18/20 RMS Question here.

Hi,
Need some help after the fact here. Launched a D13-7 reload, first attempt actually, in an Estes Nova Payloader. Had 6 launches on the
ship previously and it was suffering from the Hibachi effect as the beautiful red paint job was bubbling. Winds were from the South at roughly 4-9 mph according to my wind meter. My field is at: http://www.terraserver.microsoft.com/image.aspx?T=1&S &Z&X750&Y"481&W=3&qs@+Laurel+Drive%7cCanton%7cIllinois%7c&Addr@+Laurel+Dr%2c+Canton%2c+IL+61520&ALon=-90.0374183&ALat@.5777167 and doubles as a driving range. You see the white gravel area to the north that is the parking lot for the golfers and the driving stations are just to the south. If you look to the west and a little south, you will see a little black horizontal line which is a small parking area for about 4 cars for folks who fly R/C (and now rockets with me). My question has to do with the ejection charge as I couldn't figure it out with the instructions. I put the red cup over the end of the of the ejection chamber and crushed it and shook it. I was going to remove the cup but it seemed like there was alot of powder in there so I left it connected on the end of the engine. At a launch I went to in a May I asked a level 3 modeler, Pat Hibbs, if I could watch him do a reload. He told me to hop in his truck and he supervised his 13 year old nephew in doing an H reload. Pat had stated that one should crack the cap with the black powder and pour it into the well. He was emphatic that one should cover the well with a large piece of masking tape. In the 18/20 reload if one leaves the cap on, there is about a 1cm space between the powder in the bottom of the cap and the well on the bulkhead of the engine. Again I put the cap on the engine upright and squeezed the cap and shook the engine thinking I would get the powder into the well. I thought there might be too much powder and if I took the cap off the powder would fall out. I did not remove the cap and apply masking tape. When I saw the H reload, I distinctly remember that the black powder filled the well to the top before Pat had his nephew put the masking tape over it. He had a successful launch. All this is moot as I launched my model and my gosh, talk about noise! I've seen lots of other modelers' RMS loads G and higher go off but this little engine really roared. It sounded louder than the E30 and F23 SU motors I fired today too. Might be because I was closer to the launch pad but I was at the same distance when I did the SU's. Well the model went out of sight and never saw it again. Didn't hear an ejection charge fire although it could have been up so high I couldn't hear it. I did fire off a Quest Zenith II with a modified first stage I built from parts I had lying around. It was for a D12-0 booster instead of a B or C6-0. It shot up like the proverbial "bat out of hell", The sustainer is yellow and the booster is fluorescent orange. I saw it stage and then the sustainer went out of sight. I waited and waited and waited. I thought I had lost this model but I heard the streamer flapping in the air. I looked behind me and saw the last 200' descent of the sustainer land 150' behind me and not very far from the booster. I only mention this as it showed that a model might get so high one can't hear the ejection charge. (Or my hearing is bad.) Anyhow, appreciate any answers about my reloading technique and if anyone can point me to some websites that might have better instructions it would be most appreciated. Also lost an Eliminator on an E9-8 and a High Flier on a C6-7. Dang, my eyesight must be getting worse. I am unhappy with myself as I launched toward the south and it looks like I missed the range!! I mean look at the photo of the field. I still missed it OR I may have had recovery system failures in the Eliminator and High Flier. They were Estes stock, old and were made before I started using kevlar shock cords for everything. Put up a Super Nova Payloader and it separated from the body. Had one good flight on an E30 and then tried an F23 BJ engine. Saw the payload bay with parachute land way the heck to the north and west and went BEHIND a tree line. Too far for me to go and I have two of the Super Novas on the self with one still in kit form. There is some consolation there. TIA. Best regards, Kurt Savegnago
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Kurt wrote:

You shouldn't need to crush it. Use a pick or a pair of needle nose pliers and pull out the white cap, if there's one in there, then snap it on, place the motor right side up, and tap it a few times.

