HPR X Wing - T70

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SpaceManMat
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HPR X Wing - T70

Postby SpaceManMat » Mon Jan 27, 2020 10:14 pm

Started with belt sander to get most of the bigger bevels done, but the wing shapes limit how much this method can be used. So Had to follow up with the Dremel, then a file and finally sandpaper. Fair to say I’ve had more than enough of sanding...

Pretty happy with the end result shown here with the front of the engine in place.
Image
Wing Beveled by SpaceManMat, on Flickr

I’ve already started on forming the cardboard skin for the rear section as it is much easier to shape and test fit without the wings in place. Once I’m ready with that then I’ll put the wings on and add a beam along the bottom that will help support the linear rails. With that in place I can add the outer skin of the rear section.
QRS: 124
AMRS: 32 L2 RSO
Highest Altitude: 13,647 feet
Fastest Flight: Mach 1.55
Largest Motor: CTI 1115J530 IM
Current Project: X Wing

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str8up
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Re: HPR X Wing - T70

Postby str8up » Tue Jan 28, 2020 7:35 am

Matt, this is going to big and beautiful. Cannot wait to see it in flight.

Warren

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SpaceManMat
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Re: HPR X Wing - T70

Postby SpaceManMat » Sat Feb 01, 2020 10:09 pm

str8up wrote:Matt, this is going to big and beautiful. Cannot wait to see it in flight.
Warren

Thanks Warren, can’t wait either.

Had some great progress today. Started out by adding a bearer to support the linear launch rail lugs. It’s only 3mm balsa, but edge on it is very strong. Note that cardboard skin will cover it which will prevent sideways forces from cracking the balsa. I will fit the launch lugs at either end of the main body, one end of each launch lug will be supported by a bulk head, the other by the balsa.
Image
Bearer for Launch Rail Lugs by SpaceManMat, on Flickr

Next I had to figure out how to support the fins while the epoxy dried. The fins are fairly awkward to support so in the end I settled on building slots to hold the fins. These are just 3mm square balsa but will hold the fins accurately in place. I think I first saw Stewart use this method, although not sure if it’s his idea.
Image
Fin Slots on Flickr

This then lead to the first dry fit of the fins 8)
Image
First Fit Wings on Flickr

I found the fins take up quite a lot of room and makes it a bit unruly to deal with. My son suggested we make the wings removable but I can’t see a way to do that easily and without adding a lot of weight. I think I may end up making a stand using some 10/10 rail so I can work on it without putting weight on the wings. Also storing / displaying it will be a pain. If anyone has some good ideas please do let me know.

With the fins currently being removable, instead of permanently attaching them next I’ve had a slight change of plans. I will continue to work on the skin for the rear section, once I’m happy it will fit, then I’ll epoxy the fins in place. I think it will prove useful doing it that way.
QRS: 124
AMRS: 32 L2 RSO
Highest Altitude: 13,647 feet
Fastest Flight: Mach 1.55
Largest Motor: CTI 1115J530 IM
Current Project: X Wing

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SpaceManMat
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Re: HPR X Wing - T70

Postby SpaceManMat » Sat Mar 21, 2020 11:46 pm

After some thought about the next move I actually decided to make the nose cone next. The reason is that I want to work out the weight balance which is going to affect a bunch of decisions I’ll make. I decided that the best way to do the nose this time is to do a 3D printed one since it’s shape is so unique. In the end I took a copy of a 3D model by Simhopp on Thingiverse https://www.thingiverse.com/thing:1453973/files and modified it for use on my rocket.

Image
X Wing Nose side on Flickr

Image
X Wing Nose Back on Flickr

Image
X Wing Nose Top on Flickr

Image
X Wing Nose Pieces on Flickr

The ID is sized so a coupler can fit in, however a notch is required for the section of “intake” that protrudes internally. Need to figure out the sled next as well as the anchoring point. Will probably be a simplified version of the one I use on the purple parrot, not sure about where to put the av bay vent / switch but I’m tempted to utilise the front “intake” somehow.
QRS: 124
AMRS: 32 L2 RSO
Highest Altitude: 13,647 feet
Fastest Flight: Mach 1.55
Largest Motor: CTI 1115J530 IM
Current Project: X Wing

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SpaceManMat
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Re: HPR X Wing - T70

Postby SpaceManMat » Wed Apr 22, 2020 9:14 pm

I’ve started work on the avionics bay.
Image
Ave Bay on Flickr

I’m using a similar design to the Purple Parrot as it was also 38mm diameter.
Image
Altimeter on Flickr

The switch will be in front of the altimeter, I’ll be using a pin through a vent that exits via the ‘intake’ on the nose. Currently waiting for some brass tubing for this. In front of the switch I’ll be adding the battery. The front of the board also needs to be cut down to fit into the nose and I plan to add weights to this to get the CG as far forward as I can.

The front of the tube needs to notched to accomodate the back of the intake and I still need to figure out how I’m going to fasten the bulk head to the tube.
QRS: 124
AMRS: 32 L2 RSO
Highest Altitude: 13,647 feet
Fastest Flight: Mach 1.55
Largest Motor: CTI 1115J530 IM
Current Project: X Wing

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SpaceManMat
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Re: HPR X Wing - T70

Postby SpaceManMat » Sun May 03, 2020 2:35 pm

More progress on the X Wing nose cone...

