SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Aug 17, 2008, 02:16 AM
Park Jet Guru
jetset44's Avatar
Seattle, WA
Joined Jun 2002
5,605 Posts
MileHi,
My TP 2100 packs weigh 5.0 oz, and the 3 quarters I have in the nose add around another ounce.

FYI, I think the Grayson 2212-06 and LS Super Park Jet are roughly equivalent in performance and are ideal motors for my 100%-sized park jets. The LS motor weighs less and draws fewer amps, but also costs more. The regular LSPJ is a smaller motor, and is more appropriate for a slightly smaller model, though it can power a 100% OK (though it strains a bit to do so). Roughly speaking, the regular LSPJ is ideal for a 26" span/18 oz park jet and the other two motors can handle a 28" to 30" span/20 to 25 oz park jet.

Steve
jetset44 is offline Find More Posts by jetset44
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 17, 2008, 10:08 PM
Registered User
MileHiFlight's Avatar
Longmont, Colorado
Joined Jun 2005
115 Posts
Hi Steve,

Many thanks. 3 Quarters is about .6oz. The Grayson 2212-06 (54gr) is still a bit heavier than the LS Super Park Jet (32gr). I assume you balanced with the LSSPJ. So a set up with the Grayson would probably still need extra nose weight. I am going to try to save some money and run with a Zippy-H 2200 (190gr) which also gives me some extra peak current head room. This should balance the weight of the Grayson(s).

One mod I am looking at is to reverse the thrust vector control arm linkage so that the pushrod will be in compression when the prop hits the ground on landing. (Not all of us can catch as well as you ). The idea is that the push rod will bow in case of a prop strike, instead of directly yanking on the servo. I played with it a bit, and the long unsupported push rods bow quite nicely.

-Nick
MileHiFlight is offline Find More Posts by MileHiFlight
Reply With Quote
Old Aug 18, 2008, 07:07 AM
Bob Templeton
T3chDad's Avatar
USA, AL, Huntsville
Joined Apr 2007
3,928 Posts
I hate paint. Not because it's difficult or unpleasant, but because it amplifies every little imperfection in the finish. I did one coat of WBPU/baby powder over the entire model, sanded the entire model, coated the top again, and sanded again. I ran my hands over the entire model and it was smooth as a baby's bottom. Then I shot the bottom of the model in white and the top in the lightest gray of my paint scheme. Every little bump or hole seemed to magnify with paint.

Oh well, I should have remembered that from my plastic model days as a kid. She does look great though....starting to look like a real Su-37! Sorry, no pictures until she's finished. Top Secret.
T3chDad is offline Find More Posts by T3chDad
RCG Plus Member
Latest blog entry: RC Flight Log Update!
Reply With Quote
Old Aug 18, 2008, 07:23 AM
Registered User
Eindhoven
Joined Jul 2007
153 Posts
CG and flex pushrods

Hi Nick,

My SU is nose heavy !!
2 x 2212-06 motors, 185 gram battery pack. KOKAM 1800 H5 type 3S
I took care to make the rear light and the front strong.
Only 2 servo's HT85-MG mounted at the wing spar location.
Elevons and motors directly coupled.
ESCs fully forward in the nacelles
Front is fibre glass covered with 44 grams glas and WBPU.
And then there are the LED's at the back and switch servo in the front..

push-rods are 2 mm carbon. This is flexible !. Actually I would use stiffer push rods next time. It feels scary. 3 mm carbon tube should be nice.
So far one servo came loose but I think a storage / transport issue., but never a broken prop. It lands so smooth... no worries here.

For the elevon spars I used 3 mm carbon tube in stead of 5 mm. Not very smart this is scarily flexible as well. I thought the smaller diameter would be nice for servo force, friction under high aerodynamic load could be substantial. But these HT85's can handle a lot!

Nothing to worry thrust wise with 2 x 2212-06.
I use quite small props as with the motors inside the exhausts they should not touch. Still > 1 Kg thrust (36 A static, nearly 20.000 RPM) and just under 900 grams weight.
You could still consider LSPJ's, should be better quality . Ive had a few problems with my 2212's, loose bearing, bad bearing, one retainer clip came loose.. fortunately it is a pusher because I can not remove the motors any more.

