Replica challenge.

[Space_geek25]

I made a non DLC Falcon 1 for the mission:
It has 2 stages and can achieve easy life reach LEO:

(I tried to share the link but it didn't work)

 

[Pink]

Looks like that:

1. You need to move the 2nd stage engine (and the bottom of the second stage tank, and everything else at the bottom of the second stage) downwards by about 0.3-0.5m, by inserting more tank for the second stage (making it longer)
2. Shrink the first stage engine some more, but leave it located where it currently is (in other words, the top of the engine is in the right place, but the bottom of the engine is too far down)
3. Drain some fuel from the first and second stage to bring the mass down to, perhaps 40t?
4. Needs a payload attachment point and a small payload (5t?) for demonstration that it works.

 

[EmberSkyMedia]

View attachment 88902
Looks like that:

1. You need to move the 2nd stage engine (and the bottom of the second stage tank, and everything else at the bottom of the second stage) downwards by about 0.3-0.5m, by inserting more tank for the second stage (making it longer)
2. Shrink the first stage engine some more, but leave it located where it currently is (in other words, the top of the engine is in the right place, but the bottom of the engine is too far down)
3. Drain some fuel from the first and second stage to bring the mass down to, perhaps 40t?
4. Needs a payload attachment point and a small payload (5t?) for demonstration that it works.

Apologies to jump in here...
Falcon 1 Payload is ~0.5T not 5T. I tested with my successful entry, 5T payload and I can't even make it to space (maybe with a mod engine but not stock).

 

[Pink]

You're giving falcon 1 too much credit, it was more like 200kg to sun synchronous orbit in real life.

As it is, the in this thread here should be able to carry at least 10% of its mass in payload if you analyse its components.
A 5t payload is actually a bit on the light side for it.

I'd specify a smaller payload if that's what this rocket was actually only capable of, via less fuel and more ballast. But not less than it ought to be able to carry in real life.
And it would indeed be more accurate that way, except for the fact that the SFS solar system is 1:20 scale... So do you scale the payload mass up to compensate?

I'd expect an SFS falcon 1 to carry 200kg... in IRIS.

 

[Space_geek25]

You're giving falcon 1 too much credit, it was more like 200kg to sun synchronous orbit in real life.

As it is, the in this thread here should be able to carry at least 10% of its mass in payload if you analyse its components.
A 5t payload is actually a bit on the light side for it.

I'd specify a smaller payload if that's what this rocket was actually only capable of, via less fuel and more ballast. But not less than it ought to be able to carry in real life.
And it would indeed be more accurate that way, except for the fact that the SFS solar system is 1:20 scale... So do you scale the payload mass up to compensate?

I'd expect an SFS falcon 1 to carry 200kg... in IRIS.

I don't have IRIS so I tried to carry 13t ( 20% of the Launcher mass) in LEO and I made it.

 

[Pink]

Nice.
Include a test like that when you post your revised rocket.

 

[Space_geek25]

Here's the V2:
2nd stage 0,3m longer
Added a docking port to connect payload
Less fuel ( mass = 45t)
Smaller 1st stage engine ( 1,5 m instead of 1,8)


It can send 5t to LEO

 

[Pink]

Ah, when you increased the height of the second stage tank, you left the second stage engine where it was, and moved the top of the rocket upwards. So now it's longer.

What you should have done was leave the top of the rocket in the same place, and move the second stage engine and the other stuff downwards, keeping the overall length of the rocket the same and slightly shortening the interstage of the first stage.
Just post a photo of it fixed and I'll look it over for final approval.

 

[Space_geek25]

Ah, when you increased the height of the second stage tank, you left the second stage engine where it was, and moved the top of the rocket upwards. So now it's longer.

What you should have done was leave the top of the rocket in the same place, and move the second stage engine and the other stuff downwards, keeping the overall length of the rocket the same and slightly shortening the interstage of the first stage.
Just post a photo of it fixed and I'll look it over for final approval.

 

[EmberSkyMedia]

Here's the V2:
2nd stage 0,3m longer
Added a docking port to connect payload
Less fuel ( mass = 45t)

You launched 45t? That would explain the larger payload capacity.

Not sure if weight counts (mooncrasher decision) but the max (actual) takeoff weight of the Falcon 1 was 33T, proposed I’ve seen documentation stating 42T so you are likely packing a lot more fuel into your craft.

Falcon 1 - Wikipedia
http://www.georing.biz/usefull/Falcon1UsersGuide.pdf

 

[Pink]

Falcon 1 would also have had a much better mass fraction than our SFS rockets, so we need to make allowances.

 

[Pink]

View attachment 88990

It looks like all you need to do is LENGTHEN the fairing upwards and MOVE the engine & struts downwards without changing anything else.