Build : MAC Performance - 3" Scorpion XL on 38mm

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spigalau

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Build by: Spigalau & PyroShark aka Spyro Rocketry (a father & son team).

Ok, so first up this build is somewhat out of order, you could say upside down, but we are in New Zealand, so we do things kind of different down this way. Truth is the USPS wasn't kind to our booster tube and a replacement is being sent, so we got things underway with what we had.

Airframe: MAC Performance 3" Scorpion XL with 5:1 Von Karman fibrewound nosecone and 30" booster tube.
Motor Mount: 38mm (much easier to source 38's in NZ than 54's)
Lower Harness: OneBadHawk 25' 1/4 inch kevlar 3 loop
Drogue: 16" (or 12") X Form Parachute
Upper Harness: OneBadHawk 25' 1/4 inch kevlar 2 loop
Main Chute: 54" PML Durachute
Primary Flight Computer: EggtimerTRS
Secondary Flight Computer: MissleWorks RRC2+
Independent Altimeter: Jolly Logic 2
Name: Spyro 38 MK1
Aim: L1 / L2 certification's
Probable Launch Date: Sep 2019

So to get things underway, we started with the longest screwdriver we could buy.. all 24" of it.



Why 24"s you ask, well it's so we could still get to the nose cone screw, once we had secured the head avionics bay in to the nosecone.

Before installing, removed out the upper eye bolt from the head bay and drilled out the centre hole to allow screw driver access to the screw.

And then putty epoxyed the upper rail bolts in place to stop them from ever coming undone.



Whilst that was in the hot water cupboard curing, we started with the nosecone wrap - it's a crime to cover up the shear beauty of the nosecone - but we think the end result & appearance will be worth the effort.

So first up with the wrap on the nose, it is not as hard to do as it looks, but still a fun challenge for a wet Saturday afternoon.



And then the fun started...



It took 2 goes to do the second section, because I (he who should know better) cut it too fine and exposed a gap between the 2 panels, so we re-did that.

And then he, who is a a 'maths' whizz, who says he was only following orders, ballsed up panel 3 by cutting the last panel too narrow. Rule of the day: Measure, Measure again, Measure again and then add 1cm (or 3/8") to your measurements.

End result with tip installed was not bad for our first ever wrapping experience.



The wrap for the nosecone & fins is a Chameleon Carbon vinyl, so depending on the light either is a purple, blue or even a green.

And then to finish up the night, we sanded off the upper head bay and inside the lower nose cone, cleaned it up with isopropyl, and then mixed up a batch of strong epoxy and then rammed it on home.



Now if you look real close, you will see that the lower bulk head on the headbay is upside down, this is for a reason, we wanted to leave an air gap when inserting the bay in to the nose so as to remove any pressure plunge. And it worked, once we had it in place, we cranked it tighter and then put it to bed for the night.

The next jobs on the list are:

1) Payload tube - notching for ease of alignment and drilling for shear pins & plastic rivets.
2) Avionics Bay - assembly of centre sections, installation of ejection canisters, quick release charge connectors, etc.
3) Electronics - Eggtimer TRS assembly
4) Electronics - Eggtimer Reciever assembly
5) Motor mount - epoxy the upper ring & pin

Once the replacement booster is in NZ (2-3 weeks), we can then start on the lower end.

Our launch site closes for winter shortly, so intention is to have this ready for the spring launch day.

We would like to thank Mike (MAC), Teddy (OneBadHawk) and Cris (Eggtimer) for all of thier assistance and advice so far. The quality of all the materials has been O for awesome (
).

Any questions, either PyroShark or myself will answer.
 

spigalau

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Not much done today, sanded, cleaned & prepped for switch bands - mixed up a small batch of epoxy and put both in place. I love the smell of JB Weld.

Centre Band:


Top Band:


Am now going to let them cure and will drill them next weekend.
 

