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mmmdowning
11-15-2005, 01:41 PM
:D Has anyone recieved the Hobby People cataloge? It shows a 80 something inch wingspan. Its an ARF. It looks very sweet. I called and its listed to show up in mid December. But could be later. This is a beautiful bird. I have to have one. Keep bringing the oldies. (GOLDEN ERA)

donjiskra
11-17-2005, 09:22 PM
Can't bring it up on the internet.
Do you have any photos or details??
Thanks

mmmdowning
11-17-2005, 09:28 PM
I'll scan the picture in and post soon. I've never heard of the manufacture before.

Dereck
11-18-2005, 01:22 AM
Welcome to the pointy wingtip club!

Just bear in mind that the prototype was a blisteringly fast racer designed with the sole aim of going very fast for a long while in a straight line. I've seen the original, but it was grounded at the time as it needed a much longer into-wind runway than its owner (Old Warden / Shuttleworth Collection) ran to at the time. See http://www.shuttleworth.org/shuttleworth/ for an abridged version.

This is truly an aircraft that looks fast even when its in a hangar.

However. Any model that shape will be somewhat unforgiving. Not exactly unflyable, but extremely demanding. However, models of the 88 and its spiritual descendant, the Mosquito fighter/bomber, have flown successfully.

Having designed and successfully flown a Chilton DW1 with equally extremely tapered wings, here's a few areas I suggest you stick to lest the ground reach up and bite hard. CG is all important - too far aft, stall and those wingtips are going to squabble over who stalls first. The result can be from entertaining - a larger version of my Chilton could never get over a loop without snaprolling out off the top - to disastrous, if you tipstall turning finals...

Aileron throw - I engineered mine to be 90% up, 10% down. This, before computer radios, took some working at, but then again, I knew the design and build teams well :) This ensured I'd not get a downgoing aileron on a nearly stalled very pointy tip without a lot of effort on my part.

Wing loading. We don't have to go into why lightly loaded models tend to handle slow speeds better than heavy ones, do we? That's down to a bunch of little Chinese women building the models in a sweatshop in downtown Peking probably. I'd feel better if they were Czech, but I'd feel even better if it were me in charge of construction.

FLight profile. See comments ref what the Comet was built to do. I would be real wary of looping and rolling one - not that I'd avoid it.

Keith Shaw built a very good flying DH88 - last I heard of it flying was in the early-mid 1990's. Still, Keith knows more about this sort of thing than around a dozen of we mortals, and learned it before the Chinese had learned to say "Blought All-leady to Fry". Check out Ken Myers' pages at http://members.aol.com/kmyersefo/sitetoc.htm for all sorts of good stuff from the likes of Keith Shaw, it might look old by the dates, but the info is still rock-solid good stuff.

Finally - good luck with it. It's a model I have a bunch of stuff on and would love to find a quiet six months to build a really good big 'un (fat chance on the peaceful six months!). Sure is a showstopper in the air.

Regards

Dereck

mmmdowning
11-18-2005, 03:09 AM
Trying to add the picture of there ad. Its only posted on there catalog and not on the website. I can't wait for this bird to come out.

Derek thanks for the info. I would be happy to just park it on the field and not fly. What a beautiful plane.

Can someone tell me what this means? I try to bring the image in and I get this note:

In order to accept POST request originating from this domain, the admin must add this domain to the whitelist.

GWR
11-25-2005, 02:41 PM
D'oh!:eek:

donjiskra
11-25-2005, 10:48 PM
Photo looks very nice, Thanks.
The website states it will be available soon (?)
Can't wait!!

donjiskra
11-28-2005, 01:09 PM
Hobby People state that it is coming soon and the price is $349.00.
Guess that ends my anxiety!!:mad:

mmmdowning
11-28-2005, 01:43 PM
You know $349 doesn't seem bad if the quality is good. Has any one heard of the company. I try to go to there site and it's always down.

