Pantera FG-20 Gasser Build

[Modifyit15]

I am building a Pantera Gasser Just Because I want to use the Saito FG-20 in a helicopter. I thought the Pantera's Frame was I deal For this Motor due to its versatility. I custom made the Fan and the motor mount.

[JohnDoe.]

That's nice !!

[jbeech]

Nice? Nice? No, that's freaking awesome! Keep us in the loop. I expect you'll soon get PMs from grwarlok and Helipainter (if you haven't already) because they're on point with gasser and four stroke conversions up to now and have a wealth of data and information between them. Call if I can help.

[Finless]

Dude, that thing is looking sweet! I wanna see that fly man...

Bob

[F6Hawk]

The first pic of the fan is blurry, but even so, it looks like a work of art. How did you do that? You have your own milling machine, I take it?

[Garland]

I asked modifyit on RR and he is running a Haas VF-2 vertical machining center with mastercam X software.

very talented person and I cant WAIT to see this pantera fly!!

[helipainter]

AWESOME!!!!


Keep us updated!

[Modifyit15]

well I had a set back Last night. I was trying to remove the pinion Gear from the Clutch bell. and it turned out fine until it was most of the way out and then the treaded part of the pinion Crumble into pieces. I guess I can buy another but I am afraid it might happen again, especially after a stress it by pressing on the 17 tooth. I think I am going to have to make a shaft with my lathe that is treaded to hold the new pinion Gear and Upper bearing.

[helipainter]

a 17 tooth pinion sounds a bit steep. Since you got all this killer machinery, here is what i'd do.

Try one of these pinions. If it were mine and i was using the stock 87 main, shoot for a 14 tooth to start with. They go from 10-16 and screw on so you don't have that crap going on with this thing. A failure isn't going to end well.
http://www.heli-world.com/SearchResu...inion&All=True

You will find the proper length, but the threaded end is small. Either build a new bell or figure a way to make the pinion thread end bigger.

Thunder tiger stuff screws right onto your bell, but only up to 12 tooth

Please make sure to have some way to monitor your heat, your gonna see some.

[SabreFlyr]

If you get this thing worked out in time, will it be at IRCHA? GOT to see this!!!

[Machinehead01]

Hey Painter, what pinion are you running?

Mot

[helipainter]

The one on vid this weekend is the 12/85 raptor set. The crrc i have here with the century clutch setup has a 14 in it now, got a 11-15 in the box. Moveable starter block

Were looking to hit 6:1, seems to be what most gassers this size target. Can tell you this, 12/85 is like granny gear, no bog, ever. I keep waiting to shear a main shaft. It punches out pretty fast

I'll have some real fff vids up shortly

[Modifyit15]

I am making a new shaft for the 17 tooth and I am not using a 87 tooth main I have a different ratio. I think its an 80 tooth I did my calculations a long time ago I need to double check. i just need to find the right tap and Die M12x.08

[helipainter]

That is 4.7:1, were finding the sweet spot to be 6:1 if your spinning 11-12k. Our motors are rated for 10, but they find there calling around 11,500. Over 12 get's touchy, weird heat problems, more vibes, etc.

This one here has the complete Century predator clutch, bell, start shaft and soon starter block for diff pinions


just to point to the fan comment i made above, this is a stock vs the one were running and it barely keeps up.





it has blades on both sides of the fan and it is twice as thick, larger diameter

[Modifyit15]

The FG-20 is toping out around 9500 RPM with 8900 being at peak torque. 8900 / 4.71 = 1890. I will be fine with 1800 rotor speed.

found out today that that tap is really hard to come by so I will Tap the bell and Shave the gear and shaft for a perfect Press fit

Nice fan by the way looks almost to big to fit did you have to alter the frame.

I am sure that I will have cooling issues thats why I have a separate battery to run a cooling fan.I am going to look for a small thermistor switch. This way it wont stay on the whole time.

[grwarlock]

Your going to find that gear ratio not to work. Its way to low and you will experience clutch slip like crazy. My final ratio on the nitro version of what your making was 7.0 - 6.8
. I would as helipainter said shoot for 6.5-7.5.

If you ran a heavier weighted clutch leafs you might get away with mid 5.x 's

Cooling was the biggest issue, if that fan works as good as it looks you will have 90% of your issues resolved.

Ken

Here is a video with 4.7 ratio, notice the change in motor note and the smoke at the end. Clutch slip !

[ame]http://www.youtube.com/watch?v=eC3idXQHc0k[/ame]

[helipainter]

I predict lots of head loading and slipping clutches along with not enough rpm to get the fan into it's prime. Is this fan any bigger than stock?

When we talk about thicker heavier clutches, were talking heavy




The other thing that might make this whole thing a deal breaker is if it is not broke in like 12-15 hours of flight broke in, you may find it extremely hard to keep a one way bearing in the clutch. I went with a larger diameter and it is working killer on a brand new 1 hour of idling 26cc. a primer bulb really helped cut down on cranking it over.

[Modifyit15]

Well I did not think about Rpm engagement, I guess that will be a major factor. Only problem is my motor does not turn that kind of RPM's

Can you suggest a heavier Clutch.

[helipainter]

this is my motors recomended rpm range


it spins 12 grand all day long.

I used all these on mine, that is what is above








Little pricey but 2 major things happened. 1 i can buy any pinion from 10-16 and it screws into my bell. 2 it has a huge diameter start shaft that will let you spin that thing all day long with any starter, drill, whatever.

I still wanna know more about the fan. Is it the stock diameter or did you oversize it?

[F6Hawk]

I'm curious, helipainter... why go with a hex starter as opposed to pull start? Personally, I would think losing the battery/starter combo would be a bonus.