AT Initiator on D 12 -4's ?

AT Initiator on D 12 -4's ?

Post by DR Johnsto » Sat, 05 Jul 1997 04:00:00



Has anyone tried their Initiator on D-12-4 's?

Dave  Johnston--

d
rj
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AT Initiator on D 12 -4's ?

Post by DR Johnsto » Sat, 05 Jul 1997 04:00:00


I meant D-12-5's
--

d
rj
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Quote:
> Has anyone tried their Initiator on D-12-4 's?

> Dave  Johnston--

> d
> rj
> ||\
> |||\
> ::
> :::
> ::::


 
 
 

AT Initiator on D 12 -4's ?

Post by Foxe » Sat, 05 Jul 1997 04:00:00


Quote:

>I meant D-12-5's
>::::

>> Has anyone tried their Initiator on D-12-4 's?

>> Dave  Johnston--


I definetly would not recommend it.  Even LOC's Lil Nuke, barely gets
up enough to deploy the chute before it hits the ground.  The AT e-15
or 18 is at least the minimum motor  for this kit.  If you want to try
D's you should have bought the Mustang, its supposed to fly on D's AT
that is.  With a finished weight of between 14 and 16 oz, and a D12-5
it is about 170 feet average, and approx 38 FPS launchrod vel, which
should be ok at that speed.  It would be chancy for sure.  

By sending unsolicited commercially-oriented e-mail to this address, the
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AT Initiator on D 12 -4's ?

Post by Bob Kapl » Sat, 05 Jul 1997 04:00:00


Quote:

> I meant D-12-5's

It's awful under powered on a D12-5. A D12-3 would be a better choice. If
you ever use an extes motor in any kit that has the wire mesh baffle, clean
the baffle after EVERY such flight. All that clay crud can plug up a baffle
VERY fast. Then its Prang Crunch Ouch!

        Bob Kaplow      NAR # 18L       TRA # "Abort, Retry, Fail?"

 
 
 

AT Initiator on D 12 -4's ?

Post by DR Johnsto » Sat, 05 Jul 1997 04:00:00


AltPred says....

**************************************
***** ALTPRED Copyright (c) 1995 *****
*****   Forge Village Software   *****
**************************************

Air density CF   =      1.000

Number of stages =          1

Lift-off weight  =     15.520 oz
Total burn time  =      1.700 sec

*** Stage 1 ***

Engine type: D12-5 [1 engine(s)]

Engine weight:           1.520 oz
Propellant:              0.879 oz
Average thrust:         43.146 oz
Thrust duration:         1.700 sec

Rocket weight:          14.000 oz
Rocket diameter:         2.600 in
Rocket drag coef.:       0.750

Burnout altitude:                 83.859 ft
Burnout velocity:                 95.674 ft/sec
Altitude gained after burnout:   122.982 ft
Coast time:                        2.700 sec

Total altitude:                  206.841 ft
Peak altitude time:                4.400 sec

----------------------- Cut Here -----------------------

      Time        Altitude        Velocity

       0.0           0.000           0.000
       0.1           0.299           5.986
       0.2           1.197          11.965
       0.3           2.692          17.927
       0.4           4.782          23.865
       0.5           7.464          29.772
       0.6          10.735          35.639
       0.7          14.590          41.459
       0.8          19.025          47.226
       0.9          24.033          52.932
       1.0          29.609          58.570
       1.1          35.745          64.135
       1.2          42.434          69.620
       1.3          49.667          75.020
       1.4          57.435          80.330
       1.5          65.730          85.546
       1.6          74.541          90.662
       1.7          83.859          95.674
       1.8          93.208          91.446
       1.9         102.145          87.305
       2.0         110.672          83.247
       2.1         118.797          79.266
       2.2         126.528          75.358
       2.3         133.871          71.517
       2.4         140.834          67.739
       2.5         147.421          64.020
       2.6         153.640          60.355
       2.7         159.494          56.741
       2.8         164.990          53.175
       2.9         170.131          49.652
       3.0         174.922          46.169
       3.1         179.366          42.723
       3.2         183.468          39.311
       3.3         187.229          35.930
       3.4         190.655          32.577
       3.5         193.746          29.249
       3.6         196.505          25.944
       3.7         198.935          22.658
       3.8         201.038          19.390
       3.9         202.814          16.136
       4.0         204.265          12.894
       4.1         205.393           9.662
       4.2         206.198           6.437
       4.3         206.680           3.217

 
 
 

AT Initiator on D 12 -4's ?

