DH 2
04-06-2013, 03:27 PM
#351
RE: DH 2
Greg
04-06-2013, 03:40 PM
#352
RE: DH 2
ORIGINAL: R/C Art
Greg
I think what Sir Percy is saying is to sell your project immediately and go buy this ARF[X(] Then you can be ready to fly this season and not worry about getting caught up in the cage of wires and swirling propeller blades trying to start it up!
[:-] Am I right, Steve?
Seriously Greg, think back to your other DH2 - was it really so difficult to start and adjust? And this one is a bit bigger, so there is more room to work - remember your goals when the project was initially undertaken........just my 2 cents worth.
Art
ps It seemed so easy at first - well, maybe I need some help - and then it was ''How many people does it take to start a DH2?''
pps It looked to me like there is plenty of room available[:-].
I think what Sir Percy is saying is to sell your project immediately and go buy this ARF[X(] Then you can be ready to fly this season and not worry about getting caught up in the cage of wires and swirling propeller blades trying to start it up!
[:-] Am I right, Steve?
Seriously Greg, think back to your other DH2 - was it really so difficult to start and adjust? And this one is a bit bigger, so there is more room to work - remember your goals when the project was initially undertaken........just my 2 cents worth.
Art
ps It seemed so easy at first - well, maybe I need some help - and then it was ''How many people does it take to start a DH2?''
pps It looked to me like there is plenty of room available[:-].
Reflecting on my goals is sorta what got me to this point. I wanted wing loading to be as light as possible and to have realistic sound. Until I saw this system, a four stroke glow engine was the best option. Now I see a way further those goals assuming the hardware performs as expected.
I'm going for it, taking the plunge into giant scale electric! Wish me luck! This should be an interesting chapter in the build thread... I'll post video when I get it running so y'all can hear it too.
Greg
04-08-2013, 02:59 AM
#353
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RE: DH 2
Greg - I've got a Benedini sound system in my 1/3 Sopwith Pup - 2 x 4" speakers and 50W amplifier - sounds great, though a bit more volume might be good - I need to play around with the sound system to see if I can get a bit more out of it. Here's a link to a video of it, the wind was from behind the cameraman, so the sound gets a bit lost at times - https://vimeo.com/42216630
04-08-2013, 07:17 AM
#354
RE: DH 2
Good morning, Greg
From what I remember in all the times we flew Stephen Hill-Harriss' 1/4 scale DH-2, starting the OS 160 twin in it wasn't really a big deal.
I'd hold the nacelle with my left hand to keep everything stable, and had the transmitter handy on the ground to handle the throttle. Stephen had the starter under the booms, reached in from above, and started the motor like normal. Once started, he'd pull the starter out from below the booms while I got the motor to idle (I'd still be holding the nacelle by the nose - the plane's not going anywhere), and while he went around the right wing to retrieve that side's glow battery, I got the left cylinder undone from my side.
It always looked busier than it really was.
WAY back when the plane was brand new, he was starting it with a chicken stick as I recall. Same process, just different tool.
So long as someone has ahold of the nacelle, the plane's not going anywhere.
And yeah, oil and gunk got all over the plane's tail like you'd expect, but no more than what get's on a conventional plane's lower wing/undercarriage - and those tend to survive the ordeal for the most part just fine!!
I don't have a digital copy of us starting Stephen's DH-2 (I've GOT to get a gazillion vhs tapes converted someday to digital), but I'll reference back to Sir Percy's fine video of the DH-2 in action at the Hoosier Dawn Patrol - just as a reminder that electric ain't the only option!!
http://www.hoosierdawnpatrol.com/2008videos/dh1.wmv
Very best regards,
Lee McD
From what I remember in all the times we flew Stephen Hill-Harriss' 1/4 scale DH-2, starting the OS 160 twin in it wasn't really a big deal.
I'd hold the nacelle with my left hand to keep everything stable, and had the transmitter handy on the ground to handle the throttle. Stephen had the starter under the booms, reached in from above, and started the motor like normal. Once started, he'd pull the starter out from below the booms while I got the motor to idle (I'd still be holding the nacelle by the nose - the plane's not going anywhere), and while he went around the right wing to retrieve that side's glow battery, I got the left cylinder undone from my side.
It always looked busier than it really was.
WAY back when the plane was brand new, he was starting it with a chicken stick as I recall. Same process, just different tool.
So long as someone has ahold of the nacelle, the plane's not going anywhere.
And yeah, oil and gunk got all over the plane's tail like you'd expect, but no more than what get's on a conventional plane's lower wing/undercarriage - and those tend to survive the ordeal for the most part just fine!!