Ben Martin

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That wrap looks weirdly familiar to the one I used on my new 3D printed rocket. Nice job on the build so far, looking forward to the finished product!
20190228_004639.jpeg
 

liv3mind

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Awesome, looks like it’s going to be a nice detailed build.
 

spigalau

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That wrap looks weirdly familiar to the one I used on my new 3D printed rocket. Nice job on the build so far, looking forward to the finished product!
Hi Ben - we sourced it from: https://vinylwraps.co.nz/collection...eleon-carbon-vinyl-wrap-1?variant=45707588820 about USD$12 for 20" x 60" section. More than enough for the nose & fins. The booster tube, switch bands & payload tube are something a bit brighter... will hopefully show it on the payload next week, once I get my drilling & fiddly bits done.
 

spigalau

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Ok, so we made some progress this weekend...

Drilling






Upper Payload & Avionics bays are drilled for Shear Pins, Locating Notches, Retention Rivets & Static Pressure ports. Job is so much easier with two people & a drill press.


Locating






Spent a bit of time working out the locating notches for the payload tube - sourced an 8mm plastic rod from www.macplas.co.nz which we cut down in to small (about 8mm nubs) which we then Epoxy Puttied in to place from behind. The extra bits have been sanded back to be even with the external tubes before wrapping.

Attack of the Bora


So many holes, should rename this swiss cheese

Upper Switch Wrapped


Yes, it works !

Wrapping Payload


So much easier to do a tube over the nose cone. Just next time I shall remember not to wear shorts around a heat gun, as the results of doing so can be both warming and well I'll let the video show...

Slowly Taking Shape




Ok, that's us done for the weekend. Next Saturday we tackle the electronics assembly !

1) Payload tube - notching for ease of alignment and drilling for shear pins & plastic rivets - DONE
2) Avionics Bay - assembly of centre sections, installation of ejection canisters, quick release charge connectors, etc.
3) Electronics - Eggtimer TRS assembly
4) Electronics - Eggtimer Reciever assembly
5) Motor mount - epoxy the upper ring & pin

The replacement booster tube is in transit, somewhere between Jamaica NY and Auckland NZ - fingers crossed should be here for the end of the week.
 

spigalau

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Ok, so it was a rather busy weekend and we only managed to get a couple of things done on Spyro 38.

Day #1 - Building the Eggtimer Electronics (Eggfinder LCD-GPS Module, Eggfinder LCD Handheld Receiver & Eggtimer TRS GPS Tracker/Flight Computer

Today was the day we tackled the electronics build.

With the promise of a Kiwi BBQ & some beverages, I managed to convince 2 of my work mates (Remco & Jason) to assemble the EggTimers with PyroShark - whilst I tended to the Kamado BBQ (Peppercorn marinaded 3.5lb Pork Scotch, Sausages, Roast Potatoes, Roast Kumara [sweet potato], Roast Pumpkin, steamed Broccoli & Cauliflower. Yes, it is our winter, yes we still BBQ, and no it doesn't always have to be Lamb either.

Oh and for beverages - try and get your hands around some 'Baltika 0% Wheat Unflitered' Beer. It's quite a refreshing drop, even if it is Russian.

The Assembly Bench & Team:


Starting Small:


Multi-Tasking (Receiver & TRS):


TRS Finished & Plugged in via USB:


Building the Receiver Box:






The Receiver is fitted with three additional buttons/Switches
1) Red Switch - On / Off for Device
2) Black Switch - Turn LCD Back Light On / Off
3) Black Button (on front) - Menu Scroll for LCD interface

The receiver is powered with a single 2S 7.4V 1300mAh 35C Li-Po battery which I need to sort out a proper mounting system for.

We managed to finish the assembly of the electronics on Saturday night but our indoor testing was a bust as we couldn't get a GPS fix, either that or the team had wired the LED's in backwards. As it was down to about 45F outside, outdoor testing was wisely delayed till Sunday am.

Day #2 - Sunday, bloody Sunday...

When tested on Sunday AM, I thought we had an issue with GPS FIX as the lights were only blinking, not staying on solid. Then I referred back to the manual and found a 1 second blink was 'FIXED'. Don't ask me why I was looking for a solid color.

