RE: HARMON ROCKET
 

I"m thinking about putting an OS 50 in it, what are you thoughts? Is that enough motor? Should I go with my trusty Saito 82?

Regards,

Chuck

RE: HARMON ROCKET
 

I would say it depends on what you want the plane to do. I am thinking I will take the Saito out of mine as I use it as a funfly plane and the saito 82 is overkill for this. I have a 46fx I am going to try and see how it flies. I think I will find another home for 82?

RE: HARMON ROCKET
 

Hi all,
I've got the servos at the back and a Saito '65 at the front running an APC 13x6 and the balance is spot on. I've no stall problems even when using flapperons just the elevator goes a bit mushy. It takes off in about 25 feet and flies in whatever wind we have, in fact it flies so smoothly two others at my club now want one. I think the u/c must have been up-rated slightly as my landings are not he best and we fly on rough moorland, yet no bending so far (12 flights). I have reinforced the spats and modded the engine mount to take the saito but other than that it is stock.
Dave :^)

RE: HARMON ROCKET
 

Hey guys,

I picked up one of these planes today. I just came up from the work shop after about 2 1/2 hours of working on it, and am very happy with how quickly and easily it is going together. I wish I would have checked this thread first. I think I would have made a U wire and eliminated a servo for the elevator. I was a little surprised that they have it all set up for 2 elevator servo's.

I am going with an OS .61 fx. I was a little concerned that might be overkill, but after reading through all of your posts, I am confident that the .61 is a good choice. Sounds like the extra wieght will be a positive and not a negative. I have a .61 in a hanger 9 twist, and find it to be a great running and powerful engine. The manual mentions a muffler extension. Did any of you guys using the 2 strokes need one of these? I think the muffler on the .61 sticks out a bit further anyway. Any advice on this would be appreciated.

I don't think I am going to reinforce the landing gear or undercarriage at this point. I usually wait until I rip the gear off once or twice before I do anything that would make as much sense as reinforcing the gear.

I included a couple of pictures of the .61 for those that are interested.

Adam

RE: HARMON ROCKET
 

I opted for a Bisson Pitts muffler on my .46 powered Rocket. I have since seen a Slimline Pitts that might not have necessitated removing so much of the underside of the cowl. At least, I can remove the cowl without having to take off the muffler. The stock muffler would have required removing quite a bit of the cowl also, and I"m well pleased with the Evo .46, pitts muffler and 11.5x7 APC prop combo with all 3 servos in the tail. Your .61 powered plane should be a screamer.

The gear legs are a bit "springy" which helps soften landings. I bent one on a hard crosswind landing, but simply bent it back and everything's fine. You may find the wheels take on a "toe out" attitude after several flights. Mine have, but cause no problems with ground handling. I will eventually remedy this, though.

RE: HARMON ROCKET
 

A neighbor of mine had one that he used to fly on our golf course (yes, I strongly advised him against this!:eek:)

He had an older OS FX .60 on it and it was just a monster! Very quick! Unlimited vertical.
He did eventually manage to piss off a couple of our "afterhour golfers" and this practice quickly ceased.

His biggest complaint was definitely the gear, pretty much bent every time he landed but, very
gorgeous airplane. Handled 10mph winds nicely and knife-edges were stellar.

Congrats to all who has purchased one, looks like a lot of fun.

RE: HARMON ROCKET
 

Hi all,
just a thought but has anyone here had a servo fail? I have years ago and it wasn't nice (a Futaba 128), so I'm pleased to have two elevator and two aileron servos just in case. Half an elevator has got to be better than none!
Dave :^)

RE: HARMON ROCKET
 

Dave,

I was thinking along those lines as well. Being that it is quite tail heavy with a .46, it almosts seems like they engineered the plane thinking people would put bigger motors in it. It being a plane built with speed in mind, and knowing guys will hop it up, maybe the 2 elevator servo's makes sense. not only would it cut the loading of each servo, but if one failed you may have a chance of landing with only one servo working. I know this is the theory in the larger planes, whether it is necessary in a plane of this size or not seems to be the question.

I guess if more tail wieght is not a big issue for you, it certainly can't hurt. I am going to stick with standard 3004 servo's being I have two on the elevator. I will go standard for the rudder as well. I may go with beefier aileron servo's just in case. Are you guys using standard servo's on this thing?

Can't wait to get home and keep going on construction. Picked up the misc. parts I needed at the LHS. Hope to have her in the air this weekend.

