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Old Sep 26, 2008, 03:22 PM
Rochester, NY
JustGoFly's Avatar
United States, NY, Monroe
Joined May 2004
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Sounds like you're on the right track. 20 amps per motor is not much, so prop is likely fine. Monitor the voltage of the battery under load to decide whether you have enough battery to drive the setup. Low volts will contribute to higher temps. 2000 mah 20C should not be run at 40 amps. It will handle it - but for any duration it will get hot and heat reduces the life of the motor. Lower volts mean the battery is not handling the load and you may need either a higher capacity battery or run 2P (2 batteries in parallel).

I've rigged my FunJet with a 550TH 2700 Kv motor on a 5.1x5.1 on 3S - 39 amps motor and she's a monster ! Thinking of doing the same on the Twinjet when the 30C 2100's come in. I had a buddy beat my TwinJet the other day with my own motor - he was running a 500T 6.5x6.5 on a F16 and my TwinJet using duel 550T 6x5.5 on 3S2P. Time to change props - we can't have him whooping me

Vinnie
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Old Sep 26, 2008, 04:41 PM
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Chattanooga, Tennessee, United States
Joined May 2003
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2x HXT 2835 2200kv motors supposedly capable of taking up to 35 amps. And with 2x 5x5.1 graupner speed props. Its pulling 39 amps at WOT and about 390 watts. ......after about 1 minute run time the motors are burning up, you can smell them...and burn your fingers on them.

Interesting isn't it... el cheapo motor running at half rated amps gets burning hot after 60 seconds static.

I know this is a bit apples v. oranges/ small outrunner v. large inrunner, but I just ran a Motrolfly 2210-1700 with a 6x4 3-blade, static, for seven minutes continuous WOT - that's a 45g motor and it drew 15A/170W [a bit more than its rated maximum] and yet the case temperature rose only 16.4C over that period (21.6C to 38C). Yes, the blip, after the run was over, shows it got to a peak of 51.3C as the heat from the windings made their way to the case.

Here is the graph:

Cheers, Phil
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Old Sep 26, 2008, 06:54 PM
Rochester, NY
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United States, NY, Monroe
Joined May 2004
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Dr. Kiwi - 55 mph static - 45 in the air if you're lucky ? I sure hope it runs all day long - crank it up to 120-140 mph and lets see how long she lasts and what amps it pulls. More like comparing apples and flamingos

I advertise the extremes and let the customer cut back on the amps with smaller props and lower performance. If their batteries can't handle the performance - then back down the prop or voltage. Dr - I should send you my 550XT for some tests. I'm sure you will love it. It drives a 12x6 prop and gives my Slow Stick crazy vertical. The 12x8 warbles the wings - but lots of fun after I glassed the SS wings. This huge prop pushes the draggy Slow Stick in excess of 50 mph in the air. We'll have to race my Slow Stick against your jet Slower motors are higher efficiency. Here is what the 550TH looks like on 4S:
Angelo Fun Jet (4 min 49 sec)


Vinnie
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Old Sep 26, 2008, 08:00 PM
bucket of prop wash
garrcass's Avatar
reddinng CA
Joined Nov 2007
949 Posts
thats 1 550th right need to get one Vinnie do you know anyone who can help me with this i would realy aprichiate it thanks Garrett http://www.rcgroups.com/forums/showthread.php?t=928923
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Old Sep 26, 2008, 08:04 PM
Rochester, NY
JustGoFly's Avatar
United States, NY, Monroe
Joined May 2004
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Quote:
Originally Posted by garrcass
thats 1 550th right
Yes - Video is FunJet - One 550TH Motor.

Sorry that inrunner looks like you need microsurgery to repair. A buddy brought one over to repair and we spent the time winding him a comparable outrunner rather than attempting a repair. A bad repair could cost you a speed controller. Someone else might be able to help - wish I could.

Vinnie
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Old Sep 26, 2008, 11:52 PM
bucket of prop wash
garrcass's Avatar
reddinng CA
Joined Nov 2007
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i realy just need to know what way the spacers and washers go i cant find anone who can tell me you would think someone would know
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Old Sep 27, 2008, 07:45 PM
Rochester, NY
JustGoFly's Avatar
United States, NY, Monroe
Joined May 2004
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Quote:
Originally Posted by garrcass
i realy just need to know what way the spacers and washers go i cant find anone who can tell me you would think someone would know
I wish I could help you - sorry I'm not familiar with that motor.