Also whilst reading the manual, I found the section that talks about powering on the TRS at the bench (leaving it on), getting RSO sign-off and then launch pad enablement of the ejection charges, which then caused a minor rethink of our plans.

For the safety switch, we are using a 3 loop audio jack:


The plan was:
Loop 1 - EggTimer TRS Main
Loop 2 - EggTimer TRS Ejection Charges
Loop 3 - MissileWorks RRC2+ (Back Up)

But now will be simplified to:
Loop 1 - EggTimer TRS Ejection Charges
Loop 2 - NOT USED
Loop 3 - MissileWorks RRC2+ (Back Up)

Primary FCS - TRS has been programmed for Drogue @ Apogee, Main @ 800 Feet
Back Up FCS - RRC2+ has been switched for Drogue @ Apogee +1 second, Main at 500 feet

We are intending to mount 3 x 450mAh 2S Lipos (2 for TRS, 1 for RRC2+) within a capping channel on the reverse of the sled - I am working on the retention mechanism for this.

The Plug being used in the Jack, is a cut down axle from a kids stroller that I had lying around. I might shorten it down a bit more once we have position on sled finalized.

And then I got side tracked for 5 hours with shopping, cleaning, etc - so when we eventually got back on task late Sunday afternoon to work on the replacement booster tube that arrived Friday am. Many thanks to Mike Crupe for shipping this over, the MAC product & support is awesome.

So we started off by notching the booster to the center switch band - note the gap is different between notches for lower tube, you can't stuff this one up... well you try, but it wont fit.







We also drilled out the 4 pressure release ports for the booster - so only holes left to drill in the booster tube are for:
2 x Shear Pins @ Upper
2 x Launch Rail Buttons

We also tested out the Plastic Retention Rivets & Shear Pins for the payload section - and thankfully all the holes line up. So the notching system does work !

The upper avionics sled was fitted with the Jolly Logic mounting board. Sorry no PIC's of this - forgot to capture it.

And then we ran out of time to do much else, so we sat down and updated the Open Rocket file with our config details & build weights.

Now, as it's a 2 week winter school holiday here - PyroShark is heading south to stay with 'The Engineer' (aka Grand Pa) for a week to play in the paddocks, work on the cars (Stag, Spitfire, TR7 & Mini - notice a theme here), tend to the coffee making, etc - down here:


No he's not living in the snow, but close enough to it... I will head down later this week to look after some guests and will then return to Auckland next Monday afternoon. As a result, there will not be an update on this thread for a couple of weeks which is when we start with the motor mount & booster tube assembly. We also need to re-wrap the top switch band (not happy with finish on it) and also do the wrapping of center band.

What I do need is a suggestion on how to ensure the center avionics sled is aligned with the external safety pin port, or is this just a case of making sure you align it as you assemble it ?
 

Ben Martin

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Ok, so it was a rather busy weekend and we only managed to get a couple of things done on Spyro 38.

Day #1 - Building the Eggtimer Electronics (Eggfinder LCD-GPS Module, Eggfinder LCD Handheld Receiver & Eggtimer TRS GPS Tracker/Flight Computer

Today was the day we tackled the electronics build.

With the promise of a Kiwi BBQ & some beverages, I managed to convince 2 of my work mates (Remco & Jason) to assemble the EggTimers with PyroShark - whilst I tended to the Kamado BBQ (Peppercorn marinaded 3.5lb Pork Scotch, Sausages, Roast Potatoes, Roast Kumara [sweet potato], Roast Pumpkin, steamed Broccoli & Cauliflower. Yes, it is our winter, yes we still BBQ, and no it doesn't always have to be Lamb either.

Oh and for beverages - try and get your hands around some 'Baltika 0% Wheat Unflitered' Beer. It's quite a refreshing drop, even if it is Russian.

The Assembly Bench & Team:


Starting Small:


Multi-Tasking (Receiver & TRS):


TRS Finished & Plugged in via USB:


Building the Receiver Box:






The Receiver is fitted with three additional buttons/Switches
1) Red Switch - On / Off for Device
2) Black Switch - Turn LCD Back Light On / Off
3) Black Button (on front) - Menu Scroll for LCD interface

The receiver is powered with a single 2S 7.4V 1300mAh 35C Li-Po battery which I need to sort out a proper mounting system for.

