VP Models Cubic.

[Konrad]

Saw these at Aloft on my last visit.
https://alofthobbies.com/collections/thermal/products/cubic-3-4-by-vp-models

Really impressed by the fit and finish of these wire cut, bagged extruded polystyrene flying surfaces. The fuse fiber work was a notch above most in quality. I also saw a few 3D printed parts included with the kits. I will say that I wasn’t all that comfortable with the 3D printed motor mount, well not for the power I’d like to run through the airframe. This should be easy enough to fix with a fiberglass firewall or the many CNC aluminum motor mount on the market.

I was so impressed with the smaller glider’s glass (dyed?) weight and finish that had Aloft had a 3.4m in stock, I most likely would have walked out the door with it. Not sure I see the value in the full carbon lay up for my style of flying.

Now to be truthful I do have one configuration concern and this is with the S4083 airfoil. In the past I found that gliders with the S4083 had great lift but poor legs. I’m thinking of gliders like my Simply The Best (STB). This was a javelin launch HLG gliders back 20 to 30 years ago. If you could “see” thermals and launch into them you usually made your flight time. But if you had to travel looking for lift the drag (lower surface front separation bubble) would often cause you to come up short on your time. I’m wondering if this wing with the S4083 and flaps might be able to gain the much needed legs, by placing the TE in reflex.

Anybody have any experiance with the flapped S4083 section?

 

[Wayne]

Can't help you with your question, but I fully agree that I the glass versions on these planes are the sweet spot. Great price and all of the performance with great visibility.

Also we can get these in full glider (no motor) versions. I was not aware of that when I placed the initial order.

 

[Konrad]

I’m liking the F5X style model.

Are there any in the order pipe line? If so when do you think they will land at Aloft?

 

[Konrad]

What intrigues me about these wings is that they are “D” tube. Many models of this construction are ether “C” tube, ”I” beam or just spar caps on the foam.

Does the OEM have any white papers on how he adds the rear web of the “D” tube in his lay up?

I recall @bracesport showing his process for bagged styrene wings HERE. I’m wondering if it is practical to fold over the web’s fiber in the green state to join the LE “C” section. See Boeing’s patent.

P.S.
I don’t see VP Models on the Aloft sales page drop down filter.

P.P.S.
I found this site but nothing about the tech they use in the building of these gliders.

Vítejte v VP model

. Přečtěte si více informací

vpmodel.cz

 

[Billy Eister]

What intrigues me about these wings is that they are “D” tube. Many models of this construction are ether “C” tube, ”I” beam or just spar caps on the foam.

Does the OEM have any white papers on how he adds the rear web of the “D” tube in his lay up?

I recall @bracesport showing his process for bagged styrene wings HERE. I’m wondering if it is practical to fold over the web’s fiber in the green state to join the LE “C” section. See Boeing’s patent.

P.S.
I don’t see VP Models on the Aloft sales page drop down filter.

P.P.S.
I found this site but nothing about the tech they use in the building of these gliders.

Vítejte v VP model

. Přečtěte si více informací

vpmodel.cz

Are there any building instructions for the cubic? Just bought one.

 

[Konrad]

Don’t know. But there are some documents on VP Models site. Also there is a great write up in a German magazine.

But there really is very little to build. The only critical thing I see is that the tail boom needs to be bonded to the front pod. Then there is the normal stuff like making sure everything is square to the wing.

It’s not an ARF but it is highly fabricated. Basically install your radio and power system as you see fit.

I do see download instructions if not for the model but for the same type. https://vpmodel.cz/index.php/ke-stazeni

 

[Jerry Kirwan]

I am new to this forum and slightly new to gliders with a previous wood glider; this is my first carbon. I purchased the Cubic 3.4 and have a few questions. Is it normal to have the vertical fin just sit on the boom? it does not appear to be secured. Also the other question is on Aileron & Flap linkages. Is there any resource info on this subject? One last one is wing wiring? Do the 6-pin connectors get secured in the wing joint or float?
I have just about everything else figured out. I did look at the instruction referenced above.

 

[Konrad]

As I don’t have one in front of me I can’t help much. But I will say that now I glue my wing connector into the wing. Otherwise the wires love to cut the foam and skins like a wire cheese cutter. I leave the other end loose in the fuse.

