24mm MD

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Re: 24mm MD

Postby Lister » Sun Feb 21, 2016 3:53 pm

I was looking at a thread in TRF that viking posted on an unrelated thread.. it sounds EXACTLY the same as my 24mm MD.. even using the G150 that I plan on using dammit!


http://www.rocketryforum.com/showthread ... stes-BT-50

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Re: 24mm MD

Postby Viking » Sun Feb 21, 2016 8:22 pm

I did? Don't remember that haha.
There's a good reason I was looking at that thread though :D
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Re: 24mm MD

Postby Lister » Sun Feb 21, 2016 9:53 pm

You posted a link in the thread I mentioned the snowflake dollar tree rockets.

Sent you a PM

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Re: 24mm MD

Postby Viking » Sun Feb 21, 2016 10:26 pm

Oh ok, strange, that link should have taken you to a thread about 3D modelling the Estes Porta Pad in OR, not one about 24mm MD.
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Re: 24mm MD

Postby TRFfan2 » Tue Mar 08, 2016 6:06 am

Lister wrote:I was looking at a thread in TRF that viking posted on an unrelated thread.. it sounds EXACTLY the same as my 24mm MD.. even using the G150 that I plan on using dammit!


http://www.rocketryforum.com/showthread ... stes-BT-50


Hi Lister,

I'm the person that made that thread. I'very also been looking at this build for quite a while now, and I wanted to ask you if you have launched the rocket yet.

All the best,


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Re: 24mm MD

Postby Lister » Tue Mar 08, 2016 2:53 pm

Very nice build you have.. little different to mine but similar size and weight.. im rebuilding mine and instead of painting it I'll use tinted wests 105 and put a gel coat on that I can wet sand and polish on the lathe.. might use the other one as a test rocket ir shorten it for 24mm 3G cti motors.

I havent launched it yet.. our launch site is offline during the summer (fire restrictions) but I will be putting it up on our first launch in a month or two depending on the weather.. like you I plan on using a G150BS for and a G107W-DT the test lights but a G65LB for the record attempt. I'll post the results here.

have you launched that little bullet yet? What did/are you using for tracking?

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Re: 24mm MD

Postby Viking » Tue Mar 08, 2016 3:51 pm

Will be interesting to see how the G65's go, I ordered one too but I've since read that the offset mass of the moonburner can be a problem with MD's. May have even been mentioned in TRFfan2's thread? Will have to look again.
Starting to wonder if I should've got another G150 instead :?
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Re: 24mm MD

Postby Lister » Tue Mar 08, 2016 5:38 pm

I have used G65 motors before.. they actually have a bit of punch and the sims show that even with the long burn motor it will be going about mach 1.4.. and the expected altitude was only an extra 200ft compared with the G150 or G107.. personally the G150's are my favourite G motors, that have a lot of kick and the flame and the sound is awesome.. think I have a half dozen G150's on order 8) also have the CTI 1G case that I will use to test it as it has the same stability margin as it does with the 6G motors.

cant remember reading that but its quite a big thread.

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Re: 24mm MD

Postby TRFfan2 » Wed Mar 09, 2016 8:27 am

Lister wrote:Very nice build you have..
Likewise : )
Lister wrote:.....little different to mine but similar size and weight...
Yeah I agree. I fact some of my inspiration was taken from your build along with this one: (http://www.rocketryforum.com/showthread ... -as-of-now))
Lister wrote:im rebuilding mine and instead of painting it I'll use tinted wests 105 and put a gel coat on that I can wet sand and polish on the lathe.. might use the other one as a test rocket ir shorten it for 24mm 3G cti motors.
That's pretty cool. You should also try building a longer rocket....because from what I heard from TRF is that CTI is coming out with 24 mm 8G motors in April. :D An Imax load in that case would probaly work to be ~210 n/s!! :twisted:
Lister wrote:I havent launched it yet.. our launch site is offline during the summer (fire restrictions) but I will be putting it up on our first launch in a month or two depending on the weather.. like you I plan on using a G150BS for and a G107W-DT the test lights but a G65LB for the record attempt. I'll post the results here.
A moonburner in a light, MD will tend to corkscrew because of displaced mass. Maxvelocity (on TRF) tested a MD rocket on a G65 and it corkscrewed at a couple hundred ft in the air. (1) In all I think the G150 is the best choice since it has the largest total impulse out of all the motors (apart from the G65) and a lighter propellant mass. If you use the G65, it will probaly send your rocket off course, making you lose a couple hundred ft in altitude and sending you for a long walk to retrieve it. Originally I planned on using the G65 too, but when I saw the facts I gave up the Idea and went with the G150. :( That didn't stop from staring at it on Openrocket. LOL

