7.5" Estes Fat Boy Upscale Build

UPscaler

New Member
TRF Supporter
Joined
Nov 24, 2009
Messages
4,614
Reaction score
908
Hey Everyone!

Recently I picked up this 7.5" Fat Boy Upscale from a seller here on TRF. It's a Performance Hobbies kit and the price was awesome so I jumped on the chance to get one instantly. (Thanks @wadavidson )
1.jpg

Being a Mosquito fanatic, this might be my favorite big rocket nosecone I've ever owned. I immediately bumped it to the top of the build pile. Had some issues with the fin tabs reaching the motor tube, but some time with a die grinder bit on a dremel and a belt sander make pretty quick work of that!
2.jpg 3.jpg

After gluing the fins in place with BSI thick CA, I rushed it over to the rocket workshop that is my parents' garage and started doing some fillets. They're pretty tame on the externals with relatively beefy internals, all of which are West Systems epoxy with 406 Colloidal Silica to thicken things up.
6.jpg 7.jpg


I love Estes upscale and this is undoubtedly one of my new favorites in the collection. I've got a couple of motors kicking around that would make a great first flight. I'm thinking an I600 or J800 will be the play!

I plan on flying it mostly on motor deploy. However, I left the top ring out for the time being so I can situate an electronics bay to sit atop it that will allow my to fly motors without motor eject, should I decide to go that route.

5.jpg

I'm also considering grabbing some 3/8" brass tube and slapping a big imitation launch lug on there for proper scale purposes ;)

Braden
 

Attachments

  • 5.jpg
    5.jpg
    156.3 KB · Views: 76
Last edited:

mrwalsh85

Well-Known Member
Joined
Apr 29, 2012
Messages
1,282
Reaction score
294
I'm also considering grabbing some 3/8" brass tube and slapping a big imitation launch lug on there for proper scale purposes ;)

Braden

Don't forget the oversize engine hook... Sheesh, I should do that on mine too... I have a 7.5" Nose cone kicking around too :D
 

DAllen

Well-Known Member
Joined
Jan 17, 2009
Messages
5,564
Reaction score
2,081
Location
SW Michigan
I'm also considering grabbing some 3/8" brass tube and slapping a big imitation launch lug on there for proper scale purposes ;)

Braden

That sounds funny buuuuuutttt...I don't think 3/8 would be to scale. Also...why brass? If it's just for looks I'd slap some paper tube that's reasonably close to scale to save weight and cost. But whatever you decide this looks like a cool project.
 

jmasterj

Low and slow
TRF Supporter
Joined
Aug 16, 2021
Messages
910
Reaction score
670
Location
Maryland
That sounds funny buuuuuutttt...I don't think 3/8 would be to scale. Also...why brass? If it's just for looks I'd slap some paper tube that's reasonably close to scale to save weight and cost. But whatever you decide this looks like a cool project.
BT-80 Fat Boy used a 1/8 lug, this is about a 3x upscale so 3/8 makes sense to me.
 

UPscaler

New Member
TRF Supporter
Joined
Nov 24, 2009
Messages
4,614
Reaction score
908
That sounds funny buuuuuutttt...I don't think 3/8 would be to scale. Also...why brass? If it's just for looks I'd slap some paper tube that's reasonably close to scale to save weight and cost. But whatever you decide this looks like a cool project.
Brass was my thinking just for availability. I have a 6" Red Max too that I wanted to put fake launch lugs on and BT-5 is almost perfect for that so I may go that route for that one.

Otherwise my thinking is that brass has a better chance of surviving and avoiding being crushed in unwanted recovery incidents.


Braden
 

DAllen

Well-Known Member
Joined
Jan 17, 2009
Messages
5,564
Reaction score
2,081
Location
SW Michigan
That makes sense. Plus the tiny bit of extra weight on a rocket like this isn't going to matter much. It's not like you're trying to set altitude records with a rocket like that.
 

rharshberger

Well-Known Member
Joined
Oct 13, 2014
Messages
11,682
Reaction score
3,521
Location
Pasco, WA
Brass was my thinking just for availability. I have a 6" Red Max too that I wanted to put fake launch lugs on and BT-5 is almost perfect for that so I may go that route for that one.

Otherwise my thinking is that brass has a better chance of surviving and avoiding being crushed in unwanted recovery incidents.


Braden
Brass tubing seems to have been what I see a lot of on the old larger launch lugs, I have a couple of old Loc/Yank era rockets that have 1/2" and larger lugs on them, all brass iirc.
 

bobbyg23

Well-Known Member
Joined
Apr 15, 2020
Messages
1,234
Reaction score
1,265
Hey Everyone!

Recently I picked up this 7.5" Fat Boy Upscale from a seller here on TRF. It's a Performance Hobbies kit and the price was awesome so I jumped on the chance to get one instantly. (Thanks @wadavidson )
View attachment 505176

Being a Mosquito fanatic, this might be my favorite big rocket nosecone I've ever owned. I immediately bumped it to the top of the build pile. Had some issues with the fin tabs reaching the motor tube, but some time with a die grinder bit on a dremel and a belt sander make pretty quick work of that!
View attachment 505178 View attachment 505177

After gluing the fins in place with BSI thick CA, I rushed it over to the rocket workshop that is my parents' garage and started doing some fillets. They're pretty tame on the externals with relatively beefy internals, all of which are West Systems epoxy with 406 Colloidal Silica to thicken things up.
View attachment 505180 View attachment 505181


I love Estes upscale and this is undoubtedly one of my new favorites in the collection. I've got a couple of motors kicking around that would make a great first flight. I'm thinking an I600 or J800 will be the play!

I plan on flying it mostly on motor deploy. However, I left the top ring out for the time being so I can situate an electronics bay to sit atop it that will allow my to fly motors without motor eject, should I decide to go that route.

View attachment 505182

I'm also considering grabbing some 3/8" brass tube and slapping a big imitation launch lug on there for proper scale purposes ;)

Braden
Dang you. You were faster than I was when it went up for sale.
 

UPscaler

New Member
TRF Supporter
Joined
Nov 24, 2009
Messages
4,614
Reaction score
908
If I did my math right, I believe a 38mm motor tube could serve as a launch lug for a 1010 rail!
I actually thought about this one time for a 38mm tube fin rocket. One upper rail button and slide the rail through the corresponding fin.

These lugs are just s goofy thing for looks, though. I'm putting rail buttons on it, too.

Braden
 

Dave Frost

Member
Joined
Apr 6, 2022
Messages
14
Reaction score
13
Acquiring parts for a 3x fatboy upscale. Found a nice plastic Easter egg that should be able to be glassed for a nosecone. Looking for information about the length of the 7.5" bodytube and if there is a fin template available. Thanks, Dave
 

rharshberger

Well-Known Member
Joined
Oct 13, 2014
Messages
11,682
Reaction score
3,521
Location
Pasco, WA
Acquiring parts for a 3x fatboy upscale. Found a nice plastic Easter egg that should be able to be glassed for a nosecone. Looking for information about the length of the 7.5" bodytube and if there is a fin template available. Thanks, Dave
Get the Estes Fat Boy .rkt or .ork for Open Rocket and use the scaling function with just a couple of clicks you will have every dimension needed for the upscale and the ability to print templates for centering rings and fins.
 
Top