Balsa USA 1/4 Sopwith Pup build
#326
Senior Member
RE: Balsa USA 1/4 Sopwith Pup build
G'day Zor and Leo,
thanks for the kind words. I was lucky to have her that long, as Maremma dogs normaly only get to 10-12.
It really makes you realise how much you love them when they go.
Hopefully there is good wheather this weekend for the maiden.
Regards Mark
thanks for the kind words. I was lucky to have her that long, as Maremma dogs normaly only get to 10-12.
It really makes you realise how much you love them when they go.
Hopefully there is good wheather this weekend for the maiden.
Regards Mark
#327
Senior Member
RE: Balsa USA 1/4 Sopwith Pup build
Well the pup needed 800g of lead, she ended up a lot heavier than I expected, 8.7kg dry.
I have a 24 oz tank so she was pretty heavy on take off.
I had the best pilot in the club do the maiden, unfortunately she dropped a engine mount bolt after the maiden and I didn't have a spare so I had to go home without flying it myself. However she flew perfectly, I will change the landing gear though, it was brought too far forward.
For anyone else building this plane, don't beef up the tail like I did, it adds too much weight wich needs to be corrected with weight in the nose.
I used far to much epoxy in the build too.
Overall I'm very happy with her.
http://www.youtube.com/watch?v=kGHb1Mzvz-g&feature=plcp
http://www.youtube.com/watch?v=fHkrzlvuUGo&feature=plcp
I have a 24 oz tank so she was pretty heavy on take off.
I had the best pilot in the club do the maiden, unfortunately she dropped a engine mount bolt after the maiden and I didn't have a spare so I had to go home without flying it myself. However she flew perfectly, I will change the landing gear though, it was brought too far forward.
For anyone else building this plane, don't beef up the tail like I did, it adds too much weight wich needs to be corrected with weight in the nose.
I used far to much epoxy in the build too.
Overall I'm very happy with her.
http://www.youtube.com/watch?v=kGHb1Mzvz-g&feature=plcp
http://www.youtube.com/watch?v=fHkrzlvuUGo&feature=plcp
#328
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RE: Balsa USA 1/4 Sopwith Pup build
Hey Mark,
Thanks for the Video,
Nice Maiden, the plane surely looks great on takeoffs and landings !!
Very nice job, and wish you many and many of flying hours with this pup !!!
regards,
Thanks for the Video,
Nice Maiden, the plane surely looks great on takeoffs and landings !!
Very nice job, and wish you many and many of flying hours with this pup !!!
regards,
#329
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RE: Balsa USA 1/4 Sopwith Pup build
ORIGINAL: 3136
Well the pup needed 800g of lead, she ended up a lot heavier than I expected, 8.7kg dry.
I have a 24 oz tank so she was pretty heavy on take off.
I had the best pilot in the club do the maiden, unfortunately she dropped a engine mount bolt after the maiden and I didn't have a spare so I had to go home without flying it myself. However she flew perfectly, I will change the landing gear though, it was brought too far forward.
For anyone else building this plane, don't beef up the tail like I did, it adds too much weight wich needs to be corrected with weight in the nose.
I used far to much epoxy in the build too.
Overall I'm very happy with her.
http://www.youtube.com/watch?v=kGHb1Mzvz-g&feature=plcp
http://www.youtube.com/watch?v=fHkrzlvuUGo&feature=plcp
Well the pup needed 800g of lead, she ended up a lot heavier than I expected, 8.7kg dry.
I have a 24 oz tank so she was pretty heavy on take off.
I had the best pilot in the club do the maiden, unfortunately she dropped a engine mount bolt after the maiden and I didn't have a spare so I had to go home without flying it myself. However she flew perfectly, I will change the landing gear though, it was brought too far forward.
For anyone else building this plane, don't beef up the tail like I did, it adds too much weight wich needs to be corrected with weight in the nose.
I used far to much epoxy in the build too.
Overall I'm very happy with her.
http://www.youtube.com/watch?v=kGHb1Mzvz-g&feature=plcp
http://www.youtube.com/watch?v=fHkrzlvuUGo&feature=plcp
I was worried about this loose dog that could have jumped into that turning prop.
I now feel better .
Zor
#330
Senior Member
RE: Balsa USA 1/4 Sopwith Pup build
Thanks for the feedback guys.
I'm spewen it let go of a engine mount bolt and I couldn't have a fly myself.
However I will change the landing gear to be closer to the cg and less bouncy, also I had a 20x8 prop, I'll go down to a 19x6 as it seemed a little hot even on idle coming in for landing.
I'm surprised at that, as my se5a sinks like a rock if it isn't brought in at 1/4 throttle or above, which is still walking pace, she is 12 kg with a dle 55.
I was expecting the pup to have a lot more drag and come in a lot slower, I was very surprised at how it kept coming in. Possibly poor prop choice?