Dereck
11-28-2005, 02:22 PM
www.galaxymodels.co.uk

Second page of their "Galaxy Kits" section.

46" span, 2 x S400. Price is 60 UK Pounds - say $100 in US. Then you've shipping etc. I know there's one in the US, and the builder was pretty happy with the kit.

Slightly more affordable, doesn't need a furniture van (or a Chevy Subdivision ;) ) to haul it around... Galaxy have a good, long standing reputation in UK aeromodelling too.

I have a CAD drawing I pulled off the web sometime back for a pretty big - 80"-odd - Comet slimer. Ocassionally pull it up and mess with it with a view to electrocution, but it's far too much time and involvement than I can take right now (present project is a really basic 40" sports aerobatic model for geared S400 to baby BL!). If anyone with delusions of suchlike wants a copy - there's four or five pages of it - be happy to send them a copy. No idea as to its 'provenance' or ability to fly though ...

Dereck

donjiskra
11-28-2005, 03:45 PM
You know $349 doesn't seem bad if the quality is good. Has any one heard of the company. I try to go to there site and it's always down.

I totally agree with that philosophy, however when I factor in the cost of two brushless motors with two brushless ESC's and li-po batteries then the cost is out of my range. I can't wait to see those that can afford it put one in the air.
I've seen the full scale replica at EAA's AirVenture several times, it is awesome to behold on the ground , up close and in the air.

donjiskra
11-28-2005, 03:58 PM
www.galaxymodels.co.uk (http://www.galaxymodels.co.uk)

Second page of their "Galaxy Kits" section.

46" span, 2 x S400. Price is 60 UK Pounds - say $100 in US. Then you've shipping etc. I know there's one in the US, and the builder was pretty happy with the kit.


Dereck

.....a Westland Whirlwind, which is a neat looking plane also!!!

Dereck
11-28-2005, 05:49 PM
Don
Scrat around some more, there's definitely a Comet in there someplace, as well as a slightly larger Mossie for 480s. I tried to paste the Comet's URL in directly, but can't seem to figure out C&P into this forums reply boxes.

D

laxlife
12-30-2005, 05:38 AM
The Hobby People kit must be made by the same folks who make Stuart Mackay's version as its just too similar, see for yourself:
http://www.moki.co.uk/comet.htm
or perhaps somewhere in China someone is reverse engineering the moki.com.uk version
Either way it will be an awesome looking plane. I've been told that tip stalling is the problem with this plane and flying replicas.
We'll see...

Dereck
12-30-2005, 03:21 PM
Let's face it - you get one "made in China", you just gave it to the world.

Anyone remember what became of a copy of RCM's plan that was bought from the mag, and turned up later as Chinese made BARFs in the US, and endorsed by a top RC flier to boot? Of course, that was nearly a year ago...

As to the Comet tip-stalling. The Shuttleworth collection wouldn't fly theirs out of Old Warden because its 'original' wing was too critical on landing parameters to make it safe to operate out of their short-ish grass field.

However - the US built Comet replica had washout built into its wings, and was routinely flown from a shorter strip than Old Warden's.

The original didn't have washout as its wing was optimised for going fast in a straight line at cruising height. However, it did have a pair of extremely good pilots sitting in it, who were more than capable of dealing with making sure they didn't get out of the envelope during the approach and landing phases.

Which raises questions - is a buyer of this BARF going to take time to learn about the landing issues before a landing becomes compulsory?

Is that buyer going to select a test-flight field based on that knowledge?

Do the sellers of this model give a hoot?

One day, I'll find the time to finish off my Comet drawings, learn all about scale retracts and build one behind a couple of mid-size BLs. 100" would not be unreasonable, though 81" would be easier to haul around and still "IMAA Legal". With the correct 'fixes' in the region of the wingtips and a light airframe, I don't see it being any problem as a sports flier for nice days and very low crosswind landing limits.