Post by DR Johnsto » Sat, 05 Jul 1997 04:00:00


Will 23.8 mph be fast enough for stable flight. Sounds too slow.
Maybe I need an eight foot rod.[tower]

According to AltPred.......

**************************************
***** ALTPRED Copyright (c) 1995 *****
*****   Forge Village Software   *****
**************************************

Air density CF   =      1.000

Number of stages =          1

Lift-off weight  =     15.520 oz
Total burn time  =      1.700 sec

*** Stage 1 ***

Engine type: D12-5 [1 engine(s)]

Engine weight:           1.520 oz
Propellant:              0.879 oz
Average thrust:         43.146 oz
Thrust duration:         1.700 sec

Rocket weight:          14.000 oz
Rocket diameter:         2.600 in
Rocket drag coef.:       0.750

Burnout altitude:                 83.859 ft
Burnout velocity:                 95.674 ft/sec
Altitude gained after burnout:   122.982 ft
Coast time:                        2.700 sec

Total altitude:                  206.841 ft
Peak altitude time:                4.400 sec

----------------------------------------------

      Time        Altitude        Velocity

       0.0           0.000           0.000
       0.1           0.299           5.986
       0.2           1.197          11.965
       0.3           2.692          17.927
       0.4           4.782          23.865
       0.5           7.464          29.772
       0.6          10.735          35.639
             <cut>

a 200 ft. flight would be cool enough but I don't really want to crash this
bird.

--
Dave Johnston

d
rj
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::
:::
::::

 
 
 

AT Initiator on D 12 -4's ?

Post by The Silent Observe » Sun, 06 Jul 1997 04:00:00


Quote:

> Will 23.8 mph be fast enough for stable flight. Sounds too slow.
> Maybe I need an eight foot rod.[tower]

Should be okay, providing there's no wind.  Don't be afraid to scrub if
there's even the slightest breeze, though; a big weathercock on a low
flight like this one will be enough to ruin your day -- not to mention
your Initiator...

Note, also, that the max liftoff weight of the D12-3 is 14 ounces, but
that of the D12-5 is less...

Quote:

> Lift-off weight  =     15.520 oz
> Total burn time  =      1.700 sec

<snip>

Quote:

> Burnout altitude:                 83.859 ft
> Burnout velocity:                 95.674 ft/sec
> Altitude gained after burnout:   122.982 ft
> Coast time:                        2.700 sec

> Total altitude:                  206.841 ft
> Peak altitude time:                4.400 sec

<snip>

Quote:

> a 200 ft. flight would be cool enough but I don't really want to crash this
> bird.

Just don't launch in any kind of wind at all...and use the D12-3 instead
of the D12-5.  That peak alt time of 4.4 seconds includes the 1.7 second
burn...

--
See, the ability of the brain to interpret _text_ is learned behavior,
no older than the pyramids.  But the brain has been interpreting
_pictures_ from _in_front_.  Much older circuitry, much faster traffic
flow, much more information density.  -- The Nazz

Donald Qualls, aka The Silent Observer           NAR # 70141-SR Insured

Rocket Pages              http://members.aol.com/silntobsvr/modrocs.htm

Opinions expressed are my own -- take them for what they're worth
and don't expect them to be perfect.

 
 
 

AT Initiator on D 12 -4's ?

Post by DR Johnsto » Sun, 06 Jul 1997 04:00:00


I'm not trying to set some kinda record for the number of replys to ones
self :) but here goes..........

I remembered overnight that velocity in AltPred is measured in feet per
second, so the corrected question remains.........is 20 ft/sec fast enough
(13.63 mph) off the rod? Seems to me I remember 30 mph mentioned(or was
FPS?) at some point.
--

d
rj
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|||\
::
:::
::::

<big snip>

 
 
 

AT Initiator on D 12 -4's ?

