RE: GLAMF!!  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       



All Forums >> RC Airplanes >> "1/2 A" & "1/8 A" airplanes >> RE: GLAMF!! Page: <<   < prev  1 2 [3] 4   next >   >>  

Login
Message << Older Topic   Newer Topic >>
RE: GLAMF!! - 11/16/2005 5:05:11 AM   
scudrunner77



Posts: 644
Joined: 5/22/2003
From: Enumclaw, WA, USA
Status: offline 		I'm not sure if we had to search for gear after the GLAMF bit it... I think the worst was when the Annihilator's wing came off in flight. I think there where radio parts 10+ feet apart. Good thing the grass was short. I am sure the the GLAMF went down with my Electron six in it. All I remember is giving it full up to come out of the turn and had nothing...it just went in. I don't remember it snapping... I had this speed 400 electric job that would snap if you tried to yank it through a turn too tight... I hate it when you really don't know what happened.

I had a pretty good customer service experience with Cirrus... I emailed them about the gears stripping on a 6.4g servo that had very little use and they told me the gears could not be warrantied, but sent me a set anyways.

(in reply to combatpigg)
       Post #: 51

RE: GLAMF!! - 11/17/2005 12:44:38 AM   
combatpigg



Posts: 10140
Joined: 11/22/2003
From: arlington, WA, USA
Status: online 		That's smart business on CIRRUS part. This hobby supply business is very fickle. Look at magazine ads from 20 years ago and count the ones who are not with us any longer.

The GLAMF must have been done in by a bad battery, or one that was weak. This is a good time of year to go through all the gear and weed out the junk from the other stuff [which is basically junk waiting to happen] Charlie and I figured that we could safely run a pair of servos about a half hour off of 350 mah nimh packs that were field charged.

_____________________________

Led Zeppelin is NOT "old fogie" music.

(in reply to scudrunner77)
       Post #: 52

RE: GLAMF!! - 11/20/2005 6:39:55 AM   
combatpigg



Posts: 10140
Joined: 11/22/2003
From: arlington, WA, USA
Status: online 		Now I'm starting to confuse myself with all these acronyms........the GLHSWR was the plane that bit the dust, [this ones' predecessor], THIS is the GLAMF!

I am out of K&B yellow epoxy paint, so the cowl paint job puts the project on hold. That's OK, I need time to baseline the engine, then try to enhance the performance with some engine work. The model ends up weighing just over 14 ozs RTF because of all the little weight penalties here and there with the effort to give it some style and a little more size than the average SWR. This wing is sparless, it should hold up fine, at least for a couple of flights .

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


_____________________________

Led Zeppelin is NOT "old fogie" music.

(in reply to combatpigg)
       Post #: 53

RE: GLAMF!! - 11/20/2005 2:15:06 PM   
ptulmer



Posts: 4770
Joined: 4/28/2003
From: Brunswick, GA, USA
Status: offline 		CP, that thang looks GOOD! Don't worry about the wing being without a spar. My 3/16" (before sanding!) wing held up just fine without a real spar. It got tormented quite a bit, even crashing with no damage.

_____________________________

HomeMachinist.net!
Ulmer-RC.com

(in reply to combatpigg)
       Post #: 54

RE: GLAMF!! - 11/20/2005 4:19:05 PM   
combatpigg



Posts: 10140
Joined: 11/22/2003
From: arlington, WA, USA
Status: online 		The scary thing to consider though is that G forces build up in multiples of your original weight. Since this plane weighs so much more than the average SWR, hopefully the wood will just bend but not break. And if it does break, hopefully there will be some video .

Now for the speed tuning strategy. To make this project seem like something special, the .074 needs to turn at least a 4 pitched prop and probably more like a 5 pitch to get any speed out of this plane. The APC 4.75x4.75 might be a good choice? The engine would have to produce 22500 in order to break 100mph. It might be able to do that with just open exhaust and a C/L venturi . I don't know why NORVEL doesn't offer an AME version of the .074 already, unless they know something that I don't about the strength of the parts?

< Message edited by combatpigg -- 11/20/2005 4:31:27 PM >

_____________________________

Led Zeppelin is NOT "old fogie" music.

(in reply to ptulmer)
       Post #: 55

RE: GLAMF!! - 11/20/2005 5:19:16 PM   
scudrunner77



Posts: 644
Joined: 5/22/2003
From: Enumclaw, WA, USA
Status: offline 		This talk about your wings coming off reminded me of the G-force charts I had seen. I'm sure these numbers are for a specific plane, but if you take a rough look at it your plane wing will have to hold about 8 lbs in a pylon turn.

BTW- great looking plane! I think I saw this one in your workshop last time I was up there and I was very impressed with your glass work.. The yellow looks real sharp!

Attachments
Click to see fullsize image.
Click for fullsize

(in reply to combatpigg)
       Post #: 56

RE: GLAMF!! - 11/20/2005 5:47:05 PM   
combatpigg



Posts: 10140
Joined: 11/22/2003
From: arlington, WA, USA
Status: online 		Does this mean that I should prop up the plane by the wing tips and stack 6 pounds of weight on the center section to see if it will hold? . The glass work was needed on the fuselage, because after sanding, you could almost see through some of the wood in certain areas. It's fairly easy to do, paint all the wood with water based polyurethane with a couple of coats, let dry & sand, then drape 3M77 misted cloth on, working with as large an area as you can manage. I used .6 oz cloth and the cloth pieces overlap each other. Once you have it completely covered, then brush on the polyurethane. A heat gun will speed drying, just don't get carried away or you will blister the polyU.