Slight bias, having not only seen her for real, but even rubbed my hand over her nose-cone, but I reckon the Comet has to be one of the most beautiful aircraft ever built, and far too good looking to 'bodge' into semi-scale, IMO

Regards

Dereck

mmmdowning
01-26-2006, 07:58 PM
Recieced an email stating they just got them in. Going to place order now. (Hobby People)

donjiskra
01-26-2006, 08:39 PM
Thanks mmmdowning, here's the site for anyone interested:

http://www.hobbypeople.net/gallery/190101.asp

Truly a nice looking plane. Wish I had the $349.00

mmmdowning
01-27-2006, 06:05 PM
Well it should be here next Friday. I'm planing on 2 Axi 4130/16 motors. I will build it later around may or june. I'm working on a 80" Velocity and making it electric with the Axi 5320 and 10s packs. Going with a custom paint scheme.

donjiskra
01-27-2006, 06:29 PM
I'm almost as excited as you are! This is a fantastic plane, with an incredible history. I've seen and photgraphed the full scale replica at EAA's Air Venture several years ago. Truly a sight to behold!!!
Can't wait to get your progress reports.
Best wishes.
Don

bhchan
01-28-2006, 07:16 AM
Well it should be here next Friday. I'm planing on 2 Axi 4130/16 motors. I will build it later around may or june. I'm working on a 80" Velocity and making it electric with the Axi 5320 and 10s packs. Going with a custom paint scheme.


That may be too much motors for the the plane. I can fly an 72" Cub with the 4130/16 on 18 cells ( with a 13x8 prop). I don't think you will need two of them to fly the Comet. May be 2x Ai 2826/10. Also not sure how much prop clearance will you have with the short LG.

see http://www.wattflyer.com/forums/showpost.php?p=35169&postcount=4 He is flying a 120" aerocommander with the 4130.

Did you order the retractable landing gears? They are bit pricy at 230 a pair!!

Brian, an EAJ

mmmdowning
01-28-2006, 03:18 PM
BHCHAN,
They haven't recieved the hole package on the gear, I figured I would get the plane first then go thru everything and get a feel for whats there.

As for the motors this plane is made to fly fast and stays fast. Its a low wing and require's more motor but you may be right. If I can go with a smaller motor it would save some money. Im also waiting to see what others are going to do. I'm a little worried about there not being much info on the manufacturer. So first I would like to test the waters first. It's a lot of money to go down in flames up front with a new plane and I don't want to make a mistake. I will post pictures of this bird when it comes in.

Dereck
01-29-2006, 01:31 AM
http://members.aol.com/kmyersefo/page3.htm#TOP

Download the PDF of Keith Shaw on twins. Basic and 'mature' but the essentials are all still there.

Idly recall seeing a video of an old KRC meet with Keith's Dh88 doing a low inverted pass - as in, have to clean the green off the fin tip after flight! Keith did most of what many think is new and exciting while the rest of us were trying to figure out which end of the soldering iron was best to hold...
Dereck

bhchan
01-29-2006, 02:40 AM
mmmdowning,

The spec list the 0.32-0.40 cu in wet power. I use an AXI 2826 on my Rascal 72(which spec for 0.40-0.46 cu.in.) and the climb is good.

Brian, an EAJ

mmmdowning
01-29-2006, 06:33 PM
Dereck,
Great reading, I read allot of what was on the site from your earlier post on the site. Sometimes I tend to over power my planes.

mmmdowning
01-30-2006, 02:56 AM
Went to the Hobby People site and they raised the price to $369. They are going to turn people away. They don't list the weight of the plane. As soon as they get the struts and retracts in I'll order them.

bhchan
01-30-2006, 05:51 AM
I will wait for your report on the kit before I make my move. I will be going to Anaheim in a few week, may be I can stopin and check out the kit.

mmmdowning
02-20-2006, 11:12 PM
Here are the retracts and struts for the DH-88: They seem to be good and the struts have built in springs, the real test will be at the field.

bhchan
02-21-2006, 08:06 AM
mmm,
What about the kit itself? Is it any good?

