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Old Jul 13, 2009, 07:34 AM
The thruster don't work!
Roy E Oetting's Avatar
Fairborn, OH
Joined Oct 2002
415 Posts
Hi, The 30X-UAV had it's last crash yesterday. It is time to build another.
The plane flys pretty good and everyone who sees it fly is impressed with the acceleration. The reason for the crash is still a question. I wish I had videoed it and then maybe I could have figured it out. It had two serious crashes both looking very much like the other. I have a questionable servo on the plane that would go to 90 degrees from time to time and the spin could easily have been caused by that but when I checked the wreckage the servos were where they were supposed to be. I have one short flight video I'll edit and put that up. It shows the speed that she flys and how smooth a landing can be. I'm looking forward to building another. I'm also anxious to get the pusher done. It's flight characteristics should be different due to the lower wing loading and the lower power to weight ratio.
Roy

The Demise of the 30X-UAV-V1 & How to Make Another (7 min 7 sec)
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Old Jul 22, 2009, 01:05 AM
The thruster don't work!
Roy E Oetting's Avatar
Fairborn, OH
Joined Oct 2002
415 Posts
The 30X pusher is ready for test flight. taxi tested her in the dark and it seems like it has plenty power. I've included a couple pictures showing a size comparison. Hopefully in a few hours I'll get a chance to see if she flies. The 30X weighs 64.4 gm with the 240 mah pack which is just under twice the weight of the Park Zone Sukhoi but it has about 4 times the power as the Sukhoi so I don't think she'll have problems getting off the ground. Comparing it to the 30X-UAV EDF, she is 16 gm lighter but less than a third of the power. The pusher should be more maneuverable. Can't wait.
Roy
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Old Aug 04, 2009, 04:42 PM
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rhuber40's Avatar
Mason, Ohio
Joined Jul 2007
178 Posts
Roy,
Mayby I missed it, but how did you manage to get the lossi 12x20 motor in the GWS 30mm housing. The housing is 10mm. I would like to know as I am interested in building 30mm fan scratch builds.
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Old Aug 04, 2009, 05:24 PM
The thruster don't work!
Roy E Oetting's Avatar
Fairborn, OH
Joined Oct 2002
415 Posts
rhuber40, It is to bad that GWS doesn't make a 30 mm fan housing with a 12 mm bore but they don't. A guy from California suggested that you cut the housing out and glue the motor onto the fins. That is what I did on the 30X. I believe I made a plug to hold the motor when I glued it in place although it probably wasn't necessary. You do want to mount the impeller before gluing it in the housing to make sure you have it centered and there isn't any interference. Another way to do it is to take the motor housing out of a 40 mm fan and glue that into the 30 mm fan after you have removed the 10 mm motor mount. This lets you pull the motor easier but in all likelihood you would have to destroy the impeller to get it out. The last way to do it is to make the housing. I did that about 10 years ago and I think I still have the unit laying around someplace. That was a kit from EDF Jets. I'm glad you reminded me of that because there are definite advantages to making the housing including making the exhaust an integral part or to change the shape of the inlet and to make it part of the airframe to reduce weight.
I've enclosed two pictures of the fan assembly and you can see where I glued them together with epoxy.
Roy
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Old Aug 05, 2009, 10:44 AM
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rhuber40's Avatar
Mason, Ohio
Joined Jul 2007
178 Posts
30MM fan

Roy,

Thank you for that explanation, Did you need any special tools to reconfigure the 30mm fan housing. How thick is the 10mm housing, could it be honed out to 12mm . Finally, is the epoxy applied directly to the 12x20 mm motor?
I am going to purchase from Epyala.com both 30 and 40mm housings and impellers. I would rather run the 30mm, but if I run into too much trouble I will run the 40mm.