(1)

(http://www.rocketryforum.com/showthread ... ost1415573)
(http://www.rocketryforum.com/showthread ... post649247)
(http://www.rocketryforum.com/showthread ... post614921)
(http://www.rocketryforum.com/showthread ... ost1556130)

BTW, you want to reconsider using those 6G motors for the record attempt. In April, CTI is going to hold a cert session and from what I heard, they might be certifying a >155 n/s full G Imax motor for the 6G case.
Lister wrote:have you launched that little bullet yet?
I'm not planning to launch it soon (at least until september) and the reason for this is because my nearest club is 5 hrs away, so I can only make it there once a while. In september there's a big launch so I might as well go there then.
Lister wrote:What did/are you using for tracking?
I'm planning to use this, (https://www.apogeerockets.com/Electroni ... icroBeacon) as it's affordable and small enough to fit in a 24 mm tube.

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Re: 24mm MD

Postby TRFfan2 » Wed Mar 09, 2016 8:39 am

Viking wrote:Will be interesting to see how the G65's go, I ordered one too but I've since read that the offset mass of the moonburner can be a problem with MD's.
Yes, unfortunately. :(

Viking wrote:May have even been mentioned in TRFfan2's thread? Will have to look again.
Yes, right here. (http://www.rocketryforum.com/showthread ... ost1556130)

Viking wrote:Starting to wonder if I should've got another G150 instead :?
Probably not....unless you have a MD. In large, heavy rockets they should do fine.

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Re: 24mm MD

Postby TRFfan2 » Wed Mar 09, 2016 9:16 am

Lister wrote:I have used G65 motors before.. they actually have a bit of punch and the sims show that even with the long burn motor it will be going about mach 1.4.. and the expected altitude was only an extra 200ft compared with the G150 or G107.. personally the G150's are my favourite G motors, that have a lot of kick and the flame and the sound is awesome..
I agree. Although I haven't flown a G150 yet I've seen a couple of videos on youtube. BTW do you have any pics of the G150 load that you could share?

Lister wrote:think I have a half dozen G150's on order 8)
Wow. :O Yeah, I know, I love the G150 too...It's actually my favorite motor.

Lister wrote:also have the CTI 1G case that I will use to test it as it has the same stability margin as it does with the 6G motors.

cant remember reading that but its quite a big thread.

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Re: 24mm MD

Postby Lister » Wed Mar 09, 2016 10:13 am

these are the only pics i have of the G150 reloads.. I havent gotten my new motor order yet but when i do i will take some pics of it.
G150.jpg


I did read about the 24mm 8G cases but we have to get them certified and approved for use in australia and we wont be getting another motor shipment until next year so I'll push forward with the 6G 24mm, it wont be hard to make a new airfame and attach some fins to it when/if we get the 8G motors.. i really want to see what altitude i can get from the 6G motors.

Thanks for the heads up with the G65 motors, like i said i will be doing a few flights with different motors (may even use a G145 Pink motor :P) so i will be able to let you know what the G65 is like in one of these rockets.

Viking s doing his own 24mm MD which is why he is thinking of using the G150 too.. if our launch next month is a go i will let you both know how the G65 and G150 motors go.. just remember with sims that they arent too accurate with these small diameter MD rockets especially through the transonic region.. which is what these will be spending alot of the flight in.

I have flown a fair few of the G150's and can tell you they are even better in person :)

Im guessing your using a carboard airframe for your MD because you cant get FG 24mm tubes :?: if that's the case and you do want a FG tube for it I can make and extra one when i do mine, its only 2 layers of 290gsm (10oz) crowsfoot woven cloth with tinted wests 105/206.. when its cured i sand it back and give it a tinted gel coat and once thats cured i put it back in the lathe and wet sand it down to 2500 grit so i get a perfect tube with a polished finish.. and it helps keep the weight down and keeps the OD as small as possible.. from memory the tube your planning on using has a 2-3mm wall thickness? if you play with the sim and reduce the airframe OD to 25-25.5mm you will see quite a large difference in projected altitude.

what nose cone will you be using for yours? your putting your av bay in the airframe arent you? Seeing as mine is all scratch built i plan on making a 6:1 VK nose cone mandrel and making my own nose cone that will house my electronics. seeing as its about 20 seconds to apogee i need to use electronic deployment but im leaving a 17 sec delay grain in there to produce smoke to negate some of the base drag.

i have a heap of these mini nuke kits to finish building for your fellow yanks before i can start my own project again.

