Midwest Extra 300XS - RC Groups
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Mar 27, 2017, 12:15 AM
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Nergall's Avatar
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Midwest Extra 300XS


This build has been a long time coming. I bought this kit when Midwest was just about to discontinue the line, only shortly after re-entering the hobby after a long, long hiatus. At the time, I considered the airplane beyond my flying skill in so much as I felt one should be reasonably sure there will be no problems flying a plane before committing to a giant scale project. This from both the simple safety aspect and the economic risk involved. I was close to that point, but not ready to commit the funds just yet. However, I was kinda thinking Midwest was about to discontinue their giant scale kits as they had just marked down the prices. In fact, my kit being one of the last they sold, did not even come with the ABS cowl. Instead I got a note on how to order it - from what appeared to be a long defunct company...

When I was ready for an Extra, I built the Great Planes 1.20 sized one, which I still have - though it needs a little maintenance. It was just sooo much cheaper to build the smaller one. I had a second hand OS Max 1.20fs on hand, plenty of servos for that size and none suitable for giant scale. So, the big Extra sat on the shelf a few more years.

About three years back, my son and I had a fun evening designing a potential color scheme for it. However, I was just about to start a BUSA kit, so the idea was to start this build just after the Sopwith.

https://www.rcgroups.com/forums/show...ra-300S-Design

The design progressed a little further after that. I'll post that later when I dig it up.

I am a slow builder. I work full-time, have family obligations, and spend a good portion of my free time when the weather is good flying the planes I built or bought. So, don't expect this thread to progress quickly, but barring health disaster, I will finish it. I generally only build about 3-4 evenings a week, and then generally only for about 30 minutes at a time, and then some portion of that time is spent on the normal small repairs we have to do to keep flying the planes we have. I expect this build to take 6-12 months, and may not even really start it until after Joe Nall. The BUSA project took two years to get flying, and being a scale airplane, I wouldn't considered it done, but it does fly!

But, I'm excited! I've waited a long time, and collected quite a few bits and pieces along the way. I have the engine, the servos, the cowling, and some CF landing gear I may use. I've talked to a few people who have built this kit in the past, and have in mind a few mods to make it perform even better. And most importantly, the building table is empty!
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Mar 27, 2017, 01:16 AM
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koppterX's Avatar
hi, I built one for a mag review many many years ago. there's a lot you can do to lighten it up, balsa spars, lighter wing joiner...etc. and it should fly well with a DLE 35 or something similar. it's a big one piece wing!
Mar 27, 2017, 05:59 AM
Me Likey Scale Planes
scale_only's Avatar
I built 4 of these, the first, which was my first "giant scale" plane was the "s" flat stab version, it crashed, can't remember why so long ago,, but since I had the cowl and gear and motor, I scratch built another with a foam wing,, which folded so I built #3, that one held up for years until I sold it.. Then #4 was the SX model when I got back into flying in '08, sold that one a couple years later. Good memories with that airframe

All used a Brison 3.2, I think a DA50 would be perfect,, I had a Quadra 40 on my first one, it was gutless, so I quickly upgraded to the 3.2.

Good luck with the build,, it's a great kit and a pretty easy build, parts fit well, instructions are well done.
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Mar 27, 2017, 11:16 AM
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DGrant's Avatar
Very cool planes. I built one, and rescued one(which isn't finished yet.. saving for future time).. and yes... it was my first "giant" too... and back then, there weren't as many giants, and these were actually very large models... ha... my how things have changed. I'm still a big fan of these planes.. always will be I'm sure.

The one I built and flown has the BME-50... which seemed to give it very good power to weight ratio, as the plane when I got it done weighs a bump over 15lbs. .. like 15lbs./2oz.'s.

Mine's the flat-tail version, with the flying wires... and apparently the foiled tail version you have the flying wires aren't needed, as that foil tail is probably much stronger then the flat version. The wires on the tail definitely work though...with those it's bullet proof. I wouldn't recommend them for that beautiful foil tail though.

I'm looking forward to seeing this too... It was a great build for me... I still have it after all these years... as it was 15yrs ago I was building mine. This will be a cool build.

I have the plans on file I believe(PDF) if that might help. I've been having most of my plans output lately, rather then using the rolled up/folded up originals... as new nice plans output are a dream to work on.. and you can refer to your comp screen if you need to study them a bit too. Good luck with it, we'll follow along.
Mar 28, 2017, 02:35 AM
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Nergall's Avatar
So, I also have a DLE 55 for this, some Savox 1256TG servos, a Tech Aero IBEC and a Sullivan smoke pump.

This wouldn't be my first GS, I've been flying 30cc and up for a while now. I know about the flat stab and the flying wires. I was rather thinking I should add them anyway, but I've also heard the airfoil stab shouldn't need them.

Scale_only: did you use the flying wires on your SX version?

I looked at the spar joiner after I read the comment above, and yes, I'm pretty sure that's over kill. I think maybe drilling some lightening holes in it would work well - maybe not in the center bays, and holes small enough to fit between the top and bottom spar.

However, even at 17 lbs, I don't think it would fly too heavy. At 14 or 15 lbs though, it could fly extremely well!

DGrant: when you say you have the plans as PDF, are those the airfoil plans??
Mar 28, 2017, 08:08 AM
Me Likey Scale Planes
scale_only's Avatar
Quote:
Scale_only: did you use the flying wires on your SX version?
Yes,, because the Fin/Rudder is still flat,, only the stab is airfoil.