Brian, an EAJ

mmmdowning
02-21-2006, 08:31 AM
It seems to be, It all looks good. Very lite, the fuse is a thin plastic with carbon fiber reinforcement, it's strong but very lite. It seems well thought out. It's an awesome plane. construction of the wing seems foam and balsa sheeting. The decals are applied at the factory. I think it will be a quick build. The instructions are in color. They include the instructions for the retracts and struts.

BaldEagel
03-01-2006, 01:35 PM
mmmdowning

This kit I think in Uk is the Ripmax one, the only thing that put me off was the one piece 2M wing, are you going to keep it three piece or epoxy the tips on?

If I see another one in MLHS I may well buy it and convert to removable tips, it is such a beutiful looking aircraft I may not be able to contain myself.

Mike

mmmdowning
03-01-2006, 03:44 PM
I have a trailer so the one piece wing isn't a big deal. You could seperate but I think it might be safer to have one piece. It is an awesome plane.

Goodluck
Marty

panzerd18
03-02-2006, 04:18 AM
Its been out in Australia for awhile. The company that makes them is called "Awesome". They also make a club flyer series which are small electric aircraft and I have an Awesome Stuka Ju87

BaldEagel
03-03-2006, 01:09 PM
Anyone got one of these 2M Comet DH88's I'd love an informed opinion on build and flying?

Mike

Ron
03-30-2006, 04:03 AM
Have not flown this particular model, but have flown one same size.
It is a witch for tipstall if it gets slow..DON"T be slow in the turns, and DON'T try to extend the glide on landings it WILL drop a wing real fast,especially if it's heavy. and you're gonna need lotsa altitude to get it back...BUT...it's a really cool model, and I love it. It's much like the DH Rapide...you got to fly it every inch of the way.

gdwyer
06-16-2010, 01:58 PM
Just finished the ASM 88" comet, built so wing tips detach.
The setup includes,
E-flite 46 motors E-flite 60 amp controllers, 6S 5200mah in each nacelle, separate 6v battery for receiver and servos, Futaba 3010 digital high torque servo and metal geared futaba mini servos in the wings.
The props are 11x8 and she tachos at
2800 rpm startup / minimum idle
7800 rpm at 50% power
11800 rpm at 100% power

It weighs in at 6.45kg WITH the 2 6S Lipos in, which weigh 480g each ( could get smaller capacity lighter ones if its advisable...)

I have bench tested the model, running at 50-70% power randomly for 8 minutes, Lipos read at 55%

Ran a second 8 minutes and one motor dropped from 8000 to 5000 approx after 5 minutes more so best I could hope for is 10 good minutes and get her down quick.

Any advice? I am hoping to maiden her this weekend, runway test her this evening.
There is a bit of slop in the rudder ( poor design) it seems to wave around a few mm in the prop blast. Here are a few pics, any advice would be greatly welcome.

http://www.grahamdwyer.com/web_images/32110_1429827460018_1062783263_31209668_8036760_n. jpg
http://www.grahamdwyer.com/web_images/32110_1429827340015_1062783263_31209666_84053_n.jp g
http://www.grahamdwyer.com/web_images/32110_1429827580021_1062783263_31209670_3661164_n. jpg
http://www.grahamdwyer.com/web_images/32110_1429827420017_1062783263_31209667_1186471_n. jpg

BaldEagel
06-16-2010, 04:14 PM
Put reflexed ailerons on the throttle stick so they come up about 10mm with the throttle closed, this will put wash out on the wing tips and help prevent tip stalling which this highly tapered wing is prone to, make sure you have it mixed so they go back to center when you open the throttle in case you have to go around.

Mike

gdwyer
06-16-2010, 04:30 PM
Thanks! I have the ailerons set up about 2 mm each and was hoping that would do it.

I will have to look up how to programme that into my Futaba 10C, do you know if it is a sort of negative flaperon?

