Crazy Max 3D - Page 2

johnhlong · May 01, 2002, 09:40 PM

Any suggestions as to which plane to use with FMS before I fly the CM.

John

Ben74 · May 01, 2002, 10:11 PM

the CM is not too hard to fly, but it might be a bit much for a first aileron plane. you don't HAVE to use the rudder to fly it properly, so don't let the full house setup scare you.

my CM flies well on the stock powertrain, but i just ordered a GWS 300C DS system to try out. it's geared 6.6:1 and will spin a 12x6 prop on 8 x 720 NiMHs. i should get about 15 oz of thrust on a 14oz AUW. i'm only using one aileron servo to save weight. i'll let you know how it goes.

Basketcase · May 02, 2002, 10:10 AM

Hi John, sorry for not replying sooner. IMHO the closest flying, if not looking, models are the GP series by Shinichiro. I use the SW-Sports as a CrazyMax substitute and the GPSP as a Switchback sub.

Both have more power than the real thing but can be turned down in the .par file or just throttled back. Makes me wish I had that much (slimer) power available.

There are also some Acro planes, the Edge 540 and Giles probably fly better than the CM.

You can find them in Hanger 3 on Shinichiro's site:

http://www.hoops.ne.jp/%7Ekimagure-h...ger_index.html

BC

Kidknight · May 02, 2002, 04:43 PM

I had just measured the thrust that my 370 w/ 3.76-1 ratio setup using the stock 7.5*5 prop gives me on my f-22 raptor (It's the same exact motor used, except reversed). With an 8-cell 600mah Nicad pack I was reading 15.3 oz. of thrust static. Calculating it out, I was pulling ~7 amps at half throttle(5min. run time).
So, my question being, what's the problem? You should have a fairly good vertical, with adequate run time. To back this statement up, a local CM at my field can vertical straight up for 50-60 feet at the end of the life of the pack.

Quote:

Originally posted by Parkflyer
Greg,

What type of power system would I need? Would a 480 do it or do I need to go to a brushless motor. I guess you need about 14 oz of thrust huh?

Parkflyer

Greg Covey · May 02, 2002, 04:47 PM

The geared 370 is a real gem of a setup. It is simply good cheap power with less weight than a speed 400 system! The Wattage version bolts onto a firewall and the GWS version mounts on a post like the DX (IPS) series.

In this case, to gain enough additional power while maintaining a similar current draw, you will likely need a geared brushless solution. The stock 800mAh cells for the CM may handle a 10amp discharge rate for short periods. If not, you would need to jump up into a heavier cell...and the design issue cycles over again.

One advantage of the brushless motor is that you can simply add a cell (or two) extra to obtain a good power increase without hurting the motor.

Another option is to try a higher ratio GWS EPS (geared 370) setup. The Wattage version is a 3.75:1 ratio spinning a 7.5x5 prop. You could try a GWS version all the way up to a 6.60:1 ratio and spin an 11" or 12" prop. Essentially, you're trading top end speed for power.

In any case, the CM is a fun plane to bash because it is a great flyer and it already started out life ugly.

Regards.

Ben74 · May 02, 2002, 06:17 PM

kidknight, how did you measure your thrust? 15oz from such a little prop seems unrealistic to me. i could be wrong of course. i certainly don't get that much thrust from mine though. running 8 NiCds would probably account for some increase over the 8 x 700 NiMHs i'm using. maybe i should try running some 500ARs. i wonder if this motor can last a reasonable number of flights at that kind of power. perhaps i will find out

Kidknight · May 02, 2002, 08:43 PM

Since I have the wattage 370 motor in the f22 (pusher plane), you can easily measure thrust by holding the plane with your hands ( just enough to balance), balancing the nose on a digital scale, and by using the tare (zero) option on the scale, you can get a rough estimate of the thrust. It will fluctuate a little from holding it, but once you get it under control it'll stay within about .4 oz of the real amount of thrust.

Just so you feel that I'm not making this up, w/ a 6 cell nicad pack:

quarter throttle - 2.4 oz
half throttle - 7 oz straight (no fluctuation)
full - 12 oz

8 cell nicad 600 pack (btw, this pack came from nesail with the intention of being used with a 14t Speed 400 colbalt motor, so it might be an "AR" pack

)
half throttle - 10 oz
full "punch" - 15 and some change

after running the 6 cell pack for full duration at half power, it was fairly hot, but the motor was scortching hot!

Never Again!

Parkflyer · May 03, 2002, 06:50 PM

So KidNight, are you saying you can hover with the Crazy Max?

Kidknight · May 03, 2002, 08:23 PM

I don't have the crazy max, just the same motor that comes with the crazy max. I have the wattage f22, which happens to weigh in at 20 ounces (can't hover). I just flew the f22 today, and I was able to pull straight up from level flight for about 40-50 feet or so before stalling (this was with the 8cell pack)...

So, with this same motor in the crazy max, I'd suppose that you might have a fairly good vertical.

BTW, If I really was into hovering, I would definitly want around 18 or 20 oz of thrust, not just enough to barely keep afloat...

Kidknight · May 03, 2002, 08:31 PM

by the way, I live at 30 feet above sea level, so that might give me little bit of an advantage using the stock setup....

