Phantom V2 - DLG - design build

bracesport

Legendary member
Hi Guys - Here are some shots of my Phantom V1 - the idea was to build it with low cost methods - my inspiration was the YODA with a poly wing and the BAMF which I fly - it is not a bad build, but ended up with an AUW 100g over my target (sadly the wing weight was the major culprit as I used 100g Carbon) - the wing had a quick connect system which can be seen in the attached forum thread below (also to be refined).

I have decided to build a V2 taking what I have learned to refine my process - the fuse uses 3D printed moulds without any surface cleanup (this time I will tickle them a bit more) - I am happy to share all the files for the fuse and the wing and even do a group build.

this is some of the history of the build - https://forum.flitetest.com/index.ph...33#post-660302

381338_ad3ca3643643e5ba8afac4e43d4c670c.jpg
382280_64cc83d835b2a4ff191b8962074e3099.jpg
382282_0a32b1e2a1342fbe12af40feb766b5ef.jpg
 

bracesport

Legendary member
Here is the provisional fuse CAD - it is essentially the same as the V1 but this time I will cast the finished boom (formed on a pool cue) into the fuse moulds to get a seamless joint - last time I grafted the boom and fuse together which added more material at the joint and created alignment issues.

Screen Shot 2021-10-06 at 1.42.02 PM.png
Screen Shot 2021-10-06 at 1.43.19 PM.png
Screen Shot 2021-10-06 at 1.43.29 PM.png
 

bracesport

Legendary member
Here is the hot wire wing blanks - the blanks are further shaped before adding the skins - I plan to tweak the CAD for the wing blanks a bit more for the V2 to thin the tip chord - the middle break is thicker to fit the aileron servo but the tip can be thinner - the planform of the wing is based on my BAMF.

Screen Shot 2021-10-06 at 1.59.32 PM.png
Screen Shot 2021-10-06 at 2.00.00 PM.png
Screen Shot 2021-10-06 at 2.00.14 PM.png
 
Last edited:

bracesport

Legendary member
Here are the moulds in development - the 3D printer is limited in height so I make the parts in sections - the bottom three moulds will all be glued together - the smaller middle section allows for the LE undercut of the wing saddle to come out of the moulds - there is also an extra alignment section to place the boom into the moulds.

Screen Shot 2021-10-07 at 9.35.35 AM.png
Screen Shot 2021-10-07 at 9.35.54 AM.png
Screen Shot 2021-10-07 at 10.09.03 AM.png
 

bracesport

Legendary member
I have already made a tail boom - it is tapered 21x12 over 500mm - I also have an old BAMF boom of a similar length and by way of comparison the BAMF boom section weighs 15g and my boom weighs 16g - so this is a good start!
 

PsyBorg

Wake up! Time to fly!
Finally got around to this thread. Nicely done documenting this process as well as showing real examples of what you have done. I watched your last flying video and it amazes me how these things so gracefully slide thru the air. Like I said in the comments.. you get more flight time in one flight with zero wind then I get on powered flights so far.
 

bracesport

Legendary member
@PsyBorg - the DLGs are fun to fly as they glide on the sniff of an oily rag!

I started with the FB versions and migrated to a mouldie when a friend gave me his old one - the problem was the BAMF is a sports car and for a nube flier that's a recepie for disaster - I smashed it up pretty good and rebuilt it several times before I put out the call for a new fuse (luckily the wing has held in there - a testiment their robustness - 1.5m @120g) - the second fuse was also a well used bit of kit for $50 and I snapped the nose off at launch, so more rebuilding and the BAMFzilla was born.

The BAMFzilla is still flying and was in the last video.

My Phanton V1 with the poly wing has only had a test flight so far - it is a bit of a beast in the weight department so will only work in a breeze or on the slope - hense the V2 is underway!

With the 3D printed moulds and fiberglass instead of carbon these are cheap to build (just takes a bit of time)! - l will use carbon, but I am also considering some fibreglass where it makes sense.
 
Last edited:

bracesport

Legendary member
I had a close look at the foils I am using - my foils were originally a take on the synergyII foils and compared to my V1 build the V2 tip transition is now thinner.

In the attached image the root is on the top and the tip is the bottom one - in the background (in red) are GT's Synergy foils and mine are overlaid with the black outlines - my Root is quite similar but is a tad thinner than the Synergy and my tip is similar in thickness, but holds its thickness for a bit longer in comparison.

I have also attached an image of my V1 chord that I cut as a novice - I use 3D printed templates with tape on the surface to act as a heat shield - they are simple to make and work quite well.

synergy.jpg
370794_b8f6dcdeb544af7ec97ad98e3460a59f.jpg
Screen Shot 2021-10-09 at 6.45.53 PM.png
Screen Shot 2021-10-09 at 6.46.37 PM.png
 
Last edited:

bracesport

Legendary member
From reading other threads I can use 50g FG (1.6oz) for the wing, pultruded spar caps, FG facings on the flaps and ailerons, and some disser to stiffen things up and ditch my CF for now (something to consider)!

In my V1 wing I put a full height spar though the foil - I am now wondering if that is overkill?
 

bracesport

Legendary member
My next order of business will be to cut some wing foams and print some fuse moulds - that gives me some time to contemplate some of the finer details in the build.

If the foam cutting goes we'll I will cut two wing sets.
 

bracesport

Legendary member
My friend said why not build a wire cutter machine.

This machine uses a 4-bar linkage system to rotate the bow as the hot cutting wire cuts through the foam - when the two long link arms are parallel, the bow moves in a straight line - when the two long link arms are not parallel, the bow moves in an arc.

I made a quick CAD of a linkage system that can handle the requirements for the worst case arc which is the tip - I am 3D printing some tube bung ends that can have bearings at all the pivot joints - and I have some large diameter (29mm) CF tubes that I will use for the arms.

1.png
2.png
 

bracesport

Legendary member
Here is the CAD of the build - the boom for the wire can rock - the main arms can be adjusted on the base slider to change the cutting arc - the main arms can raise and lower - the outrigger tube is for a counter weight.

Screen Shot 2021-10-14 at 1.47.36 PM.png
Screen Shot 2021-10-14 at 1.50.11 PM.png
 
Last edited:

bracesport

Legendary member
A dry fit of the wire rig this morning is look pretty good - I need to get some nuts and bolts to finish it off - the last two pictures show an example of the cutting boom sweeping an extreme (tip) taper.

IMG_21102021_080847_(1000_x_500_pixel).jpg
IMG_21102021_081008_(1000_x_500_pixel).jpg
IMG_21102021_081023_(1000_x_500_pixel).jpg
IMG_21102021_081041_(1000_x_500_pixel).jpg
 

bracesport

Legendary member
the updated picture looks similar to the last one, but now I have the wire cutting rig all glued and bolted together - I am printing a collar for the counter balance weight and looking for some parts to make the weighted pull string system to pull it through the foam automatically - the idea is to have one pull point at the centre of the wire cutting bar - I will make the pull string pulley adjustable in height - it looks like it might work!

20211102_080900.jpg
 

bracesport

Legendary member
I have finally got the fuse moulds printed and they are looking pretty good.

They are split top to bottom through the centre and I will lay them up in their halves and then set the join with a balloon - I am thinking to cure the wing saddle section of the top mould with one layer of CF and then set the wing mount nuts into that - otherwise it will be a difficult process to add them later especially as this will be a one piece fuse mould.

The second stage would be to complete the layups, adding the boom and curing the final product.

IMG_04112021_082027_(1000_x_500_pixel).jpg
IMG_04112021_082049_(1000_x_500_pixel).jpg