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Aug 09, 2014, 02:40 AM
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Thanks for the update, btw love the pictures, I only asked about the gear as I have only stripped the paint off and fixed a few things that's about it!!!
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Aug 27, 2014, 12:40 AM
Quote:
Originally Posted by jetjock50
The performance better be substantially better than the original. or this whole exercise has been a waste. I am hopeful that it is comparable to Jim Drews Yellow f-15 if not better, as this should come in lighter by a good bit. He was getting 135mph out of it, sooooooo.
We shall see!!!
Regards, Roger
We get 131MPH flat and level - with our fan, or a 32 pound thrust turbine! The limiting factor is the Yellow Aircraft scale F-15 airframe. If you want a fast F-15, use a Skymaster or Jet Legend version. Those are over 160MPH.
Aug 27, 2014, 09:59 AM
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jetjock50's Avatar

I stand corrected Jim


131 will be fine if I can achieve that straight and level with my plane. Not going to quibble about the 4 mph. Hopefully I can get some of that back by being lighter.
Hopefully, one of these days battery technology will find some improvements. That is still the limiting factor in my opinion to having good flight times once we get the performance where we want it.
Still working on the plane, glassing surfaces etc, hope to start assembling it all now that the duct is done. My next real goal is getting $ 650 for the landing gear so I can bash the heck out of the formers to make some good gear mounts.
Roger
Aug 27, 2014, 12:31 PM
Weight doesn't matter. In fact, the heavier the plane, the longer it will sustain the speed out of a dive. Our electric weighed 26 pounds with 5000mAh packs and 28 pounds with 6800mAh packs. The turbine version weighed 32 pounds full of fuel and about 24 pounds on landing. The speed flat and level was identical, even though the turbine had more than 1:1 thrust to weight. Uphill is a completely different story, since the fan had about 14.5 pounds of installed thrust. We did the turbine version first, and I was pretty skeptical that the fan version would even fly it.
Last edited by JimDrew; Aug 27, 2014 at 08:12 PM.
Aug 28, 2014, 07:39 PM
Not a Drone pilot
lashmett75's Avatar
Quote:
Originally Posted by JimDrew
Weight doesn't matter. In fact, the heavier the plane, the longer it will sustain the speed out of a dive. Our electric weighed 26 pounds with 5000mAh packs and 28 pounds with 6800mAh packs. The turbine version weighed 32 pounds full of fuel and about 24 pounds on landing. The speed flat and level was identical, even though the turbine had more than 1:1 thrust to weight. Uphill is a completely different story, since the fan had about 14.5 pounds of installed thrust. We did the turbine version first, and I was pretty skeptical that the fan version would even fly it.
You still hangin around..LOL

Good to see you poppin in hear and there. Miss hanging out...

James
Aug 30, 2014, 12:25 AM
Registered User
Roger,
Camlex rc in Oregon sells just the struts for the jet legend f-18 I think they are $270 you can also get the tires and wheels as well just FYI
Sep 09, 2014, 05:39 PM
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jetjock50's Avatar

Motor is on the way


I ordered the HET 800-68-685 from Gary at Efflux Rc, he shipped it out this morning. I have to see when it gets here if it fits the center body I have. (Fred Baldwins) , Specs say motor is 50mm, this center body measures 50mm, so we shall see. I dug out my trusty brake cylinder hone, just in case. Hey guys, what exactly is this thermal paste//grease I have been seeing mentioned on the threads??? And where can I get it if needed??
Roger
Sep 09, 2014, 07:05 PM
world's slowest builder
Air-Jon's Avatar
Radio shack or Fry's Electronics will have thermal paste...or buy some on Amazon. The cheap white stuff works fine...and a drop or two is all you need. Fancy silver stuff has been proven to only have a minor advantage if any. Hope the motor fit well in your housing.
Sep 09, 2014, 09:42 PM
Registered User
A10pilot's Avatar
Quote:
Originally Posted by jetjock50
I ordered the HET 800-68-685 from Gary at Efflux Rc, he shipped it out this morning. I have to see when it gets here if it fits the center body I have. (Fred Baldwins) , Specs say motor is 50mm, this center body measures 50mm, so we shall see. I dug out my trusty brake cylinder hone, just in case. Hey guys, what exactly is this thermal paste//grease I have been seeing mentioned on the threads??? And where can I get it if needed??
Roger
Roger:

I am using the HET 800- 685 KV motor in one of Tams aluminum center bodies for my Dynamax. When I tried to fit the motor inside the center body it went in a bit and then got tight. I took the motor and the center body to a machinist friend of mine and asked him to "make the motor fit" . I got the stuff back and he told me that the HET 800 was tapered from front to rear. It is about .002 smaller diameter at the front than at the back. Just FYI.