Anyway a little more tweaking and she will be even better, it's funny how they look similar but behave completely different to each other.
Regards Mark
I'm spewen it let go of a engine mount bolt and I couldn't have a fly myself.
However I will change the landing gear to be closer to the cg and less bouncy, also I had a 20x8 prop, I'll go down to a 19x6 as it seemed a little hot even on idle coming in for landing.
I'm surprised at that, as my se5a sinks like a rock if it isn't brought in at 1/4 throttle or above, which is still walking pace, she is 12 kg with a dle 55.
I was expecting the pup to have a lot more drag and come in a lot slower, I was very surprised at how it kept coming in. Possibly poor prop choice?
Anyway a little more tweaking and she will be even better, it's funny how they look similar but behave completely different to each other.
Regards Mark
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RE: Balsa USA 1/4 Sopwith Pup build
Great stuff there Mark ! so glad to see that mine is not to heavy. Now i cant wait to get mine in the air,looks and sounds awesome. Are you also using a Dle 30 ?
#332
Senior Member
RE: Balsa USA 1/4 Sopwith Pup build
Hi Barry, (ALO111) I thought you would be glad to see those videos, considering yours was the same weight as mine.
That extra weight didn't bother is at all.
I have a pte36cc engine in it. they are a rear exhaust and have the same footprint as a dle30, I already had it from another plane.
It did work in well with the metal cowl as it just needed a small area taken from the back where the stingers are.
I extended the front like Senrak did, the standoffs are mounted directly to the firewall.
A dle30 will have heaps of power to fly at that weight, in the second video it is climbing vertical at one point, my engine is only 6cc bigger, so don't worry about your 30, it will be more than enough.
Regards Mark
That extra weight didn't bother is at all.
I have a pte36cc engine in it. they are a rear exhaust and have the same footprint as a dle30, I already had it from another plane.
It did work in well with the metal cowl as it just needed a small area taken from the back where the stingers are.
I extended the front like Senrak did, the standoffs are mounted directly to the firewall.
A dle30 will have heaps of power to fly at that weight, in the second video it is climbing vertical at one point, my engine is only 6cc bigger, so don't worry about your 30, it will be more than enough.
Regards Mark
#333
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RE: Balsa USA 1/4 Sopwith Pup build
Okay, I guess it's time for me to chime in here. My Pup flys like it had been in the sky long before I came along. It has never made a bad move without me causing it. The DLE 30 runs like a top and is rarely over 1/2 thottle. It is so realistic in the air that I get an audience every time it takes off. Only thing I would caution one on is that you (or at least I) have a tendancy to fly it to slow. It is a bipe and bipes do have a lot of drag. Keep in mind that if your glide is not very steep, it will stall before you realize what's going on. I have found it best to keep the power on untill you are close to touching the runway.
Get out and fly your airplane. These Sopwith Pups are a rush!
DW
Get out and fly your airplane. These Sopwith Pups are a rush!
DW
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RE: Balsa USA 1/4 Sopwith Pup build
Hi Senrak , what prop you spinning? I fitted a 23/6 to keep speed down and power up it also looks scale. Seems good on the ground run ,plenty power and not over reving. Got the advice from a very experinced Dle guy. Will let you guys know how it works when the wind finaly gives up.
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RE: Balsa USA 1/4 Sopwith Pup build
I am using an 18-6. blows a lot of air. turns maybe 8500. and that's not to say a bigger diameter wouldn't be better. DL enginne certainly makes great power.
#336
Senior Member
RE: Balsa USA 1/4 Sopwith Pup build
Hi ALO111, DLE recomend 20x6 and 20x8 as the largest prop for the 30.
I have never heard of anyone running a 23x6 on a 30, does it run ok? What revs are you getting?
I was running a 20x8 and it was too fast on landing, I'm going down to a 19x6.
Regards Mark
I have never heard of anyone running a 23x6 on a 30, does it run ok? What revs are you getting?
I was running a 20x8 and it was too fast on landing, I'm going down to a 19x6.
Regards Mark
#338
RE: Balsa USA 1/4 Sopwith Pup build
Does any one have pics of this pup with a dle 30 with rear exhaust mounted with the carb through the firewall and the cowel in the scale position? Pics with out the cowl on?
Thnx
Thnx
#339
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RE: Balsa USA 1/4 Sopwith Pup build
I will take a few today. Just mounted the throttle and choke. I am slow. Have not worked on this build in quite a while, but with the colder weather coming in, I am ready to finish it up.
