4Ghz outfit so yes, I will upgrade the radio though the old servos (JR 4002) were fairly good in their day and still seem OK. I will have a good look at the switch harness and yes, probably replace that too. I think one of the most difficult things to refurbish is likely to be the Rom-air retracts...... All the plastic plumbing has gone crisp and some has even snapped off! 'don't yet know about seals etc. As I said in an earlier post, I have another project on the bench at the moment but 2014 promises to be an interesting year........ Happy New Year one and all! [Edited at Poster's request] Edited By Biggles' Elder Brother - Moderator on 27/12/2013 18:48:45

This is she..... freshly ironed! It is suffering a bit of "Hanger rash" (or perhaps I should call it loft rash) and I have found some delamination between the fuselage sides and ply doublers which I think should be repairable but apart from that and the fact that the engine needs de-gumming I think it could fly again. I think the thing to do will be to take it over an open piece of land where there is nothing to hit and do a few flick rolls and if it survives that then I think we can assume that the glue is still ok. From other parts of this forum I see that the cutoff date for "Classic" models is 1986........ This flew in the 1987 season but was designed and built during the winter of 1986/7. Does that qualify?

It was (still is!) an own design with balsa skinned foam wings and a balsa and ply fus. OPS .60 rear exhaust + pipe. It was called "Symphony No.3" but I don't have any pics. I will dig it out and iron it (Solarfilm has gone a bit wrinkly!) and post a pic in the not too distant future.

Thanks chaps for these replies. It was a good model so I will try to refurbish it. I have another project on the bench at the moment...... I will let you know how it goes "in the fullness of time".

Hi Folks, I am trying to get back into model flying after a twenty six year layoff. I used to fly aerobatics (or tried to!), my last Nats was in 1987. It is nice to see that there is still an interest in the old designs and that some of the "old faces" are still around......... and still building beautiful models Terry! I still have the model I flew in 1987 but I have not flown it mainly because I am a bit nervous about the strength of the glue after all these years! It was built using both cyano and PVA. So I am prompted to ask....... Has anybody flow an aerobatic model of this age? It needs a little TLC but if I did refurbish it, could I expect it to hang together when I start pulling G? Paul Jefferies