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Aug 21, 2019, 02:15 PM
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I regularly check the availability of spare parts ... Most notably absent are the elevators :

https://hobbyking.com/en_us/catalogs...sult/?q=fresco

https://hobbyking.com/en_us/catalogs...bal%7C3&is_v=1

https://hobbyking.com/en_us/catalogs...bal%7C3&is_v=1
Last edited by Herb; Aug 21, 2019 at 02:21 PM.
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Aug 21, 2019, 06:58 PM
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This is my latest FMS 90mm fan / inrunner setup, with a HK SK3 1900kv ($47 with disc code) motor - I have like three of those in the WeMoTec Evo 90mm fan and they are excellent motors for what they cost.

https://hobbyking.com/en_us/turnigy-...html?wrh_pdp=2

The rotor was statically balanced on a magnetic balancer and it was very very close, near perfect !

I will run it up on the bench to double check for vibrations once the ge silicone II cures ... It will go the MiG-17 to replace what looks like an inefficient $3 stock outrunner

Expect to pull roughly ~112A and ~2500 Watts based on my calculation.

.
Last edited by Herb; Aug 23, 2019 at 01:05 AM.
Aug 22, 2019, 05:11 PM
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The next step is the removal from the MiG-17 of the stock AF-Model outrunner fan.

It comes pre-balanced (see blue weight in spinner) so it's important - if taken apart - to mark with a pen the exact location of the spinner

Edit : A Google search reveals that the stock fan looks rather similar to the HSD Viper 90mm fan :

https://rcsa.org.za/product/v4-90mm-...6s-duct-motor/

which uses the exact same D3541 1550kv outrunner motor ... Nevertheless there are some differences.

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Last edited by Herb; Aug 23, 2019 at 04:21 PM.
Aug 22, 2019, 05:19 PM
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Next is the FMS fan / SK3 inrunner install, some very minor foam shaving required ~4mm at the back (the FMS fan shroud is 4mm longer).

Fits like a glove

Also, a rotation direction check & an esc re-program for a 4-pole inrunner (6 degrees timing advance).

EDIT :

I measured this setup with a watt meter, and on a fully charged HRB 50C 5000 I get 124A and 2805W with the stock esc on low (6 deg) timing.

Might have to either fly mostly at half throttle or upgrade the ESC to a YEP 150A ...


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Last edited by Herb; Aug 24, 2019 at 11:19 AM.
Aug 25, 2019, 12:05 AM
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Three more good flights today ... One of the easiest edf jets to land if you control the speed, comes down nice and stable

The FMS / inrunner fan provides a very significant power boost - which the MiG-17 can use ... Might try a WeMoTec evo next week.

On the last flight the right retract unit quit and would not go up past ~45 degrees, a bit frustrating ... ordered a replacement. One of the gear door servos plastic gears must have stripped as well.

Soo, gear doors are gone now

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Last edited by Herb; Sep 11, 2019 at 08:33 PM.
Aug 25, 2019, 01:29 PM
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Quote:
Originally Posted by Herb
... On the last flight the right retract unit quit and would not go up past ~45 degrees, a bit frustrating ... ordered a replacement.
It turns out it was just dust ... these units have tight tolerances and seem very sensitive to the smallest grains of sand or dust slowing down the screw mechanism.

Took out and cleaned both units with compressed air and later wd-40, and now they seem to work fine ... till the next jam

.
Aug 25, 2019, 01:36 PM
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Going to try next the WeMoTec Evo fan with HK SK3 1900kv inruner ...

80mm diam outlet too big for most 90mm edf fans.

.
Last edited by Herb; Aug 28, 2019 at 04:05 PM.
Aug 25, 2019, 04:11 PM
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Quote:
Originally Posted by Herb
It turns out it was just dust ... these units have tight tolerances and seem very sensitive to the smallest grains of sand or dust slowing down the screw mechanism.

Took out and cleaned both units with compressed air and later wd-40, and now they seem to work fine ... till the next jam

.
Herb - thank you for posting these detailed pictures!

Info please regarding one picture - it shows 4.8 V batt.
Is this the operating voltage for retracts (did you measure the voltage on original unit), or just allows you to test, albeit with less deployment speed ?

Thanks in advance, Darko.
Aug 25, 2019, 04:37 PM
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I think the retracts can take higher voltage (BEC's nowadays are 5.5 to 6.0V) but the 4.8V nicad was for testing purposes only.

The MiG-17 kit has a separate retract actuator box, which cuts off the voltage to the retract unit (any one of the three) if a certain amp load is exceeded...
Aug 25, 2019, 05:06 PM
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Thank you!
Aug 25, 2019, 11:41 PM
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Six flights today now with the WeMoTec Evo / inrunner setup.

Flies just as well as with the FMS 90 fan / inrunner setup of yesterday if not better, but picked up some extra speed in spite of the added steel grille ...

It seems the WeMoTec setup is a bit more efficient (at least in this airframe) than the FMS inrunner setup.

Next have to clean up the intakes a bit, there's still a lot of junk (servo wires, rods and blunt edges) hanging in there.

After sucking in a small stone, I put a steel mesh over the intake. But unless you have lots of stones & such on your runway, you can be better off without one. That's why it's always a good idea for it to be removable, & the process to be reversible.

All my stainless steel meshes are from $3 walmart 6" mainstay strainers,

https://www.walmart.com/ip/Winco-MS3...lspartner=wlpa

.

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Last edited by Herb; Sep 10, 2019 at 04:33 PM.
Aug 26, 2019, 12:00 AM
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Today's visitor at the field

Wile E. Coyote Wondering around the Flying Field (0 min 26 sec)
Aug 26, 2019, 04:14 AM
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Quote:
Originally Posted by Herb
Going to try next the WeMoTec Evo fan with HK SK3 1900kv inruner,

.
Hi Herb!

Also have an WeMoTec Midi-Fan EVO 90mm (acquired previously for planed 3D print project) - can you please tell me how many amps your setup is pulling - what ESC you will recommend?
Any info on settings is also very appreciated.

Interested only in general terms - Avios MiG is my first EDF and for sure will not experiment with that for now - many things to lean before ..
Aug 26, 2019, 10:41 AM
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Yesterday I've flown the MiG-17 with the WeMoTec Evo fan / HK SK3 1900kv inrunner motor on 6S using still the ESC that comes with the MiG !

The above WeMoTec setup pulls ca ~105A and ~2200W :

.
Aug 26, 2019, 10:45 AM
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Thank you again!


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