Switch added, note that the altimeter and switch sit on the underside of the board, the pin comes in through the top.
The sled has been shaped to fit in the nose. Note that forward of the switch will be used for weights and the battery will be fixed to the top side of the sled above the altimeter.
The coupler was notched to allow room for the back of the inlet area as this protrudes into the avionics bay.
The nose cone was drilled to allow for atmospheric venting and this also doubles as access for the pin switch.
The inlet piece was reprinted with a matching hole for the vent.

Image
Nose Cone on Flickr

Here’s a picture of the assembled unit.
Image
Nose Cone on Flickr

Next up I need to add the battery and wire everything together, add weights, add fasteners for the bulkhead and epoxy everything together.
QRS: 124
AMRS: 32 L2 RSO
Highest Altitude: 13,647 feet
Fastest Flight: Mach 1.55
Largest Motor: CTI 1115J530 IM
Current Project: X Wing

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OverTheTop
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Re: HPR X Wing - T70

Postby OverTheTop » Sun May 03, 2020 7:06 pm

Looking great 8)
TRA #13430
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Aquaman33
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Re: HPR X Wing - T70

Postby Aquaman33 » Mon May 04, 2020 12:29 pm

Awesome work.

This build is a big commitment, so well done.

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SpaceManMat
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Re: HPR X Wing - T70

Postby SpaceManMat » Sat May 16, 2020 9:11 pm

Altimeter wiring is complete. This was done in a similar style to the Purple Parrot, with a mini header for the altimeter power and an additional twin terminal block for the positive power to the ematches. Note that it is not obvious from the picture, but the terminal block is bridged so powering on the switch provides power to both ematches as well as the altimeter.

Image
Altimeter Wiring on Flickr

Image
Altimeter Wiring on Flickr

Next I’ll work on weights in the tip of the nose cone. Once I’m done there it’s back to the rear, to consider if I should go with removable wings based on CG etc.
QRS: 124
AMRS: 32 L2 RSO
Highest Altitude: 13,647 feet
Fastest Flight: Mach 1.55
Largest Motor: CTI 1115J530 IM
Current Project: X Wing

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SpaceManMat
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Location: Brisbane

Re: HPR X Wing - T70

Postby SpaceManMat » Sat May 30, 2020 1:11 pm

So the plan with the nose weight is to 3D print the shape of weight, this will be used to make a clay mould that I can fill with molten lead. So far I printed out the shape and I estimate I can make a weight up to about 200g.

Image
Nose Weight on Flickr

I have also been working on modelling a mount to attach the fins to so they can be removable.

Image
Fin Bracket on Flickr

So this brings me to a decision point. I am looking at achieving stability by balancing the nose weight, removable fins and the length of the X Wing. At the moment the X Wing is about 22 cm longer than it should be to keep it scale (about 30%), it was always planned to reduce this as the build progressed. The weight of the 3D printed mount comes out to 55g, I’ll need 2 per fin plus metal brackets and screws so that’s in the order of half a kilogram. Even if I could halve the weight, 250g at the wrong end would require lots of nose weight to get the CG forward. So that rules out removable wings.

I have updated my simulation in OR with the weights and dimensions of what has been built to date. My current plan is to reduce the length by about 12 cm and put around 100g in the nose. It will then be about 14% longer which will look normal (X Wings are actually quite stubby but the impression they leave is that they are longer). Now that I have decided not to build removable fins, the exact amount of nose weight available is not so critical, therefore I will put the nose weight aside and go back to attaching wings and building the rear body.
QRS: 124
AMRS: 32 L2 RSO
Highest Altitude: 13,647 feet
Fastest Flight: Mach 1.55
Largest Motor: CTI 1115J530 IM
Current Project: X Wing

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SpaceManMat
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Re: HPR X Wing - T70

Postby SpaceManMat » Wed Jun 10, 2020 11:38 pm

Work has been super busy but managed to find time to attach the wings.

Image
Wings Attached on Flickr

The balsa strips are for attaching the rear body panels.

Sure enough it’s getting A bit cumbersome.

Image
Wings Attached on Flickr

Currently I’m working on producing the rear body panels. I’ve also been investigating chute size / packing and max motor size. Looks like I’ll be using a 36 inch chute and allow for up to a 5G CTI 38mm case. So potentially I’ll be able to fly a baby J motor if I’m game, but I’m thinking I’ll work my way up to a big I sparky 8) Should be something awesome to watch :!:
QRS: 124
AMRS: 32 L2 RSO
Highest Altitude: 13,647 feet
Fastest Flight: Mach 1.55
Largest Motor: CTI 1115J530 IM
Current Project: X Wing

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SpaceManMat
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Posts: 2262
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Location: Brisbane

Re: HPR X Wing - T70

Postby SpaceManMat » Mon Jun 22, 2020 8:58 am

Body starting to take shape
Image
Body Pannels on Flickr

I built up the underside to support the rail guides.
Image
Underside on Flickr

Image
Underside on Flickr

Rear body is now complete, next up are the engines.
QRS: 124
AMRS: 32 L2 RSO
Highest Altitude: 13,647 feet
Fastest Flight: Mach 1.55
Largest Motor: CTI 1115J530 IM
Current Project: X Wing


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