Ye Olde Rocket Forum

Go Back   Ye Olde Rocket Forum > Semroc > SVDT - Semroc Virtual Design Team
User Name
Password
Auctions Register FAQ Members List Calendar Today's Posts Search Mark Forums Read


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 01-05-2007, 04:48 PM
Mark+3 Mark+3 is offline
Intermediate Rocketeer
 
Join Date: Jan 2007
Posts: 45
Default Initial Motor Requests

What motors would everyone like to see Semroc release first?

Carl: "The order of release will be based on discussions here. The smaller 18mm and under machine is being built first. Engines over 70mm long or over 18mm in diameter will be done on the larger machine."

Carl: "The absence of 1/2A and A boosters is a good example of why there is little new or innovative kits to use low power boosters. The places available to fly two-stage rockets with a minimum of a C6-0 is growing smaller all the time. If the C6 was a C12 or C20, at least you could do low altitude two-stage rockets with heavier designs. That is just my opinion. I always liked two-stage rockets that you could see and recover. I also liked the B14-0 because I could make the rocket a little heavier."

13mm 1/2A and A boosters, 18mm A and B power boosters are first on my wish list.
Obviously the B-14 is in high demand as I don't believe a day goes by that someone doesn't publicly mourn it's absence
Reply With Quote
  #2  
Old 01-05-2007, 06:13 PM
Royatl's Avatar
Royatl Royatl is offline
SPEV/Orion wrangler
 
Join Date: Mar 2005
Location: Atlanta, GA
Posts: 2,645
Default

Quote:
Originally Posted by Mark+3
What motors would everyone like to see Semroc release first?13mm 1/2A and A boosters, 18mm A and B power boosters are first on my wish list.
Obviously the B-14 is in high demand as I don't believe a day goes by that someone doesn't publicly mourn it's absence


Definitely with the 13mm motors. I'd like to be able to fly the Fire Fly! and I'd like to be able to build and fly a Midget.
__________________
Roy
nar12605
Reply With Quote
  #3  
Old 01-05-2007, 06:18 PM
CPMcGraw's Avatar
CPMcGraw CPMcGraw is offline
BARCLONE Rocketry
 
Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,357
Default

I highly agree -- 13mm boosters, 18mm A and B boosters, and better variety of power choices among both 13mm and 18mm A and B single-stage motors. "C" class is nice, but I'm not able to take advantage of them as much where I fly.
__________________
Craig McGraw

BARCLONE Rocketry -- http://barclone.rocketshoppe.com
BARCLONE Blogsite -- http://barclone.wordpress.com
BARCLONE Forum -- BARCLONE Forum

BARs helping BARs

SAM 0044
AMA 352635
Reply With Quote
  #4  
Old 01-05-2007, 06:24 PM
Doug Sams's Avatar
Doug Sams Doug Sams is offline
Old Far...er...Rocketeer
 
Join Date: Mar 2005
Location: Plano, TX resident since 1998.
Posts: 3,965
Default

Quote:
Originally Posted by Mark+3
What motors would everyone like to see Semroc release first?
While making motors equivalent to the commonly available, medium thrust motors already out there makes sense in the long run, I'd say that the differentiated products should be first. 29mm cored BP motors - woo hoo! I never go to play with any of these (eg, F100, et al) but I am chomping at the bit.

Likewise, I want to see cored 24mm versions, too. D30, E40. In 18mm, a C20 to go with the B14 (if it's possible...to fit in that much impulse/powder along with a deep core).

If the reliability problems of cored motors can be solved/avoided, then it's possible to position these fast burn/high thrust motors against medium thrust motors. IOW, almost any rocket than can fly on a B6-6 can fly on a B14-6 without adverse consequences. So a high thrust motor can be sold into mainstream applications as well as heavy lift.

OTOH, while low thrust motors are fun, they can't cross over into medium thrust applications without lots of complaints and/or warrany claims. So the high thrust motors should have the best potential for getting a return on investment in a timely fashion. IOW, save the low-thrust and medium thrust motors for later.

I wonder about reliability and cost. I've heard that some large BP motors had fiberglass cases. If that's what it takes, then I wonder if the added cost will pose retail price problems. I'm willing to pay extra, but I worry about others.

Seeing Carl's old catalog along with the AVI motors, the idea of adjustable delays is stuck in my head. If I understand it correctly, a booster motor plus DECAP makes a delay motor, right? Will it be possible for the user to trim the delay before gluing it in? Will it even be sold in pieces to allow that?