I'm also getting a 24mm MD from Charlie at Carolina Composites that im going to use as a comparison between mine and his.. but the one Charlie is sending me has a CF airframe but the rest is much the same.

L

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Re: 24mm MD

Postby TRFfan2 » Wed Mar 09, 2016 12:50 pm

Lister wrote:these are the only pics i have of the G150 reloads.. I havent gotten my new motor order yet but when i do i will take some pics of it.
G150.jpg

Thanks, those are cool. If you ever unbox one can you take a pic of the grains and the other components?
Lister wrote:I did read about the 24mm 8G cases but we have to get them certified and approved for use in australia and we wont be getting another motor shipment until next year so I'll push forward with the 6G 24mm, it wont be hard to make a new airfame and attach some fins to it when/if we get the 8G motors.. i really want to see what altitude i can get from the 6G motors.

That's a bummer. Here in canada, the motors are available instantly after they are certified, since CTI is in toronto.

BTW, make sure to post a build thread of your 24 mm MD 8G rocket. ; ) I'd to see that one fly! :D
Lister wrote:Thanks for the heads up with the G65 motors, like i said i will be doing a few flights with different motors (may even use a G145 Pink motor :P) so i will be able to let you know what the G65 is like in one of these rockets.

Thanks. Also, take note that the G145 doesn't really have 145 n/s, as it says on the CTI website. That's actually a typo and the real total impulse is 139 n/s. In reality, pink is a mix of BS and RL, which is why its performance is halfway between red and blue.
Lister wrote:Viking s doing his own 24mm MD which is why he is thinking of using the G150 too.. if our launch next month is a go i will let you both know how the G65 and G150 motors go.. just remember with sims that they arent too accurate with these small diameter MD rockets especially through the transonic region.. which is what these will be spending alot of the flight in.

Thanks. I would like to know what happens in your launch.
Lister wrote:I have flown a fair few of the G150's and can tell you they are even better in person :)

Yeah, videos never capture the real "essence" of a rocket flight. Even launching a C6 motor is hundreds of times more exciting than watching a video on a N5800 motor.
Lister wrote:Im guessing your using a carboard airframe for your MD because you cant get FG 24mm tubes :?: if that's the case and you do want a FG tube for it I can make and extra one when i do mine, its only 2 layers of 290gsm (10oz) crowsfoot woven cloth with tinted wests 105/206.. when its cured i sand it back and give it a tinted gel coat and once thats cured i put it back in the lathe and wet sand it down to 2500 grit so i get a perfect tube with a polished finish.. and it helps keep the weight down and keeps the OD as small as possible..

I was actually using a paper tube to keep costs down.......but since the price of the rocket has become so high, I'm going ahead and using composite material. The fins will be made using CF, and the BT, I'm not so certain. FG has its advantages (cheaper) but CF is stronger and lighter. I also could use a polished BT so I might take up your offer. : )
Lister wrote:from memory the tube your planning on using has a 2-3mm wall thickness? if you play with the sim and reduce the airframe OD to 25-25.5mm you will see quite a large difference in projected altitude.

The OD of the BT is 24.8 mm, that about as far as I can go without making the tube too weak. : )
Lister wrote:what nose cone will you be using for yours? your putting your av bay in the airframe arent you? Seeing as mine is all scratch built i plan on making a 6:1 VK nose cone mandrel and making my own nose cone that will house my electronics. seeing as its about 20 seconds to apogee i need to use electronic deployment but im leaving a 17 sec delay grain in there to produce smoke to negate some of the base drag.

I'm using a 110 mm ogive NC for my rocket. I'm probably not going to put my av-bay in there, since most of the room in the NC is taken up by my weight anyway........so then the only place to put it in would be the BT. I'm also going to be using an av-bay since the optimum delay of my rocket is 19 seconds. Funny how all the 24 mm MD rockets have optimum delays over 13 sec. :?
Lister wrote:i have a heap of these mini nuke kits to finish building for your fellow yanks before i can start my own project again.
I'm also getting a 24mm MD from Charlie at Carolina Composites that im going to use as a comparison between mine and his.. but the one Charlie is sending me has a CF airframe but the rest is much the same.

