What engines does the LOC Forte use?

What engines does the LOC Forte use?

Post by Joe Cacciato » Sun, 03 Sep 2000 01:51:21



I don't have the sheet that came with my Forte. Anyone have the list
of 29 mm engines reccomented by LOC for the Forte? Thank you.

Joe C.

 
 
 

What engines does the LOC Forte use?

Post by GaryKinnam » Sun, 03 Sep 2000 02:19:57


Quote:

>I don't have the sheet that came with my Forte. Anyone have the list
>of 29 mm engines reccomented by LOC for the Forte? Thank you.

According to my latest LOC catalog, it lists a F50-6 and a G40-7.

Gary Kinnamon   NOVAAR

 
 
 

What engines does the LOC Forte use?

Post by Joe Cacciato » Sun, 03 Sep 2000 03:25:45


Thanks, Gary. By the way, does it say predicted height? I am planning
to fly mine for the first time this weekend and  want to impress some
people but I won't if I loose it. I would guess the F50 is around 600'
and the G40 at 900' but it would be nice to know for sure.

Joe C.



Quote:

>>I don't have the sheet that came with my Forte. Anyone have the list
>>of 29 mm engines reccomented by LOC for the Forte? Thank you.

>According to my latest LOC catalog, it lists a F50-6 and a G40-7.

>Gary Kinnamon   NOVAAR

 
 
 

What engines does the LOC Forte use?

Post by GaryKinnam » Sun, 03 Sep 2000 05:03:01


Quote:
>Thanks, Gary. By the way, does it say predicted height? I am planning
>to fly mine for the first time this weekend and  want to impress some
>people but I won't if I loose it. I would guess the F50 is around 600'
>and the G40 at 900' but it would be nice to know for sure.

>Joe C.

The catalog says "Impressive fllights to over 1500 ft. can be reached using a G
motor."  That's all there is.  It's too bad their website doesn't give
predicted altitudes for different rocket/engine combinations, as does the PML
site.

Gary Kinnamon      NOVAAR
===================

Quote:


>>>I don't have the sheet that came with my Forte. Anyone have the list
>>>of 29 mm engines reccomented by LOC for the Forte? Thank you.
>>According to my latest LOC catalog, it lists a F50-6 and a G40-7.

>>Gary Kinnamon   NOVAAR

 
 
 

What engines does the LOC Forte use?

Post by Jackbear » Sun, 03 Sep 2000 08:24:40


Quote:
>I don't have the sheet that came with my Forte. Anyone have the list
>of 29 mm engines reccomented by LOC for the Forte?

It also flies well on an F40-4 reload, and a G80-7.  Mine, with an extra
centering ring to make an ejection baffle, and internal epoxy fillets on the
fin roots (on the inside of the tube, put on before the aft CR), and more shock
cord, also flies well on an H180-10, and an I200-14. But be prepared for a long
walk if you launch it on the I200.
Jack W. Kale, Jr. NAR #70384 Insured, Tripoli #5798 Level 2

Timmy, you can't take it with you, so if you have a sandwich and your blue
jeans, chill. Your old man, Paul. (1st century, paraphrased)

 
 
 

What engines does the LOC Forte use?

Post by daz.. » Sun, 03 Sep 2000 10:14:57


Quote:

> It's too bad their website doesn't give predicted altitudes for
> different rocket/engine combinations, as does the PML site.

Has anyone noticed that manufacturers' estimates seem to be all over
the map? PML's altitude predictions often seem over-optimistic,
while the "recommended max. liftoff weights" for Aerotech model rocket
motors sometimes seem over-conservative.

A few examples... G-wiz readings vs. kit mfr's predictions
on my PML X-Calibur:
Motor    predicted   actual
G80-7T   1274        973
H128W-M  1825        1399

Another: For the F25-W motor (29mm single use), the recommended max.
weights are 24, 18, and 12.3 oz. for the 4, 6, and 9 second delays.
However, my PML Cirrus Dart (22oz. ready to launch with F motor)
flew quite nicely on an F25-9W - with ejection way up near apogee.
(I suspect that Aerotech was assuming a rocket with more drag and
less "coast" when they made those figures.)