Skin repair of molded models (60" glass and rohacell racer)

It pains me to admit this in front of everyone, but I damaged my little 60" moldie racer. The good news is I don't think I damaged the main spar. You can see that the wing skins are showing damage. At the flap hinge line both the upper and lower skins are showing tension damage. A head of the...

forum.alofthobbies.com

This might help. It looks like the tail is bolted on to the boom. Or are you asking if you should provide an epoxy micro balloon bed to give some stability to the fin fuse part line? Can you give us a photo of the bottom of the fin?

Note that it looks like you are to line the servo pocket in the wings with a carbon liner.

https://vpmodel.cz/index.php/ke-stazeni?download=2:no-body-stavebni-navod-cz

 

[Jerry Kirwan]

Thank you for the quick reply! These are the pics of the vertical fin as it came. I just stuck the pins in the fin for the pic. As you can see, there is no additional mounting hardware to secure the fin in place unless I am missing something. There is an accessory that is 3D printed I have not identified yet, it is a channel about 1.25" x 5/8", but I do not see how it would work into this scheme. The Instructions listed above for another model shows a nylon bolt inserted from the bottom of the boom.

It is a gorgeous model.

 

[Billy Eister]

VP sent me some pictures of the tail being glued to the boom. I just finished mine yesterday and hope to test it later this week.

 

[Wayne]

I was thinking it was glued on in this model, but was not sure. Thanks for sharing!

Wire harness plugs - I usually glue them to the fuselage side and let them float on the wing side, but maybe that is just me. On a few planes I have secured them at both ends, but I don't totally trust that setup should the plane be upset enough to back the wing off some. It is also more work to get both mounted and working well.

Wing linkages are pretty straight forward:

 

[Jerry Kirwan]

Guys,

Thank you for the responses! Aloft has provided a series of pics that answered most of my questions. I believe I have a path forward in my mind and will begin construction soon. I may return to give updates on my progress.

 

[Wayne]

Looking forward to it. I really like these planes. I have been resisting buying one mostly because we have a hard time keeping them in stock. I know one of these will be in my collection in the future.

 

[Konrad]

Looking forward to it. I really like these planes. I have been resisting buying one mostly because we have a hard time keeping them in stock. I know one of these will be in my collection in the future.

That’s an issue with being a hobby shop owner I hadn’t thought of. That is sacrificing your personal purchase in support of your customer’s experience (moving merch).

 

[Jerry Kirwan]

Wayne, If you have the ear of the designer, I wanted to point out he should incorporate a hard point into the center of the stab. I began building from the rear of the plane and when attaching the stab, the bolts seemed to sink into the carbon fiber. If there is nothing hard in there, this will be a future problem for me.

 

[Jerry Kirwan]

Billy,
Do you have any pics of your wing Linkage? Did you utilize the supplied servo trays & Control horns? I am to that point and trying to establish control throws regarding horn length so I can use full servo travel. The supplied trays are very compact, limiting servo arm selection. The supplied control horns are very short which required using short servo arms. I have graphed the geometry for selecting arm length. I find this area to be neglected without accompanying build instruction or at least direction. everything else can be figured out with the pics supplied.

 

[Konrad]

Elsewhere you were mentioning wanting to use an IDS. These are usually used with hollow core molded wings. But there are many offered for the bagged cut foam wing such as what you have here. Take a look at the product aimed at the DLG aircraft. Also give this thread a good read.

These should work well for both the ailerons and flaps.
This might help.

P.S.
I find a lot of the success in installing the wing servos and drives are dependent on the programing one is using. Please focus of the Ackermann effect (differential throw with the placement of the servo arm or control horn) and please be aware of the 3 point line issue with actuation linkages.

 

[Jerry Kirwan]

Konrad, Thank you for the reply I will look into the links.

I have surmised that about the LDS System in the reading, I have done. I am flying a JR 12X with a glider program which I am having problems figuring out. It is just taking time, this is my second excursion into gliders but my 2m I am using plane programming. I have flown complex models before using the full capabilities of that radio, but glider programming is new to me. I am leaning toward using the supplied servo trays for the KST X08s as the best solution.

 

[Konrad]

You aren’t alone with the JR programing. I like the XO8 and still use them. But if buying new servos I’d look at the HS 08a. I think these work better on 2 lipos and I like that the motor is held captive.

 

[Jerry Kirwan]

I wish I had gone with the A08's instead. I am going to run them on 2s I found an ESC that goes that high then I switch in a 2s 300mAh battery as a buffer. In this setup the buffer pack never needs to be charged. I have been using this system for a few years.