Lego guillotine fin alignment

[barn]

I made a guillotine fin jig out of Lego. it works good for smaller rockets.

 

[Cl(VII)]

Well played.

 

[BDB]

This. Is. Brilliant.


Sent from my iPhone using Rocketry Forum

 

[dr wogz]

First off, way cool!! Nice idea, nicely played out. With a few technics parts you could eliminate the two metal angles and get better centerablility..

But sorry to be the skeptic..

While the metal angles keep the fin 90°, what keeps the fin perpendicular to the tube? Since the fin / metal angle assembly is free to float left & right , you may have a 90° fin, but slightly askew to the tube axis, and/or offset from the perpendicular point on the tube..

 

[barn]

While the metal angles keep the fin 90°, what keeps the fin perpendicular to the tube? Since the fin / metal angle assembly is free to float left & right , you may have a 90° fin, but slightly askew to the tube axis, and/or offset from the perpendicular point on the tube..

The metal angle does not float. it's not a great picture but in the first pic you can see the "V" that aligns the metal angle with help from a scrap piece of balsa. the Lego part used is this:

https://www.bricklink.com/v2/catalog/catalogitem.page?P=26047#T=C

another picture with the "V" groove disassembled:

 

[Nytrunner]

Well played.

Don't you mean: "Play Well!"..?

points to those that know

 

[dhbarr]

Don't you mean: "Play Well!"..?

points to those that know

Godt 'em!

 

[dr wogz]

The metal angle does not float. it's not a great picture but in the first pic you can see the "V" that aligns the metal angle with help from a scrap piece of balsa. the Lego part used is this:

https://www.bricklink.com/v2/catalog/catalogitem.page?P=26047#T=C

another picture with the "V" groove disassembled:View attachment 330879

Ahhh, OK, now I get it!! yes, well thought out! (sorry I missed that.. too quick to judge! sorry!)

 

[Bat-mite]

I think you just wanted to play with Legos. :wink:

 

[barn]

I think you just wanted to play with Legos. :wink:

I do love playing with Lego

 

[Bat-mite]

I do love playing with Lego

WOW!

 

[LithosphereRocketry]

I do love playing with Lego

Nothing wrong with that... Besides, Legos AND rockets? It doesn't get better than that...

 

[barn]

Nothing wrong with that... Besides, Legos AND rockets? It doesn't get better than that...
View attachment 331006

Nice job on the Black Star!

 

[Tobor]

Genius! Way Cool..
My hat's off to you Sir.

Was this conceived using LegoCAD? If so, mind posting it? If not, do you a parts list for this?

 

[BDB]

My 9 year-old daughter, who is a certifiable Lego fanatic, decided to make a jig to help her brother build his BT-60 rocket. I showed her the pics from this thread, and she went to work in her Lego lab. She didn't have enough sloped pieces to build both halves of the guillotine (without breaking up her other creations), so she improvised a little. It works great!

 

[barn]

Genius! Way Cool..
My hat's off to you Sir.

Was this conceived using LegoCAD? If so, mind posting it? If not, do you a parts list for this?

I don't use Lego CAD programs. The jig is built with pieces of different color so I would think you can copy the design from the pictures. if you want me to take some more pics of some aspect of the structure let me know.

 

[barn]

My 9 year-old daughter, who is a certifiable Lego fanatic, decided to make a jig to help her brother build his BT-60 rocket. I showed her the pics from this thread, and she went to work in her Lego lab. She didn't have enough sloped pieces to build both halves of the guillotine (without breaking up her other creations), so she improvised a little. It works great!
View attachment 335503

That's awesome! Lego is so accurate your daughter didn't even need to make the "V" groove, the Lego studs line up everything for you. plus it's easy to customize for bigger, smaller, big fin, small fin, longer or shorter rockets.

 

[neil_w]

I don't use Lego CAD programs. The jig is built with pieces of different color so I would think you can copy the design from the pictures. if you want me to take some more pics of some aspect of the structure let me know.

I admit I'm not still 100% clear how the vertical spacer pieces are held into the little clampy things.

This whole thread really does make me want to try this, although I don't know if I'd be able to scam those pieces from my daughter's (extensive) collection. The cool thing is that it would be so easy to try out all different variations, and even customize for the needs of a particular model.

Although I would definitely be tempted to whip out the Kragle to secure some parts of it.

 

[barn]

I admit I'm not still 100% clear how the vertical spacer pieces are held into the little clampy things.

This whole thread really does make me want to try this, although I don't know if I'd be able to scam those pieces from my daughter's (extensive) collection. The cool thing is that it would be so easy to try out all different variations, and even customize for the needs of a particular model.

Although I would definitely be tempted to whip out the Kragle to secure some parts of it.

I'll take some better pictures if I get time tonight. The vertical spacers are scrap balsa (with the same thickness as your fin) wedged into the "V" groove or "little clampy thing. The binder clips and aluminum angles then hold them in place. The Lego part used is not that common:
https://www.bricklink.com/v2/catalog/catalogitem.page?P=26047#T=C
but you can easily buy pieces from the bricklink site. Bricklink will also show you which Lego sets you can find the piece in, then you can show the list to your daughter and ask her if she has any of those sets. All the other pieces are quite common.

Just say NO to the Kragle if you want to be able to customize it. ...or you might have to give the pieces back to your daughter when she finds out you scammed them.

 

[barn]

I don't understand why the link in post #19 doesn't seem to work but the link in post #5 does work. If you want to see the Lego part, check out the link in post #5.

 

[K'Tesh]

A way to carefully align your fins all while torturing yourself (or others)...

While I love Legos, I sure hate stepping barefoot on the damned things.

 

[neil_w]

I don't understand why the link in post #19 doesn't seem to work but the link in post #5 does work. If you want to see the Lego part, check out the link in post #5.

It's because in the post 19, you seem to have copy/pasted from the displayed text in post 5. The forum shortens display of URLs, so you essentially copied a corrupted URL. Visually, it all looks the same, but if you hold the mouse over the links in the two posts you'll see they're pointing differently.

To do it correctly you would want to right click and "Copy link address" from the link in post 5 and then paste to wherever.

 

[barn]

the guillotine blade with "V" groove:



the black and yellow bricks are there to help align the fin line you've drawn on the rocket tube.

 

[barn]

scrap balsa in "V" groove shown with one of the aluminum angles. I used a 0.75" x 0.5" aluminum angle with the 0.75" side as the vertical holding the fin and the 0.5" side horizontal against the Lego. The jig would need to be built wider if larger aluminum angle was used.

 

[barn]

It's because in the post 19, you seem to have copy/pasted from the displayed text in post 5.

yes, that's what I did. Thanks for the help.

 

[barn]

guillotine blade can be built to accommodate shorter fins:

 

[Tobor]

@Barn: Thx for the pictorial. Looks like it would easily scale to accommodate any fin/airframe combo.