Go Back  RCU Forums > RC Airplanes > ARF or RTF
Reload this Page >

New Giant GP Super Sportster!!!!!

Community
Search
Notices
ARF or RTF Discuss ARF (Almost Ready to Fly) radio control airplanes here.

New Giant GP Super Sportster!!!!!

Thread Tools
 
Search this Thread
 
Old 04-19-2013, 05:43 PM
  #2526  
Charlie P.
 
Charlie P.'s Avatar
 
Join Date: Feb 2003
Location: Port Crane, NY
Posts: 5,117
Received 8 Likes on 8 Posts
Default RE: New Giant GP Super Sportster!!!!!

They are 38" floats from Maxford USA. Rugged and light, but thehardware they send with them is crap. Ihad one float curl into the prop while taxiing. Iswitched to two Duraluminum straps andcutsome 1" aluminum stock tomake float fittings. Moved thestep back so it sits morelevel at restas well. Iunderstand they have improved the strength of the aluminum straps for "V2.0" http://www.maxfordusa.com/hz-40-fiber-floats-3-1-1.aspx

They are too short for use with the Super Sportster . . . probably. A float should be 80% of fuselage length(prop washer to rudder hinge line x 0.8).



Old 05-19-2013, 12:34 PM
  #2527  
Joystick TX
 
Joystick TX's Avatar
 
Join Date: Aug 2008
Location: Diamondhead, MS
Posts: 1,448
Received 9 Likes on 8 Posts
Default RE: New Giant GP Super Sportster!!!!!

Had to send my old engine into the manuf. for repair. At this time of year, it takes a while to get it back, soooo.

Decided to try the DLE 35R on the GSS to see how a little more power would be. Sincethe DLE weighed about four oz more than my old engine and it was going from a three-bolt engine mount to a four-bolt pattern,I decided to remove the engine box I had built for my Syssa 30 and mount the DLE directly to the firewall.

I didn't check the CG before flight because according to my TLAR engineering math, a heavier engine movedtoward the rear MAY cancel outand leave the CG alone or hopefullythere would not be a large amount of change.

Seems like there was quite a bit of change. It was hard to get the plane to land, it just wanted to float down like a parachute. It was pretty tail heavy. When going inverted, from level flight, the plane would climb out at about 2 or 3 degrees. Had the opposite effect with the old engine, always needed a little down elevator to keep level flight.

I just measured it and it was 3/4" farther back than usual. Wound up at 71/4".

It is still a great flying plane and no crashes or really bad landings, but I would not want the CG any more to the rear. I may leave it this far back, it may do some great flatspins now.

The DLE had only 15 min. run time before the first flight. It was easy to start, ran great, sounded great and the idle was solid at 1,700 to 1,800 rpm. Great vertical performance. Got another hour of fun on the airframe. Using a 19x10 prop right now. May go to a 22" after break-in.
Old 05-19-2013, 07:20 PM
  #2528  
ahicks
My Feedback: (2)
 
Join Date: Aug 2008
Location: Waterford, Mi/Citrus Springs, Fl
Posts: 3,821
Received 19 Likes on 17 Posts
Default RE: New Giant GP Super Sportster!!!!!

You REALLY need to watch it on short final, sometimes holding down elevator to keep the nose low enough to maintain airspeed? Quite disconcerting for a rookie pilot, but fun to play with for those willing/able to pay attention to little things like airspeed? Gone are the "landomatic" features found when using a CG closer to that recommended. Found is the planes ability to float at speeds that are "just not right"! ;^)

I would add enough nose weight to keep it from climbing inverted though... to help keep the plane safe enough to fly tomorrow. -Al
Old 05-20-2013, 04:32 AM
  #2529  
Joystick TX
 
Joystick TX's Avatar
 
Join Date: Aug 2008
Location: Diamondhead, MS
Posts: 1,448
Received 9 Likes on 8 Posts
Default RE: New Giant GP Super Sportster!!!!!

Adding weight to an airplane is against my religion. Spent too manyyearsas an engineeron the F-16, IDF and JSF. Same thing for drag counts, but at model speeds I'm not so anal about them.

Before I mount the new cowl, I may add 1/2" to 3/4"standoffs to the firewall; according to my TLAR math it should makethe balanceclose to neutral.

It is interesting to fly like this. I made about 80 landings with no problems. If I don't give it some down elevator, it does not have enough forward speed to flare, it just plops down in a three-point attitude. With a little wind it willjust fly back wards. Cool.

Old 05-20-2013, 05:17 AM
  #2530  
ahicks
My Feedback: (2)
 
Join Date: Aug 2008
Location: Waterford, Mi/Citrus Springs, Fl
Posts: 3,821
Received 19 Likes on 17 Posts
Default RE: New Giant GP Super Sportster!!!!!

