Here is a list of all the postings Peter Jenkins has made in our forums. Click on a thread name to jump to the thread.
Peter, once you have flown and aircraft successfully, ignore measuring where the CG is and just follow the advice that Robert Welford has given. Measuring CG accurately is not especially helpful as the optimum CG position will only be found by flying the aircraft and adjusting the CG to meet the criteria set out. Once you have established the optimum CG by experimentation then by all means measure it accurately to allow you to return to it if you ever make any major repairs or change equipment.
The single most powerful trimming tool we have it adjusting the CG position. Any CG position given by a designer will only be there as the starting point as each aircraft will be different.
|Thread: Mick Reeves Gangster 63 Lite|
If you are still searching for a colour scheme for your Gangster, here's what I did for my Gangster 75 which I built from an unbuilt original kit. This is a foam wing and unfortunately is made out of rather heavy foam. All the covering was either Solarfilm or Hobby King sourced. In the air, the scheme is very easy to see with great differentiation between the top and bottom pattern.
|Thread: Daks Over Normandy|
I also went to Duxford today. Sad that it took 2 hrs to get the last 2 miles to the car park. I guess I underestimated how many people would attend a mid-week event at Duxford and this event in particular!
I agree with you Jon about the massed formation but all became clear when I consulted by rain app and found that there was a front with heavy rain traversing the whole of NW France. It would have been helpful for the commentator to say so! I suspect that given the 2 hr delay in the take off, there was no time to waste in building up the formation prior to flying across Duxford. As you say, a bit of a shame, but quite understandable in the circumstances. I overheard a conversation with one of the parachutists (who I have to say looked pretty large to be a jumper!) and he said the flight time was 2 hrs to the DZ. That would mean they would be jumping at around 7 pm BST!
I did get some nice shots of Spitfires - one of the best formation aerobatic shows with a pair of close formation Spits:
the P47, beautifully displayed by Paul Bonhomme
and a Martlett, as flown by Winkle Brown when he was flying fighters off a flat top for the Fleet Air Arm.
|Thread: Model flying Ooop North...|
Have you tried the BMFA Club Finder?
|Thread: Beginner scale model flying resources|
Chris, you will learn an awful lot on how to set up a model by attending one of the Aerobatic days at Buckminster. Its worth trying some aerobatics as you may choose to fly an aerobatic scale aircraft. Also, it will get you used to seeing your aircraft at odd angles and how to recover safely from them. That will help your flying to improve when you fly scale models.
|Thread: Interesting reply from email to Richard Moriarty, CAA|
Chinese whispers again Percy?
|Thread: Cambria Slingsby Eagle Restoration|
Nice model but is it really a Slingsby Eagle? The full size was a 2 seater with the instructor seated behind the wing leading edge and the second canopy opening upwards - you closed that one first before the side hinged front cockpit. I know all this because I learned to fly in a Slingsby Eagle - aka the mahogony bomber on account of its weight! Sorry to be picky but it ain't an Eagle especially with dihedral outboard of the centre section.
|Thread: CAA registration consulation|
Done the consultation, written to the Baroness and Moriarty on 100 gm paper(!) and sent by snail mail and emailed my MP. It would be interesting to know how many BMFA members have actually answered the Call to Action and done all 4 actions requested. I do hope it is at least 70%.
Charlie, as a new member of the BMFA, you may not be aware that you can go on their website to the News Page and register with your name and email address and get sent News bulletins, the latest of a long line of which deal with the issue, has just been published. You will then be able to keep up to date with all the work that the BMFA has, and continues to do on our behalf, with the CAA, DfT, EASA and so on. You may even find that the Area to which your Club belongs has a website that has some useful information on it as well. As you have just done your A Test, you will be familiar with the BMFA Handbook. That contains details of how the BMFA is structured. Your Club Secretary should be able to tell you in which Area the Club is and you can find the Area Website by going onto the BMFA website and navigating via "The BMFA", then "Areas" and look on the right hand side half way down. Most Areas have a website.
Hope you feel that the BMFA has indeed been actively pursuing our interests since it was formed and, on this topic, ever since EASA first published its intention to legislate on enabling airspace utilisation by drones a few years ago.
