Almost ready... Next is adding the chute and nose weight and then testing it... Maiden flight will be in december 
TLP - Hellfire build
- Thread starter McTschegsn
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Looks like you do some slope soaring? PSS?
I missed seeing what brand and specific color of paint you used,
I used to but I have no more PSS models ans the slopes here in the region are a bit limited. Doing RC flying as my main hobby tho. Rockets are only a sidekick if you want to call that so. Nevertheless its great fun
Or do you mean because of the Me-163? Its actually radiocontrolles and rocket powered.
Its rattlecan spray paint from Ludwig Lacke here in germany. Nothing special. We found that over ebay looking for an olive drab tone.
Im a bit astonished by the CG in Rocksim. Is it possible that is this far forward?
Found the Rocksim file it in the internet.
Can anyone confirm that? The manual just says to add that clay weight. Front mass object is the clay weight, other mass objects are shock cord and screw eye.
Found the Rocksim file it in the internet.
Can anyone confirm that? The manual just says to add that clay weight. Front mass object is the clay weight, other mass objects are shock cord and screw eye.
Looking at that image, I would trust NEITHER your CG, NOR your CP as being accurate. in Rocksim.
Dave F.
Based on the "Cardboard Cutout" method, that CP is in the correct location.
However, that method places the CP forward of its true location . . . The method in the PDF below can be used to calculate the CP, using simplified Barrowman equations. ( by Rocketeer, Bruce Lee ).
NEVER trust a CG location, in ANY "Sim" . . . ALWAYS be sure to VERIFY stability !
Dave F.
Personally, I could see it possible. Any time you have forward fins and/or small rear fins, the CP moves up, so the CG also needs to...with both, it moves up even more. You can try swing tests to see how your build is and adjust nose weight accordingly.
You can also try removing those forward fins and see how the CG moves...is it then more in line with normal rockets?
Also TLP kits are based off military missiles and rockets, which often have guidance and so is usually much less stable vs. traditional unguided rockets.
Here's a scratchbuilt one with note:
"The main CON is the CP is so far forward that it requires lots of nose weight to be stable."
"The main CON is the CP is so far forward that it requires lots of nose weight to be stable."
Found that too Ill give it a try in Rocksim. Good idea. Thanks
Ill give it a try in Rocksim. Good idea. Thanks
You're very welcome! I'm actually lucky enough to have a SBR 5.5" Hellfire (incredible kit) and I've messaged Scott to see if there is a Rocksim for that, which would be good guidance. I plan to build it this winter.
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That's the one! I didn't see any notes in the instructions about nose weight in my initial scan, but had heard back and was told:
"Sorry - I don't have a sim for the Hellfire - I can tell you, though, it does require a good deal of nose weight. Maybe a pound.... and I like to use a fast burning motor to get it up to speed as soon as possible...... Good luck and thanks!"
Of note is that the forward fins on the 5.5" SBR Hellfire appear to be much smaller than on the TLP design.
"Sorry - I don't have a sim for the Hellfire - I can tell you, though, it does require a good deal of nose weight. Maybe a pound.... and I like to use a fast burning motor to get it up to speed as soon as possible...... Good luck and thanks!"
Of note is that the forward fins on the 5.5" SBR Hellfire appear to be much smaller than on the TLP design.
Bruiser
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It looks like you don't have a motor installed in that rocket... That would affect the CG in the sim
It's always a good idea to actually check the CG and verify what the sim is telling you. Your actual weight can vary from the default weights of your parts.
-Bob
It's always a good idea to actually check the CG and verify what the sim is telling you. Your actual weight can vary from the default weights of your parts.
-Bob
OK I should be more precise... I meant the CP location. The GC varies of course adding different motor sizes. Sorry. Relatively new to this (into rocketry since may but an avid rc mdoeler since I was 6 )
I have to get used to different stability margings regarding the difference between planes and rockets.
Well I will have a look at the different solutions Thank you guys for the heads up
Btw: That Hellfire is definitely a beast
)I have to get used to different stability margings regarding the difference between planes and rockets.
Well I will have a look at the different solutions
Thank you guys for the heads up Btw: That Hellfire is definitely a beast
The TLP Hellfire is not very true to scale according to my measurements. Its a good lookalike I think. We will see how it flies in december. I chose to trust rocksim regarding the CP. Moving the CG to about 60-90mm forward of the CP. Its about 1 - 1.5 calibers. Rocksin tells me that this is ok
Thank you. Will check that against mine but I think they are almost equal.
And test flights went well LAst weekend in germany:
LAst weekend in germany:
FANTASTIC job! Thanks for sharing! 