Again, thank you.
Bob
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Old Aug 05, 2009, 12:22 PM
The thruster don't work!
Roy E Oetting's Avatar
Fairborn, OH
Joined Oct 2002
415 Posts
Hi Bob, The OD of the motor housing of the 30 mm fan is approximately 12 mm so there isn't sufficient material to bore out. I believe the first time I made one this way I used a #11 Exacto blade and slowly cut thru it. I can't remember, but I need to make another so I'll tell you how I make the next one probably by tomorrow. I'm going to use a hot knife to cut the housing out and then remove excess material with a Dremmel type hand tool.
The most important part of doing this is getting the motor secure and centered. I think after I press the 30 mm impeller onto the motor I'll make a foam stand and tack glue the impeller spinner to the stand so that the motor stands vertically. I then can drop the housing down over it and get it aligned and glue the vanes directly to the motor.
Roy
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Old Aug 05, 2009, 06:27 PM
The thruster don't work!
Roy E Oetting's Avatar
Fairborn, OH
Joined Oct 2002
415 Posts
Hi Bob, I have some more info. The hot knife method works but it is messy and hard to clean up. I managed to break a vane off and had to repair that and I still have a lot of grinding to do before I can mount a motor.
Since that didn't work out as well as I hoped I cut the motor mount out of another 30mm fan housing but this time I did it with a fine tooth Zona saw shown in the picture. This method probably took out to much plastic but it was fast. I should be able to build a dam using clay as I did when I repaired the broken vane. If you use a saw, one word of caution, support both the motor mount and the housing with one hand and cut with the other. If you don't support both parts you will probably break the vane.
So its back to the EDF fan factory.
Roy
PS The use of a mechanical inker to administer CA was not my idea but I have been using it for years. You can set the width of the quill opening so you can use different thicknesses of CA and you deliver a precise amount.
When the CA hardens in the quill I just take a knife and cut it out.
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Old Aug 05, 2009, 07:31 PM
The thruster don't work!
Roy E Oetting's Avatar
Fairborn, OH
Joined Oct 2002
415 Posts
Hi Bob, Hold the fort. I went to my drill bit tool box and saw that I had a whole bunch of drill bits between 25/64 and 15/32 (31/64). These drill bits could be used to take out the mount by step drilling until the mount was gone.(just a little plastic to file away) It was at that moment that I remembered that is how I did it in the first place. Someone else, I'm sorry I can't remember had suggested it and I bought the two extra drills I needed to go up in 64 th's. I just did another housing and the nice part is there is very little to clean up and there is a bore in the fins that hugs the motor. I wish my memory was a bit better. I could have saved myself a lot of work.
I'm pretty sure the impeller will require reaming to accommodate the shaft. When I press the impeller onto the shaft I use my drill press as the press and I'll make something to support the opposite end of the motor shaft so no forces are applied to either bearing housing.
Roy

PS Since it is getting late I think I'll wait till tomorrow morning to buy some connectors to go between the motor and the ESC. I want to standardize my small brushless motor connectors and I want to put the connector on before I press the impeller on which I want to do before I glue the motor in the housing. By lunch tomorrow I should have a few more 30 mm EDF's.
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Last edited by Roy E Oetting; Aug 06, 2009 at 08:07 AM.
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Old Aug 20, 2009, 11:45 AM
Registered User
Chicago Northwest subs
Joined Jan 2007
2,240 Posts
10mm EDF motor