Tjarko
tjarko is offline Find More Posts by tjarko
Reply With Quote
Old Aug 20, 2008, 04:47 PM
Registered User
Joined May 2008
77 Posts
hey all, after a few flights on my SU i am starting to realize that I may need to upgrade my remote. I am using a DX6i which in 'elevon' mode does not seem to give me much control authority over the teilerons. I have the controls turned up to 125% on all 4 servos that run these control surfaces, yet the throws are short. I did all of the hardware exactly to specs. anyone else had this problem?
Tim6806 is offline Find More Posts by Tim6806
Reply With Quote
Old Aug 21, 2008, 09:12 AM
Bob Templeton
T3chDad's Avatar
USA, AL, Huntsville
Joined Apr 2007
3,928 Posts
Sounds like a mechanical limitation. What holes in the servo horns and control surface horns did you use? I use a DX7. I actually had to tame my elevator throws and mixes and add a bunch of expo.
T3chDad is offline Find More Posts by T3chDad
RCG Plus Member
Latest blog entry: RC Flight Log Update!
Reply With Quote
Old Aug 21, 2008, 12:14 PM
Registered User
Joined May 2008
77 Posts
i used the 2nd furthest hole in the servo arm and the 2nd closest hole in the stabilitor which should give me near maximum throws.... my dad has a Dx7 and in elevon mode it allows him to have full throws on his control issue, it must be a controller issue.
Tim6806 is offline Find More Posts by Tim6806
Reply With Quote
Old Aug 21, 2008, 12:59 PM
That thing's operational!
birdlives1955's Avatar
New Orleans/Dallas
Joined Jan 2006
4,706 Posts
The control authority problem sounds, as T3chDad pointed out, a mechanical set-up problem. Just FYI, the most control throw you can get from a servo arm is to put it on the last hole at the end of the arm (the one furthest away from the actual servo, the 3rd one). This gives the servo's control arm the most leverage.
However, it's different on the control horn that is for a control surface. The most control throw that you can get from a control horn on a control surface is to put the control rod wire in the 1st hole, the one nearest the center of the control horn itself. This is because distance that the control rod that's attached to the servo moves doesn't change once it's attached to the servo, and the most leverage you can get from it for the control surface's control horn is to attach it at the closest possible point to the control surface, which is the first point on the control horn.

Hope that helps! If you have already painted your Su-37, I guess it would be sort of a drag to change this now... However, it might be worth it just to fix it and then maybe it would be more fun to fly. I've got an F-16 with this same problem and someday I really want to just fix it, but for now I'm just enjoying flying it slowly and doing dives/loops, but it can't do a roll unless you point it straight up and have plenty of room for a possible stall since it turns so slowly.
birdlives1955 is offline Find More Posts by birdlives1955
Reply With Quote
Old Aug 21, 2008, 07:31 PM
Registered User
Joined May 2008
77 Posts
Yeah, I understand that, the only reason I went 1 hole from the outside was because I am using thick control rods and I had to bore out the holes bigger to get them to fit. It isnt a hardware problem because I only have this control throw problem when I have it set on flaperon mode. I have built 4 of Steve's F-22s so I am more than familiar with the TV setup. I ran into this problem with Rc Superpowers F117 as well, as it is a flaperon setup. I just wanted to consult with anyone who has this TX to make sure I am not missing something on the remote.
Tim6806 is offline Find More Posts by Tim6806
Reply With Quote
Old Aug 22, 2008, 07:28 AM
Bob Templeton
T3chDad's Avatar
USA, AL, Huntsville
Joined Apr 2007
3,928 Posts
Tim, you might try clearing the program and starting fresh. While the display is different, since your dad's DX7 seemed to work well for you, you might use that as a reference.


Side note: I'm almost finished with mine. It's been in the top-secret finishing hanger all week. Just a few more things left to do....panel lines, decals, engine exhaust, and clear-coat. I'm sure I'll have something to show you by the end of the weekend.
T3chDad is offline Find More Posts by T3chDad
RCG Plus Member
Latest blog entry: RC Flight Log Update!
Reply With Quote
Old Aug 24, 2008, 05:42 PM
Bob Templeton
T3chDad's Avatar
USA, AL, Huntsville
Joined Apr 2007
3,928 Posts
She's Done!!!!

