Mid-Jet Build Log

[Mucksmear]

Once upon a time while I was in college, my mom had just returned from a trip to the UK and she brought back for me a copy of the Sept 1984 issue of RCM&E‘s Silent Flight Inside was a pull-out plan for Les Rudd’s Mid-Jet. There was instant appeal for an aileron sloper that could fit inside backpack for the bike ride out to the cliffs at Elwood a mile north of UCSB.

The first 3 that I built over the next few years were pretty much stock other than a few reinforcing mods to the fuselage. I love the plug-in, fully sheeted, all balsa, spar-less wings. The sliding tray also addressed my budget Futaba TX that lacked channel mixing.

 

[Wayne]

Oz : Mid Jet 2 plan - free download

outerzone.co.uk

That is one ugly airfoil, but the rest is pretty sweet. Did it fly well with that airfoil?

 

[Mucksmear]

Oz : Mid Jet 2 plan - free download

outerzone.co.uk

That is one ugly airfoil, but the rest is pretty sweet. Did it fly well with that airfoil?

Super ugly, but really easy to build up. It flew surprisingly well with that “airfoil”! Built stock, light and covered with iron-on film it could stay up with a Gentle Lady in medium-light thermals. With about 4oz of ballast it could fly in stormy conditions where u had to lean forward into the wind just to stand still. Inverted was poor, but roll rate was around 720/sec

 

[Red]

Super ugly, but really easy to build up. It flew surprisingly well with that “airfoil”! Built stock, light and covered with iron-on film it could stay up with a Gentle Lady in medium-light thermals. With about 4oz of ballast it could fly in stormy conditions where u had to lean forward into the wind just to stand still. Inverted was poor, but roll rate was around 720/sec

Can't help but think how cool that would be with an airfoil facelift.

 

[Mucksmear]

Can't help but think how cool that would be with an airfoil facelift.

So the 4th one I built used whatever is on the Son of Savage, which resulted in a faster model with good inverted but also a wicked tip stall. The 5th one used an SD3014 (It was lost at Tick a year or two ago). Of course none of these are reflexed sections but on the MidJet they had to flown with reflex…

This build is using MH45. There’s a fellow on RCG that did this too but he didn’t post a flight report.

 

[Red]

So the 4th one I built used whatever is on the Son of Savage, which resulted in a faster model with good inverted but also a wicked tip stall. The 5th one used an SD 3021 (I think. It was lost at Tick a year or two ago). Of course none of these are reflexed sections but on the MidJet they had to flown with reflex…

This build is using MH45. There’s a fellow on RCG that did this too but he didn’t post a flight report.

A little bit of airfoil tailoring along the span could cure the tip stall and have good inverted performance as well. Looking forward to hearing. Sure is cute!

 

[Wayne]

Ok - Good to hear. I sort of amazed the original could float well.

 

[Mucksmear]

The original plan was to get my son to build one too (to graduate from the Ridge Runt) but he went off to college before he could glass the fuse or sheet the wings…

Fast forward 6 years: my fuse has been glassed and primered. Cores cut and sheeted with 1/16” balsa and a basswood LE.

This weekend I added the wingtips and cut/capped the elevons. Today I started glassing with 0.73oz/yd^2 cloth.

 

[Wayne]

How light do these planes turn out for you? What do you use for the wing joiner? You used 1/16" balsa sheeting over the ribs?

 

[Mucksmear]

How light do these planes turn out for you? What do you use for the wing joiner? You used 1/16" balsa sheeting over the ribs?

Can’t remeber the weight, it was so long ago. #1-3 were pretty stock per plans. 1/16” sheet skins over the ribs. 1/4” balsa triangle LE. If u chose medium to light balsa it could come out pretty light, especially today with our tiny radio equipment. Joiner rod is solid steel, but today u could use CF.

None of my MidJet builds from #4 onwards were optimize for light weight because I expected to fly them in med/strong conditions at Tick

 

[Mucksmear]

Got everything glassed. In 40 years, I’ve never mistakenly glassed a surface twice - until yesterday. Finished glassing the “other side” of the vertical fin, flipped it over and was surprised to see bare balsa, so I had to apply a 3rd layer…

Hot glued a #11 blade to a block of wood to cut the vertical slot through the top of the hatch. The fuselage has parallel flat sides so this is a convenient way to scribe and cut the vertical channel into the curved surface and guarantee it’s vertical, aligned and centered. Cut one edge of the slot, flip the fuse over and cut the other edge.

I never really liked the lines around the nose, cockpit area or the fin of the original design so after #3 they’ve all had more pointy angular shapes like you see here. I will eventually add a tailcone that does not look like a bottle cap to the rear bulkhead:

 

[Wayne]

Love it, and another great tip!

 

[Mucksmear]

Photoshop mockup. Maybe metallic orange if I can find some rattle cans, otherwise plain old gloss orange.

 

[Red]

Love it!

 

[Mucksmear]

After plotting out the pattern, and testing it with paper, I made the tail cone from some manilla folder card stock and glassed it with 0.73 oz cloth. A balsa disk reinforces the forward end.

Radio hatch is secured with a steel wire inserted through the tail cone and captured by a brass tube mounted at the rear of the hatch under the fin.

Torque rods! Remeber those? Servos will sit side by side on a ply deck that also supports the torque rods.

Wing retention clip:

 

[G-man]

I admire your design ideas, and appreciate your ingenious tools and careful fitting of components and parts.
Here's hoping for great flight performance from this plane.

 

[Mucksmear]

I admire your design ideas, and appreciate your ingenious tools and careful fitting of components and parts.
Here's hoping for great flight performance from this plane.

Thanks G-man, although most of these ideas are stock from the designer Les Rudd. My only contribution here is the revised fuselage + fin profile and the retention pin through the tailcone!

 

[Mucksmear]

It’s done!

 

[Red]

Looks great! Please get some video of it airborne if you are able.

 

[Wayne]

Just in time for Los Banos!