Loc-Precision BT question

Loc-Precision BT question

Post by Rose Michael » Mon, 17 Apr 2000 04:00:00



I just recently bought a Loc-Precision body tube
that is 3.9 in diameter and 34 inches long, But
it isn't slotted, Can I get away with unslotted tube and still hang on
to my fins under a E or G
engine?!? Help!!!!

               James

 
 
 

Loc-Precision BT question

Post by BJames » Tue, 18 Apr 2000 04:00:00


Quote:
>I just recently bought a Loc-Precision body tube
>that is 3.9 in diameter and 34 inches long, But
>it isn't slotted, Can I get away with unslotted tube and still hang on
>to my fins under a E or G
>engine?!?

With good glue fillets, the fins should stay on.  However, it isn't that hard
to slot the tubes using a sharp Xacto knife.  The edges of the cut don't have
to be perfect, since they will be covered by the glue fillets anyway.

 
 
 

Loc-Precision BT question

Post by Paul Dimin » Tue, 18 Apr 2000 04:00:00


I'd go to the extra effort to slot the fins so that you can take advantage
of a TTW fin mount which is much stronger than a traditional approach.  It
really isn't that hard.  Just be careful when you're measuring where to
place the slots.  You'll be able to cut them out with a hobby knife.  One
person on RMR suggested that you could glue on some paper cut to the size of
the slot.  Make sure you measured and positioned the paper correctly.  Then
just cut out the BT with a hobby knife following the edge of the paper.

Paul.


Quote:
> I just recently bought a Loc-Precision body tube
> that is 3.9 in diameter and 34 inches long, But
> it isn't slotted, Can I get away with unslotted tube and still hang on
> to my fins under a E or G
> engine?!? Help!!!!

>                James

 
 
 

Loc-Precision BT question

Post by RTaylor6 » Wed, 19 Apr 2000 04:00:00


Hi Rose, It is worth the extra effort to slot the body tube and epoxy the fins
to the motor tube. I have built and flown a LOC IV
(the kit BT is slotted) on the original plans the fins are mounted through the
tube but not to the motor tube. The first flight landed on a paved road
snapping 2 fins off. I then traced the original fin pattern with an extension
tab to the motor tube, works great, very strong.    Bob.
 
 
 

Loc-Precision BT question

Post by Steven Piett » Thu, 20 Apr 2000 04:00:00


Quote:

> I just recently bought a Loc-Precision body tube
> that is 3.9 in diameter and 34 inches long, But
> it isn't slotted, Can I get away with unslotted tube and still hang on
> to my fins under a E or G
> engine?!? Help!!!!

>                James

As others has suggested slot the tube, it will take you about 5 min each with
a fresh new blade. Are you planning on using the whole 34" length?
If so I think you'll find E's underpowered. Most of my 4" rockets fly on F40's
or bigger. Oops, your on webtv. I was going to suggest you download rocksim
and simulate your plans before finding out the hard way.

--
Steve Piette                                       Applied Computer Technology

(630) 513-6920                                     St. Charles, IL 60175-6868
-------------------------------------------------------------------------------

 
 
 

Loc-Precision BT question

Post by kdray.. » Fri, 21 Apr 2000 04:00:00


Quote:

>> I just recently bought a Loc-Precision body tube
>> that is 3.9 in diameter and 34 inches long, But
>> it isn't slotted, Can I get away with unslotted tube and still hang on
>> to my fins under a E or G
>> engine?!? Help!!!!

>>                James

James, provided you reinforce the fins sufficiently, you don't need to
mount the fins TTW for E-G motors. Just be sure to fillet those fins
well, and you'll be fine. Heck, the strakes on my NCR Archer are
surface mounted, and she flew fine on an H. Also, it isn't necessarily
so much the size of the motor you use, as it is the speed the rocket
will reach. Higher speeds will obviously put greater stress on the
fins. Even then, surface-mounting may still be sufficient (for
example, I have a 24mm minimum diameter ship that tops out at just
over Mach 1 on an E30. The fins are surface mounted (obviously), and
I've had to trouble yet!)

Kevin Drayson
CAR #S369
Atlantic Director, Canadian Association of Rocketry

 
 
 

Loc-Precision BT question

Post by Bob Kapl » Fri, 21 Apr 2000 04:00:00



Quote:
> I just recently bought a Loc-Precision body tube
> that is 3.9 in diameter and 34 inches long, But
> it isn't slotted, Can I get away with unslotted tube and still hang on
> to my fins under a E or G
> engine?!? Help!!!!

Lots of good responses so far. I just wanted to add that LOC and other HPR
manufacturers DO sell preslotted tubes.

        Bob Kaplow      NAR # 18L       TRA # "Ctrl-Alt-Del"

Kaplow Klips:   http://members.aol.com/myhprcato/KaplowKlips.html (baffle too!)
NIRA:           http://www.nira.chicago.il.us  NAR:    http://www.nar.org

 
 
 

Loc-Precision BT question

Post by Bill Nelso » Sun, 23 Apr 2000 04:00:00



: I just recently bought a Loc-Precision body tube
: that is 3.9 in diameter and 34 inches long, But
: it isn't slotted, Can I get away with unslotted tube and still hang on
: to my fins under a E or G
: engine?!? Help!!!!

With careful construction, there is no reason why surface mounting will not
stand the acceleration.

I have launched H238 motors in my Lil' Nuke.  20+ launches and still no
sign of failure.  They were surface mounted without pinholes or anything
else that will weaken the tube.

--

 
 
 

Loc-Precision BT question

Post by Tom Binfor » Sun, 23 Apr 2000 04:00:00


Quote:


> : I just recently bought a Loc-Precision body tube
> : that is 3.9 in diameter and 34 inches long, But
> : it isn't slotted, Can I get away with unslotted tube and still hang on
> : to my fins under a E or G
> : engine?!? Help!!!!

> With careful construction, there is no reason why surface mounting will not
> stand the acceleration.

> I have launched H238 motors in my Lil' Nuke.  20+ launches and still no
> sign of failure.  They were surface mounted without pinholes or anything
> else that will weaken the tube.

You do need to remove the glassine coating in the area where the epoxy
will be.

Tom