Just ordered some props from APC, 4.7x4.7, 5x5, and 5.5x4.5, all electric 400 speed types.
Just ordered some paint from K&B, 1/2 pint yellow, $10 and 1/2 pint hardener, $15 ! Thankfully, a little goes a long way if you limit it to just painting cowls.

_____________________________

Led Zeppelin is NOT "old fogie" music.

(in reply to scudrunner77)
       Post #: 57

RE: GLAMF!! - 11/20/2005 8:14:17 PM   
scudrunner77



Posts: 644
Joined: 5/22/2003
From: Enumclaw, WA, USA
Status: offline 		I would put the wings tips between two chairs and drop a bowling ball on it.

CP- I also bought some of those speed 400 props. I've got a 4.7 x 4.25 here in my hands and it's very thin. You can see light through it and if you put pressure on the tip of one of the blades you can fold it over 90 degree easliy. Has anyone tried one of these things on a 1/2a before? Looks kinda scarry to me. If you can't use them for glow I guess you will have to build a e-powered speed plane. That would be fun... speed 400 vs 049 around the pylons.

(in reply to combatpigg)
       Post #: 58

RE: GLAMF!! - 11/20/2005 8:22:16 PM   
combatpigg



Posts: 10140
Joined: 11/22/2003
From: arlington, WA, USA
Status: online 		Got a little data on the .074. This one doesn't have much POP, it needs to be electric started, but the bottom end seems OK.

Stock muffler 7x3 APC 15% nitro BYRONS' 17,200 rpm
Open exhaust " " " " " " 17,500 rpm
" " 5x4 fiberglass prop [LARRY D]26,000 rpm

There doesn't seem like much point in going further with testing until the props from APC get here. There also doesn't seem like much reason to touch the engine either, it seems very happy running high revs, the last reading was slightly rich, like a good launch rpm. This set up would generate 98 mph and 1.25 pounds of thrust, if it hooks up to the airframe. So far, so good .

_____________________________

Led Zeppelin is NOT "old fogie" music.

(in reply to combatpigg)
       Post #: 59

RE: GLAMF!! - 11/20/2005 9:28:30 PM   
combatpigg



Posts: 10140
Joined: 11/22/2003
From: arlington, WA, USA
Status: online 		I would use the E props up to 5 inches in diameter. If one threw a blade, it wouldn't be the first time a prop let go. As far as I know, the 4.2x4 and 4.75x4.75 that I have been running for a couple of years are E props. The 4.2x4 has seen 42,000 on the G&Z, and the APC safety margin is 190,000 divided by diameter on their sport props. I'm sure that they have tested their props to the point of failure on a test motor, but I doubt if they have a CYCLON set up in the back to really see if those E props will blow on nitro power?

< Message edited by combatpigg -- 11/20/2005 9:30:26 PM >

_____________________________

Led Zeppelin is NOT "old fogie" music.

(in reply to scudrunner77)
       Post #: 60

RE: GLAMF!! - 11/20/2005 9:41:45 PM   
ptulmer



Posts: 4770
Joined: 4/28/2003
From: Brunswick, GA, USA
Status: offline 		CP, since when are the tips the only part of the wing that gets loaded? You'd need to apply the weight in a more even manner to get something realistic.

E-props are supposedly designed to take advantage of the greater torque of an electric motor. I guess they're thinner at the hub because of the lack of a "power pulse". The 4.2x4 is a nitro blade fer sure. APC markets them as 1/2a props and they have a thicker blade at the hub. What all this means in the long run is beyond me, just reporting observations!

_____________________________

HomeMachinist.net!
Ulmer-RC.com

(in reply to combatpigg)
       Post #: 61

RE: GLAMF!! - 11/20/2005 10:54:32 PM   
combatpigg



Posts: 10140
Joined: 11/22/2003
From: arlington, WA, USA
Status: online 		Well, you will never see a wing panel break at half span, normally. Most of the inflight weight that is working against the wing is in the middle getting multiplied. I saw when the VOYAGER wing was being stress tested, they just hung jugs of water off of it until it buckled. If you remember, that plane was made with 55 gallon drums full of CA . I wonder if they used odorless?

Do you remember that AD for a model plane where there was a photo of a guy standing on the center of the wing as it was supported on cinder blocks? It used to run in the back pages of one of the mags. Don't know how well those planes sold, something that strong might scare some buyers away!

_____________________________

Led Zeppelin is NOT "old fogie" music.

(in reply to ptulmer)
       Post #: 62

RE: GLAMF!! - 11/21/2005 12:06:09 AM   
ptulmer



Posts: 4770
Joined: 4/28/2003
From: Brunswick, GA, USA
Status: offline 		You're right about the center being the critical point, but the 6lbs of force won't be put squarely on that joint. I'm sure there's some math you could do to determine that, but it don't seem worth the effort.
I remember that ad. The blocks weren't anywhere near the tips. More or less, it was near the center of each half-span. That is, if it was the Mustang that I remember. I don't read any of the mags anymore.

_____________________________

HomeMachinist.net!
Ulmer-RC.com

(in reply to combatpigg)
       Post #: 63

RE: GLAMF!! - 11/21/2005 1:16:37 AM   
flyswatter



Posts: 499
Joined: 2/21/2004
From: St. Simons Island, GA, USA
Status: offline