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Danny Fenton
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Thanks, I think I understand it now. There is a lot of confusing `looking down through a convex shape` on the plan.

Currently working out how to eventually get the rudder fitted and aligned with the torque rod while everything is coated in epoxy, so have embedded a brass tube in the base leaving just the hinges to glue in. In my case the rod is not fixed vertically otherwise, and is critical to clear the elevator rod and tail wheel springs.

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Getting somewhere now. With a lot of work over the last couple of days I have the rear end done as near as I can get it. Just applying the second coat of filler. Those little strips on the side of the fus. in front of the tail appear on full size pics but not on the models I have seen so far so I have fitted them.

Since the canopy is in green I shall do the camouflage colours to match it, not my first choice but at least I already have most of the paint. Itching to get on with the glassing and the cowl but not quite there yet.

chipmunk 031.jpg

chipmunk 032.jpg

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Martin looks really good. Be careful here, the plan is for a DHC1 there are very few of those flying. Most are T10 or later 22. In fact i only know of one DHC1 still around, G-AKDN.

The early version has dual elevator trim tabs a narrow rudder and no anti spin strakes in front of the tailplane. The roof of the canopy is different too.

However only anoraks like me would know

Cheers

Danny

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Colin is correct the wider chord rudder and strakes were brought about to deal with perceived issues with spin recovery.

I have a couple of docs that I am happy to share with peeps, but as they are both PDFS this forum cannot help us here. So if you want to read them drop me a message.

here is the cover page from the Australian document::

spinning cover page.jpg

Cheers

Danny

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Throughout its long career, there has been debate about Chipmunk spin recovery, despite modifications and the Canadian built planes having a re-designed elevator. In one case the pilot in desperation at the plane’s refusal to come out of the spin opened the canopy (to jump out?) and it immediately recovered! There could be aerodynamic reasons for that, it’s a lot of surface area moving backwards. Here’s one of the original Canadian development planes after a problem trying to recover from a spin, the crash that started the whole thing off. 2a951d4d-556b-49a7-abf1-c9b6b9d2322b.jpeg

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Thanks for that. I found a clear pic of the rhs which may be another aircraft repainted, around 1970. I assume that the underside is light grey? No good lhs or top view of the wing as yet but will google that reg.

Currently trying to carve the plug for the glass cowl; I have never seen such a pile of shavings. Best part of a plantation of precious balsa trees used up but since this has an overlap (vowel?) I could not use my normal method of making it whilst attached to the fus. Even when this is done there will be a couple of weeks` work to get a result.

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Had a look at that reg. as suggested and now have good pics if each side. I may need to guess at little at the wing which seems to be in olive drab and a brown rather lighter than dark earth but this could just be the pics.

Pics of said plug now ready for final sanding prior to applying 25g cloth, plus one of the servo installation. I have not compromised this in order to get the seating in.

Got some of the Fighter Aces cloth to see if it goes round compound curves better than the HK stuff.

chipmunk 034.jpg

chipmunk 035.jpg

chipmunk 033.jpg

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  • 2 weeks later...

The cloth went on OK, and the fus has now been sanded and coated with Halfords grey primer then sanded back again. By far the most tedious glassing job I have done, especially the rear end. The wing has been done with a lot of my precious stock of `tex which is now rather depleted. After doing a successful test piece I shall mask off the LE and give it a coat of primer to simulate a metal skin. Because I will be using a Failover Switch I have had to make a hatch cover for it on the rhs. I bought some pinking shears but the smallest available were 3mm and it will not look right so have ordered the proper stuff at an eye watering price from MRM. While I was on the site I found some Chippy cockpit dashes of the right size so ordered these too to replace my paper ones.

I have my fingers crossed for the cowl, now residing in the airing cupboard to harden. The female part of the mould was rather reluctant to part from the plug but I got there in the end.

I have looked at some more pics of the army version and think that the brown parts are in khaki, not dark earth, so got some on order.

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Eventually got that cowl out of the mould, but what hard work it was. A small piece sticking to the female around the nose was the problem but easily filled. Despite increasing the size compared with the fus in the appropriate places it was a very tight fit with no gaps at the sides or bottom so after adding some internal sheeting I sanded down the top and bottom so that the sides squeeze out a little. Best I could do. Spent the last two days trying to fit the cowl fixings, tank, plumbing and remote glow lead, then found that the cowl would not bend enough to clear the latter two so had to reposition them. I have managed to hide the silencer completely and hope that I have enough cooling, but if not I could add baffles and enlarge the exit holes.

Pics show motor installation and the cowl simply pushed over; also the switch hatch.

I have left off the fin strake for now too avoid it getting damaged.

Been hunting down some pics to find out where the main riveting is done so guess what will keep me busy for the next few days.

chipmunk 036.jpg

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chipmunk 038.jpg

chipmunk 039.jpgchipmunk 040.jpg

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Hi Geoff,

I said PVA because everyone knows it,any brand would do but changed to aliphatic because it sets quicker and harder. Don`t try canopy glue. On this model I am trying a joiner`s wood glue from Howdens (trade only) which sets very hard and quickly and seems rather easier to use. All must be diluted slightly with water and you need to experiment to get the right consistency. Pic below.wood glue 001.jpg

wood glue 002.jpg

wood glue 003.jpg

These are the applicator tools I made. Not my idea, thank TN. Note the slight curve on each so that they can be rolled on. The first is made from piano wire, ground to a slight cone at the ends and soldered to a couple of pieces of 0.1" pitch Vero board. Second is similar but using larger wire at 0.2" pitch with a staggered double row. Third is from tubing, only used on tissued surfaces where it can be dug into the surface, no glue needed. Got the pics on the PC but not on this site yet! will come back soon.

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Here they are. The last shows the glue in a tray. Note that I have dragged some up from the main pool to form a thin layer above. This is what I dip the tool onto. Constant cleaning of the applicator is required.

 

chipmunk 044.jpg

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It may all sound rather complex but that tail only took a few minutes to do. For large, widely spaced rivets I use a cocktail stick with a bit chopped off the end.

Edited By Martin McIntosh on 28/12/2020 15:02:30

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