Quote:
Originally Posted by Roy E Oetting
Hi Bob, I have some more info. The hot knife method works but it is messy and hard to clean up. I managed to break a vane off and had to repair that and I still have a lot of grinding to do before I can mount a motor.
Since that didn't work out as well as I hoped I cut the motor mount out of another 30mm fan housing but this time I did it with a fine tooth Zona saw shown in the picture. This method probably took out to much plastic but it was fast. I should be able to build a dam using clay as I did when I repaired the broken vane. If you use a saw, one word of caution, support both the motor mount and the housing with one hand and cut with the other. If you don't support both parts you will probably break the vane.
So its back to the EDF fan factory.
Roy
PS The use of a mechanical inker to administer CA was not my idea but I have been using it for years. You can set the width of the quill opening so you can use different thicknesses of CA and you deliver a precise amount.
When the CA hardens in the quill I just take a knife and cut it out.
Roy-Great work, as usual with the EDF "Skunk Works". Have you considered the mighty midget motors? They're not cheap, but they're drop-ins. I haven't personally used them, but I have used their outrunners on 2S. They're beautifully made!
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Old Aug 20, 2009, 12:39 PM
The thruster don't work!
Roy E Oetting's Avatar
Fairborn, OH
Joined Oct 2002
415 Posts
minirips2, Thanks and I've used the motor in a pusher configuration on a small F-18 and it worked really good. These in runners are a lot less money and they produce a bunch of power. The effort to bore them out isn't much and now that I remembered to use the step drill method the whole thing is a pretty clean operation.
Hobby City offers a 30 mm fan with an out runner for about $25. They don't get the impeller centered and as a result you wind up with a lot of vibration and not much thrust. I replaced the impeller with one I reamed out and it ran much smoother. I should get that out and do some testing with it.
Roy
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Old Sep 01, 2009, 09:03 AM
I Can Fly An FP Inverted!
Hal_The_Hacker's Avatar
Teddington, Middlesex, UK
Joined Jun 2008
1,536 Posts
what motor and prop are you using in the pusher? another losi motor?

I have a losi 10250 sitting around just waiting to be used, i would love to run it in a pusher with a 2s400, can anyone reccomend a prop? to hand I have a 3x2 and a 2.5x0.8

I am worried about unloading on the smaller prop and burning out on the larger one

would be great if i could make one of the pusher style jets with it, i prefer pusher to edf even if it is less scale
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Old Sep 01, 2009, 12:13 PM
The thruster don't work!
Roy E Oetting's Avatar
Fairborn, OH
Joined Oct 2002
415 Posts
Quote:
Originally Posted by Hal_The_Hacker
what motor and prop are you using in the pusher? another losi motor?

I have a losi 10250 sitting around just waiting to be used, i would love to run it in a pusher with a 2s400, can anyone reccomend a prop? to hand I have a 3x2 and a 2.5x0.8

I am worried about unloading on the smaller prop and burning out on the larger one

would be great if i could make one of the pusher style jets with it, i prefer pusher to edf even if it is less scale
Hi Hal, I'm using a 2.5x1.0 GWS prop on a motor that is similar to the Losi but less money. The rated Kv for that motor is 10300.
http://www.rcgroups.com/forums/showt...1073542&page=2

This is the thread for the pusher. You got me thinking, I know the rpm of the pusher but I don't remember if I ever found out the rpm of the 30EDF so Later today I'll do some bench testing and compare the two. As you can see from the other thread the pusher was tached at over 44,000 rpm.
I'll pass on what I learn.
Roy
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Old Sep 02, 2009, 06:25 PM
The thruster don't work!
Roy E Oetting's Avatar
Fairborn, OH
Joined Oct 2002
415 Posts
Hal, I finally got some numbers. Haven't been feeling to good.
I first ran the 30mm EDF on a 3s pack and got 6.2A and 74W.
I then by accident ran the Losi (like) 12x20 on 3S. Holy smoke but really there wasn't any smoke as soon as I saw the numbers I shut it down - about 10A and 104W. It was getting hot quick. I let it cool down and ran it on two cells with the 2.5x1.0 prop and got 4.7 amps and 30W @ 45472 rpm.
I tried to tach the EDF but the tape flew off and hit me in the finger.
Hope this helps.
Roy
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Old Sep 02, 2009, 07:17 PM
The thruster don't work!
Roy E Oetting's Avatar
Fairborn, OH
Joined Oct 2002
415 Posts
This is two of 4 drawings of the EDF which can be built as a pusher..
Sheet 1 can be mirrored to get the other side. That is why it is #8.
Roy
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Last edited by Roy E Oetting; Sep 02, 2009 at 08:46 PM.
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Old Sep 02, 2009, 07:26 PM
Registered User
Chicago Northwest subs
Joined Jan 2007
2,240 Posts
File

Roy- The pdf unzipped and loaded fine for me. Effortless. That's more than I can say for many files I've tried to open on RCG!
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