What are these tailless models?

[tonym]

I bought several old balsa gliders from a guy that I think enjoyed building more than flying. The most interesting are two tailless gliders that are similar but not quite the same, one at 60" span (not flown) and the other just 36". They are around 20 years old (two Futaba FP-T5N Callenger Txs came in the lot), the method of mixing the elevons is mechinical at the servos. The link to the elevons are just rods out of the fuselage that sits between to rods out the end of each elevon.

 

I've attached some photos below, does anyone know what they might be? Name? maker? and where the CoG might be - or where I should start with one?

 

Hope you guys can help

Tony

 

[paul w]

The 36" one is a Midet designed by Les Rudd

 

Cg is about 110mm b/h LE at the root

 

Set the elevons at about 10deg in their neutral position

 

Plans say start with 1/4" throws for elevator and aileron.

[tonym]

Thanks Paul, a little Googleing found a Les Rudd plan called a Go-Jet so tried 'Les Rudd Mid-Jet' and got this on RCGroups - http://www.rcgroups.com/forums/showthread.php?t=1457504 and this - http://www.elliotfan.com/temp/midjet.html

 

Tried a search for 'Les Rudd Big-Jet' but no joy.

 

I would have set the elevons level with the underside of the airfoil, is the 10deg up from a midpoint in the airfoil (neutral)?

 

Tony

[patmac]

Hi Tony, I built & flew one of these from the mag plan back around 1984. It was mainly slope soared but occasionaly flown with a Cox 049 pusher at my club field. About 6 years ago I moded the surviving original wings to take a pair of 9g servos & built a new fuse with a pusher brushless motor on 3s 1300 lipos.

The revived version flew well both as a sloper & with power for a year or two. Then I had some trouble with the motor & one of the servos after about 18 months so it hasn't been aired for a while.

 

 

The cg range is 1/4" either side of the wire wing joiner, elevons 10deg at neutral.

 

Back in the 1980's I met Les Rudd at one of the Primrose Valley model holiday flying weeks, he had the bigger version with him (48" span ?) it actually didn't look as good as the smaller version because at that scale the fuselage had a more boxy appearance. It was powered with a pusher 540 can motor & nicads. Motor control was a micro switch operated by a servo. In the "Off" position the servo also pushed a rod into the prop arc near the root so the prop stopped in the horizontal.

 

Cheers,

Pat.

[oipigface]

I can confirm that the 36" one was published as Mi-Jet in an Aeromodeller or Q&EFI many years ago. I don't know if I have still got mine or not, but I always think of it as my first RDS model. It was an excellent design, and flew well. I remember having to borrow a ladder in Rhossili once to retrieve mine from underneath the N slope.

[patmac]

The ones pictured above are from the free plan with a Silent Flight special by RCM&E in published in 1984 - name of the model is Mid-Jet.

[tonym]

Thanks for your replies guys

 

Just missed this by a few days - RCM&E mag on ebay - I've not found the wing joiner or wing retaining clip for the smaller stock(?) Mid-Jet in amongst all the stuff I bought. Could someone let me know the dimensions off the plan or post a photo of the relevant part of the plan?

 

Thnaks again

Tony

 

(Photos from ebay listing, not big enough to see detail though.)

[patmac]

The wing joiner is 6.75" of 10SWG piano wire. The retaining clip is an omega shaped piece of 18SWG piano wire, it's in the top right of your second photo. Sorry I'm having trouble with my scanner at the mo or I'd post an better image.

 

Here's some scans I did previously when I revived mine unfortunately the parts you want aren't in any of them.

 

 

 

 

The cut away part of the aileron shown was replaced by a fixed piece when I fitted seperate servos to each wing.

 

Cheers

Pat.

[tonym]

Thanks Pat

 

I wondered if that shape in the top right was the wing clip. I can do the shape fine without a 1:1 plan.

 

Just tried to save the images, do the gifs have a transparent background? or has the forum software done that when attaching them?

 

Tony

[patmac]

Tony, the AFAIK the gifs have a white background. If you want full size working drawings in pdf format (as above + ribs & wing retainer clip) that should print off at A1 size drop me a PM with your email address.

 

Cheers

Pat.