BaldEagel
06-16-2010, 04:40 PM
I think you have to set it up on the Airbrake function, if you have one on the 10, that's how I set it on my 12FG, choose the switch as the throttle and then go to the switch set up screen and set the thottle at the position you want it to activate, very easy on the 12FG, but I don't know about the 10.

You have to choose the percentage of movement also in the airbrake function, I don't think 2mm will be enough, it all accords how much aileron movement you can get as you still need aileron when they are reflexed.

Hope this helps, good luck on the maiden.
Mike

donjiskra
06-16-2010, 11:09 PM
I've seen the full scale replica at EAA's "AirVenture" several years ago and talked to the owner/pilot. He said the wings do not have much lift and the landing speed must be kept up (very similar to the GeeBee).
I've also spoken to a modeler who had one and he had the same comment, so be advised!!!!
Yours is a beauty, very striking design that evolved into the famous "Mosquito". Best wishes for your maiden flight. I look forward to your report.
Wish I could be there in person to witness,to cheer you on and celebrate with a few pints afterwards.
Don

BaldEagel
06-16-2010, 11:15 PM
Unfortunatly models fly in full size air, the Renolds numbers are totaly different, so you can not compare full size to the model, I helped set up and flew one of the models when it first came out, so my advise is based on the model not on hear say, but please make up your own mind, it is your model after all.

Mike

gdwyer
06-17-2010, 09:29 AM
Ran it up and down the runway last night at the flying field, not enough rudder authority as no wash over the tail, and it ran into the long grass at speed, breaking off a nacelle. Minor damage, partly caused by the very heavy (480g) batteries in each of them I guess.

I can increase the rudder throws, but is there a way ( or would it be wise ) to try and link the motor speed to the rudder?
http://www.grahamdwyer.com/web_images/comet_test.jpg

Dr Speed
06-29-2010, 06:26 PM
I have this beautiful beast as well and I could tame it by following measures:

1. counter rotating props to avoid breaking out to the left during take off. In flight direction the left prop is rotating clockwise, the right one counter clockwise. I have a 10x8 APC regular and pusher prop.

2. Gyro on ailerons (Fuzzy ACT)

3. During take off and landing the ailerons are set up about 5mm negative each (programmed flight phases)

4. In the normal flight phase the ailerons are neutral but they are connected via mixer with the elevevator. Full elevator give 5 mm aileron movement. This avoids tip stalling in a turn.

5. Speed breaks at 40 for landing

6. Mechanical Turbulator / zig-zag tape 300 mm from the wing tips to the fuselage at 25% of chord length

Sorry to say that but your plane is with 6.45 kg by far too heavy! Please, don't try to fly it with this weight. It is advisable to stay in a range of 5 to 5.5 kg which already results in a wing load of over 100g/sdm.

Here is my set up:

2 x Flyware engines 680 rpm/V
1 x 6S 5000 mAh Lipo placed in the fuselage
APC props 10X8 normal / pusher
12.500 rpm at 100% throttle
ca. 800W each engine = 1.6kW
retracts
BEC power supply
Weight = 5.4 kg

Here you can watch a video of the plane:
http://www.youtube.com/watch?v=R3YsmGm2QKU&playnext_from=TL&videos=37UVbtQhdxc
There was a medium cross wind from the right. As you can see this is a real racer and the landing speed should be pretty high to avoid tip stalling.

I hope my English was good enough to get the infos across.

Armin

MaxAdventure
06-29-2010, 07:02 PM
I can increase the rudder throws, but is there a way ( or would it be wise ) to try and link the motor speed to the rudder?


You can certainly program differential thrust into the motors if you have enough channels and open mixes. This will require the throttles to be on seperate channels, and I would suggest a switch to activate only when you are on the ground. It sets you up for some scary possibilities if you hit the wrong switch at the wrong time.

gdwyer
06-30-2010, 10:56 AM
Thank you so much, I will definately try your setup.
One thing, I was setting my elevator UP 5mm on each side permanently to try and create washout so the fuselage end of the wing would stall first and keep the tips flying?