We managed to finish the assembly of the electronics on Saturday night but our indoor testing was a bust as we couldn't get a GPS fix, either that or the team had wired the LED's in backwards. As it was down to about 45F outside, outdoor testing was wisely delayed till Sunday am.

Day #2 - Sunday, bloody Sunday...

When tested on Sunday AM, I thought we had an issue with GPS FIX as the lights were only blinking, not staying on solid. Then I referred back to the manual and found a 1 second blink was 'FIXED'. Don't ask me why I was looking for a solid color.

Also whilst reading the manual, I found the section that talks about powering on the TRS at the bench (leaving it on), getting RSO sign-off and then launch pad enablement of the ejection charges, which then caused a minor rethink of our plans.

For the safety switch, we are using a 3 loop audio jack:


The plan was:
Loop 1 - EggTimer TRS Main
Loop 2 - EggTimer TRS Ejection Charges
Loop 3 - MissileWorks RRC2+ (Back Up)

But now will be simplified to:
Loop 1 - EggTimer TRS Ejection Charges
Loop 2 - NOT USED
Loop 3 - MissileWorks RRC2+ (Back Up)

Primary FCS - TRS has been programmed for Drogue @ Apogee, Main @ 800 Feet
Back Up FCS - RRC2+ has been switched for Drogue @ Apogee +1 second, Main at 500 feet

We are intending to mount 3 x 450mAh 2S Lipos (2 for TRS, 1 for RRC2+) within a capping channel on the reverse of the sled - I am working on the retention mechanism for this.

The Plug being used in the Jack, is a cut down axle from a kids stroller that I had lying around. I might shorten it down a bit more once we have position on sled finalized.

And then I got side tracked for 5 hours with shopping, cleaning, etc - so when we eventually got back on task late Sunday afternoon to work on the replacement booster tube that arrived Friday am. Many thanks to Mike Crupe for shipping this over, the MAC product & support is awesome.

So we started off by notching the booster to the center switch band - note the gap is different between notches for lower tube, you can't stuff this one up... well you try, but it wont fit.







We also drilled out the 4 pressure release ports for the booster - so only holes left to drill in the booster tube are for:
2 x Shear Pins @ Upper
2 x Launch Rail Buttons

We also tested out the Plastic Retention Rivets & Shear Pins for the payload section - and thankfully all the holes line up. So the notching system does work !

The upper avionics sled was fitted with the Jolly Logic mounting board. Sorry no PIC's of this - forgot to capture it.

And then we ran out of time to do much else, so we sat down and updated the Open Rocket file with our config details & build weights.

Now, as it's a 2 week winter school holiday here - PyroShark is heading south to stay with 'The Engineer' (aka Grand Pa) for a week to play in the paddocks, work on the cars (Stag, Spitfire, TR7 & Mini - notice a theme here), tend to the coffee making, etc - down here:


No he's not living in the snow, but close enough to it... I will head down later this week to look after some guests and will then return to Auckland next Monday afternoon. As a result, there will not be an update on this thread for a couple of weeks which is when we start with the motor mount & booster tube assembly. We also need to re-wrap the top switch band (not happy with finish on it) and also do the wrapping of center band.

What I do need is a suggestion on how to ensure the center avionics sled is aligned with the external safety pin port, or is this just a case of making sure you align it as you assemble it ?
Looking good! A suggestion to ensure alignment of the sled is to epoxy a piece of material on the bulkhead and two in the electronics bay so that when you insert the sled it can only be inserted in one position. I can make a diagram if my wording is confusing. This would make assembly simpler and allow for the safety pin to always be aligned.
 

spigalau

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Ok, I think I get what you mean. From the top bulkhead (aka the fixed one) - put a dollop of need-it epoxy on it with a smooth side (surface A), and then do same on coupler inner (surface B) so that the 2 smooth sides match each other, like so:
 

Ben Martin

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Ok, I think I get what you mean. From the top bulkhead (aka the fixed one) - put a dollop of need-it epoxy on it with a smooth side (surface A), and then do same on coupler inner (surface B) so that the 2 smooth sides match each other, like so:
Exactly, but you want two "B"s to keep it from rotating either direction. It would pretty much just mean that your bulkhead would only slide in at one spot.
 

spigalau

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So first up, yes it's 'No Rocket Monday' but 'she who must be obeyed' and 'she who thinks she should also be obeyed' have both gone out for a couple of hours, so the boys are at play.