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RE: Balsa USA 1/4 Sopwith Pup build
Meant to add the following: Standoffs are exactly 1 inch. Perfect to set the adjustment screws just behind the firewall. I plan to use the scale access panel to hide my access holes to allow me to get to the adjustment screws. Once set, I should not need to access very often. If so, I can remove the scale access panel. Or, drill a small hole for easy access anytime. The interior is completely fuel-proofed. if I need to, I can make a cover around the carb, and use the scale exhaust ports to provide airflow to the carb. I just want to make sure I don't get fuel blow-back inside the fuel tank compartment. I built and mounted a brace behind the firewall for the linkages. Very simple to do. I ran my choke linkage to the cockpit (flex golden rod - no metal linkage) and this operates nicely without a servo. Am considering adding a servo for this but is manual for now (like to keep weight down also). I don't like seeing a bunch of stuff mounted to the outside of my planes. I will also install my switches in the cockpit, and mount my batteries and ignition to the front of the firewall. I want everything hidden as much as possible. Still need to cut the cowling to allow for spark plug.
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RE: Balsa USA 1/4 Sopwith Pup build
I may even trim 1/2 inch off the cowling to give it a more scale-like appearance. With the 1 inch standoffs, this gives me extra cowling to work with.
#344
Senior Member
RE: Balsa USA 1/4 Sopwith Pup build
That's a very neat install KD, is that a metal clevis I see on your throttle arm?
Have you maidened yours yet ALO111/Barry? Been crap weather here since last chance.
Regards Mark
Have you maidened yours yet ALO111/Barry? Been crap weather here since last chance.
Regards Mark
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RE: Balsa USA 1/4 Sopwith Pup build
Very nice work KD. You Pup is coming along well. I don't know if I would shorten the cowl. It looks like the prop is about the correct distance from the cowl the way it is now.
#346
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RE: Balsa USA 1/4 Sopwith Pup build
Thanks guys. Like Isaid... I am slow. Too many other things to do. The metal clevis is not permanent and simplly there to check throttle alignment. I will use a Sullivan spring quick link (ball). Also, if I trim the cowl, I would trim off the back and not affect the mounting position. It currently overlaps the fuse almost a full inch. I would trim to just behind the current mounting screws to simply give it a shorter look without affecting the current position. Just a bit more scale-like look. The plan is to be as scale-like as possible, with the convenience built in for flight and engine adjustment. What is interesting with this forum is to see all of the various configurations and ideas. Ihave learned quite a bit! Thanks!
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RE: Balsa USA 1/4 Sopwith Pup build
KD. Just another quick thought. These models are really tail heavy. Mostly due to the short nose. Those old radial engines must have been very heavy. Have you checked the balance yet? You may have to line the cowl with lead.
#348
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RE: Balsa USA 1/4 Sopwith Pup build
Hi Senrak, Ihave read many posts regarding the weight and balance requirements. I am expecting to add quite a bit of weight to the front of the firewall, but will do the final balancing after covering is added, radio component install, etc. Hard to get an accurate weight at this point. I am trying to keep the tail and aft section very light, although I am using the standard pushrods rather than a pull/pull system. I am keeping everything as far forward as possible, but am maintaining minimum distances to avoid any interference issues. Once done, I will post the weight specs.
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RE: Balsa USA 1/4 Sopwith Pup build
I thought I was keeping the tail light on mine. I stuck the engine out as far as I dared, probably a good inch farther than yours. My landing gear is an inch and a half forward of the plans and still I needed 24oz of lead in front. The only way it could have been less is if I had attached it right to the cowl!
Anyway, be aware of what you may be up against. And keep up the great work.
DW
Anyway, be aware of what you may be up against. And keep up the great work.
DW
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RE: Balsa USA 1/4 Sopwith Pup build
Thanks Senrak.
How does yours handle with the gear pushed forward? Does that help the landings and any bounce? I've been watching the posts and have been concerned with the weight. Again, I am planning to mount the batteries up front, along with ignition, so am hoping that this will help to redistribute the weight somewhat. The fuel tank is centered on the CG. I am not planning to mount too much weight directly on the inside of the cowl surface to avoid stress on the cowl mounts. Although, Ihave reinforced the mounts just in case. I can line with some weight to help save room on the firewall. Instead of a flat weight that takes up space on the firewall with a large footprint, Ican use more of a cylindrical shape that will extend out further, and mount with a long bolt and blind nut. Similar in shape to engine standoffs. Your opinion? This would also put weight forward, like your engine being mounted forward. Always looking for ideas!
How does yours handle with the gear pushed forward? Does that help the landings and any bounce? I've been watching the posts and have been concerned with the weight. Again, I am planning to mount the batteries up front, along with ignition, so am hoping that this will help to redistribute the weight somewhat. The fuel tank is centered on the CG. I am not planning to mount too much weight directly on the inside of the cowl surface to avoid stress on the cowl mounts. Although, Ihave reinforced the mounts just in case. I can line with some weight to help save room on the firewall. Instead of a flat weight that takes up space on the firewall with a large footprint, Ican use more of a cylindrical shape that will extend out further, and mount with a long bolt and blind nut. Similar in shape to engine standoffs. Your opinion? This would also put weight forward, like your engine being mounted forward. Always looking for ideas!