Regarding 'ballast', came from the same school.

I know you've been flying forever, but when I went from 2 nicad packs (1 sub C, 1 aa) stuffed up in the nose, to a single 2300 LiFe, I had to move the ign. module as far forward as possible. Then I tie wrapped a piece of ply to the upper standoffs to mount the battery on. Last, I got rid of my HD metal pushrods in the tail and replaced them with carbon fiber. This left me with a fairly manageable plane - but nothing I would recommend for anyone without some 3D experience? This is with the Syssa up front. -Al
Old 05-20-2013, 07:24 AM
  #2531  
MKnutson
 
Join Date: Sep 2003
Location: Shoreline, WA
Posts: 97
Likes: 0
Received 1 Like on 1 Post
Default RE: New Giant GP Super Sportster!!!!!

Just finished up the GSS, and maidened it on Sunday. It is a nice change back to old school from the extras and yaks.
This plane lands so nice it would make anyone look good. Iv'e got one of the new OS GF40 4 stroke engines on it and I think this combo is going to be hard to beat.
The engine was a little bit of a pain at first, then it started to come around real good, after each flight it was getting smoother and higher rpm. Now running a Xoar 19-8.

Mark
Old 05-20-2013, 09:40 AM
  #2532  
Joystick TX
 
Joystick TX's Avatar
 
Join Date: Aug 2008
Location: Diamondhead, MS
Posts: 1,448
Received 9 Likes on 8 Posts
Default RE: New Giant GP Super Sportster!!!!!

I think I'll move my batteries about 12" forward. Still using two 2000+ mA NMH packs, they are pretty light, but it will make some CG difference. The ignition module is already pretty far forward. Not much else can be moved forward, except the engine.

The OS 40 4-stroke gasser sounds like a great engine for the GSS. It should also be pretty quiet.
Old 05-27-2013, 09:29 AM
  #2533  
Joystick TX
 
Joystick TX's Avatar
 
Join Date: Aug 2008
Location: Diamondhead, MS
Posts: 1,448
Received 9 Likes on 8 Posts
Default RE: New Giant GP Super Sportster!!!!!

Just finished the first gallon of fuel through the DLE 35ra and the engine started acting like a WWI fighter plane engine, burrrrp, burrrp, etc. and would not pick up rpm well at all. Long story short, the ignition module developed a strange problem. All my regular tests passed okay, so I looked at the timing with an O'Scope. The chart shows a good A-01 ignition module along with the bad A-02 Ignition module for the DLE 35.
Attached Files
File Type: pdf
Ki19915.pdf (168.5 KB, 95 views)
Old 05-27-2013, 05:53 PM
  #2534  
ahicks
My Feedback: (2)
 
Join Date: Aug 2008
Location: Waterford, Mi/Citrus Springs, Fl
Posts: 3,821
Received 19 Likes on 17 Posts
Default RE: New Giant GP Super Sportster!!!!!

Seems to me I was reading there was a problem with some of the 35 modules early on when they were first coming out - and maybe the plug boot?
Old 05-28-2013, 04:22 AM
  #2535  
Joystick TX
 
Joystick TX's Avatar
 
Join Date: Aug 2008
Location: Diamondhead, MS
Posts: 1,448
Received 9 Likes on 8 Posts
Default RE: New Giant GP Super Sportster!!!!!

ahicks - Did you look at the attachment?

The chart was made from data obtained using an ignition tester to simulate the output from the Hall sensor at various RPMs. The data points on the graphare the RPMs measuredat 1 mSec intervals.

I don't know how it would bepossible for the plug boot to cause a repeatable 3 mSec timing jump at the same RPM.
Old 05-28-2013, 11:32 AM
  #2536  
SkyPilot101
Senior Member
 
Join Date: Jun 2007
Location: Freedom, PA
Posts: 574
Likes: 0
Received 0 Likes on 0 Posts
Default RE: New Giant GP Super Sportster!!!!!

Mark! You don't think you can get away with putting that OS-40 four stroke in a GSS and not post some pics at least, eh?
Old 05-28-2013, 01:18 PM
  #2537  
ahicks
My Feedback: (2)
 
Join Date: Aug 2008
Location: Waterford, Mi/Citrus Springs, Fl
Posts: 3,821
Received 19 Likes on 17 Posts
Default RE: New Giant GP Super Sportster!!!!!