PyroShark pointed out something tonight, it's not a regular MAC Performance 3" Scorpion XL, it's a MAC Performance 3" Scorpion XXL ! The regular Scorpion XL has a 26" Booster, this one has been extended out to 30".

And what did we do ? Well we celebrated our new found freedom with mixing up the smallest batch of Epoxy we could play with.
With a total weight of 2.5g (0.0881849 oz) we mixed up a batch of West HPR25 (https://www.adhesivetechnologies.co.nz/Products/High-Performance,-toughened-adhesives/) for the securement of the booster harness pin.

Dispensed with the bottom of a small paint brush...


See 4 to 1 mix


Now resting/curing for next day or so


According to the marketing blub HPR25 is...

HPR25 is a rubber toughed epoxy paste formulated to produce a high strength bond with excellent resisance to peel.

HPR 25 system was originally developed for the bonding of aluminium sheets onto low density cores.

Additionally HPR 25 system exceeds the requirements pertaining to ASTM D1002; which are called for in certain military applications. it has subsequently been modified to offer high strength bonding to composite and occasionally metal parts.

HPR25 is designed for room temperature cure applications but does have a range of hardeners giving longer working times if required.

HPR25 is commonly used for:
• Metal bonding. Steel and Aluminium.
• Bonding composite components
• Bonding prefabricated components in to pre-preg structures often with the use of HPR 5 as a primer.
And that's all for tonight - but my parting question is 'why are motors & motor mounts in mm, yet tubes & parachutes are in inches?'
We have had some local difficulties obtaining anything 'imperial' in NZ, it's either metric or no-mate - and seeing decimalised inches (eg 0.150 of an inch) is just weird.
 

mike2wander

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Great job on the build guys and always remember....When the girls are away the boys will play. ;)
 

Nytrunner

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nd that's all for tonight - but my parting question is 'why are motors & motor mounts in mm, yet tubes & parachutes are in inches?'
We have had some local difficulties obtaining anything 'imperial' in NZ, it's either metric or no-mate - and seeing decimalised inches (eg 0.150 of an inch) is just weird.
Limited answer here
https://www.rocketryforum.com/threads/why-mixed-units-for-motors-18mm-by-2-75-inches.3601/

Machining experience gave me an appreciation for decimal inches. I now support the death of all fractions smaller than 1/4
 

spigalau

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Ok, so back at it for a couple of nights.. progress is slow when you are waiting on things to cure.

So first up, the Upper Ring on the Motor Mount Tube, our first attempt & trial of filleting...

Tube Sanded & Market, lower location of ring marked


Smeared with a liberal dose of Epoxy and then the ring was slid up the tube over this (turning ring as it progressed over the epoxy)


Keeping the poop off the Kevlar


Filleting the Underside of the Ring


And whilst that was off in the corner curing, we then did some preliminary work on the booster tube.

Sanding the inside (Pool Noodle + Sand Paper)


Taping off the fin can (ready for a future step)


Drilling for lower launch lugg


And then we killed some more time by wrapping the center switch band on the avionics bay.



And then the following night, we did the center motor mount ring. But because we cocked it up (by not looking at our marks correctly), we epoxied it badly and out of alignment. So last night, with the help of our trusty heat gun, we managed to heat & remove the misaligned part, sanded things down and did it all again. This time, things are where they should be.

The Mid-Ring ! (tape to stop it moving down)


We have also made progress on the avionics sled, with placement of batteries (x3), the RRC2+, the EggTimer TRS, the safety switch and a few other bits. Will do a pictorial for this next week, once completed.