Adam

RE: HARMON ROCKET
 

Hi Adam,
get that plane finished, you.ll love it. I've just got standard servos in except for the ailerons which are 6.5Kg ones. with the rx and battery attached to to servo tray and the tank empty it balances 3 1/4" back from the LE with only the Saito '65 for front end weight. I'm using a muffler from a firm in the UK called Just Engines and it has a lovely quiet growl. With a 13x6 APC it's pretty fast but not excessively so I'll try and get it on video but the first attempt was a failure, my cameraman couldn't keep up with it! never the less he's gone and ordered one! I think I may upgrade the u/c to a carbon one but not at the moment as opposed to the trend it seems to be holding out OK although it has gone a little toe out. I fly on the fells on the edge of the Lake District where it's a little windy which isn't a problem, in fact it's a help to slow it down for landing. a Saito '80 would probably be nice but even with the '65 I can take off in about 25 feet and climb out at 45deg. Don't listen too much to the grumbles, the earlier ones don't seem to have been as well made, (especially the blue u/c) for the money (90GBP over here) you're getting an impressive little model.
Enjoy
Dave :^)

RE: HARMON ROCKET
 

Dave,

Thank you for the reply. Glad to hear that they have made some improvement on the undercarriage. It seems plenty sturdy, but I have had my shar of landings where a gust balloons me up only to stall out and drop the plane like a rock from 4ft off of the field. Sometimes the give in the struts, and in extreme cases, the gear sheering off, is a good thing to protect the plane in real hard landings. I suspect that your Saito is lighter than my O.S. I amy have to mount the battery pack back a ways, but I am determined not to add any more wieght.

The build is going very well and I am impressed with the hardware. Trimming the cowl has been the most time consuming part so far. Would love to see a video of your in action!

Adam

RE: HARMON ROCKET
 

Hi Adam,
I've uploaded a small video to my website - the quality isn't great but I've edited out hours of blue sky and ended up with a take off and a slow circuit! the file is about 2.5Mb
got to www(dot)qsl(dot)net/m5txj/planes.htm
Dave :^)

RE: HARMON ROCKET
 

Dave,

I went to your site and viewed the video. I enjoyed it very much. Gotta love the sound of a four stroke. Beautiflul area you fly in. FYI- I tried to sign your guest book, but it appears it didn't get through.

Construction is coming along good. I am guessing I have 5 to 7 more hours of construction and setting everything up yet to go. If it takes me 6 more hours, that would be a total of 17 hours start to finish. This will include centering all servo's, setting endpoints, and all fine tuning needed to get her in the air. I would have to say this is one of the fastest ARF's I have put together. This is my first Seagull model, and I am impressed with it. Little things like the canopy being on, the hinges being preslotted, and the engine mount being predrilled with the blind nuts in place have made this a pleasant experience.

The only complaint I have thus far is the manuel could be a little more thorough in a couple of areas. If memory serves, I think that the picture in the manuel showing the step where you glue the white wooden washers to the wing over the nylon bolt holes shows them mounting them on the top of the wing instead of the bottom. I had to look that over a couple of times before it dawned on me that they wouldn't do any good on the inside or top side of the wing, they were meant to dispurse the pressure of the nylon bolt head on the outside of the wing. There were a couple other spots where you got a series of pictures without much of a description. I just had to look them over a few times, and I was able to figure everything out. Overall I thought they did a good job laying things out in the manuel.

Adam

RE: HARMON ROCKET
 

Adam,
I've been having one or two problems with my guestbook but glad you enjoyed the video. I did get another take off but the run was about 6ft :^)) and I was called a bl**$y hooligan! Because of work, I won't be out flying for a week although I'll try to get some better video next time.
Dave :^)

RE: HARMON ROCKET
 

I got one of these about a month ago. I have a Saito 100 in it. i had to move the firewall back about 3/4 inch to have the spinner correct and still ended up putting 2.75 ounces behind the goofy looking pilot. I like the gear as it seems to float along the grass, but it doesn't spend much time on the ground. I was pleased with the way it handles the wind and we almost always have a crosswind. I had a 14x6 prop, but I found when I pulled it back ti idle, it would act like an airbrake and get real squirrelly. I replaced it with a 13x8 and it really comes in nice.

RE: HARMON ROCKET
 

Got mine finished today. I managed to get it to balance out without adding any wieght. In order to accomplish this, I had to move the receiver battery back to just in front of the servo's. I made a removable balsa panel that I can insert from the wing opening. I am anxious to maiden it tomorrow. I will post a couple of pics of the finished product tomorrow.

Adam

RE: HARMON ROCKET
 

Well done Adam,
expect to come home to "what are you grinning about" mine balanced without any weight added at 3 3/16" from LE and it seems near enough.
Dave :^)

RE: HARMON ROCKET
 

Haven't had a chance to post an update in a few days, but I have been flying the wings off of my Harmon Rocket all week. I have to say that the plane flies really well. It goes through the air nice and straight, and is very streamlined. It makes a nice hum when you do a high speed pass from the air moving across that huge cowling.