That having been said, we now need to show that all BMFA (and LMA, SAA and FPV UK) members care enough about this to respond to the CAA consultation but please check you have the facts right before doing so.
|Thread: Holding screws in|
I slip a bit of fuel tubing over the bolt but with a washer between the bolt head and fuel tubing. When tightened, the fuel tubing provides sufficient pressure to stop the bolt loosening and falling out. I've used this to retain the canopy on a Capiche 140 with what has to be the roughest 4 stroke 180 made - Saito! The bolts stayed tight all day. Cheap and very effective.
|Thread: Build your own telemetry sensors.|
Do you know if this will interface with a JR XG system? I have a brilliant little sensor pack made by SM Modelbau called UniSense E. They cost Euro 70 so I've only got one! It would be nice to build a few more but only if they work with JR radio kit.
|Thread: Forum members' new models: Let's see them.|
I think I'm the 4th owner of this Loaded Dice III. This is the 2 mtr free style version of the Loaded Dice stable. It now has an electric drive train. This provides 2,500 watts of power at 65 amps on a 10 cell pack. The retracts are EFlite 120s, installed by the last owner, and they work reliably. The biggest difference between this aircraft and current F3A birds is the side area of the fuselage and so it requires much more rudder movement for both rolling and knife edge flying which is as expected. Apart from that, it's a lovely model to fly.
|Thread: Infinity 90 Build|
Cymaz, sorry, I clearly didn't read your words closely enough. You can still use the bar for the tailplane incidence but you do need the elevator servo powered up to avoid the elevator dropping with the weight of the bar and sensor. As you say, time was short but thought it worth mentioning as others may not realise that just using a sensor with a very short measuring length will lead to significant inaccuracies.
Cymaz, you would get a more accurate reading of incidence if you use a bar with clamps that centre the TE and LE as in the photo below. This is a Robart incidence meter and it is also available as a digital readout meter.
In this case, it is a Gangster 75, the aircraft was specified as 0 deg for tailplane, wing and engine down thrust. Side thrust was 2 deg but I've since increased it to 2.5 and it looks like it will need almost 3 deg to go straight up.
Bruce, there is no absolute downthrust setting. You just keep adding down thrust until when the aircraft is trimmed for half throttle, or possibly a bit more, you do not get any pitch up or down when you smoothly apply full power. That is until the aircraft has accelerated sufficiently to increase the lift being generated by the wing when it will start a gentle climb. Equally, when closing the throttle, you don't want the aircraft to pitch up or down as the throttle is closed.
On my Agenda, which has an electric contra drive, the setup is -1 for the motor, +1.5 for the wing and zero for the tailplane which happens to be an all flying tailplane. There is no side thrust in this instance as the contra prop removes the need for any.
Hope that helps.
Edited By Peter Jenkins on 16/04/2019 23:53:59
Cymaz, I would recommend that you alter the engine downthrust rather than use an elevator/throttle mix. Why? Well, the elevator/throttle mix cannot be right for every speed and power selection situation whereas with the correct downthrust you will not have that problem. On the other hand, if it's a devil of a job to alter engine down thrust then the mix may be a simpler, but not the best, route. Presumably the side thrust is OK otherwise you will again have the decision of alter the side thrust or mix in some rudder.
|Thread: Taping Aileron and Elevator|
Geoff, I've used Robart pin hinges for a recent build. The ailerons had to be top hinged with required drilling without a guide but provided you mark both the wing and aileron with where to drill it was no problem. The rudder and elevator needed to be centre hinged and I used the Robart drilling jig to provide the centre. It was a piece of cake! Worth investing in a Robart drill jig to make the job really easy.
|Thread: DLE 2-strokes|
I should have said that it might take a little while before I can get the noise test re-done!
I have a DLE35RA in a 2 mtr Majestic aerobatic airframe. There is a large belly pan in which to hide a canister. The first canister was a cheap (£35) off Ebay but a much better option is a JMB Can which I got from IAD Designs. The difference in sound is quite impressive. The engine was turning an 18x10 Falcon Beechwood prop at around 8,000 rpm. On the day I did the noise test, the only reading over 82db was with the airframe facing the noise meter. I think that was primarily due to a strong wind blowing into the back of the prop. It would have been interesting to have swapped around so the wind was blowing into the front of the prop and re-tested but time was short so we didn't. Vertical performance was not unlimited!
Having said that, there is much more power with a 17x10 which pulls 8,400 static and gives good vertical performance but not quite up to my electric 2 mtr standard. The engine has now accumulated a lot more running since the test and I may try the 18x10 and 19x 8 for performance again before submitting them to a noise test. It would be really helpful to have a sub 82 db machine for the noise sensitve field I sometimes fly at but there is no point in doing that if the vertical performance is poor. The empty weight of the airframe is 5.4 Kg and it has a 12 oz tank that is good for 14-15 mins. I'll post the results when I get them.
|Thread: Infinity 90 Build|
Congrats. Now you can start the trimming process and then on to aerobatics! Look forward to hearing how it performs.
Well done on the fault finding. Will go and check the condition of the wires into and out of my CDI!
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