I don't have a digital copy of us starting Stephen's DH-2 (I've GOT to get a gazillion vhs tapes converted someday to digital), but I'll reference back to Sir Percy's fine video of the DH-2 in action at the Hoosier Dawn Patrol - just as a reminder that electric ain't the only option!!
http://www.hoosierdawnpatrol.com/2008videos/dh1.wmv
Very best regards,
Lee McD
04-09-2013, 03:21 PM
#355
RE: DH 2
ORIGINAL: WinterHawke
Good morning, Greg
From what I remember in all the times we flew Stephen Hill-Harriss' 1/4 scale DH-2, starting the OS 160 twin in it wasn't really a big deal.
I'd hold the nacelle with my left hand to keep everything stable, and had the transmitter handy on the ground to handle the throttle. Stephen had the starter under the booms, reached in from above, and started the motor like normal. Once started, he'd pull the starter out from below the booms while I got the motor to idle (I'd still be holding the nacelle by the nose - the plane's not going anywhere), and while he went around the right wing to retrieve that side's glow battery, I got the left cylinder undone from my side.
It always looked busier than it really was.
WAY back when the plane was brand new, he was starting it with a chicken stick as I recall. Same process, just different tool.
So long as someone has ahold of the nacelle, the plane's not going anywhere.
And yeah, oil and gunk got all over the plane's tail like you'd expect, but no more than what get's on a conventional plane's lower wing/undercarriage - and those tend to survive the ordeal for the most part just fine!!
I don't have a digital copy of us starting Stephen's DH-2 (I've GOT to get a gazillion vhs tapes converted someday to digital), but I'll reference back to Sir Percy's fine video of the DH-2 in action at the Hoosier Dawn Patrol - just as a reminder that electric ain't the only option!!
http://www.hoosierdawnpatrol.com/2008videos/dh1.wmv
Very best regards,
Lee McD
Good morning, Greg
From what I remember in all the times we flew Stephen Hill-Harriss' 1/4 scale DH-2, starting the OS 160 twin in it wasn't really a big deal.
I'd hold the nacelle with my left hand to keep everything stable, and had the transmitter handy on the ground to handle the throttle. Stephen had the starter under the booms, reached in from above, and started the motor like normal. Once started, he'd pull the starter out from below the booms while I got the motor to idle (I'd still be holding the nacelle by the nose - the plane's not going anywhere), and while he went around the right wing to retrieve that side's glow battery, I got the left cylinder undone from my side.
It always looked busier than it really was.
WAY back when the plane was brand new, he was starting it with a chicken stick as I recall. Same process, just different tool.
So long as someone has ahold of the nacelle, the plane's not going anywhere.
And yeah, oil and gunk got all over the plane's tail like you'd expect, but no more than what get's on a conventional plane's lower wing/undercarriage - and those tend to survive the ordeal for the most part just fine!!
I don't have a digital copy of us starting Stephen's DH-2 (I've GOT to get a gazillion vhs tapes converted someday to digital), but I'll reference back to Sir Percy's fine video of the DH-2 in action at the Hoosier Dawn Patrol - just as a reminder that electric ain't the only option!!
http://www.hoosierdawnpatrol.com/2008videos/dh1.wmv
Very best regards,
Lee McD
Mr. Hill-Harris' DH-2 is a mighty fine aircraft indeed!
My old boss once said: "When you have ham & eggs for breakfast, remember this: The chicken was "involved", the pig was committed! Be committed."
I've committed money to trying out this electric sound system so we'll see how it goes. Best case scenario, I save half a pound in ballast weight, and not only have a good engine sound but I also gain a machine gun sound effect without the weight of the paintball system. Worst case scenario, the system doesn't work as well as advertised. If it doesn't work out, I fall back to the original plan of 4-stroke glow power (after taking a season to financially recover from the gamble!). good to hear from you,
Greg
03-09-2014, 02:01 PM
#356
My 1/4 scale DH2 is framed up enough now for a static thurst test of the power system. Here are the specs:
Motor - RimFire 1.20
ESC - Electrifly 80
Prop - 18x6 Menz
Battery - 6S Lipo
Here are the results! I'm projecting the biplane to come in at about 16 pounds total finished weight, so I think these thrust calculations are encouraging to say that I sized the electric power system correctly. The first datapoint on the plot is about 1/4 throttle, half throttle was at 41 Amps, Full throttle was at 72 Amps.