Ed
Sep 10, 2014, 12:44 AM
Still Screamin'!
rvincent's Avatar
Interesting... Wonder why they did that?
Sep 10, 2014, 01:07 AM
efflux RC's Avatar
Quote:
Originally Posted by A10pilot
Roger:

I am using the HET 800- 685 KV motor in one of Tams aluminum center bodies for my Dynamax. When I tried to fit the motor inside the center body it went in a bit and then got tight. I took the motor and the center body to a machinist friend of mine and asked him to "make the motor fit" . I got the stuff back and he told me that the HET 800 was tapered from front to rear. It is about .002 smaller diameter at the front than at the back. Just FYI.

Ed
One would never expect the tolerances on a motor case O.D. to be +0.000" minus (-) whatever.
If it's + or - .005" consider yourself lucky. (tolerances are not specified) Tolerances tighter than this would only drive the cost up.

Now.....consider that the center body should have been designed to accept the maximum allowable motor "+" tolerance for any motor (IE: HET, Neu, etc.) that it is intended to accept.
Last edited by efflux RC; Sep 10, 2014 at 01:12 AM.
Sep 10, 2014, 08:11 AM
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A10pilot's Avatar
Gary:
Not my intention to argue but I am simply telling you what I was told my a machinist that is imminently more qualified than me to measure stuff. What I can tell you is that I could insert the motor form the aft end of the center body and it only went in about 1/2" before it got so tight I could not go any further. Whether the motor "taper" was intentional or not I do not know. Simply telling you my experience. Perhaps when jetjock gets his motor he can comment.

I just got my digital calipers out to measure an HET 700-98-935. The O.D. of the case at the front is 1.534 and the aft end if 1.536. I am using some good quality digital calipers and not any micrometers so the numbers might be off a little but this is what I measured.

Additionally, in order to get the most of the center body as a heat sink you have to have a reasonably tight/snug fit otherwise the motor can not transfer all of its heat out to the finned center body. Tams center body was designed around the Neu motors and as has been posted in other RCG threads, using an HET motor requires one to "open up" the center body or reduce the O.D. of the HET motor. If you go to the mechanical drawings for Steve Neu motors you will see that is tolerances are to three decimal places (0.xxx) In all my years in mechanical design and reading drawings, the number of decimal places in the dimenbsion of the part defines the tolerances and one must specify the +/- tolerance for the part on the drawing. In looking at the Neu drawing for the 19XX motor (smooth case) his tolerance for the case dimensions it +/-0.05mm which is +/- 0.002". Now, if you are machining the motor then the O.D. of the case could be +0.002 to -0.002 which means that you could have a swing of as much as 0.004 and still be within tolerance of the drawings. Perhaps this is what happened to my HET 800 motor but since the 700 motor is similar then perhaps they have an intentional taper. To me, a slight taper on the motor (or the center body) would make sense as it would make inserting the motor into the center body easier.

Just my 2c.
Ed
Sep 10, 2014, 10:34 AM
Registered User
jetjock50's Avatar

motor size


Well this is all good information, I will break out the micrometer when it gets here so we can see what it is.
Ed, do you have any amp and watt numbers yet on your 685 motor in the dynamax fan?? Also curious to see some operating temps, or at least some post run temps. I will be getting an Ice 2 HV160 ESC as my next investment in this project, when the funds become available.
Roger
Sep 10, 2014, 01:33 PM
Registered User
A10pilot's Avatar
Roger:

I got a flight on the plane last week with the Castle 160 ESC in it but I have not downloaded he data yet. I will do this today or tomorrow.

Ed
Sep 11, 2014, 10:11 AM
Registered User
A10pilot's Avatar
Quote:
Originally Posted by jetjock50
Well this is all good information, I will break out the micrometer when it gets here so we can see what it is.
Ed, do you have any amp and watt numbers yet on your 685 motor in the dynamax fan?? Also curious to see some operating temps, or at least some post run temps. I will be getting an Ice 2 HV160 ESC as my next investment in this project, when the funds become available.
Roger
Roger:
Just downloaded the Castle link from the Falcon 120. Here is the data.

Fan: Dynamax with Tam center body and HET 800- 685KV motor
ESC: Castle 160 amp HV Edge
Batteries: Haiyin 5000 mah 40C 12S ( 3 ea. 4S packs in series)

Power: 4951 watts at full throttle
Current: 123 amps (max current @ full throttle)
RPM: 25K max
ESC temp: 112* max temp

One thing to note is that my ESC is mounted on the bottom of the fuse directly under the engine mount. I have attached a photo.

Ed


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