I must have gotten the old landing gear because mine are very weak. They flex quite a bit when the plane is just sitting on the tarmack. I will have to make some new landing gear at some point.

You have to land the plane with some pretty good speed. Our runway is smaller than ideal for a plane of this size and speed. The thing looks really nice coming in. You have to be carful not to pull in too much up elevator or you get an exagerated flare.

Overall I am very pleased with my new purchase. The .61 with an 11x7 has power and speed to spare. I could use a bigger fuel tank. I only get about 10-12 minutes flying time. The smile factor is definately there!

Adam

RE: HARMON ROCKET
 

Welcome to the BIG GRIN club! I've posted a slightly longer video - scenic view of flying site + same flying + crap landing on http://myweb.tiscali.co.uk/kirkbyflier I hope to add one or two other short videos soon.

RE: HARMON ROCKET
 

Dave,

I enjoyed the additional footage on your video. I have had a couple of landings like that myself. I just got back from a couple of flights with gusty winds around 12-18 kts. There was a bit of a crosswind as well. I thought she handled then quit well. I did have a couple of hard landing due to the wings rocking back and forth with the wind gusts. The gears bends and takes most of the impact. No damage was done to the plane.

I went from an 11x7 to a 12x7 apc prop, and she slows down much better. The engine seems to handle the extra load with no problem. It is not quite as fast due to decreased RPM, but the extra thrust shortens the take off run to next to nothing.

Adam G

RE: HARMON ROCKET
 

Perhaps the gear is designed to be "shock absorbing" Adam ;^p it seems to work that way!
Dave

RE: HARMON ROCKET
 

Dave,

I am not sure that "springs" were in the engineering plan when they designed thsi landing gear, but that sure is what they got. As mentioned earlier, they do tend to toe out so to speak. Even on a normal landing mine tend to bend a bit. I just bend them down as I pick up the plane. I have a buddy who is a machinist. I may take one off and make a template for him so he can make me some new ones that are a little stiffer. I am just concerned that I may put a wheel pant throught the bottom of my wing on a hard landing.

The good thing is the landings seem to be getting better. I am putting the wheels down with more airspeed and then just bleeding off speed with a small amount of up elevater. The toe out condition of my gear helps slow me down as well.

I have gotten several compliments about her looks. The guys at the field really like the wide body and big cowling.

Adam

RE: HARMON ROCKET
 

Here's Mine. I originally had a Magnum 52 in it. Flew well but the engine just wouldn't idle right. Since these pics were taken I put in a Magnum 40. Flies just as fast as the 52, plus is lighter. I run a 11-5 APC prop. I spent a little time cutting the bottom of the cowling to glove around the muffler just right. It looks good and is a slick little airplane. It does have a slight tail wag that seems to be a trademark of a lot of Seagull airplanes.

RE: HARMON ROCKET
 

flyingvranch,

Your plane looks great. That is a really nice job you did of cutting out around the cowl. I am happy with the way mine turned out, but it is not as close as yours. I am surprised that the .40 is enough power for you. I suppose it is quite a bit lighter, so that helps a lot. A .61 is overkill. I fly it at half throttle most of the time. I like the extra power for vertical climbs mostly. I bet the added fuel economy is nice. How long do you get out of the stock tank?

Adam

RE: HARMON ROCKET
 

Adam,
Thanks for the compliment. I just used a Dremel Tool with a small 1/4" sanding drum to gradually enlarge the opening till it fits just right. It isn't difficult really, just takes a lot of patience. The Magnum 40 is running pretty good with this plane and I really don't have any complaints with it's performance. It's not going to outrun a 60 in the straights, but it's still pretty darn fast. It's pretty funny to blow by some of my friends in their giant scale whatevers and I've earned the name flash. LOL Anyway it's a good "goes where you point it" airplane. I still use the stock tank but I usually only fill it just over half full. I usually get about 15 minutes of full throttle stuff with that amount.
Bud

RE: HARMON ROCKET
 

flyingvranch,

I used the same exact technique, and even the same sanding wheel that you did. I think the patience part is what I was lacking. I kept grinding a little bit, and then putting it on the plane, then taking it off and grinding it some more. The last try I decided to make it my last, and ground out about a 1/2 too wide by about 1 1/2 inches too long. Luckily it is on the inside of the plane, so you can't see it when the plane is sitting on the ground. Oh well, hind site is 20/20. Next time I will take the extra 10 minutes.

That .40 of your is really efficient! I am lucky to get more than 10 minutes on a full tank. I set my timer for 10, and when I bring it down I am lucky to get a couple of cranks of fuel back out of the tank. I haven't ran it dry yet, but I am sure that I will. I have to admit that I have a lead thumb. I just love to see her fly by at mach 10.

Adam