Valenta Salto + Mig Flight JETEC EDF

[Steve P]

While some scale purists do not like the extended wing on the Valenta Salto, I can say for certain that if flies amazingly well. This thread is an add on to my original -- https://forum.scalesoaring.com/forum...tanced-version

I needed a project and have come to love flying my EMS Arcus with a 12S EDF. So, time to cut a hole in a perfectly good sailplane!

Valenta Salto
4.5 meter span
HQ 2,5/12 airfoil
Mig Flight JETEC E-80
Leo 2.5Y motor for 8-10S
HET Zeus 150A OPTO HV ESC
2 packs 5S 4000, 65C for 10S power
Projected 130 Amp draw

My main concern is that this sailplane has proven to be a joy flying the slope lift at Cumberland. Adding all this weight may not make it a candidate for the evening smooth air, but what the heck.

Time to make a mess...

[Steve P]

This beauty sourced from Etienne at ICARE will live inside the fuselage.

[Steve P]

Before the stupidity of cutting a hole in the top of a perfectly good sailplane that flies beautifully and is all set up, one must rip the guts out!

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[Steve P]

Job one was taking out both my equipment and the floor of the fuselage as the seat pan would not permit for the addition of power batteries below. Out came the floor and 2.3 pounds of lead.



The tow release in this plane was tiny and always a PITA. Good opportunity to rip it out as the release servo needed to be relocated. We can do better...



Finally clean out the joint, all the epoxy bits and such with the Proxxon hand belt sander...

[Steve P]

I was fortunate as Etienne had done a number of EDF installs for customers, so he had a template for the buulkhead. He emailed it to me and I printed it several times until my metric ruler and the one in the photo matched.



And here it is, glued to cardboard and cut out to test fit before heading the the scroll saw and plywood

[Steve P]

Next up the stupidity begins. Laying out the proposed hole, checking, re-checking, checking again and saying a prayer.



Fortunately, Mig Flight posts measurements for their units on their website...

[Steve P]

Out comes the moto tool, deep breath, go...



Light sanding of the edges. My next steps is to add three layers of carbon cloth -- at each side of the cutout L/R and along the floor of the fuselage for reinforcement! This photo is in process -- the first layer with each successive larger and longer...



Simple wet out of a piece of 3 inch fiberglass tape that will be put into a press and when cured, cut into strips and glued inside with 1/8" protruding -- used as the lining of the hole so that when the lid comes down it seals all the way around. The edges of the cutout and door will be painted white. The illusion should work pretty well.



A good day of sailplanes. Practiced F5J landings in the morning, now this. Finishing out all of the reinforcements should make it a wrap for this Sunday afternoon.

Back on this project whenever...

[Steve P]

Went back to the shop with every intention simply to clean up and this happened. At least the dust stage is now over.

Actual needed to be slightly larger than the template



Notches match



Reinforcements curing

[Sinkhappens86]

Seeing that massive hole in the top of the fuse without any context about gave me a heart attack, and its not even my glider!

Looking good Steve!

[Soaranator]

Looks good! Glad to see you are putting your time to good work instead of wasting your life on that work crap...

[DennisB]

You are very brave cutting that hole. I did it for a few customer models using the Jetec but not my own.

[Steve P]

You are very brave cutting that hole. I did it for a few customer models using the Jetec but not my own.

Thanks, Dennis. I obsessed over it for quite a while and finally said enough. It's pretty okay as a first attempt. Next time I would use an even smaller diameter cutting wheel (I used a worn down one, but could have gone smaller) to work the curves. Far more fear here than cutting gear doors on the bottom -- nobody really sees those and they're dead straight.

A bit of Friday evening work done....

First up was installing the bulkhead. Using the bandsaw, I cut small slots all along the joint surface. Next I bolted the unit to the bulkhead and did a couple trial fits. Once happy, I tacked it into place with four spots of 5 minute epoxy giving me time to hold it in what looked like alignment and then able to give it a minor twist when the 5-minute cured (as we know 5 minute is crap, so it's ideal for this as it's a bit rubbery when first cured).

Once happy with alignment, time for another commitment. I popped the bulkhead back out making the epoxy spots now the key-in places for the permanent install. I was torn between my retract go-to which is Hysol E-90FL, the 90-minute impact resistant gray version and E-60HP the 60-minute faithful white Hysol. I decided to use both! The bulkhead went in with the 60 and a fillet along the rear side. Then, the front was filled (the slots and very most front edge given the taper of the fuselage were not completely filled with the 60) and filleted with the 90.

Whatever.

[Steve P]

Patience was the only tool needed from there...

[Steve P]

I've read that the quality EDF install should also include blocking off the back of the fuselage as when that gaping hole on top is open and there's a giant windmill pumping air across it one does not want it to go down the fuselage. Or, act like an massive airbrake. This is certainly true on my EMS arcus as the airflow is smooth and quiet with the rear bulkhead in place.

So, to keep weight down I simply fashioned one from a piece of blue foam board tapered to fit. Covered with some black vinyl and tacked in place with a five-minute.

[Steve P]

Mostly at a standstill now waiting for a few more electronics bits.

Needing to upgrade from the nine-channel receiver now that there are 11 channels in this bird, I decided to go with a pair of 26D receivers and a PowerBox Pioneer unit. One receiver will go in the nose and the other mid-ship. I can solder up the long leads to the motor and do some other basic stuff waiting for the UPS man to arrive this coming week.

Power will be via a pair of 5S 4000 MAH 65C Lipos and a 150 amp ESC. The C rate might be a bit low but I have them so they'll get first crack at this. I broke with my relentless commitment and ease of programming of Castle Creations controllers and went with the Zeus 150 amp. It was a great deal and came with a programmer, I had it here and it needs a home. My Arcus has a YGE and my DG-1001 a Castle, so we shall see.