I looked at it Steve, but had no clue how to interpet what I was seeing.
Old 05-28-2013, 06:07 PM
  #2538  
Joystick TX
 
Joystick TX's Avatar
 
Join Date: Aug 2008
Location: Diamondhead, MS
Posts: 1,448
Received 9 Likes on 8 Posts
Default RE: New Giant GP Super Sportster!!!!!

ahicks - Sorry about that, hope this helps:

The vertical scale represents the timing delay, provided by the ignition module, in one mili-second increments, i.e. on the A-02 chart, the 10 represents 0.010 seconds (10 mSec).
The horizontal scale represents the proprpm at each whole mili-second value, i.e. on the A-02 chart, the rpm of 1000 would have a timing delay of 0.003 seconds (3 mSec).
At a little over 4100 rpm, there is no “programmed” delay from the ignition module due to the time the magnet passes the Hall sensor until the spark plug fires. Any rpm in excess of that provides the maximum advance set by the magnet and hall sensor location relative to the piston TDC which is normally set at 28 or 30 degrees BTDC.

The top chart shows a smooth advance curve which is normal, the bottom chart shows what I believe is an error in the advance curve where the timing delay jumps up to 4 mSec and starts down again.
Old 06-02-2013, 07:14 PM
  #2539  
Joystick TX
 
Joystick TX's Avatar
 
Join Date: Aug 2008
Location: Diamondhead, MS
Posts: 1,448
Received 9 Likes on 8 Posts
Default RE: New Giant GP Super Sportster!!!!!

Thought it might make more sense to show the results in degrees related to Top-Dead-Center. It is easier to see why the engine had trouble gaining rpms and had such low power, the spark plug was firing after TDC for a while. The negative numbers show the engine is firing after TDC.

Finally got to fly the plane today, the winds dropped down below hurricane force, it did great on the A-01 type ignition module. Can't wait to get the new module back to see what the curve difference is between the two.

Have about 1-1/2 gallons of fuel through the engine so far, it seems to be broken in. No bad habits, power seems to be about the same. Gives the GSS unlimited vertical.
Attached Files
File Type: pdf
Cz79838.pdf (21.3 KB, 41 views)
Old 06-03-2013, 08:30 PM
  #2540  
MKnutson
 
Join Date: Sep 2003
Location: Shoreline, WA
Posts: 97
Likes: 0
Received 1 Like on 1 Post
Default RE: New Giant GP Super Sportster!!!!!

Skypilot,
If I could figure out how to do pics I would. This new engine pulls this plane perfect, even the 3d guys at the field like it!
I used the fiberglass gear off the GP ultimate bipe 160, absolutly perfect fit and look for this plane. The gear sweep back so the axles are near the original position so you don't get the lame bounce on landing like gear that are too far forward.
This is a cool flying plane! Way kick back type flying! This is fun just to do touch and goes all day! If you can't grease it in every time with this plane you better give it up!


Mark.
Old 06-04-2013, 04:25 AM
  #2541  
ahicks
My Feedback: (2)
 
Join Date: Aug 2008
Location: Waterford, Mi/Citrus Springs, Fl
Posts: 3,821
Received 19 Likes on 17 Posts
Default RE: New Giant GP Super Sportster!!!!!


ORIGINAL: Joystick TX

Thought it might make more sense to show the results in degrees related to Top-Dead-Center. It is easier to see why the engine had trouble gaining rpms and had such low power, the spark plug was firing after TDC for a while. The negative numbers show the engine is firing after TDC.

Finally got to fly the plane today, the winds dropped down below hurricane force, it did great on the A-01 type ignition module. Can't wait to get the new module back to see what the curve difference is between the two.

Have about 1-1/2 gallons of fuel through the engine so far, it seems to be broken in. No bad habits, power seems to be about the same. Gives the GSS unlimited vertical.
Yes, got it now! That seems whacked? I doubt (hope?) that's not normal. Will be following your adventures there closely.

Interesting you aren't noticing any more power. Are you running the same size prop you were running on the Syssa? RPM's? Have you tried a bigger one?
Old 06-04-2013, 06:11 AM
  #2542  
Joystick TX
 
Joystick TX's Avatar
 
Join Date: Aug 2008
Location: Diamondhead, MS
Posts: 1,448
Received 9 Likes on 8 Posts
Default RE: New Giant GP Super Sportster!!!!!

I ran an 18.5 x 5.5 prop on the Syssa, running a 19 x10 on the DLE 35. Edit: forgot to add the rpm info. Getting 6700 rpm on the DLE.

Had an email that they received my ignition module at the repair facility. Will be interested to see what they do with it.
Old 11-12-2013, 03:33 AM
  #2543  
Joystick TX
 
Joystick TX's Avatar
 
Join Date: Aug 2008
Location: Diamondhead, MS
Posts: 1,448
Received 9 Likes on 8 Posts
Default

Got my new ignition module back. Same timing curve as all the others. Same problem with another DLE-35 engine.