L
Carolina Composites make custom rockets?

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Re: 24mm MD

Postby Lister » Wed Mar 09, 2016 2:26 pm

TRFfan2 wrote:Lister wrote:
these are the only pics i have of the G150 reloads.. I havent gotten my new motor order yet but when i do i will take some pics of it.
Attachment:
G150.jpg

Thanks, those are cool. If you ever unbox one can you take a pic of the grains and the other components?

Those two G150's were burnt months ago... all these have been :)
Motors.jpg


TRFfan2 wrote:That's a bummer. Here in canada, the motors are available instantly after they are certified, since CTI is in toronto.

BTW, make sure to post a build thread of your 24 mm MD 8G rocket. ; ) I'd to see that one fly! :D

Yeah but hopefully our fearless leader will have them in stock when the next order hits the shore.
I normally post all my build threads.. if you look at the scratch and MPR/HPR sections you should see my name a coupler of times :P I'll be posting the rebuild of th 24mm MD when i get around to building it.

i dont look on the cti website, i look on www.ausrocketry.com.au/motors.html because that the only place i can get composite motors from and that motors listed as HP140G145-15A (PI)

TRFfan2 wrote:Yeah, videos never capture the real "essence" of a rocket flight. Even launching a C6 motor is hundreds of times more exciting than watching a video on a N5800 motor.
it doesnt matter what size motor you use, when you get to watch something go WOOSH! its always cool 8)

TRFfan2 wrote:I was actually using a paper tube to keep costs down.......but since the price of the rocket has become so high, I'm going ahead and using composite material. The fins will be made using CF, and the BT, I'm not so certain. FG has its advantages (cheaper) but CF is stronger and lighter. I also could use a polished BT so I might take up your offer. : )

with the 24mm its not really going to need a heap of strength, that's why i have only used 2 layers of 287gsm cloth with wests 105 epoxy resin.. i could probably get away with on layer of 287 and one layer of 185 gsm to reduce weight more but this isnt built for speed, its built to get the highest altitude so I need some weight to it so it has enough mass and velocity so when its coasting it doesnt just stop.. if i made it ultra light it would be great for speed though but you would need a bit more strength so you need to find the balance for what your planning on doing with it ;)

I might use the CF tape i have here for the airframe on my MD so i can keep the diameter down to around 24.6mm-24.8mm. I dont like friction fitting so i will mount a bit of all thread in the charge holder of the motor (i wont be using the deployment charge because of the long coast time) and screwing the all thread into a nut that will be modified to fit in the tube and to be the shock mount.. might be a good way for you to mount yours?

why dont y
TRFfan2 wrote:I'm using a 110 mm ogive NC for my rocket. I'm probably not going to put my av-bay in there, since most of the room in the NC is taken up by weight anyway........so then the only place to put it in would be the BT. I'm also going to be using an av-bay since the optimum delay of my rocket is 19 seconds. Funny how all the 24 mm MD rockets have optimum delays over 13 sec.

Why dont you cut the bottom of the nose cone shoulder and attach that to a small payload bay with the bottom of the shoulder mounted in the base of a coupler thats epoxied in to the payload bay.. then you can just use a plastic rivet to hold the nose cone in place and use some of the nose and the payload bay to house your electronics?

I dont know if Carolina Composites does custom stuff but they have some 24mm stuff thats bases on the same design as the 38mm MD that Charlie used to break the I altitude record.. if you want i can ask him if he has any of the 24mm 6:1 or 7:1 VK (cant remember what size they were) FG nose cones but they weren't cheap. if you want other bits from him im sure you can find his email on the carolina composites website :)

L

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Re: 24mm MD

Postby Viking » Wed Mar 09, 2016 3:23 pm

Woah! A lot of new activity here I need to catch up on after work.
TRFfan2 wrote:
Viking wrote:May have even been mentioned in TRFfan2's thread? Will have to look again.
Yes, right here. (http://www.rocketryforum.com/showthread ... ost1556130)

Thanks, I spent all night(!) searching TRF trying to find the first-hand reference I had seen, I thought it was in your thread but it was actually Maxvelocity's post in another thread that you have linked to here:
http://www.rocketryforum.com/showthread ... post614921
TRFfan2 wrote:
Viking wrote:Starting to wonder if I should've got another G150 instead :?
Probably not....unless you have a MD. In large, heavy rockets they should do fine.

Yep, I'm going MD too ;)
You guys are way ahead of me, I'm struggling to find the time.
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