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Member postings for Chris Walby

Here is a list of all the postings Chris Walby has made in our forums. Click on a thread name to jump to the thread.

Thread: Cambrian / Cambria Funfighter-----which to choose!
24/06/2019 12:05:44

I went for a Cambrian as I didn't know of the others (sorry and they are local to me! could have saved the P&P).

Nice kit of bits, instructions had a few extras/missing bits but not an issue and went together easily.

20170201_220001.jpg

Now here's my problem (mine) I wanted something fast, hence it high visibility colour scheme. I have totally maxed out my 1700KV 48A power train and it is not that fast....If you want fast try an EFXtra!

Good news is it flies very nicely, is tough as old boots and eats a lipo in under 4 minutes at full throttle.

Not so sure how much "fun" it will be in windy conditions

Next time I will go for the "other" manufacture (thinner wing section & local).

Thread: Laser Engines - Technical questions
22/06/2019 07:04:04

Martin, I can't really speak from experience, but picking up info from the SG Hurricane thread and Jon's comments I was not expecting mine (Hurricane) to be anything but throttle/pitch sensitive. I am sure Jon advised me to trim at around 1/2 throttle for level flight and use the elevator for other settings.

I appreciate if its really bad it might need adjusting. Good luck wit the Spit and let us know how you get on

Thread: RCM&E Fly-In 2019 - general chatter
21/06/2019 10:34:43

A - Better pull finger out and finish my renaissance

B - Book a camping spot

Flew there a couple of years ago and it was a great day (thanks pylon guys for puting up with the slowest model!)

No pressure...could do your A on the day....with your Renaissance ! cheeky

Thread: Good news thread.
21/06/2019 10:04:05

Placed order with 4-max, George let me know there was a delay with some parts by email.

Emailed and then phoned to find George was under the weather with a cold, but said their supplied had just delivered and would dispatch.

Parcel arrived with full parts ordered by 9:30 today and I only spoke to George yesterday !

Should have a enough Lipos to fly 4 Nutballs 6 times in an hour (pilots permitting!) - The Scouts will be pleased!

Nice weather...days holiday....just got to head off to the field!

Thread: Laser Engines - Technical questions
13/06/2019 06:46:23

Now that looks a nice model and I am sure with the 180 in it the will sound just great...please please build thread wink

12/06/2019 22:51:51

...most important question...what's it going in...?

Thread: Seagull Mosquito Laser build
10/06/2019 12:46:06

Jon, If you don't have a pair of 70's you could drop the lead/tail wheel lump and squeeze a pair of 80's in. The bulkheads have to be moved back anyway, so it would only be the tanks needing a bit of a tweak. Don't get me wrong the 70's are more than okay, just best if kept 3/4 to full throttle to keep her hustling along.

Don't forget there's a try before you buy offer from me just in case your on the fence....wink (Free with any hurrie maiden).

10/06/2019 09:59:20

Once I found out what I had done with the mixes in my TX and got rid of the throttle cut feature that was screwing things up (could not inhibit the knob on DX8g1) I decided to leave it as it is.

I'll need to take the cowls off and while I am doing that I change the linkage to adjustable clevis set up. Winter project!

I think I'll try Jon's suggestion of setting it up with WOT at 100% servo travel, then sub trim at shut is good advice (not that other is wrong) as I am a bit nervous of putting anything solid down the carb inlet and closing the barrel against it. Not an issue with a gentle finger, but if I forget/mess up and drive a servo against it, it may do it some harm.

PS the twin set up is super easy on my DX8g2 (with no mixes) + they are running in sync now so not an issue. Just spending more time fixing the U/C, but that's mu fault!

10/06/2019 07:47:44

Sorted the TX out and have since found a much more elegant way of doing the mix, but that's for another day.

Yesterday was all about having some real fun (although still getting used to this war bird) with the wide sweeping low pass. Climb out and perhaps a cheeky slow roll.

Tried a big loop and just kept the power on until well over the top with no issues.