Next jobs will be started on Sunday, where the plan is to fit the motor mount to the booster tube. And then, we tackle the fins... (why can I hear Jaws music ?)
 

spigalau

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Ok, so we are back in to this for a couple of more nights of fun.

Night 1 - Epoxying the assembled motor mount in to the booster tube

Apply a double ring of epoxy to the inner of the booster tube below where fore center rings final resting place, and around about where mid center ring will sit


From here, the booster tube was inserting from below and in a twisting motion, raised to it's final resting place.

The shock cord was taped to the top of the booster tube to ensure no epoxy contaminated this work of art.


And to assist with overnight curing, we reused the protective mailing tube to act as a temporary vertical stand


A night later we were on to, prepping the fins for the patented MAC triple dip your fin for success insertion method. I would just like to say that, Mike has been a great sounding board for advice and working with his kit has made us want to build another, the quality, fit & finish is spot on. Now to convince management that a Hyper 54 is a great Xmas present...

Step 1: Mask the Fin


Step 2: Sand the fin


Step 3: Test Fit


Step 4: Apply a liberal amount of epoxy, insert, remove, dose, insert, remove, dose & then insert for one last time.


Step5 : Admire how easy that was (and clean up any bad excess you left lying around)


Step 6: Re-use the mail tube & fin jig to hold everything back in place.




And then last night, we completed the installation of the lower rail button & removal mechanism

Bolting Rail Thread & Button in to place


Epoxied in to Place


Yay - we have a use-able thread !


The plan for this weekend is to:
a) Foam the can (calculations complete, going to do a small test [25ml to 250 cm3] to make sure the product works as expected)
b) External fillet the fins
c) Epoxy Lower Motor Ring
d) Epoxy Motor Retainer

We have 38 days left till launch area re-opens (Sep 1) - things are slowly coming together, there are a few fiddly jobs left to do, so fun times ahead.
 

spigalau

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Ok, so we have made some progress over the last 10 days.

In to the fillets with great gusto..






We did the fillets, side by side over a 24 hour period. Masking them off, epoxy and then cleaned off.

Then on to the foaming of the fin can, despite some minor miscalculations in our foam calculation, we managed to get things done.
Reminder: Foam expansion effected by ambient temperature and humidity. Better to under fill than over fill.






After a couple of days curing, we got around to sanding things down:


I started with 80 grit for knocking off the big lumps, switched to 180, then 280 and finished on 800 grit... smooth like a badgers bottom.

Our first mock-up of the 'nearly' fully assembled air-frame. It's all coming together now.


Now, for the 'we stuffed up story' - DO NOT DRY FIT an aerotech motor retainer when you are not ready to secure it. They have VERY sharp edges and damage really easy when you try to remove them... so after damaging the retainer, we switched to a locally made RED is for Rockets, Bunker Works retainer. If you ever find yourself with a retainer stuck in place before it's supposed to be, use a jubilee clip on the based of the retainer and use that to apply upwards leverage to remove the retainer. DO NOT try to use rubber nose pliers on the thread end, it damages & tears easily. DO NOT try and grip the thread without gloves, they cut your fingers :(







The plan for this week ahead is:

1) Finish the AV bay
2) Drill top launch lugg
3) Wrap Booster tube

Electronics testing is set down for weekend of 17/18 August.

27 days to launch day.
 

spigalau

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Aug 18 - Update.

1) Finish the AV bay - 99% Done - will post pictures once its all done, labelled & tidied up.
2) Drill top launch lugg - Done
3) Wrap Booster tube - Done

Fin 1 Wrapped


Half Way / 2 done


Measuring Up the panel inserts


4 Inserts Ready to go


Top Launch Lugg In


Resting in Cradle


Now for the not so great news, Due to inclement New Zealand weather (it's been raining here for last 3 weeks), we have aborted the testing of the ejection charges this weekend and have deffered to a later date (TBA). I shouldn't be so harsh, it is our winter after all and here we are suffering with low 40's.

