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Author Topic: Fora Jr.  (Read 2123 times)

Offline Dave Hull

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Fora Jr.
« on: June 16, 2019, 02:23:19 AM »
Managed to get out to the field (not our home field which is still closed down) and get some work in on Mike's Fora-powered SCAR Goodyear. We had it out only once previously and mostly worked on break-in. Today did some prop selection. We finally got it unloaded and sounding happy. Still coming in I think. Fun times.

The engine has a fair bit of hysteresis in the compression screw, which is manageable. Needle seemed plenty fine. The tank (Akre?) ran really well top to bottom and the engine held settings surprisingly well.

Now that we know about what size prop it likes, we need to find a range of them to try.

Oh, and we have to stop arguing over who gets to be the pitman. And we need to have a new rule--the pit man has gotta catch the plane!

Forgot Mike was bringing a diesel and wore my stunt shirt. Rookie mistake....

Divot McSlow

Offline Les Akre

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Re: Fora Jr.
« Reply #1 on: June 17, 2019, 05:31:15 PM »
Hey Mcdiesel

I know of no better way to christen a "Stunt Shirt"

Les

Offline Dave Hull

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Re: Fora Jr.
« Reply #2 on: June 17, 2019, 06:53:27 PM »
MM,

Keep guessing. Lot's of choices. But if you need to know, you're gonna hafta try one yourself....

Jake, Les,

It was a perfectly good stunt shirt, still white and (mostly) clean. Now it has exhaust splatter all over it and I have to hang it outside....or else leave the windows open.

The Fora didn't have the conejos of an AAC Nelson, but I didn't expect that. But we had very little trouble managing the temperature and the settings. Nice.

Divot McSlow

Offline Les Akre

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Re: Fora Jr.
« Reply #3 on: June 18, 2019, 02:30:09 AM »
Is this a Fora Junior such as those sold by Hobbyclub, or the new, more expensive rear exh. F2D combat engine??

On a side note, you might be interested in knowing that Paul And I tested the now twice repaired "Little Mike" AMA Scaleracer last night. I'm happy to report that after the fuselage and control system repairs, it flies more stable than before, although it could use a bit of nose weight. At least I was able to take it home in one piece for a change...

Les

Offline Dave Hull

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Re: Fora Jr.
« Reply #4 on: June 18, 2019, 02:11:03 PM »
Mike said it was a Fora Jr.

Sounds like you have your Mike racer just about sorted out. T-tails seem to have their challenges....

I need to find some time to put the wing and tail on my '74 Shoestring  "Elenya Special."  Everything is done, but if I glued the big pieces together, I'd have to paint it.

Divot McSlow

Offline Mike Callas

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Re: Fora Jr.
« Reply #5 on: June 18, 2019, 07:47:34 PM »
The Fora Jr is the $149 special from Hobbyclub. There is a less expensive version, and several more expensive motors, including the combat and F2 CN motors ($279 to 379?). I opted for the $149 motor as the SCAR rules allow up to $150.
We tried some APC  6.5 X 5.5, 7 X 3, a 5.84 X 5?
I ordered several 6.5 X 5.0 from APC and a smattering of 162mm fiberglass props from Hobbyclub.

Fuel was Davis Diesel. I goy some ether from ebay to try and make my own brew. 20% oil/78% kerosene, 2% snake oil?

Motor restarted best (note this is a relative term) after a prime in the venturi.

Lap times for the different props were from 22.5 to 24 seconds 8 lap intervals. On the best prop my Shestring ran 63 laps. More than sufficient for a 1 pitstop race.

I did find an article from the Aussie newsletter describing some mods to the Fora jr crank timing. Their motor came with crank closing at 40 deg ATDC. They increased that opening by 1mm ~ .039", and opening the venturi (unknown dia.). Their lap times decreased from 24 sec 10 lap intervals, to 22 sec. This came at the cost of reduced laps.

So next step is to try the different props while I con Dave into more piloting chores. And yes, I pit and watch the plane roll by on landing (the tail is super weak after snapping off 3 or 4 times).




Offline john e. holliday

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Re: Fora Jr.
« Reply #6 on: July 02, 2019, 11:12:18 AM »
The Fora Jr is the $149 special from Hobbyclub. There is a less expensive version, and several more expensive motors, including the combat and F2 CN motors ($279 to 379?). I opted for the $149 motor as the SCAR rules allow up to $150.
We tried some APC  6.5 X 5.5, 7 X 3, a 5.84 X 5?
I ordered several 6.5 X 5.0 from APC and a smattering of 162mm fiberglass props from Hobbyclub.