Another: my LOC Norad... LOC recommends F60-6 (is there such a
motor anymore?) or F40-6, and it flew real nice on the F50-6T...
lots of altitude (not measured) - ejection way up there. Liftoff weight
was 24oz.; AT recommends max. 20oz. for this motor. (Judging by the
F50 flight, I'm suspecting that it would actually fly well on an
E30-4T, despite the AT weight rating of 16oz. for that motor.)

-dave w

Sent via Deja.com http://www.deja.com/
Before you buy.

 
 
 

What engines does the LOC Forte use?

Post by Claude Paqui » Sun, 03 Sep 2000 10:25:09



Quote:

> >I don't have the sheet that came with my Forte. Anyone have the list
> >of 29 mm engines reccomented by LOC for the Forte? Thank you.

> According to my latest LOC catalog, it lists a F50-6 and a G40-7.

> Gary Kinnamon   NOVAAR

I have used my LOC Forte for my level 1 certification.  I have flown it on
an F50-6 at first and if I remember correctly the ejection occured after
apogee.  I then flew it on a G80-7 for a great fligth and on a H55 for a
successful level-1 cert.  Since then I have flown it on a G125-10 and I am
planning to fly it this fall on a H180.  This is a great kit and you should
not be affraid to fly it on G motors.

Claude

 
 
 

What engines does the LOC Forte use?

Post by L.C. » Sun, 03 Sep 2000 22:02:51


Regarding the short altitude:

Manufacturers' altitude estimates are notoriously high. Nevertheless,
out of curiosity, how do your actual liftoff weights compare with the
manufacturer's quoted (typically low) weights?  Was the weight
measured just before launch? Also, were your launches vertical?
How fast was the wind? How many times did you measure the
altitude? What year was the motor manufactured.

I've seen *average* impulse ratings vary 17% from one year to
the next on several motors. Don't know if this reflects design
changes over time, bad QA, small N and bad sampling by
testers, any two, or all three.

If the average varies this much, one would expect individual
specimens to vary more. How you gunna predict when the
system itself is unpredictable?

Regards,
-Larry (Rocketeer on sabbatical) C.

Quote:


> > It's too bad their website doesn't give predicted altitudes for
> > different rocket/engine combinations, as does the PML site.

> Has anyone noticed that manufacturers' estimates seem to be all over
> the map? PML's altitude predictions often seem over-optimistic,
> while the "recommended max. liftoff weights" for Aerotech model rocket
> motors sometimes seem over-conservative.

> A few examples... G-wiz readings vs. kit mfr's predictions
> on my PML X-Calibur:
> Motor    predicted   actual
> G80-7T   1274        973
> H128W-M  1825        1399

> Another: For the F25-W motor (29mm single use), the recommended max.
> weights are 24, 18, and 12.3 oz. for the 4, 6, and 9 second delays.
> However, my PML Cirrus Dart (22oz. ready to launch with F motor)
> flew quite nicely on an F25-9W - with ejection way up near apogee.
> (I suspect that Aerotech was assuming a rocket with more drag and
> less "coast" when they made those figures.)

> Another: my LOC Norad... LOC recommends F60-6 (is there such a
> motor anymore?) or F40-6, and it flew real nice on the F50-6T...
> lots of altitude (not measured) - ejection way up there. Liftoff weight
> was 24oz.; AT recommends max. 20oz. for this motor. (Judging by the
> F50 flight, I'm suspecting that it would actually fly well on an
> E30-4T, despite the AT weight rating of 16oz. for that motor.)

> -dave w

> Sent via Deja.com http://www.deja.com/
> Before you buy.

 
 
 

What engines does the LOC Forte use?

Post by Ron Zeppi » Sun, 03 Sep 2000 23:53:18


I flew mine twice on a Kosdon I-800. Rocket held up fine.  I built it
bone stock, except for dousing the inside fin tabs with epoxy.
Recommended delay is around 10 seconds or so, maybe 12. I painted mine
with fleckstone paint, which is REALLY rough. I think the Cd on my
Forte' was around .9 or so. I had a brain fart and stuck a 16 second
delay in it...needless to say, the ejection charge fired on the ground.
I knew 16 was a bit long, but I failed to take into account just how
much drag that paint causes! Oh well...If the thing goes straight, it
should hold up to almost anything!

