DIY 50mm EDF Grunjet

jaredstrees

Well-known member
Well, Griff, got to say what a great plane. This flies wonderfully. I think the cg may need to be closer to 4", but it only took half a second to trim her out. She just flew awesome. This is my first EDF, so if anyone's looking for a good introduction this is it! Very quick and agile but would slow down and just float in for a landing. I did notice she liked a little speed through the turns. A couple times I was a little slow and she wanted to drop a wing, but it was easily recoverable. Well done! Can't wait to put her in the air again. Got two packs in and would have gone for more except you can see my edf was starting to come out of the thrust tube. A little glue and good again for today if the weather cooperates. Well done!

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Grifflyer

WWII fanatic
Well, Griff, got to say what a great plane. This flies wonderfully. I think the cg may need to be closer to 4", but it only took half a second to trim her out. She just flew awesome. This is my first EDF, so if anyone's looking for a good introduction this is it! Very quick and agile but would slow down and just float in for a landing. I did notice she liked a little speed through the turns. A couple times I was a little slow and she wanted to drop a wing, but it was easily recoverable. Well done! Can't wait to put her in the air again. Got two packs in and would have gone for more except you can see my edf was starting to come out of the thrust tube. A little glue and good again for today if the weather cooperates. Well done!

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Congratulations on the maiden! I've never had a problem with the EDF coming out, but I used plenty of glue:cool:
 

jaredstrees

Well-known member
Yeah, probably too little glue, but I was looking at making it easier to clean the glue off when that edf goes into the next plane. It's not coming out now!
 

jpot1

Elite member
Grifflyer - I don't have an EDF experience but this one sounds like a great trainer. Question for your - I'm trying to stay consistent to fly everything off of 3S 2200 or 3S 1300mah batteries. The EDF you link to in the first post has a 3S option - any feedback on it?
 

Grifflyer

WWII fanatic
Grifflyer - I don't have an EDF experience but this one sounds like a great trainer. Question for your - I'm trying to stay consistent to fly everything off of 3S 2200 or 3S 1300mah batteries. The EDF you link to in the first post has a 3S option - any feedback on it?

Well I have no feedback on the 3s version so I can't give you any suggestions, but I 'll try and fly my Grunjet with a 3s battery on a 4s fan (lower kv) and give you feedback, because if the 4s fan can fly on 3s I'm sure a 3s fan with a 3s battery will do just fine. do you see what I'm saying lots of S's
 

jpot1

Elite member
Well I have no feedback on the 3s version so I can't give you any suggestions, but I 'll try and fly my Grunjet with a 3s battery on a 4s fan (lower kv) and give you feedback, because if the 4s fan can fly on 3s I'm sure a 3s fan with a 3s battery will do just fine. do you see what I'm saying lots of S's


Sssssounds perfect. Thanks!
 

jpot1

Elite member
Thanks man. What flight times are you getting on the 3s? Unfortunately banggood is “under restocking”.
 
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jaredstrees

Well-known member
Awesome to hear. I was going to try that this weekend, but my flying area was a little too congested for this plane. Only have a couple 4s batteries, but loads of 3s 1300's!
 

jpot1

Elite member
Finally going to build this. HK order took 2.5 weeks to finally ship but will be here early next week. Any building tips not in the thread yet?
 

Grifflyer

WWII fanatic
Finally going to build this. HK order took 2.5 weeks to finally ship but will be here early next week. Any building tips not in the thread yet?

I don't have any tips that come to mind, but don't hesitate to ask questions if you have one.

Good luck.
 

jpot1

Elite member
Grifflyer do you have a weight on yours without the battery? I realized the EDF I picked up was the one used by Aircninsei on his Eazy build. It only has 450g thrust on a 3s which is all I have. Not sure if it will be enough depending on the weight of the Grunjet?
 

Grifflyer

WWII fanatic
Grifflyer do you have a weight on yours without the battery? I realized the EDF I picked up was the one used by Aircninsei on his Eazy build. It only has 450g thrust on a 3s which is all I have. Not sure if it will be enough depending on the weight of the Grunjet?

Mine weighs 320g without a battery, and I believe you'll be using a heavier EDF than what I'm using. So I think it would fly, but only at WOT.

But the Eazy looks like a great plane so I'm sure you'll have fun with that plane!
 

Grifflyer

WWII fanatic
Well I hate to inform you all that the Grunjet and all its parts have gone to a better place *a-hem..cough tree cough*
but on the bright side banggood is back in stock
 

Zoltenburg

New member
Introducing the Grunjet, a two sheet foamboard performance jet flying fast and sporty, and slows down to a solid run on landings, and is packed with amazing vertical performance, all only costing 80$ built to BNF standards

-Video

-Parts list
two sheets of adams readi-board

FMS 50mm 11 blade EDF 4s version

4s 1300mah 45C

40a esc

three 9g servos

-Review

-Speed
I would say roughly 70mph

-Handling
smooth but fast roll rate with the same tendencies on the elevator which makes a great introduction to jets

-Slow speed
This is one of the strongest points for the design, so it comes in really slow compared to other jets in its class.

-Stalls
A little rough but I have yet to drop a wing

-Aerobatics
This plane doesn't have a rudder so you're limited to basics: rolls, loops, and inverted flight.

-Take offs
You can either do an underhand launch while holding the thrust tube, or my favorite, just plop it on the grass and give it full throttle and off she goes!

-Vertical
Nearly unlimited

-CG
4.5 to 5 in/11.5 to 12.5 cm from leading edge

-Gallery

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-Plans
Grunjet Plans V1.0

-Decals
Grunjet Decals

Hello, Is there a build video for this jet? I would really like to make one. I need to bring the plans to staples to make them bigger but not sure how big to make them. I'm guessing the size of the foam board.