The predicted thrust came from an equation found at this website: http://electricrcaircraftguy.blogspo...-equation.html
Motor - RimFire 1.20
ESC - Electrifly 80
Prop - 18x6 Menz
Battery - 6S Lipo
Here are the results! I'm projecting the biplane to come in at about 16 pounds total finished weight, so I think these thrust calculations are encouraging to say that I sized the electric power system correctly. The first datapoint on the plot is about 1/4 throttle, half throttle was at 41 Amps, Full throttle was at 72 Amps.
The predicted thrust came from an equation found at this website: http://electricrcaircraftguy.blogspo...-equation.html
Last edited by Eindecker_pilot; 03-09-2014 at 02:04 PM.
07-06-2014, 12:02 PM
#357
Here are some photos of the recent progress on my 1/4 scale DH2. Points of interest:
- Tail booms are carbon fiber rods with heavy-duty dubro steel clevises JB welded into the ends. As you can see in the photo, they bolt to a dubro steel strap that is itself bolted to the wing.
- Fuselage nacelle and wing center sections are covered in Solartex antique linen. All the struts are stained in cherry finish. Most of my documentation shows pictures of the struts colored gray but the natural stain looked too good to pass up. The documentation I've got says some were stained & others were painted gray so it isn't unrealistic
- The landing gear & tail skid are functionally sprung.
- The rudder has been drilled for hinge points, but not glued yet, it's just been trial fitted for this photo.
- I'm going to move the motor mount back another half inch or so to better clear the wing's trailing edges with the prop.
- The model has come out nose heavy, at least to this point. I still have to add quite a bit of hardware to the tail so that will help some but not enough I think. I have installed provisions for two battery locations, one behind the firewall (rear of the nacelle behind the CG) and another upfront in the cockpit.
- Weight at this point is 12 pounds, before adding another 2 pounds for flight batteries. I figure another couple of pounds for the rest of the servos, associated control system hardware, covering, other stuff will put it at about 16 pounds. This puts it inline with my 1/4 scale Pup.
- Wires are from the Balsa USA 1/4 scale nicropress system. Turnbuckles & fittings are from Proctor mostly, Sullivan on the ends.
I hope I do not have to add lead in the tail. I never thought this would be a nose heavy aircraft but going electric completely obliterated the chances of it being tail heavy. In retrospect, I could have built the tail booms out of wooden dowels. They would have been heavier, but far cheaper and it would likely have balanced out just fine.
I'm really happy with how it looks & the sound system is amazing. Still remains to be seen if it's loud enough in the air but on the ground the tests are encouraging.
-Greg
07-06-2014, 12:22 PM
#358
Kudos Greg! She's looking very good. I admire your patience and tenacity and I must admit that I am a bit envious, too. Maybe sometime in the near future I can get back to finishing mine. 
Do you think a maiden is in the cards for this flying season?
Do you think a maiden is in the cards for this flying season?
07-06-2014, 12:55 PM
#359
Hey Art, thanks!! I think it will look even better once I've added stitching around the nacelle and weathered it up a bit.
Of course it also needs a gun upfront too. And a pilot bust. Lots to do still. My guess is it could be ready to fly this year just about the time the first snow hits! It's tantalizingly close. I had to get it assembled to this point in order to start routing the pull-pull systems. I'll have some more photos of that in the coming weeks. I need to tackle that next just to get that monkey off my back. After that challenge the rest is just the fun stuff.
-Greg
Of course it also needs a gun upfront too. And a pilot bust. Lots to do still. My guess is it could be ready to fly this year just about the time the first snow hits! It's tantalizingly close. I had to get it assembled to this point in order to start routing the pull-pull systems. I'll have some more photos of that in the coming weeks. I need to tackle that next just to get that monkey off my back. After that challenge the rest is just the fun stuff.
-Greg
Last edited by Eindecker_pilot; 07-07-2014 at 02:38 AM.
07-07-2014, 04:31 PM
#361
Thanks Jim! I agree, I want to try a system where I can leave the upper and lower panels subassembled and plug them in as a module.
Greg
Greg
Last edited by Eindecker_pilot; 07-09-2014 at 06:30 AM.
06-14-2015, 11:38 AM
#362
Folks,
The maiden flight of my 1/4 scale DH2 is a success! Here are some photos by Mike (Lucky Dog). I love this aircraft. She flew wonderfully straight the first time up; only required some up elevator trim. Handles like any other lightly loaded WWI biplane, but looks very interesting in the air with this pusher configuration. These pictures were taken at my home field, the Bartholomew County RC Fliers.
Using my sound system, the scale engine sound is really cool, the bass carries pretty well across the air (although more volume would be even better, I'm at maximum voltage & power). I do wish the gun sound was louder; I think because it's higher frequency it just doesn't carry as far.