The ejection caculations for booster separation are:
10 Psi - 0.59g BP
11 Psi - 0.65g BP
12 Psi - 0.71g BP
13 Psi - 0.77g BP
14 Psi - 0.83g BP
15 Psi - 0.89g BP

The ejection caculations for payload separation are:
10 Psi - 0.46g BP
11 Psi - 0.50g BP
12 Psi - 0.55g BP
13 Psi - 0.59g BP
14 Psi - 0.64g BP
15 Psi - 0.68g BP

We shall have a play over next couple of weeks and finalise what actual charges we shall run with.

Fully assembled Spyro 38 is weighing in at 2740g (96.65Oz) - without motors.
We have weighed the individual components, and OpenRocket SIM file & total match each other. With lagestest 38mm motor the CG lands 06cm from tip, and CP sits 131cm from Tip. Both are now marked on the booster tube.

Oh and I don't know what magic MAC Performance puts in his Rockets, but somehow our girl (Spyro 38) has given us a wee surprise. We are pleased to announce the arrival of a baby girl - 'gold member (aka Spyro 13/18), weighing in at 0.63oz. Mother & baby are doing well, we expect to see them both in the New Zealand air in 14 days time...

Mother & Baby on Arrival


To do:
1) Ejection & Electronics testing
2) Decals
3) Show the AV build !

Have a great week !
 

spigalau

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Avionics Bay - Assembly
The primary flight computer for us is the Eggtimer TRS and the secondary flight computer is a MissileWorks RRC2+.

The TRS is programmed for Apogee for Drogue and 800 feet for Main
The RRC2+ is programmed for Apogee + 1 second for Drougue and 500 feet for Main

To make things a bit easier, we invested in some quick release connectors to allow us to wire in the 4 x ejection starters/e-matches.





On the front side of the sled (3D printed, provided by MAC Performance Rocketry) we glued / bonded the mounting posts.

The isolation switch in a former life was an audio jack point, we are using the middle & outer swicthes for isolating the TRS ejection battery & the battery for the RRC2+.



And after a bit of playing, we ended up with the finished & labelled front side of the sled.







On the rear side of the sled, we bonded some 1" capping to provide a caged environment for our 3 batteries:
1) TRS Main
2) TRS Ejection
3) RRC2+



Two of the batteries are wired to the isolation switch and the main flight is plugged in directly.



Branding
We ordered some decals & branding materials from a 'local' online printing shop (BannerBuzz). Well we though it was sort of local (Australia) but when the goods shipped from India, it became not so local. Service was not bad and materials produced are suited to purpose.





We still need to undertake testing of our ejection charges, hopefully we might get the weather to do that tomorrow. Launch date for next Sunday (Sep 1) may still be marginal for us, the NZ winter has been _very_ wet, so we may have to delay till range is open for us.
 

Nick Hutton

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Looks awesome. Are you going to fly it at Havoc? How tricky were the Eggtimer builds? I’m looking at getting some for my L2 project and I really can’t workout if the difficulty rating means I am not up to the task?
 

spigalau

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Looks awesome. Are you going to fly it at Havoc? How tricky were the Eggtimer builds? I’m looking at getting some for my L2 project and I really can’t workout if the difficulty rating means I am not up to the task?
Yes, intention is L1's this side of Xmas for myself & pyroshark and then L2's at Havok, we have also cooked up a little something else to have some fun with.

For Eggtimers, I exchanged BBQ with work boys for soldering efforts - they liked the challenge and it took an afternoon to make both TRS & reciever.
 

BradMilkomeda

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Great build thread. Thanks for sharing all the details. Very well built and good luck on your certification flight flights. Are you able to do a shake down flight or will your L1 be the first flight?
 

spigalau

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Great build thread. Thanks for sharing all the details. Very well built and good luck on your certification flight flights. Are you able to do a shake down flight or will your L1 be the first flight?
First flight will be my L1 on I140, 2nd flight (same day, if things go to plan) will be Pyro's L1 on I280DM, so first flight should be around 1450 feet, 2nd around 3.2K feet
 

mpitfield

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Nice build, I like the wrap. I have yet to wrap a rocket, so you're inspiring me to give it a go. BTW, do you have a link to Bunker Works?
 
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