The potential beauty of this is that only two pieces are required (plus glue) to make a myriad of delay options. Looking at Aerotech thru an accountant's eyes, I was able to learn the huge costs they have tied up in delays and delay spacers. They have over 20 of each for their 29 and 38mm motors. Cesaroni has 1. They use the same delay grain in all 38's and (I think) 54's. It may be 13 secs in one motor and a 15 in another, but it's the same delay. 1 inventory item. (BTW, with BP motors, there will be no variations due to motor burn pressure since the delays don't light until motor burnout.)

From a manufacturing perspective, delay grains would be cranked out along with 0 delay motors. Advanced users - us - would buy these two piece motors and use them however we need - eg, C20-0, C20-5, C20-10. But ordinary retail channels can be served with pre-trimmed, pre-glued products as well. However, these would be built up using the same two pieces. There would be no large factory inventories of pre-trimmed, pre-glued motors.

Again, I'm not sure it's possible to build a trimmable delay for BP motors. One experiment I have yet to try is gluing an AT delay into a BP booster motor. If it will light, then it will be possible to trim custom delays with that method. I do wonder if having an APCP delay and BP together poses any sore of shelf life issues.

I also wonder about assembly issues. There needs to be a way to reliably glue the delay in without getting glue on the delay face while getting a good seal around the delay.

Anyway, the idea of a universal motor-delay combo is very tantalizing. There's a potential for having wide variety without proliferation of parts/part numbers.

So, in summary, I'll take:

29mm F100-adj
24mm E40-adj
24mm D30-adj
18mm C20-adj
18mm B14-adj
13mm 1/2A8-0T

Doug
Reply With Quote
  #5  
Old 01-05-2007, 06:54 PM
Mark+3 Mark+3 is offline
Intermediate Rocketeer
 
Join Date: Jan 2007
Posts: 45
Default

Quote:
Originally Posted by Doug Sams
I'd say that the differentiated products should be first. 29mm cored BP motors - woo hoo!

Likewise, I want to see cored 24mm versions, too. D30, E40.


Per Carl: " The smaller 18mm and under machine is being built first. Engines over 70mm long or over 18mm in diameter will be done on the larger machine."

Last edited by Mark+3 : 01-08-2007 at 01:40 PM.
Reply With Quote
  #6  
Old 01-05-2007, 10:48 PM
Carl@Semroc's Avatar
Carl@Semroc Carl@Semroc is offline
Junior ??? Rocketeer
 
Join Date: Mar 2005
Location: Knightdale, NC
Posts: 1,470
Default

Good input! This is very well received. As I said, the first step is to get a large enough list to get started, get the list approved, then be able to ship samples for testing.

How about any other different sizes? The 15mm will probably be removed. It just does not have too many good uses.

About the port burning C engines, we did have a 3/4C19 that was reliable in testing, but the full C was too much to drill. Maybe if it was done in two operations... In any case, it would be closer to a C32 with the same .3 second burn. Peak thrust of 60 N - 13 pounds. That looks like too much warranty work! >400G's in a Sky Hook!
__________________
Carl McLawhorn
NAR#4717 L2
semroc.com
Reply With Quote
  #7  
Old 01-05-2007, 10:54 PM
Eagle3 Eagle3 is offline
Administrator
 
Join Date: Jun 2004
Posts: 1,265
Default

Quote:
Originally Posted by Carl@Semroc
Good input! This is very well received. As I said, the first step is to get a large enough list to get started, get the list approved, then be able to ship samples for testing.

How about any other different sizes? The 15mm will probably be removed. It just does not have too many good uses.

About the port burning C engines, we did have a 3/4C19 that was reliable in testing, but the full C was too much to drill. Maybe if it was done in two operations... In any case, it would be closer to a C32 with the same .3 second burn. Peak thrust of 60 N - 13 pounds. That looks like too much warranty work! >400G's in a Sky Hook!


Imagine clustering 3 of those C32's! <BG>

I guess I would suggest waiting on the 15mm until after the 10, 13, 18mm line. Then see if there is a real need/interest?

*still thinking about port burning C's* Imagine a Cobra or Ranger on 3xC19's!
__________________
Quando Omni Flunkus Moritati
Reply With Quote
  #8  
Old 01-05-2007, 11:37 PM
snaquin snaquin is offline
The_Ripper
 
Join Date: Jun 2005
Location: Louisiana
Posts: 1,941
Default

Quote:
Originally Posted by Eagle3
*still thinking about port burning C's* Imagine a Cobra or Ranger on 3xC19's!