"Black Rufe" on a low pass (credit to Dave for the photo)

img-20190610-wa0000.jpg

Landing was pants, but that's just me as it sent the warning message out and I just backed off the throttles too quick, caught out by something that lands short ever weighing this much wink

Once again thanks to all that have given advice over the build and flight.

Thread: RPM Conundrum
09/06/2019 21:53:46

My vote is with Trevor,

Example, I use standard, nanotech, and Graphene lipo and the battery voltage at full throttle drops less wit the Graphene hence the motor turns faster and absorbs more power.

As Scotty would say "You cannot change the laws of physics" and at least some of the additional consumed power should be turned into more speed.

On a different tack, if you wanted to bend the rules then reducing the models drag would probably produce a greater climb rate... especially if the model lost some weight...

The new lightweight gilder depending on the event might not work as well as its heavier brother...swings and roundabouts!

Thread: Electric Motor 'clunk' When Opening Throttle
04/06/2019 19:08:21

Off topic, sorry. Thanks TR, I thought as much...just can't find the time to take to swap the ESC's over...better get back to the mass build or should I pop my Laser 80 in it wink

04/06/2019 16:44:32

From stationary you are asking the ESC to accelerate the motor shaft very quickly and it might just be a feature of that type of motor where it produces a "clunk" as it starts. Same sort of thing when its wind milling as you are asking the ESC to catch the motor shaft on the fly and accelerate it.

I have a motor/ESC combination that really does not like that if the throttle is picked up too quick and makes a right squeal.

Only other issue was a motor that would once in a while do a 1/4 back turn before rotating as normal...found the problem on the maiden at WOT when the manufacturers motor connector failed and dead stick on me. Not nice as it was a war bird twin at lowish level!

As previous post could just live with it or change the motor and or ESC out.

Thread: The Difference a Prop (Pitch) Makes?
02/06/2019 06:43:10

IMHO, coarser prop gives higher top speed, but is less efficient at very low speeds + becomes "grabby". If you have a model with a high pitch its harder to control low speed flight (when landing).

12x6 and 12x8 are not that different, try a 10x10 and 14x4, that should be noticeable!.

PS if you don't need the speed (or keep the noise down for ic) go with the finer pitch....as George recommended wink

Thread: Daks Over Normandy
31/05/2019 09:08:41

Not sure how you find the route, but air space notifications look like this.

dak route.jpg

For the 5th so is this the route they will fly out to Caens?

31/05/2019 08:48:06

Will -0 the link does not work for me....and I don't think they are coming back for a few days...

Denis - which one of the DC3's/C47's has the transponder...or do all 35 have one each?

Can't miss this many Daks in one place, wink

Edited By Chris Walby on 31/05/2019 08:49:09

Thread: Seagull Mosquito Laser build
27/05/2019 09:18:06

Thanks Cymaz, I warm each one up individually and set the main needle WOT, then run both up and check they are in sync.

My problem is that I have each servo on a separate channel with a couple of mixes in to get throttle and throttle cut to work, Somewhere in there I have messed it up and the Aux channel does not follow the throttle for the initial 0 to 35% although it catches up by 40%. Adds to the excitement of taking off and I didn't think it would make much difference in flight...I hadn't anticipated doing an inverted stall test (top of loop!). I'll do what Jon suggested (teach me!) and set them on a single channel and spend more time mechanically setting them up. Live and learn.

20190527_082124.jpg

What I need is a simple and elegant solution that results in a clevis so I can tweak it by 1/2 turn to get them spot on.

PS I like your idea of a pin to set the throttles at the same place and that might get me close enough.

27/05/2019 06:22:44

Thanks again for everyone's input, I think I'll go for a combination of too slow over the top (tip stall) made worse by the engine imbalance at low throttle setting and a dob of cross wind as well.

The numpty on the sticks will have hopefully learnt his lesson which leaves some advice for the mechanical modification to do.

throttle servo linkage.jpg

The current arrangement is quite thin wire and barrel on the end of the servo arm. What I would like is a clevis, but I am not sure the best way of fixing the small diameter wire to a threaded stud for the clevis.