There a few places to loose a little weight,, but I can't see getting it down to under 15lbs. It'd with fly fine in the heavier weight range,, it's not a 3D machine,, but I could hover mine with the 3.2,, the smaller control surfaces are more of a challenge,, but for general aerobatic or IMAC style flying,, it's a great bird

Extra 300 at Cleveland Radio Control Club airfield.. (6 min 54 sec)
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Mar 28, 2017, 12:27 PM
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DGrant's Avatar
Quote:
Originally Posted by Nergall
So, I also have a DLE 55 for this, some Savox 1256TG servos, a Tech Aero IBEC and a Sullivan smoke pump.

This wouldn't be my first GS, I've been flying 30cc and up for a while now. I know about the flat stab and the flying wires. I was rather thinking I should add them anyway, but I've also heard the airfoil stab shouldn't need them.

Scale_only: did you use the flying wires on your SX version?

I looked at the spar joiner after I read the comment above, and yes, I'm pretty sure that's over kill. I think maybe drilling some lightening holes in it would work well - maybe not in the center bays, and holes small enough to fit between the top and bottom spar.

However, even at 17 lbs, I don't think it would fly too heavy. At 14 or 15 lbs though, it could fly extremely well!

DGrant: when you say you have the plans as PDF, are those the airfoil plans??
The plans are the "flat-tail" (S) version. I'll attach them here for your reference. Yeah, definitely use them on the flat version, and I would say as well on the foil version if you like too. I only have experience with the flat version, and I can say they most definitely make a huge difference in rigidity. I used "coated kevlar" for the wires, along with 2/56 rigging. Before the wires went on there was a bit of flex, after the wires there's little to no flex... dramatic diff.

I also changed out the spruce(or bass..can't remember..).. anyway... those heavy wing spars for balsa, that I laminated c/f too.. then did the sheeting as called for... so that saved quite a bit of weight in the wing... as that was some heavy wood if memory serves. I had to rip down new spars from 3/8"x48" balsa... as I had problems finding 3/8" square balsa that was long enough.... everything was 36", and I needed well over 40" ... so I just made my own 48". Problem solved...

I also used coated-kevlar for the pull-pull rudder cabling... and used 4/40 hardware/rigging.

Interesting... I just found out, I can't upload anything over 3.0MB in a post. Hmm... I was going to upload the plans here.... hmmm... I seem to recall getting the plans from this very site... as well as several other plans I've obtained over the years. Is that somthing new, or am I missing something.?..

I won't go into that issue here, sorry.. but I'm going to check it out, as I/we have all shared plans and files for years... and I don't recall a 3MB limit.

So.. back to the plane... If you'd like those plans, just PM me with your email addy, and I'll ship them over no problem. My plane was built pretty much exactly to plans, with the above mentioned mods, and a few more too, but nothing radical... as they do fly very good.

I almost bought the Midwest Cap a few weeks back... there was a great deal in the classifieds.... but I figured it was just my sickness talking...fortunately the feeling of wanting it passed in a day... Can't wait to see your plane though.
Mar 28, 2017, 12:44 PM
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Nergall's Avatar
16 lbs would be OK by me. Sounds like I will do the tail rigging. I guess I need to make a list of planned mods. Right now, the only things I'm considering are mods to lighten the airframe or fix know issues. I thought about enlarging the ailerons, but that seems like too much effort trying to make this into something it isn't. Anyway, so far, I have in mind the following:

1. Dump the aluminum gear for Carbon Fiber.

2. Lightening on the spar doubler.

3. Light, minimal tail rigging - thinking I will just order this:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFV30

4. Depending on the balance, pull-pull rudder.

5. Possibly lightening the rear fuselage frame? I'm less sure about this, but the fuselage does seem to have more plywood than it needs?


Covering looked real nice in that video, but it was hard to see? Do you have a still picture of it?
Mar 29, 2017, 08:42 AM
Me Likey Scale Planes
scale_only's Avatar
Looks like I need to correct my previous statement,, I didn't use flying wires on that one

p.s.
You can hear some sputtering in the vid,,, After my buddy stopped filming,, the motor quit in no mans land, had to make an dead stick landing in the parking lot

I had covered it to replicate a Ultimate I had years before,, but the scheme didn't really translate to the Extra, I was going to recover it,, but ended up selling it
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Apr 06, 2017, 12:02 AM
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Nergall's Avatar
I finally got enough space cleaned up around the work area to move the box off the building table and start punching out the die cut pieces. Die cutting is exceptionally good.

It's my practice to scan the parts as I go, so first couple of evenings will just be scanning.

Sample below - I had the idea to include a ruler in all the scans this time.
Apr 08, 2017, 10:59 AM
michigan jet guy
mrshea's Avatar
i don't have the extra, but i have the cap 232 that i am going to build here this next off season and i am going to ditch most of the plywood and replace it with balsa lamination's. Balsa plywood in other words. I think they can be brought down weight wise much more. The structure of these these while not over engineered
, materials could be much lighter. Just my opinion. Watching with great interest. Phil
Apr 11, 2017, 11:34 PM
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Nergall's Avatar
I also looked up whether two fortitude fuel tanks would fit in the 5" space in the engine box.

Looks like they will if I go with 16 oz. tanks, but I'm thinking a 20 oz gas tank and a smaller 12 or 16 oz smoke tank?
Apr 15, 2017, 04:35 PM
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Nergall's Avatar
OK, I made the cuts. Beforehand, the two pieces weighed 4.05 ounces, afterward it was down to 3.45 ounces.


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