..... or a Goliath

Would make for a nice fire and smoke video with 3xC19's in a Goliath fitted with the Oracle camera

The availability of these new Semroc motors will open up many new opportunities! When the new port burners are produced they will be great for getting staged models moving off the rod a little quicker. I'm really interested in clustering and staging them .....



.
__________________
Steve Naquin
TRA# 677 L2
NAR# 85518 L2
SAM# 0052

🚀 In Construction: Der Blue Maxx/Minie-Magg 5.5” & Vander-Burn MDRM Clone w/Stickershock23 Custom Decals
🚀 In Paint & Detail: USR Banshee
🚀 In Build Queue: Estes Doorknob w/Vander-Burn Rocketry Upgrade Kit [Sport Decor], Semroc Centurion-F, Semroc Egg Crate
🚀 In Repair: SLS Lil’ Hustler, SLS Aero-Dart 1969 Trim
🚀 Stay Tuned For Fall 2021 Launch Dates
Reply With Quote
  #9  
Old 01-31-2008, 12:40 PM
Rocket Doctor Rocket Doctor is offline
Master Modeler
 
Join Date: Jan 2007
Posts: 2,400
Default

As we can all see, the thread "Motor matters" has generated a lot of discussion.

When the estes forum was up and running, we also discussed motors there. From the input that we received on the forum, I passed this information along to Barry and Joe Sieberlich, their engine production manager, also, Mike Dorffler got involved.

The type of motors were discussed, and, the B14 was shot down immediately. Also requested was the C5-3, mini boosters and lower power boosters. Right now, you can purchase an educators bulk b pack that included the B6-0, but, Estes is way too stubborn to put those in three packs for whatever reason.

I was told that a lot of motors were dropped because of the units sold didn't make it worth them to produce them anymore.

Estes deals in voulume and $$$, if it's not bringing in the bucks, it's dropped.

Also discussed was bulk packs of "D" motors being sold in walMart, which, Estes will not do either.

As I have mentioned previously under "Motor matters" we need competiton, Estes is the "bully" on the block, they know they don't have competition form anyone (Quest is not a threat as far as motors go) and they feel, if your going to fly rockets, you have to buy your motors from us.

The prices have jumped up again, way, way too high in my opinion.

Last edited by Ltvscout : 01-31-2008 at 02:43 PM.
Reply With Quote
  #10  
Old 01-05-2007, 11:34 PM
CPMcGraw's Avatar
CPMcGraw CPMcGraw is offline
BARCLONE Rocketry
 
Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,357
Default

Quote:
Originally Posted by Carl@Semroc
Good input! This is very well received. As I said, the first step is to get a large enough list to get started, get the list approved, then be able to ship samples for testing.

How about any other different sizes? The 15mm will probably be removed. It just does not have too many good uses.


I wouldn't discount this size just yet, Carl. This is an intermediate diameter between the standard 18 and the mini 13; I can see possibilities here for "B" class motors that can't be done in 13. If I had some power numbers that I could feed into RockSim's Motor Editor, I could run some tests on various designs. Since we don't have those numbers yet, I really don't know what the potential is.

Maybe that is something you could work up for us -- a RockSim motor chart with all of the data you've worked out to this point. With a starting point like that, we can start playing with the motors before you get them in production, and we can give you additional feedback as to what works and what doesn't.

I'm also interested in the 10 as a class; if I can get 500' from a 13mm A3, and even 200' on a 1/2 A3, then there is potential in this size. What have you been able to realistically predict as far as power in this size package?

Side thought here -- are you considering the 18mm "S" series for anything, or is this a dead size?

Quote:
About the port burning C engines, we did have a 3/4C19 that was reliable in testing, but the full C was too much to drill. Maybe if it was done in two operations... In any case, it would be closer to a C32 with the same .3 second burn. Peak thrust of 60 N - 13 pounds. That looks like too much warranty work! >400G's in a Sky Hook!


My Triton 3-stage design needs a reliable 18mm booster for the first stage. Right now, it will take a D12 to get it off the pad with enough kick for a 48" rod; I'd like something in the 18mm size for lifting heavier stacks like this, and like the old Centuri T-Bird.
__________________
Craig McGraw

BARCLONE Rocketry -- http://barclone.rocketshoppe.com
BARCLONE Blogsite -- http://barclone.wordpress.com
BARCLONE Forum -- BARCLONE Forum

BARs helping BARs

SAM 0044
AMA 352635
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT -5. The time now is 12:04 AM.


Powered by: vBulletin Version 3.0.7
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Ye Olde Rocket Shoppe © 1998-2024