VP Model, NoBody (3.8 meter F5J type foamy)

[Konrad]

I recently purchased a VP model NoBody on the secondary market. This was a NIB purchase and the seller was going to pay shipping. So why not.

 

What was driving this purchase was that I'm currently flying a Top Model 3.2m Samsara for the last 4 years and she is getting long in the tooth. Meaning I need to take her down for some much needed maintenance and a recovering. What I really liked about the Samsara was that she is sporting a 1.8m long fuselage. This is key to allowing her to signal air (hopefully lift). This is so much better than the normal 1.5 meter fuselages.

 

This VP Models NoBody has a 1.8 meter long fuselage.  True this is a pod and boom fuselage rather than a one piece molding. And some of this length is going forward to aid in balance. This VP Models fuselage addresses one of the few issues I had with the Samsara in that the nose of the NoBody is pointed down to meet the up coming air, I love this feature.

 

Searching the web I'm not finding much on this model. It does look to be an older design. And looking at the spec's this is NOT a full blown F5J model as the weight is coming in at 1.8Kg closer to 2.Kg. I think I'd classify this as a very high performance sport model that won't embarrass you should you find yourself at a local F5J contest. That is to say I and most pilots won't be equipment limited flying the NoBody. About the only thing I found in english was a write up on the USA distributor's Aloft Hobbies sales page. Having now held the model in my hands I see some discrepancies in what got and what Aloft is showing in the  spec's.

 

The first and most egregious error is that the wings of the NoBody are NOT of a "D" tube type configuration. My NoBody is sporting a Leading Edge (LE) with a carbon "C" cross section. "D" and "C" cross section wings have very different performance profiles (flex and life expectancies). Now the wings do have a web that ties the upper and lower carbon LE sheeting to the wing joiner tub. This sort of looks like a "D" cross section in the area of the joiner tube. I really like this web as opposed to some other designs that just use partial ribs to tie the wing joiner to the LE sheeting. Another mis-characterization is that the Nobody is not sporting a shoulder mounted wing. The wings are 3 piece with the center section is bolted to the top of the fuselage. 

 

As I did not receive this from Aloft Hobbies but rather in the secondary market I can't complain. But if you are looking at some models from VP Models to give the photos and write a real close examination. 

https://alofthobbies.com/collections/electric-gliders/products/no-body-3-8m-by-vp-models

 

Now I'm suffering from a lack of foresight. I purchased this model wanting a replacement for my Samsara here in San Francisco but I had the Nobody shipped to my family home in Denver. This really doesn't help with my need to find a replacement for my Samsara while I have her down for maintenance. I do have a Multiplex Lentus here in San Francisco that I should use as my Samsara stand in.

 

As I said I couldn't find much written on the NoBody model. So I'd like to ask the hive mind of RCM&E what experience you might have with this model.

 

 

[Konrad]

Yikes, I see that the fuselage for the NoBody is a full carbon lay up. As such it is NOT a 2.4gHz safe fuselage. This means that all the RX antennas must be placed outside the fuselage. I wonder how old this design really is. I haven't seen a non 2.4gHz fuselage since the turn of the millennium.  

 

Also of note the canopy is also a full carbon lay up. Other than marketing I see no advantage of this. In fact it looks like another attempt to keep RF signals out of the fuselage. because I don't think there will be much of a chance for the RF signals to reach inside the fuselage where I normally place the 900mHz antennas. I've decided to try FrSky's Twin system. This is a dual band system where there are two separate 2.4 GHz RF sections operating all the time (true redundancy). I know this will result in the NoBody looking like a porcupine with all the 2.4gHz antennas pointing out of the carbon fuselage. This will be a good test of the twin system as the NoBody is about 1/4 the cost of my usual 4 meter ships. Along with testing the twin system this will also be a test for FrSky's F-Port servos. This will cut down on the wiring weight but also give real time telemetry as to servo loads (amp draw) and temps (pending over load).

  https://alofthobbies.com/collections/modules/products/frsky-tw-lite-pro-module   https://alofthobbies.com/collections/frsky-twin/products/frsky-tw-gr8

[Konrad]

Been spending some time planning (something the wife says I fail to do 🤔). I'm having some concerns about the servo mounting in the wings. I see that VP Models has provided a lot of support to the servo pocket with the addition of the carbon tongue in the top skin lay up. I'm sure this is more than adiquate for any flight loads. My concern is to build a model that will survive my landings. 

 

I'm thinking of lining the foam servo pocket with some carbon tissue. This should not only add some stiffness but it should add a lot of strength as I will be tying the pocket to the bottom skins. Normally I'd do an overlay onto the skin. But I don't want to damage (much) the bottom skin's finish. I'm thinking of under cutting the foam 1mm or 2mm to leave a small pock to allow the formation of an epoxy Cab-O-Sil bead under the bottom skin. To help with the one wall I'm going to remove part of the plastic wire tunnel.

 

Another concern of mine is that I'm planning to use an undersized flap servo. Undersized as in an 18 gram servo with what I think will be too small a gear train for typical flap landing shock loads. To address this I'm planing to use an external bearing supported servo tray in conjunction with override springs on the flap push rods. 

https://alofthobbies.com/collections/servos/products/frsky-xact-hv5101-6-8kg-94-4-oz-in-0-10-sec-18g-wing-servo

 

[Konrad]

Here are what my flap push rods look like on my 3.2m 1.9Kg Samsara. I'm planing to use much the same setup on the 3.8m Nobody. It is interesting to note that before I used the override spring push rods I suffered a stripped gear box at a rate of close to one every other landing. With the override spring I think I'm sill on the same set of servo gears.

 

What I'd like folks to notice is that the flap horn is set way aft of the hinge line to maintain leverage when the flaps are down (80° to 90°). This does result in a non-linear flap response and should be addressed in your radio setup (programing). At the weight I think I'll be flying, I'm thinking that the spring should be wound from 0.50mm wire.