Here is a list of all the postings Andy Blackburn has made in our forums. Click on a thread name to jump to the thread.
|Thread: Hangar 9 Showtime 50|
The usual u/c fix seems to be
1. BEFORE ASSEMBLY, examine the undercarriage mount
2. If it isn't at least 6mm good-quality ply, take the covering off and replace it with 1/4 inch aircraft-quality ply.
Of course, we shouldn't have to do this...
About a year and a half ago I bought a Hangar 9 Showtime 50 as my first I/C model for about 20 years; it was a nice model with very good manners and reasonable performance with a an OS 55 AX, but it was quite heavy and could really have done with something like a Saito 82.
However, the undercarriage wasn't well thought-out. The supplied wheels and spats were far too small and were thrown away in favour of a pair of 3 inch wheels. The undercarriage legs are very long but the undercarriage mounting plate is two layers of laminated, fairly soft lite ply and just isn't up to the job; I damaged mine after a slightly heavy landing which should have resulted in nothing more than some slightly bent undercarriage legs.
Rather than repeat everything here, the full story is on a Showtime 50 Undercarriage thread at the Slough club website, but the damage was obvious when the covering was stripped away:
I had to make a replacement undercarriage mounting plate and a doubler for the front former from 1/4" ply (to the accompaniment of much bad language) which were installed with 30 minute epoxy, and this did the trick.
The only other real gripe I have is that the recommended engine size is "2-stroke .40-.52, 4-stroke.56-.82". This is just fanciful nonsense - a 6 1/4 pound model of that size is not going to have a "remarkable 3D performance"
on a .40.
I am vastly unimpressed by the design of many ARTFs - superficially they're nice and shiny and the instruction manuals are usually impeccable, but sometimes they're just not fit for purpose.
Edited By Andy Blackburn on 10/07/2009 12:37:52
|Thread: OS 46 LA inverted, won't idle|
After much faffing around, it looks very much to me as though the issue is with the fuel tank height - on close inspection , fuel is dripping from the spray bar and I think the tank is just just too high for an inverted set-up with an engine that has a cheap carb, it might or might not be any better with a more sophisticated engine.
I've got it to the point where the top end is fine and the idle has been adjusted to be as good as it's going to get, using the procedure described in the O.S. manual. However, it still stops in flight after about 10-15 seconds of idle, or when spinning (this after testing with a variety of plugs, including an O.S. A3 and 8, and a Taylor plug with an idle bar). I must admit, if I'd had a box of matches at the field today I'd have rescued the 2.4 GHz Rx(es) and set fire to what was left .
|Thread: Fokker DVII by Flair|
That looks really fantastic! Glad the first flight went OK.
|Thread: Building the Balsacraft Hurricane|
> Any questions or comments from all welcome.
You did ask!
I had one of these a while back for slope use, it was a really nice build. I eventually flew it into a barbed wire fence and gave away the bits. It went like the clappers off the slope but there's a couple of things that you might like to be aware of.
1. The wing bolt plate pulls out at the slightest opportunity; this is a fault,if it was meant to break in a crash it'd have been a frangible bolt plate arrangement as on the phase 6. I seem to remember that I used some 1/16" ply cladding on the outside of the 2mm ply box structure (which always seems to break at the corner of the "lightening" holes), and bonded everything in place with white glue and lots of 1/2" triangle stock.
2. The fuselage is a bit weak. I fixed mine with two bits of 1/4" x 1/8" spruce in the corners of the battery box, extending from as far forward as possible to aft of the former at the wing root trailing edge. You might be able to do something with some smaller-section carbon rod or tube.
3. The wing has been enlarged but - as far as I can tell - the tailplane hasn't been enlarged to the same extent, it at all. The real one wasn't stable in pitch anyway which was partly why it was so maneuverable, and I couldn't get the c.g. of the model aft of about 28.5% MAC without it becoming unstable. The side effect of this was that it required constant re-trimming and tended to lift its nose in lift - like the real one, it had to be 'flown' all the time. This behavior might not bother you but if you have any doubt, a slightly larger tailplane wouldn't hurt. It might make the enlarged wing a little less noticeable as well.
|Thread: Pick a plane 2009|
> Electric is the way to go - its now cheaper than ever.
But is it cheap enough? 100 cycles from LiPos if you're lucky?
There are other, more significant issues with electric
a) LiPos take forever to charge (each one takes over an hour on my 6-330d);
b) You have to keep an eye on them whilst they're charging;
c) Each pack provides a flight of only 6-10 minutes, depending on throttle use.
I don't think the preparation time vs. flying time equation stacks up. For that reason, I'd rather whatever subject is chosen be designed for I.C. as well as electric.
What about a biplane? In no particular order;
I'd rather fly i.c., but If you design them for electric I'd prefer something that'd suit 3 cell LiPos or equivalent -I haven't got anything bigger.
|Thread: The new Nijhuis Hawker Hurricane|
> what colour scheme to do????
I've always thought that the desert schemes were most attractive but if you're not going to have a vokes filter, what about one of the Mk IIc night intruder schemes (dark green/medium sea grey topsides, black lower surfaces, code letters sometimes red e.g. LK-A, JX-E).
|Thread: OS 46 LA inverted, won't idle|
I believe the OS 46 LA manual reccommends that you turn the air bleed screw "...half a turn at a time...". Does that sound about right, or not?
I've taken the engine out and checked the backplate (which was OK) and the carb (which was secure, with both screws present). It's not the plug (tried several).
I'll look at the air bleed hole and the main needle over the next few days, if that doesn't work I'll try an OS type F. I have to say, though, that it looked more like a fuel issue than a plug problem...
Thanks for the suggestions, I'll fettle it over the weekend and probably try another run next week. BTW, tried 3 separate plugs without success.
It did subsequently occur to me that the carb air bleed hole might be blocked. Or maybe the needle is bent?
I have a second-hand OS 46 LA bought from a fellow club member, mounted inverted in a Great Planes Venus 40; starting is OK although it occasionally starts backwards when starting by hand. In its previous incarnation, it ran fine when mounted upright.
Full power looks OK (about 11,000 rpm on an 11 x 7) but the problem is that it just won't idle for any length of time, even when set quite fast (3-4,000 rpm). The idle is a bit erratic anyway and gradually gets slower over the course of about 20-30 seconds and then it stops. If the throttle is opened before it stops it hesitates and there's a lot of white smoke from the exhaust so it's clearly running far too rich, but no amount of fiddling with the carb air-bleed adjustment makes any difference at all. The fuel system is as per the kit (3 line set-up), and the tank won't fit any lower.
Something is clearly Not Quite Right, but I have no idea what it might be. Anyone got any ideas?
|Thread: Pick a plane 2008|
My top three of the top 12 on the shortlist:
1. Mosquito (preferably Mk XIII, with retracts).
2. Hurricane (with retracts).
NOT the Whirlwind. Sorry.
|Thread: Pick a plane 2008!|
> Lots of people are asking for plans that are easily available for a few £, $ or €.Or even plans that have been published as RCME free plans within the last decade or so.
Personally, I think it's OK to vote for models that already exist; if a model is popular, it'll probably have been "done" many times. And the perfect plan has yet to be drawn...
My votes are:
1. Hawker Hunter (EDF) - maybe the two-seater to be a bit different (please use a proper airfoil so that it can also be flown off the slope)
2. Folland Gnat (EDF
3. Fairey Flycatcher (electric, maybe 3s/10 cells)
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