May 01, 2002, 09:40 PM	#16
johnhlong Hobby Hopper Join Date: Apr 2002 Location: Issaquah, Wa, USA Posts: 229	CM & FMS Any suggestions as to which plane to use with FMS before I fly the CM. John

May 02, 2002, 10:10 AM	#18
Basketcase an earth bound misfit, I Join Date: Sep 2001 Location: St. Pete, Florida Posts: 9,410	FMS planes Hi John, sorry for not replying sooner. IMHO the closest flying, if not looking, models are the GP series by Shinichiro. I use the SW-Sports as a CrazyMax substitute and the GPSP as a Switchback sub. Both have more power than the real thing but can be turned down in the .par file or just throttled back. Makes me wish I had that much (slimer) power available. There are also some Acro planes, the Edge 540 and Giles probably fly better than the CM. You can find them in Hanger 3 on Shinichiro's site: http://www.hoops.ne.jp/%7Ekimagure-h...ger_index.html BC

May 02, 2002, 04:47 PM	#20
Greg Covey Registered User Join Date: Aug 2000 Location: Rochester, NY, USA Posts: 5,776	The geared 370 is a real gem of a setup. It is simply good cheap power with less weight than a speed 400 system! The Wattage version bolts onto a firewall and the GWS version mounts on a post like the DX (IPS) series. In this case, to gain enough additional power while maintaining a similar current draw, you will likely need a geared brushless solution. The stock 800mAh cells for the CM may handle a 10amp discharge rate for short periods. If not, you would need to jump up into a heavier cell...and the design issue cycles over again. One advantage of the brushless motor is that you can simply add a cell (or two) extra to obtain a good power increase without hurting the motor. Another option is to try a higher ratio GWS EPS (geared 370) setup. The Wattage version is a 3.75:1 ratio spinning a 7.5x5 prop. You could try a GWS version all the way up to a 6.60:1 ratio and spin an 11" or 12" prop. Essentially, you're trading top end speed for power. In any case, the CM is a fun plane to bash because it is a great flyer and it already started out life ugly. Regards. Last edited by Greg Covey; May 02, 2002 at 05:02 PM.

May 03, 2002, 08:23 PM	#24
Kidknight Addicted to Feigao... Join Date: Sep 2001 Location: Lakewood, CA Posts: 414	wait a minute... I don't have the crazy max, just the same motor that comes with the crazy max. I have the wattage f22, which happens to weigh in at 20 ounces (can't hover). I just flew the f22 today, and I was able to pull straight up from level flight for about 40-50 feet or so before stalling (this was with the 8cell pack)... So, with this same motor in the crazy max, I'd suppose that you might have a fairly good vertical. BTW, If I really was into hovering, I would definitly want around 18 or 20 oz of thrust, not just enough to barely keep afloat...

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May 01, 2002, 10:11 PM	#17
Ben74 Registered User Join Date: Jun 2001 Location: San Francisco, CA, USA Posts: 2,748	the CM is not too hard to fly, but it might be a bit much for a first aileron plane. you don't HAVE to use the rudder to fly it properly, so don't let the full house setup scare you. my CM flies well on the stock powertrain, but i just ordered a GWS 300C DS system to try out. it's geared 6.6:1 and will spin a 12x6 prop on 8 x 720 NiMHs. i should get about 15 oz of thrust on a 14oz AUW. i'm only using one aileron servo to save weight. i'll let you know how it goes.

May 02, 2002, 06:17 PM	#21
Ben74 Registered User Join Date: Jun 2001 Location: San Francisco, CA, USA Posts: 2,748	kidknight, how did you measure your thrust? 15oz from such a little prop seems unrealistic to me. i could be wrong of course. i certainly don't get that much thrust from mine though. running 8 NiCds would probably account for some increase over the 8 x 700 NiMHs i'm using. maybe i should try running some 500ARs. i wonder if this motor can last a reasonable number of flights at that kind of power. perhaps i will find out

May 02, 2002, 08:43 PM	#22
Kidknight Addicted to Feigao... Join Date: Sep 2001 Location: Lakewood, CA Posts: 414	Since I have the wattage 370 motor in the f22 (pusher plane), you can easily measure thrust by holding the plane with your hands ( just enough to balance), balancing the nose on a digital scale, and by using the tare (zero) option on the scale, you can get a rough estimate of the thrust. It will fluctuate a little from holding it, but once you get it under control it'll stay within about .4 oz of the real amount of thrust. Just so you feel that I'm not making this up, w/ a 6 cell nicad pack: quarter throttle - 2.4 oz half throttle - 7 oz straight (no fluctuation) full - 12 oz 8 cell nicad 600 pack (btw, this pack came from nesail with the intention of being used with a 14t Speed 400 colbalt motor, so it might be an "AR" pack ) half throttle - 10 oz full "punch" - 15 and some change after running the 6 cell pack for full duration at half power, it was fairly hot, but the motor was scortching hot! Never Again!

May 03, 2002, 06:50 PM	#23
Parkflyer Registered User Join Date: Apr 2002 Location: Richmond, VA Posts: 993	So KidNight, are you saying you can hover with the Crazy Max?

May 03, 2002, 08:31 PM	#25
Kidknight Addicted to Feigao... Join Date: Sep 2001 Location: Lakewood, CA Posts: 414	by the way, I live at 30 feet above sea level, so that might give me little bit of an advantage using the stock setup....