Found that the problem was due to the use of 4.8Volt NiMh battery pack, WITH the IBEC AND the new A-02 RCEXL ignition. The new ignition draws more current during the capacitor charge cycles which drops the voltage below the optimum value for operation.

Went to the 5 cell, 6 Volt battery packs and the problem was solved.
Old 11-12-2013, 05:33 AM
  #2544  
ahicks
My Feedback: (2)
 
Join Date: Aug 2008
Location: Waterford, Mi/Citrus Springs, Fl
Posts: 3,821
Received 19 Likes on 17 Posts
Default

When I saw your note I wondered if you ever got your issue resolved. Glad you figured it out! Do you figure that voltage drop is due to the wimpy nature of the NiMh chemistry (low amperage output)?

Probably a moot point. Guessing one of these days you'll convert to LiFe? That will have you running on about what you're at with the 5 cell. -Al
Old 11-12-2013, 06:57 AM
  #2545  
PacificNWSkyPilot
My Feedback: (19)
 
PacificNWSkyPilot's Avatar
 
Join Date: Feb 2004
Location: Raeford, North Carolina
Posts: 3,988
Likes: 0
Received 2 Likes on 2 Posts
Default

How weird. They used to post warnings NOT to use a 6-Volt source on those ignition modules. Mine are all set up with 4-cell 4.8 packs, though without looking, I can't say whether they are NiCad or NiMh ignition packs. I'm thinking they're NiMh. I don't have any problems with them, but I don't use any IBECs, either.

Greg talked me into using A123s for this new project. Any contraindications? I haven't checked this new Valley View 40CC twin to see what type of module it uses.

Jim

Last edited by PacificNWSkyPilot; 11-12-2013 at 07:03 AM.
Old 11-12-2013, 10:30 AM
  #2546  
Joystick TX
 
Joystick TX's Avatar
 
Join Date: Aug 2008
Location: Diamondhead, MS
Posts: 1,448
Received 9 Likes on 8 Posts
Default

@ Jim - They increased the voltage that the new ignition module will work with to 8.4 volts. IMO the problem at the low-voltage end is just an unintended consequence of that increase.

@ Ahicks - I don't think it matters if NiCad or NiMh batteries are used, the voltage difference between them was only 0.03 volts under load. My packs had a drop of 0.04 vs 0.07 volts respectively, with a 3 Amp pulse load.
Both of them will drop below 4.1 volts at the input to the ignition module when the IBEC is used. The ignition module is designed to work with 4.8 volts, nominal, but it seems to be okay with spikes as low as 4.2 volts.

Last edited by Joystick TX; 11-12-2013 at 11:00 AM.
Old 11-12-2013, 11:17 AM
  #2547  
PacificNWSkyPilot
My Feedback: (19)
 
PacificNWSkyPilot's Avatar
 
Join Date: Feb 2004
Location: Raeford, North Carolina
Posts: 3,988
Likes: 0
Received 2 Likes on 2 Posts
Default

I think any electronic item has a "bottom line" voltage where it fails. If it's not an IBEC or ignition module, it's a radio receiver browning out. Now you have me curious about the operating voltage of the module on this Valley View gasser. Off to my shop. . .
Old 11-13-2013, 04:44 AM
  #2548  
ahicks
My Feedback: (2)
 
Join Date: Aug 2008
Location: Waterford, Mi/Citrus Springs, Fl
Posts: 3,821
Received 19 Likes on 17 Posts
Default

Not that it makes a lot of difference at this point, but wondering if the IBEC isn't designed to be used only with input voltages in excess of 6v? Otherwise, there's not much need for the voltage regulation the IBEC is designed to control. On 4.8v input, the only usefull purpose it's really serving is as an optical switch?
Old 11-13-2013, 05:40 PM
  #2549  
PacificNWSkyPilot
My Feedback: (19)
 
PacificNWSkyPilot's Avatar
 
Join Date: Feb 2004
Location: Raeford, North Carolina
Posts: 3,988
Likes: 0
Received 2 Likes on 2 Posts
Default

I just checked my module on my Valley View 40CC twin, and it clearly shows: 4.8 / 8.4 Volts. That's good news for this A123 application I'm planning!

Nice workmanship on this engine. I'm looking forward to seeing how it runs. Many good reports so far out there. This one's going into an RC Guys Decathlon.

Al - the only interest I had with the IBEC was in using it as an optical switch.

Jim
Old 11-13-2013, 06:02 PM
  #2550  
ahicks
My Feedback: (2)
 
Join Date: Aug 2008
Location: Waterford, Mi/Citrus Springs, Fl
Posts: 3,821
Received 19 Likes on 17 Posts
Default

So why use an IBEC? The Rcexl opti switches are about 15.00 now, and have a pretty good reputation?


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.