Foamboard SAAB JAS-39 Gripen EDF (images, plans, build)
- Thread starter Widkin
- Start date
-
- Tags
- edf gripen saab scratchbuild
Thank you, I'm really worry about how slow it. If it not fast enogh may be i gonna crash it some day.
Bayboos
Active member
I did some more 4s flying, mostly to learn the plane and check how the electronics survives the 4s torture (mind you the drive was designed for 3s application). Here what I found after one moderate to intense flight:
All temps on the images are in the normal scale, which translates to (roughly) 100, 125 and 150F, respectively. I did more measurements of course, and those numbers are a good average - I did notice slightly higher temps after one or two very intense flights, but usually it's a bit lower than that.
I'm a little surprised that the motor remains relatively cold; but the ESC's temperature is definitely something to worry about. At this point however it's not actively cooled, so it may be a good idea to figure out a way to push some cool air trough the battery/ESC compartment. Right now I just need to wait a bit between the flights to let it cool down by itself; which is a bit difficult because the plane flies beautifully... And I already bought some acrylic paints, including bright/metallic ones, and some water-based varnish to go on top of them...
Stay tuned.
All temps on the images are in the normal scale, which translates to (roughly) 100, 125 and 150F, respectively. I did more measurements of course, and those numbers are a good average - I did notice slightly higher temps after one or two very intense flights, but usually it's a bit lower than that.
I'm a little surprised that the motor remains relatively cold; but the ESC's temperature is definitely something to worry about. At this point however it's not actively cooled, so it may be a good idea to figure out a way to push some cool air trough the battery/ESC compartment. Right now I just need to wait a bit between the flights to let it cool down by itself; which is a bit difficult because the plane flies beautifully... And I already bought some acrylic paints, including bright/metallic ones, and some water-based varnish to go on top of them...
Stay tuned.
Bayboos
Active member
Nice video. It looks like the area you are flying in is somewhat tight for this airplane. It would be impossible to fly there with my current setup 
Be careful with this ESC and those plugs. The outside temperature have very little impact on cooling such components, especially when those are installed inside closed, insulated space (boamboards are very good insulators). You should definitely upgrade to something more robust.
Good luck, and have fun!
Be careful with this ESC and those plugs. The outside temperature have very little impact on cooling such components, especially when those are installed inside closed, insulated space (boamboards are very good insulators). You should definitely upgrade to something more robust.
Good luck, and have fun!
Stonewall
New member
I know I'm a bit late to the party, but hopefully people are still posting. I really love the looks of the Gripen and when I did a Google search I saw this thread on FT and got all giddy. I don't have any EDFs on-hand for scratch builds, but one thing I do have enough of is outrunner brushless motors. Would this be practical to modify for prop build with a prop cutout somewhere down the midline? I'm currently working on an F-117 and hope to finish it up either this evening or tomorrow, and then I do believe this Gripen has my name on it.
Bayboos
Active member
Hello, and welcome!
Every DIY foamboard EDF can be converted to a prop setup, either classic pusher (or tractor, if you wish) or prop'n'slot. But it's not always easy. The latter one seems to be what you have in mind, and in case of this particular design, it may require too mamy changes in the structure to provide enough free air for the prop and still keep it's structural integrity.
I wasn't able to easily find nice looking prop'n'slot Gripens on the web, but there are plenty of those in pusher prop configuration. One particularily good looking example can be found on the RC Groups forum: https://www.rcgroups.com/forums/showthread.php?308830-JAS-39-Gripen-Park-Jet - it's a little bit smaller (just a bit though) and should be even easier to build because of the flat box fuselage. I'm sure you can find other examples as well.
Good luck, and have fun!
Every DIY foamboard EDF can be converted to a prop setup, either classic pusher (or tractor, if you wish) or prop'n'slot. But it's not always easy. The latter one seems to be what you have in mind, and in case of this particular design, it may require too mamy changes in the structure to provide enough free air for the prop and still keep it's structural integrity.
I wasn't able to easily find nice looking prop'n'slot Gripens on the web, but there are plenty of those in pusher prop configuration. One particularily good looking example can be found on the RC Groups forum: https://www.rcgroups.com/forums/showthread.php?308830-JAS-39-Gripen-Park-Jet - it's a little bit smaller (just a bit though) and should be even easier to build because of the flat box fuselage. I'm sure you can find other examples as well.
Good luck, and have fun!
Quinnyperks
Legendary member
I am building one of these!
Looking good 👍👍👍
NandanPrabu
New member
Am 11 years old and a big fan of SAAB Gripen. Been flying RC models for a while now and always wanted to build a Gripen. My dad and I looked up various places for a plan and Widkin's plan was simply the best we could find. We have adapted this plan for a 50mm EDF and did not do a perfect job with a few aspects - front nose (width), canopy and the canard system. We printed the plan @ 75%...80% could have been better.
Attachments
NandanPrabu
New member
Tack så mycket Widkin...
The model we built based on your plan flies...and I did a maiden today. Will share the youtube link shortly
The model we built based on your plan flies...and I did a maiden today. Will share the youtube link shortly
NandanPrabu
New member
Widkin
Member
Hello Nandan,
Great work, that was a good maiden! Way better than mine
So cool to see you build this, and I'm glad that it also worked on a smaller scale. I would not have thought this possible due to the already low wing area of the plane but your video clearly shows it works. Good job!
NandanPrabu
New member
Thank You for the kind wordsHello Nandan,
Great work, that was a good maiden! Way better than mine
So cool to see you build this, and I'm glad that it also worked on a smaller scale. I would not have thought this possible due to the already low wing area of the plane but your video clearly shows it works. Good job!