I went with a Rim Fire 1.60 using 8S 5000mah Lipos. It runs an 18x10 prop which provides plenty of power for scale flight. I set the timer for 10 minutes & see no loss of performance, cruising around at half-throttle ( I'm estimating it's got about 25% of it's juice left at the 10 minute mark).
I took it out this past Tuesday as well for 3 more flights and had a ball. Enjoy the photos. That Lucky Dog is pretty good with a camera. Time to put some scale details on it and take it to Ohio Dawn Patrol next month!
Greg
The maiden flight of my 1/4 scale DH2 is a success! Here are some photos by Mike (Lucky Dog). I love this aircraft. She flew wonderfully straight the first time up; only required some up elevator trim. Handles like any other lightly loaded WWI biplane, but looks very interesting in the air with this pusher configuration. These pictures were taken at my home field, the Bartholomew County RC Fliers.
Using my sound system, the scale engine sound is really cool, the bass carries pretty well across the air (although more volume would be even better, I'm at maximum voltage & power). I do wish the gun sound was louder; I think because it's higher frequency it just doesn't carry as far.
I went with a Rim Fire 1.60 using 8S 5000mah Lipos. It runs an 18x10 prop which provides plenty of power for scale flight. I set the timer for 10 minutes & see no loss of performance, cruising around at half-throttle ( I'm estimating it's got about 25% of it's juice left at the 10 minute mark).
I took it out this past Tuesday as well for 3 more flights and had a ball. Enjoy the photos. That Lucky Dog is pretty good with a camera. Time to put some scale details on it and take it to Ohio Dawn Patrol next month!
Greg
06-15-2015, 04:23 PM
#368
Thanks for the comments guys!
Dave, the hat is hiding my share of gray hair; proudly earned thru worrying about my kids for the past 11 years plus 20 years as a mechanical engineer!
Best regards,
Greg
Dave, the hat is hiding my share of gray hair; proudly earned thru worrying about my kids for the past 11 years plus 20 years as a mechanical engineer!
Best regards,
Greg
06-19-2015, 05:01 AM
#373
06-19-2015, 05:39 AM
#374
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Folks,
The maiden flight of my 1/4 scale DH2 is a success! Here are some photos by Mike (Lucky Dog). I love this aircraft. She flew wonderfully straight the first time up; only required some up elevator trim. Handles like any other lightly loaded WWI biplane, but looks very interesting in the air with this pusher configuration. These pictures were taken at my home field, the Bartholomew County RC Fliers.
Using my sound system, the scale engine sound is really cool, the bass carries pretty well across the air (although more volume would be even better, I'm at maximum voltage & power). I do wish the gun sound was louder; I think because it's higher frequency it just doesn't carry as far.
I went with a Rim Fire 1.60 using 8S 5000mah Lipos. It runs an 18x10 prop which provides plenty of power for scale flight. I set the timer for 10 minutes & see no loss of performance, cruising around at half-throttle ( I'm estimating it's got about 25% of it's juice left at the 10 minute mark).
I took it out this past Tuesday as well for 3 more flights and had a ball. Enjoy the photos. That Lucky Dog is pretty good with a camera. Time to put some scale details on it and take it to Ohio Dawn Patrol next month!
Greg
The maiden flight of my 1/4 scale DH2 is a success! Here are some photos by Mike (Lucky Dog). I love this aircraft. She flew wonderfully straight the first time up; only required some up elevator trim. Handles like any other lightly loaded WWI biplane, but looks very interesting in the air with this pusher configuration. These pictures were taken at my home field, the Bartholomew County RC Fliers.
Using my sound system, the scale engine sound is really cool, the bass carries pretty well across the air (although more volume would be even better, I'm at maximum voltage & power). I do wish the gun sound was louder; I think because it's higher frequency it just doesn't carry as far.
I went with a Rim Fire 1.60 using 8S 5000mah Lipos. It runs an 18x10 prop which provides plenty of power for scale flight. I set the timer for 10 minutes & see no loss of performance, cruising around at half-throttle ( I'm estimating it's got about 25% of it's juice left at the 10 minute mark).
I took it out this past Tuesday as well for 3 more flights and had a ball. Enjoy the photos. That Lucky Dog is pretty good with a camera. Time to put some scale details on it and take it to Ohio Dawn Patrol next month!
Greg
I am soo jealous. That is one of my top 3 planes of all time!
Between YOU, Andy, Jim, Opie.........You guys are killing me!!!
I cant wait so see it fly. The plane look really good! Congrats on finishing!
HPA