I finally finished her. Here are the pics of the finished product. As I said before, inspiration for this was the arch-nemesis Yellow 13 from Ace Combat 4.

Finish is WBPU/Baby powder, then craft paint airbrushed-on, then one last shot of clear-coat. Panel lines were made with a black pen. I made the decals from scratch. First I tried water-slide decals and that just didn't work for various reasons. I ended up printing them on CD label paper and applied them before the clear-coat.

All in all, it's been a fun build. I almost can't believe I made this out of two sheets of depron.

Steve, thank you very much for your work. I love this plane .
.
T3chDad is offline Find More Posts by T3chDad
RCG Plus Member
Last edited by T3chDad; Aug 24, 2008 at 05:57 PM.
Reply With Quote
Old Aug 24, 2008, 06:35 PM
Park Jet Guru
jetset44's Avatar
Seattle, WA
Joined Jun 2002
5,605 Posts
HOLY MACKERAL!! That ship is BEAUTIFUL, T3chDad! Just fantastic craftsmanship. You're welcome for the plans--I'm certainly thrilled to see what you've done with them!

Steve
jetset44 is offline Find More Posts by jetset44
Reply With Quote
Old Aug 24, 2008, 06:38 PM
Park Jet Guru
jetset44's Avatar
Seattle, WA
Joined Jun 2002
5,605 Posts
My latest project

This is off-topic, but I thought you park jet fans out there might enjoy seeing my latest project—a Depron version of Laddie Mikulasko’s beautiful Northstar seaplane, which I’ve dubbed the Polaris. This model spans 29” , uses the same construction method as my park jets designs, and is powered by a Grayson 2212-06 motor. I test flew this model a couple days ago, and it flew AWESOME!! Super stable and smooth as silk in the air, with excellent handling qualities throughout the flight envelope. Top speed is an easy 70+ mph, yet it slows down to a stable 10 mph high alpha crawl at the low end. Plus, with the prop right in front of the elevator and rudder, it handles like one of my thrust-vectored park jets with precise control at even the slowest speeds (plus the ability to do 5 ft diameter loops!). Even better, the model took off from grass in about 10 feet and could do easy touch and go’s off the grass. I hope to make the first flights off water in the next few days, but given how easily it handled the grass I have no doubt it’s going to fly well off of water.

I’ll post plans for this bird after I get time to update the beta plans with all the fixes learned during the build. Since this isn’t a pusher prop jet, I won’t post them in this forum, but instead probably in the Foamies scratchbuild forum.

Steve
jetset44 is offline Find More Posts by jetset44
Reply With Quote
Old Aug 24, 2008, 06:42 PM
KK6MQJ
Bajora's Avatar
Joined Sep 2004
13,621 Posts
Awesome job T3chDad! Wow, that baby looks VERY crisp!

Looking forward to some in-flight photos!
Bajora is online now Find More Posts by Bajora
RCG Plus Member
Old Aug 24, 2008, 06:46 PM
Registered User
HULL, UK
Joined Jun 2007
84 Posts
very nice T3chdad, you have done a fantastic job

Singion
singion is offline Find More Posts by singion
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log Super Bandit Park Jet jetset44 Pusher Prop Jet Models 1084 Jan 07, 2014 12:52 AM
Discussion SU-38 super Flanker... pps/ going e-power Insanety Pusher Prop Jet Models 2 May 02, 2008 09:47 AM
Video Sukhoi Su-37 Maiden Flight Nadim Electric Plane Talk 2 Jul 12, 2007 04:41 AM
For Sale Walkera SU-27m/SU-35 Super Flanker $100 skotbro Aircraft - Electric - Jets (FS/W) 3 Dec 06, 2006 08:42 AM
Power set up for Great Planes Sukhoi SU-31 3D Profile Park Flyer Airplane? ChrisK7 Beginner Training Area (Aircraft-Electric) 0 May 14, 2005 06:15 PM