Dr Speed
06-30-2010, 07:13 PM
this assumption would be correct for a "normal" wing dimension. But the DH-88 has such an extreme proportion between the wing tips and the wing at the fuselage that a whash out of the inner part is very unlikely regardless which ailoren set-up you will apply. In addition the slim wing tips are operated below the critical Reynolds number during take off and landing or in low speed turns what intensifies the nasty behaviour at low speed. However, this measure will mitigate the tip stalling danger a bit.

The best advise is to keep the plane on speed and operate it like a Jet (no too narrow turns). This sounds very scary but I assume that you are not a beginner and that you can handle that. I admit that I was in a blue funk during the first flights but this will be compensated when this plane passes with full speed. Good luck!

Armin

eye4wings
07-07-2010, 04:00 PM
Thank you so much, I will definately try your setup.
One thing, I was setting my elevator UP 5mm on each side permanently to try and create washout so the fuselage end of the wing would stall first and keep the tips flying?

I DO hope you meant aileron - not elevator!
Elevator does NOT need to be set permanently up - or you'll regret it a split second after lift-off!
Leave the model to ift off the ground on its own if you can, at least for first flight and until you know how the tips will behave.
Happy landings!

gdwyer
08-23-2010, 11:49 AM
Three serious attempts by this slippery plane to stall, very lucky to get it down safely......

http://www.youtube.com/watch?v=T0TW87dACNw

eye4wings
08-23-2010, 02:54 PM
Well that was certainly a lively couple of minutes for you!
Well done! I'm not sure I could cope with a helpfully intended 'right on, right on, right on' in my ear either.
So no serious damage? Bent port undercarriage and a broken prop?

I think at this stage I would do violence to the wing tips. I would cut away the bottom surface for a couple of bays and carve some serious washout into it before reskinning and re-covering. I would also include the outer sections of the aileron in this treatment to make sure I had a good 3 degrees of washout. That should calm it down a bit.

How much differential did you have on the ailerons?

I think over-all that it looked like it would probably fly fine once you are used to it, but it obviously didn't like you trying to steer at low speed so you're going to need to set up for the landing well out and do a straight approach with minimal flare out.

Dr Speed
08-23-2010, 09:46 PM
Congratulations! Well done!

I was not so lucky last week when I got an unexpected crosswind from the back during landing. In a split second the left wing touched the ground and the fuselage and the left nacelle got some bad cracks. But I can repair the damage. The plastic material of the fuselage can be glued surprisingly well with CA-Glue. After over 30 flights I was too careless given unfavourable wind conditions.

Which setup did you apply now (motors, battery, weight)?

rterhune
11-02-2010, 12:33 AM
I have this plane, but have yet to maiden it. Rather than modify the wing to induce washout, you can just adjust the aileron linkage so that both ailerons are slightly "up"; the opposite of a flaperon, which is the same thing as adding washout to the outter wing. I re-did the elevator push rod as the supplied would flex under load. also added a support bushing where the tail wheel wire exited the fuse, as it is very slender and subject to bending.

eye4wings
11-02-2010, 09:33 AM
The up adjustment of the ailerons is a ploy used by quite a few modellers, but I would still be a little nervous of it in practice because the aileron does not go all the way to the tip which can still stall if the angle of attack is too high - producing turbulent tip vortices. It could prevent the tip stall from spreading down the wing towards the root however... but actually I don't like to see control surfaces out of line. Sometimes it just has to be done though.

May the almighty smile kindly upon your maiden flight!

Bellakelpie
12-11-2010, 05:53 AM
I have seen an example of this lovely model flying. The owner has trimmed it out and it flies well. No mods to wingtips etc . He chose NOT to use APC "E" Props and as a consequence his model is a lot quieter than the one in gdwyers video.
I liked the video, despite the hard landing. Just listening to the guys comments as they trimmed it out imparted a lot of good information.
It is definitely NOT a model for the novice.
Hope yours is fixed and flying o.k. now.