EMS 6.1 meter Quintus with FES - build thread

[Steve P]

This will be a thread more to catalog it for the forum, please ask any questions along the way. I'm in no hurry to complete the build.

First a bit about the full scale Schempp-Hirth Quintus, single-seat 23-meter open-class sailplane... The Quintus is the follow-up to the Antares (Lange) done as a joint venture between the two companies that reportedly went bad with only a handful produced -- as I understand it. They share a common wing design with the inner section developed by Lange. Here's the Quintus promo sheet: https://www.schempp-hirth.com/filead...intus_M_EN.pdf

I absolutely love the EMS Duo pure glider and my EMS Arcus with a 12S EDF. While I had eyed the new Quintus, I would have wanted it fully loaded with carbon Dbox and other additions, all the options and then shipped to the USA -- all a bit too far given my workshop is already full. Then I saw that Bruce at Rosenthal USA had one going at a super clearance price to make room for his own incoming inventory. I pounced! Then I put my Paritech Nimbus 4D up for sale and it quickly found a new home in California. Funds secured, marriage saved. Bruce delivered the Qunitus at Cumberland Summer Soar. Can't beat that!

DETAILS

- It's 6.1 meters for a scale of 1:3.75. It has a new airfoil called Aerotech M23108G wherein Ralf at EMS claims a wider dynamic speed range, better thermaling, and higher glide speeds. This is the AQX GT-R version which basically stands for built like a brick $#!+house: full CFRP + CFRP D-Box wing with cross-linked CFRP; it's very strong for extreme performance.

- Sports a fiberglass and carbon fuselage; the hollow-molded 4-piece wings (plus winglets) and tail; wings have the monoblock retention system; 4 servos per wing half (F, S, A and A). Best of all, the wings came fully pre-wired for all the servos and lighting leading to a single fuselage-to-wing plug, and Bruce also had a TEK probe mount and tubing installed for GPS triangle (damn, I can hear Stephane and Len now).

- The sailplane has a nice fully finished cockpit, detailed instrument panel, removable seat pan, canopy lock/release (dual locks on each side), the canopy swings upward on a super-strong carbon mount that locks up with a magnet, a typical retract setup with brake installed. A full fuselage bag and wing bag were included.

- LED lighting is via disc strobes in the wing bottom servo covers — each disc having nine 5-watt LEDs — and LED strobe bar built inside the fin that feeds a three clear posts in the vertical stab leading edge. The system is completely preinstalled and mounted (servo leads in the cockpit with white dots indicate the three LED circuits to plug into the controller while the control board is an Power Modellbau 2K Flasher unit using a single receiver channel to be operated by the transmitter.

Link to the disc strobes that claim visibility at altitude in sunny conditions…. https://www.hacker-motor-shop.com/Li...PT4143&p=10758

This sailplane will be getting a super cool PowerBox Pioneer unit fed by two 2200 mAh 7.4V lipos and two PowerBox 26D receivers.

VIDEO

I will be building this as an FES using the Torcman system and a Hacker A50-14L motor turning a 14x10 on 10S 4000. Here's a similar setup flown by Ralf at EMS.

[Steve P]

General overview. This has some heft and feels incredibly sturdy when handling the fuse and wings. Carbon be good.



The long skinny wings



Ralf loves his purple



close-up of one of the 9-LED servo cover strobes

[Steve P]

A look inside the cockpit. Pre-wired is a nice option!!



The retract will be getting a MKS 777HV



Steerable tail wheel just like the Antares

[Steve P]

The tail is constructed to take a full size elevator servo while the rudder takes a midsize. The rudder servo mounts onto a slide that slips into the fuselage, bolts in place and has a short direct link. For a plane that is all multiple layers of carbon and with a FES in the nose this extra weight and the tail is really a non-issue but hard to wrap my brain around as I’m used to saving every quarter ounce back here.



The great servo debate has begun. These are what I have already in my supply. Currently thinking of the MKS 6625 for the flaps which fit perfectly in the mounts that are already installed inside the wing. The JR 189HV seem like a good choice for the spoilers at they get little abuse on landing and also fit nicely for the center ailerons but might be a little weaker than I’d like. Out at the tip ailerons, skinny is the order of the day and calls for an 8 mm servo shoehorned in at best —I have a couple KST X10s left over from some slope projects where they have performed very well.

[Hoot]

Nice thread for those of us who are new to big scale sailplanes !
Steve Hoot Gibson

[Steve P]

The standard bits and pieces for an FES setup. Bruce gave me two different bearing sets so I can use the one that works best and send the other back.

My DG used a Torcman motor, but for this I am going with the EMS specifications…

[Steve P]

Finally got some time last night to stop looking at… and start working on this sailplane. Given the wings are prewired and the flap servo mounts are built-in, those will be an easy straightforward task. The fuselage is where the real fun is.