Fuel was Davis Diesel. I goy some ether from ebay to try and make my own brew. 20% oil/78% kerosene, 2% snake oil?

Motor restarted best (note this is a relative term) after a prime in the venturi.

Lap times for the different props were from 22.5 to 24 seconds 8 lap intervals. On the best prop my Shestring ran 63 laps. More than sufficient for a 1 pitstop race.

I did find an article from the Aussie newsletter describing some mods to the Fora jr crank timing. Their motor came with crank closing at 40 deg ATDC. They increased that opening by 1mm ~ .039", and opening the venturi (unknown dia.). Their lap times decreased from 24 sec 10 lap intervals, to 22 sec. This came at the cost of reduced laps.

So next step is to try the different props while I con Dave into more piloting chores. And yes, I pit and watch the plane roll by on landing (the tail is super weak after snapping off 3 or 4 times).


Ah, pitting is an art.  I had Bill Wright teaching me how to pit F2C planes and it ran ovr into the other racing events.  I've watched guys break props and planes.  Need a plane that will roll into the pit stop.  Have to give with the plane as you grab the wing. I always liked pitting as it was easier to find a decent pilot.  But then teams started forming.  Also takes a lot of practice. D>K
John E. "DOC" Holliday
10421 West 56th Terrace
Shawnee, KANSAS  66203
AMA 23530  Have fun as I have and I am still breaking a record.

Offline Mike Callas

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Re: Fora Jr.
« Reply #7 on: July 03, 2019, 05:31:18 PM »
 
Ah, pitting is an art.  I had Bill Wright teaching me how to pit F2C planes and it ran ovr into the other racing events.  I've watched guys break props and planes.  Need a plane that will roll into the pit stop.  Have to give with the plane as you grab the wing. I always liked pitting as it was easier to find a decent pilot.  But then teams started forming.  Also takes a lot of practice. D>K
[/quote]

My instinct is to scoop up the plane as quickly as possible and throw it to first base.

Offline john e. holliday

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Re: Fora Jr.
« Reply #8 on: July 03, 2019, 09:52:27 PM »
If you can watch some video of F2C racing.  It would be nice to slow down the video so you could see the action.  But, the pit stop is so fast now a days it looks like a blur.   In F2C the pit is done in a box of sorts.  There is a line in witch the plane crosses as you catch it and then the plane must be put back behind the line for fueling to start. D>K

Also it is such a thrill to get that one flip pit stop. H^^
John E. "DOC" Holliday
10421 West 56th Terrace
Shawnee, KANSAS  66203
AMA 23530  Have fun as I have and I am still breaking a record.

Offline Dave Hull

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Re: Fora Jr.
« Reply #9 on: July 04, 2019, 01:37:50 AM »
In the past, when I tried to describe F2C pitmen to non-flyers, the best I could come up with was a guy that had hands like a MLB third-baseman who also had a PhD in diesel theory. They didn't understand that explanation either, but started to get the idea that it wasn't easy....

I probably should have included at least a Masters in petroleum chemistry--unless someone helps you out with your fuel mix. I got out all the old stuff last Saturday and mixed up a batch for Mike to try next time out. A standard recipe. Gifted to me by them that know. Should help with the slow takeoffs and allow a bit more compression. We'll see.

Most pitmen can grab a plane. A good pitman will still have the fuselage attached to the wing after a hot landing....

Divot McSlow

Offline Dave Hull

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Re: Fora Jr.
« Reply #10 on: July 08, 2019, 06:40:09 PM »
Tried out the new fuel in the Fora Jr. on Sunday.  Easier to set, ran a little more comp, and everything turned into one and two flip starts. Between the Akre tank and the forgiving nature of the Fora, Mike was able to tweak the engine until it sounded just right. Oh, and he caught 'em all, too. Nothing broke--but he needs to use more tire glue....

The Divot

Offline Mike Callas

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Re: Fora Jr.
« Reply #11 on: July 08, 2019, 10:11:15 PM »
Just following orders Dave.
Not bad for a $150 motor. A few more tweeks, a better wheel and we'll be ready to race. I'm still pondering the Aussie mods to the Fora Jr, I read about in a Torque Roll from days gone by.



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