Hi Gang

I finished her today and wanted to ask a question to those of you that have flown her.

The weight ready to Fly is right at 37oz and she is producing 23oz of thrust.

My Large Scale Turbine powered jets also run around this Thrust to weight Ratio just wondering what the weight of some other Snipers are?

Also I am pulling right at 400 watts and 26 amps running a Mega 16 15 3 with a CC35amp controller using a Polyquest 4s2p 3100 pack.

I know there are a few Guys hand launcing this Sniper.

Any Opinions?

Ian

Hi Flyjets,
I just finished my Sniper on the weekend as well. My AUW is 37.0 oz too. This includes 1.25 oz that I had to add to the tail to make the C of G work out to 90mm.

I am running Mega 16/15/2, CC-45, and TP 3S2P 4200. Drawing 45amps peak and dropping back to 40 amps or so.

I flew two flights on Sunday. Using bungee launch with slide rails for the model. I have never used a bungee before so things were a bit dicey. I used the rule of 5 lbs bungee force per pound of model. I found this too be a bit soft. My confusion is in how much length of rubber should be used. Can someone help me here ? I had lots of opinions at the field.... The model and pilot both survived the launches. I would not recommend hand launching.

The flights went well, but I have some fine tuning to do on the controller. I think I have to program "low advance" timing. The controller is cutting out after a minute or so at full power. It seems to run at 2/3 power but this is not acceptable. It flys well, lands very nicely with no bad habits.

I wouldn't say it's really fast, although I am a competitive Q40 pylon racer and very comfortable with Q40 racers at 180 mph. I think it scoots along nicely for a sport plane. Haven't had a chance to radar gun it flat and level but I suspect it won't be much over 100 mph or so. I am at 3300 ft above sea level.

Wish you luck on yours.



Randy Smith

Randy,

Glad you got to maiden it! Mine weighs in at 43oz with FAUP packs and about 38 oz with Lipos, so you guy's weight is right in range. As far as Bungee cord goes, I use 30-33 feet of 1/2" diameter x 1/8" wall surgical tubing. I also use both a portable fish scale and a digital fish scale to set the pull. I go for 15lbs on the digital ascale and on the cheap hand scale, it is showing more like 19lbs. The cheaper scale is off by about 4 lbs, so if you used one of them, that could account for your lighter pull.

Carl

Randy

Thanks for the Info I to added 1 Ounce just under the exhaust duct in about 1 from the exit of Thrust tube.

I am curious if you measured how much thrust yours is producing so I can tell if mine is in line with some of you guys.

Even though my setup pulls alot less amps according to Motocalc she should run somewhere around 90 to 110.

27amp is all mine is setup for at this point with the Mega 16 15 3.

The only other item I am not crazy about is the elevator rode to the HS85 servo I used HET fitting on the servo arm and Locktight the locking screw so the rod wouldn't loosen and using there hardware?

What about control throws and is anyone using Flaps or Speedbrake for landing?

Ian

Flyjets & Others
I bought a Sniper kit and a Mega 16 15 3. I have not purchased a controller or battery pack yet. Any suggestions would be appreciated. Also are you using a home made launcher?
Geno

Hi Guys

I just wanted to publish a Photo of my Sniper and make one comment.

In test launching the Sniper I am under the impression that with a good toss the model will fly given 23 onces of Thrust and a launch weight of 37 Ounces.

Gborn

I run a Castle Creations 35amp contoller and a 4s1P3100 Lipo from Polyquest.
Ailerons are 2 HS81 and Elevator is 1 HS85 HiTec with a Electron 6 and a Revolution Antenna

Ian

Flyjets
Sorry for the delayed response. I have not measured my static thrust. Doesn't really concern me
My Mega 2T pulls about 45 amps on a TP 3S2P 4200. However, I think my inner duct tube is effectively pinching the exhaust nozzle to around 40 mm or so. I think this is bumping the amps up a bit. Some are opening the exhaust nozzle to 56mm and having better performance and reducing motor cut out.

I am using Hitec HS-56 on the elevator and ailerons. I just put a Z-bend in the servo end and Hayes plastic clevis with steel pin on the elevator. I set up the throws as per instructions but I find them a bit sensitive. However, I tend to prefer my controls soft. Set up a high and low setting on your dual rate switches and you'll be fine.

Carl, thanks for the tips on the bungee. Yes, I was using a cheapie spring scale. therefore likely softer than indicated.
30 - 33ft of rubber. Do you use any monofilament fishing line or other leader running from the rubber to the model ? If so how long ?


Randy

Randy...

Go here to a post that has links to my bungee launcher and all the parts and a lot of pics...it should explain it better:

http://www.rcuniverse.com/forum/Help...2370992/tm.htm

Carl

Hey Guys,

I'm almost done putting my Sniper together. Does anyone have any suggestions on mounting landing gear??

Thanks,

Ed

Hi Ed,

I got your e-mail. see the pics on post 73 of this thread http://www.rcgroups.com/forums/showt...2&page=5&pp=15
The nose gear is a robart 1/2 A. The mains were built with plywood on the bottom and bass on the sides. 4-40 bolt for the axles. styrofoam blocks in front of and behind gear were sanded to shape and painted white.

Darren,

Hey guys I just made a bungee laucher , using 20 feet of bungee cord, 10 feet of light rope with a leader of 6 inches with rings attached. The cool part is the laucher is servo actuated by a female plug on the belly of the plane, with the male end of the servo plugging in it going to the gear channel, So far ten plus flights have proved flawless!. I used 15% on the rail angle, A little up input at lauch, you'd think it was taking off a runway! I'll take a pic and post!

Servo accuated launch..... now that's COOL. [sm=thumbup.gif]

Would love to see pictures.



Randy

Ok. here is a few pics , I made it quick and simple! It works flawless!

Hey Mark,

Thanks for the info on the landing gear. I found that when I bent the main landing gear so it wound squat a bit, take offs were much better although it takes some footage to get it off the ground. On the 5th flight today, I was so fortunate to get a really nice glitch and put it in. Our field has been blessed with RF. Has anybody out there had problems with their JR R610UL 6 channel receivers?? Please let me know if you have had a glitching problem!! Before the crash I must say that this plane just rocks! We had our jet fly this past weekend and you will probaly get a bunch of calls from guys our here in California. Thanks again for your help and put me down for two more!

Ed