Starting small, setting up the retract was a simple task. Holes needed to be drilled in the steel mount and then bolts, washers and nuts sourced…



Plenty of muscle (527 oz!) and I went with a 3mm linkage. If I would have had 4mm, that’s an even better option…

[Steve P]

By contrast, the next task was a €¥£§!?&@ and a #%¥!

This model’s fuselage has a factory installed tow release. Well installed. Apparently, it was intended to survive nuclear war. I had to remove it to begin the FES setup. $#!+

The main body was twisted out, but the big wad of epoxy and large end remained. I essentially milled out the epoxy craning my neck and reaching in using a drywall zip bit in my cordless moto tool, slowly, carefully, lots of fine expletives employed. My primary concern was not punching through to the outside or even weakening the nose area. In the end, I removed a lot, but the large “nub” at the front of the release was a no go.

Given this, the normal bearing for an FES could not go far enough forward! Fortunately while Bruce and I were shooting the breeze up in the hanger at Cumberland, I routed through some of his boxes and found a large size bearing from Torcman. While too large, much easier to reduce size than manufacture it. The large one fits nicely up front in the cleaned-out area.

A look down the black hole of hell when the excitement was over…



Bearing comparison. The simple one to the right is for a typical install. The other for a fat fuselage. With my bench top sander, I slightly reduced it and tapered the back side similar to the fuselage taper to facilitate another bit of forward placement…



All in all, with 1/2” yet to be removed from the motor shaft the bearing and FES units align in the fuselage perfectly…

[Mosquito]

I'm having the exact same issue with my Torcman install into my H Model 7.6m Quintus. After getting the tow release out, you end up with a build up of epoxy in an area very difficult to reach to Dremel it out. I sent an email to Bruce D to see if the bearing you obtained is available before I continue my efforts to remover even yet more material in the nose of my glider.

[Steve P]

Found a few photos I forgot to add. I do hope to get back into this project over the weekend.

For my fellow Antares owners, this is what that canopy hinge should look like! Super strong and snaps open held with two magnets. It can be entirely removed with a twist. I have it installed without the canopy so that I can be certain it misses the motor upon closing.




The rudder servo installation is also super strong direct connection. It has as much travel as I would ever need and a lot of authority, no slop. While it looks like a bit of a mess and crooked back there behind the scenes, the rudder aligns perfectly when installed.



The wheel is removed and a screw comes down to release the rudder from the hinges. All clean straight and sleek when installed. All I need now is a small white circle to cover over the axle head and we’re in business.

[Steve P]

There is no magic to the elevator install, but after squeezing in mini servos in other planes, it’s odd to see that powerful beast in there…




The 7.4v tail strobes are insanely bright. And this is just a test on 4.8v!

[Steve P]

After incessant measuring while building my DG-1000 FES, this time I’m taking a simpler approach. After getting the front bearing and the main mount contoured to the shape of the fuselage and both installed in a mock up, I can simply go forward just making sure things look straight and right.

Once the main bearing is in, I was able to install the motor mount, getting it right. You will note my high tech alignment device. Works like a charm.




Here is what I mean about having the canopy hinge clear the spinning can of the motor.




Come on epoxy, do your stuff!

[Soarntz]

lookin good!

[Scalesoaring]

Lookin' good - you make it look so easy. Nice work! FYI - Torcman now has "twisted" prop yokes to let the blades lie flat on bulkier fuselages. We are using a wide one on the 1:2-scale AS33.

Bruce

[Steve P]

Just too beautiful of a day to spend it in the workshop. Maybe tomorrow?

Early this morning I did do a small arts-n-crafts project. I plan to keep the EMS markings, but white wing bottoms and my eyes are not a good combination. In addition to being able to flash the strobes, some stripes….

[Steve P]

Back to some actual work. Good way to spend a little quiet time on a Sunday morning. I knew this was gonna be one of the challenges when I saw the pile of components that was going to need to go into the cockpit bottom area knowing I did want the seat pan and a proper pilot in place.

Simply put, there’s a bunch of stuff for the available space— two large LiPos, 120A ESC, 2200 mAh receiver/servo battery packs, small LiPo for the strobes, Pioneer hub, two receivers, tow release and servo, motor, FES setup.

I looked at putting the Pioneer and some of the other parts on top of the retract but while the packs fit it’s still a squeeze down below with wires in the area where a servo and tow release need to go. It can work that way. The bulky things that DO fit very nicely on top of the retract are the two battery packs for the motor. I would put a shelf in on top of the retract and they would live there. Seems a reasonable option to consider.

Last night I asked Ralf to send me a photo of his Quintus. It just came. Oh! The “ordered from the factory” FES fuselage version has a door in the top of the fuselage where batteries can be inserted.

Here is a look at the mock up. I can either place the two motor batteries here or move the receiver and the two receiver packs up here. The original EMS config has a receiver on top. Nice to have options.



And factory for comparison. The packs are actually farther backward from the retract top location.