Post by Foxe » Sun, 06 Jul 1997 04:00:00


Yes, 20 fps is to slow....need it in the 30's say 35+ fps or so.
I figured your stats on alticalc and it gave me 33 fps with a weight
of 16oz,  if I remember correctly....but the altitude is still around
170 ft.  Kinda risky, under anything but "Ideal" conditions.......why
is it you want to use a D motor, is your flying field too small?   An
AT E-154W takes it up pretty decent about 450 to 500 feet, and if you
reef your parachutes shroud lines somewhat you should be able to
recover in a smaller area.  We have launched my sons AT on E15-4's and
reefed the shroudlines about 1/2 the length and can launch and recover
in an area as small as 1/2 football field or about say 1 to 1 1/2
acres

Quote:

>I'm not trying to set some kinda record for the number of replys to ones
>self :) but here goes..........

>I remembered overnight that velocity in AltPred is measured in feet per
>second, so the corrected question remains.........is 20 ft/sec fast enough
>(13.63 mph) off the rod? Seems to me I remember 30 mph mentioned(or was
>FPS?) at some point.
>--

>d
>rj
>||\
>|||\
>::
>:::
>::::

><big snip>


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sender agrees to pay a $100 flat fee to the recipient for proofreading
services.  Take the www out of address to send email.
 
 
 

AT Initiator on D 12 -4's ?

Post by DR Johnsto » Mon, 07 Jul 1997 04:00:00


interested mostly because of a small field right out the backdoor where
B-6-4's on my Astrocam are just right...... launching on F's requires me
packing up and going somewhere.
And sounds like a D-12-3 would be the obvious choice if I wan't to try it.
Thanks for the response

Dave Johnston

--

d
rj
||\
|||\
::
:::
::::

Foxeye wrote
<snip, snip>  why

Quote:
> is it you want to use a D motor, is your flying field too small?   An
> AT E-154W takes it up pretty decent about 450 to 500 feet, and if you
> reef your parachutes shroud lines somewhat you should be able to
> recover in a smaller area.  We have launched my sons AT on E15-4's and
> reefed the shroudlines about 1/2 the length and can launch and recover
> in an area as small as 1/2 football field or about say 1 to 1 1/2
> acres

 
 
 

AT Initiator on D 12 -4's ?

Post by DR Johnsto » Mon, 07 Jul 1997 04:00:00


The Silent Observer wrote in article

Quote:

> <snip> <snip>
> Just don't launch in any kind of wind at all...and use the D12-3 instead
> of the D12-5.  That peak alt time of 4.4 seconds includes the 1.7 second
> burn...

 Thanks, TSO,......No wind..... D12-3.....I'll give 'er a shot and will
report.
 
 
 

AT Initiator on D 12 -4's ?

Post by Bob Kapl » Mon, 07 Jul 1997 04:00:00


Quote:

> interested mostly because of a small field right out the backdoor where
> B-6-4's on my Astrocam are just right...... launching on F's requires me
> packing up and going somewhere.
> And sounds like a D-12-3 would be the obvious choice if I wan't to try it.

If you're looking for D alternatives, consider either the D13-4, E25-4, or
D15-4 reloads. All would require the use of an adapter, the first two a 18mm
to 29mm, and the latter a more common 24mm to 29mm adapter.

I've built a 18mm to 29mm adapter for just such flights. I've got several
rockets that fly fine on the D13 reload even thou they have 29mm motor
mounts in them. The list includes my Graduator, my 3X Sprite, and a few
scratch models that are under a pound. The adaptor itself is a 5" length of
HD BT-20 (I got this from the MARS section a while back, BT-20 with a wrap
of glass would do as an alternate), two custom cut centering rings, and a
stop ring against the aft centering ring that functions in place of the tape
ring, plus it has 2 slots cut in the ring for the Kaplow Klips to grab. All
the rings are cut from 1/4" SIG Lite ply, as I'm more interested in contact
area than the ultimate strength in this case. The adapter itself has a
standard questes motor clip, with the forward end filed down to clear the
red cap on the reload.

BTW, the D24-4 would be on this list too if it were certified...

        Bob Kaplow      NAR # 18L       TRA # "Abort, Retry, Fail?"

 
 
 

AT Initiator on D 12 -4's ?

Post by john.w. lyngd » Wed, 09 Jul 1997 04:00:00


Quote:


>Subject: AT Initiator on D 12 -4's ?
>Date: 4 Jul 1997 03:14:29 GMT
>Has anyone tried their Initiator on D-12-4 's?
>Dave  Johnston--

Dave,

        I flew my LOC Lil' Nuke on a D12-3 once and it wasn't worth the effort of
packing the parachute(IMHO).

        John Lyngdal
        NAR 69264 Level L