Ron

Quote:

> I don't have the sheet that came with my Forte. Anyone have the list
> of 29 mm engines reccomented by LOC for the Forte? Thank you.

> Joe C.

--
Ron Zeppin
Access Rocketry
http://www.accessrocketry.com
TRA# 6024
AHPRA
XRAA
 
 
 

What engines does the LOC Forte use?

Post by Alan Jon » Thu, 07 Sep 2000 09:21:29


Quote:


>> It's too bad their website doesn't give predicted altitudes for
>> different rocket/engine combinations, as does the PML site.

>Has anyone noticed that manufacturers' estimates seem to be all over
>the map? PML's altitude predictions often seem over-optimistic,
>while the "recommended max. liftoff weights" for Aerotech model rocket
>motors sometimes seem over-conservative.

>A few examples... G-wiz readings vs. kit mfr's predictions
>on my PML X-Calibur:
>Motor    predicted   actual
>G80-7T   1274        973
>H128W-M  1825        1399
>-dave w

Always take manufacturers performance claims with a grain of salt.  I
think PML's altitude claims are based on Rocksim rather than tracked
flights.  They may make optomistic assumptions when using Rocksim, but
they maintain thier Rocksim files on thier Web site, so you can see
exactly what they used.

Alan Jones

 
 
 

What engines does the LOC Forte use?

Post by Andy Waddel » Thu, 07 Sep 2000 09:23:00


Alan, you're exactly right. We use RockSim as our tool because it's one
that's readily available and that many modelers have. As I've said many
times, real-life conditions in flight like temperature, launch site
altitude, humidity, launch lug drag on the rod, winds (a biggie) and
(another biggie)
variation in motor performance from the "perfect motor" RockSim uses are
going to affect the real flight, sometimes substantially. Motor performance
can vary up to 15% from manufacturer's specs and still achieve TMT
certification according to Sue McMurray; I presume NAR is similar. Also, the
user's ignition technique
and/or device can make a big difference as well. A motor chuffing a bit on
the pad can make a big difference in an actual flight performance vs. the
simulation which of course "perfectly ignites" every time.

RockSim (or any simulator) is just that, a simulation, so use it as a guide,
not a gospel. We've provided the information to assist our customers in
motor and delay selection, but everyone needs to understand that it is
indeed only a simulation. However, since we do use RockSim for all our
simulations, and also include the files we use as you noted, the individual
modeler can download the files and run their own sims for the flight
conditions they usually experience. As noted on the front page of our Motor
Recommendations Chart:

"All data was produced from RockSim 4.0 simulation software with 500'
elevation launch site, 70% humidity, 75 deg. F, 0 mph wind, 0 deg launch rod
angle."

These are clearly relatively "perfect" conditions to allow repeatability in
producing our charts. Sure, 0 mph wind might be unrealistic for most
people's flying conditions, but what is "realistic"? Depending on your
regular launch sites, anything from 2 to 20 mph might be a typical wind
condition you're flying in. So, the only "fair" way for us to produce the
chart is to set it at the known/published conditions, and leave it to the
user's experience (or THEIR copy of RockSim) to make adjustments to the data
we provide as they deem prudent.

--
Andrew D. Waddell
PML Online Support Rep
TRA 2043 L2/NAR 52875 L2

PML: www.publicmissiles.com

Quote:


> >> It's too bad their website doesn't give predicted altitudes for
> >> different rocket/engine combinations, as does the PML site.

> >Has anyone noticed that manufacturers' estimates seem to be all over
> >the map? PML's altitude predictions often seem over-optimistic,
> >while the "recommended max. liftoff weights" for Aerotech model rocket
> >motors sometimes seem over-conservative.

> >A few examples... G-wiz readings vs. kit mfr's predictions
> >on my PML X-Calibur:
> >Motor    predicted   actual
> >G80-7T   1274        973
> >H128W-M  1825        1399

> >-dave w

> Always take manufacturers performance claims with a grain of salt.  I
> think PML's altitude claims are based on Rocksim rather than tracked
> flights.  They may make optomistic assumptions when using Rocksim, but
> they maintain thier Rocksim files on thier Web site, so you can see
> exactly what they used.

> Alan Jones