Vinnie
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Old Sep 30, 2008, 03:54 PM
BLANIK213
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United States, NY, Phoenicia
Joined Feb 2008
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TJ Mods

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Last edited by blanik213; Jan 23, 2009 at 01:23 AM. Reason: pics
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Old Sep 30, 2008, 04:03 PM
BLANIK213
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United States, NY, Phoenicia
Joined Feb 2008
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TJ Mods

Just thought I'd post some shots of the nacelles that have been enlarged (ID) to accommodate from a 28mm motor up to a 34mm.The rim of the nacelle is reinforced with carbon fiber strands taken from heavy weight carbon cloth.The inside has been covered with 6oz carbon cloth as well,not shown in these photos.The vertical fins are cover with 2oz glass applied using the bagging method,glassed and placed in one of those vacuum bags made for food, real neat little system made by Reynolds the Handi-vac ,pulls enough vacuum to get a really dry strong layup of small parts the largest bag available is 10 9/16x11 1/2. I cover the elevons with the same 2oz glass but added a layer of carbon vial to their topside and font edge of the bottom. The entire plane will be glassed using a large bag and a real vacuum pump. but I must be careful not to crush it just squeeze out enough resin to get a light yet strong layup .
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Old Sep 30, 2008, 05:44 PM
Registered User
USA, MO, O'Fallon
Joined Dec 2003
2,087 Posts
I would post photos of mine, but I am stuck without a trip to the hobby store for some 3mm blind nuts to attach the JustGoFly 500T's to their backplates so I can the attach the baseplates to the plane. I also have to get some CF to strengthen the elevons and rudders. I do have the hinges...
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Old Sep 30, 2008, 07:55 PM
BLANIK213
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United States, NY, Phoenicia
Joined Feb 2008
665 Posts
TJ Mods

What kind of hinges are you using ,the ca fiber ones work very well .
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Old Sep 30, 2008, 09:33 PM
Rochester, NY
JustGoFly's Avatar
United States, NY, Monroe
Joined May 2004
1,881 Posts
Blanik - I think you're going to need an experienced TwinJet flyer to take that baby up for the first time.

I used the default hinges with Blenderm tape over them - it's held through many flights without any issue I was concerned that a few single points in foam wouldn't be as strong as a long strip.

I upgraded the prop from 6x5.5 to 6x6 Cam speed prop and got back into scarey speed zone. A couple guys stood between the cars when I flew. Next come the 6.5x6.5 or 550TH. Weather here is rainy.

Vinnie
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Old Sep 30, 2008, 10:27 PM
BLANIK213
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United States, NY, Phoenicia
Joined Feb 2008
665 Posts
TJ Mods

Hey Vinnie from the sound of it you must be knocking at the 110mhp door.Thanks for the maiden suggestion but me and the TJ go back to 2004 flying almost every day,the modified TJ in post #366 was my 2004-5 plane with cobalt motors/3 cell lipo,it was maybe pushing 80 this one will be ballistic.Trust me with all the work invested I'll be taking my time to get everything dialed in. Are you using 3 or4 cell and what mAh value & c rate.Have you regained your speed throne back from your buddy with the 6x6 or maybe the 6.5x6.5 will be the one.
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Last edited by blanik213; Sep 30, 2008 at 10:33 PM. Reason: additional verbich
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Old Oct 01, 2008, 01:48 AM
More props are better than One
TaSaJaRa's Avatar
United States, AL
Joined Nov 2004
2,163 Posts
Quote:
Originally Posted by blanik213
Hey Vinnie from the sound of it you must be knocking at the 110mhp door.
On the 450th, 4s , and a 4.5x4.1 apc I did get a radar check and hit 110mph. I have the 500th mounted now. I have to redo a little wiring and it will be ready to go. Also double check the air vent exit hole make sure it will be large enough.

I had the 500th on 4s and it was faster than the 450th. I got a little glitch before and that was why it went down.
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Old Oct 01, 2008, 01:55 AM
More props are better than One
TaSaJaRa's Avatar
United States, AL
Joined Nov 2004
2,163 Posts
Quote:
Originally Posted by blanik213
What kind of hinges are you using ,the ca fiber ones work very well .
Myself I used a few CA hinges then glassed over the joint. 1/2oz glass and water base poly. The CA hinge held the elevon in the center while I worked the elevon in each direction to glass it. Once it dried you just work it from top to bottom and it will free up very nice.
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