Idea's anyone please

I'll take some better photos and post

PS its the servo on the right behind the wires wrapped around the oleo (removed before flight!)

 

Edited By Chris Walby on 27/05/2019 06:25:51

26/05/2019 07:00:39

Thanks guys for all of the helpful advice and I agree with your analysis.

In preparation to flying the Laser Mosquito (my much needed experience of running glow and flying twins) I build the pair of 70's into a SG Dual Ace. Jon's advice has been very helpful throughout the entire process, but especially with twins and the general concept of always having a plan B in case something goes pear shaped. With that I mind practiced on the simulator with various engine cut scenarios.

Just as well as my electric BH Mossie suffered a loss of a motor on a low fast pass and survived by more luck and me not doing the wrong thing!

JD 8 I have not seen the RR299 footage for quite some time, but the way mine rolled in is very similar, just I had a lot more height on my side. My passion is for the wooden wonder and there are some interesting comments from Mosquito pilots about its flying characteristics, but equally its sting if things don't go well. There were quite a few losses on take off if one engine lost power. The additional drag of the prop and low air speed combined with the urge to apply more power from the good engine would end in disaster.

A reminder to me that it is not the Dual Ace by a very long way and that the greatest enjoyment often needs a proportional amount of effort from me (and respect!).

25/05/2019 07:59:28

With the impending rubbish weather forecast for this weekend and a couple on nice flights with my BH Hurricane the pervious day I though it would be a good idea to get the mossie out.

Last weeks engine test seemed to show up a port idle issue and minor idle to 1/2 throttle RPM difference where the starboard would not be consistent.

At the field the Dual Ace assembled and flew a treat although it was getting buffeted in the breeze (lowish pass roll and loops ok).

Back to the continuing aggravation with the mossie and with the idle and WOT set (good tweak on the port main needle had it all sorted). However it still had the idle to 1/2 throttle inconsistent pickup on the starboard engine of about 1000 RPM. I know what it is....between the mixes and different end point settings the TX delays the initial output on the aux (starboard) output.

The motto don't push a poor decision was well and truly ignored in part as this idle/pick up issue was just winding me up, the cloud had come over and the wind picked up , but the wind was straight down the runway so what the..lets just get on with it.

I can only say the practice take off runs installed little confidence with a couple of wild swings either way so another poor decision was made and I lined up and took off. Lively climb out and gear away with the speed picking up she circled around all be it with a couple lively roll/yaw moments (I put down to wind & slower airspeed).

Lowish pass and nice rolls complete I though I would try a nice big loop and was very slightly surprised with it twisting out of the top of the loopl, but that could have just been with a lack of rudder input. Another poor decision to continue.

At the far down wind end I thought I another loop would be nice, however at the top (might have slowed too much with the throttles backed off and it was slightly cross wind).

This is where it all unravelled and at the top of the loop it rolled and yawed into a very unpleasant spiral dive. It was quite a long way out and high so tricky to see in detail but looked like it was having nothing with the throttles up so I chopped the throttles and prepared for a very long walk with a couple of bin liners. At that point it stopped rolling (in the dive) so I levelled and got the power back on...circled and landed. Rubbish landing and bent the U/C pin/oleo block and retract mech, but nothing else.

The mossi is quite heavy and with a thick wing, but I can't see why it would yaw at the top of the roll so much even with the engines out of sync at the low end?

My initial thought was one engine had quit, hence leaving it in the dive, getting the air speed back and then returning to near full power to see if I could get her back to the field.

Can anyone explain the why it yaw/rolled at the top of the loop?

Lessons learnt

  • Don't mess about at the field unless the problem is fully fixed
  • If its not 100% don't fly
  • If it does something odd, don't give it another go just to see it will do.It might be worse the second time
  • Back to the shed and modify so that it can be mechanically adjusted to be in sync
  • Listen to Jon more
Thread: Gutted!
24/05/2019 11:00:31

Well done, I resorted to a very powerful bungee (25kg pull) to get the Vulcan off and it takes two to set up and launch.

So extra kudos for the leap of faith with the hand launch. smiley

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