The H loads don't come with caps, and there's no way to snap something onto the end of the closures. I think the cap is just a convenience in the hobby line (18mm, 24mm, 29/40-120) as opposed to the tape that we use on high power reloads.
It sounds to me like you did just fine in assembling your reload. If you're not sure, your best bet is to find someone locally who has used the same (or similar) reloads and have them watch you during the assembly process.
-Kevin
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Hey Kevin,
Thanks for the advice. It looked to me that there was a wax covering in the ejection charge but I have two reloads left I can look at. Using a pick or needle nose pliers might have been a key point I missed out. I remember Pat breaking something and telling me "Not to use the cap". but I don't think that is a big deal. I think the answer I am looking for is that one is supposed to fill the well at the end of the engine with the BP ejection charge? I didn't mind losing the Nova Payloader as the BT was beginning to get cooked. I am saddened about losing the hardware though. Have a new engine on order. :) I was about to use the 18/20 in the Zenith II sustainer for a single stage flight. (Yes I know one can't use APCP engines in multi-staging like BP engines and need timers/igniters to do an air start) I had second thoughts about the Zenith because if I lost it, I would have two booster sections remaining. Am glad I chose the partially cooked N.P. for the flight.
Kurt Savegnago
Kevin Trojanowski wrote:

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Kurt wrote:

To reiterate, HP reloads use a red cap that is ultimately used to cover the nozzle to 'package' the ejection charge. This is covered with a circular piece of paper that is bent into place to keep it there (but I don't need to tell you how often this DOESN'T work, and I end up with a reload kit filled with loose black powder). For the hobby reloads, the ejection charge is contained WITHIN two red caps -- the smaller one (IIRC) is used to go on the ejection end of the casing, and the larger one is used on the nozzle.
Don't confuse the white cardboard (bent/crimped) disc that HP guys remove (and throw away) with the way that the hobby RMS charges are supplied.
David Erbas-White
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On Sun, 12 Jun 2005 13:31:38 -0700, David Erbas-White

ANd I thought I was getting special limited edition motors. 8-)
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Phil Stein wrote:

And they messed up this BAR of a modeler!! Lost the rocket although I think it would have cooked through past the motor mount if I would have launched it a few more times with BP motors. I crushed the heck out of the end of the BP carrier and I suspect I didn't crack the danged paper properly. Am going to use a "pick" or some pointy device to get at the gal danged powder to pour into the ejection cup in the engine. I'll get the son of a buck to work ultimately!!!
Kurt Savegnago
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I've seen video of proper assembly on these on AT's web site. You might want to check that out.
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Do me a favor please. Lighten up on the profanity, fella.......okay?
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Interesting factiod.
--
Jerry Irvine, Box 1242, Claremont, California 91711 USA
Opinion, the whole thing. <mail to: snipped-for-privacy@gte.net>
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Kevin Trojanowski wrote:

Kevin (and Kurt),
For the hobby RMS motors, the 'nozzle' red cap and the 'ejection charge' red cap are 'snapped together' to hold the ejection charge during shipment. In other words, there is no 'white cap' like there is on the HP stuff (which just has the nozzle cap, not the ejection cap).
I've found that the best way is to hold the ejection cap (the smaller of the two) with the opening up (obviously, unless you want to sprinkle the BP on your shoes), and then put the assembled motor on from the top -- then snap the cap into place. This should work perfectly, with no crushing. There is a lip on the ejection cap that should exactly be captured by the ejection end of the motor. Then, you're left with the nozzle cap to use to hold the igniter in place. Once the ejection cap has been snapped into place, you simply turn it over, and tap the side of the case to distribute the BP into the ejection well for good ignition.
It sounds as though everything was done correctly, except that you don't (shouldn't) be crushing the cap. The reason I suggest the above method, BTW, is to keep granules of the BP from getting 'stuck' in the lip area, which may be why yours didn't "snap" into place.
Side note: for folks who don't do the hobby reloads (doing HP only), this is a bit different than the method of pouring the BP into the well, then covering with the tape disc. I really wish the tape discs were just a little bit bigger, with just a little bit more adhesive. I found out the hard way (early on) that you MUST use masking tape on top of the disc, because those darn discs just DON'T stay in place. I prefer using the disc topped by a piece of masking tape, because using just the tape can sometimes leave minor gaps for the powder to leak out. I actually like the hobby method of using the plastic cap -- it is really simple, and pretty idiot proof (and I can be a pretty advanced idiot when I want to be)...
David Erbas-White
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David Erbas-White wrote:

Thanks; I couldn't remember if there was a white paper cap in there, or not -- it's been a while since I assembled a hobby reload.
-Kevin
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That's a good problem to have :)
--
Jerry Irvine, Box 1242, Claremont, California 91711 USA
Opinion, the whole thing. <mail to: snipped-for-privacy@gte.net>
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Unless you're looking for help in assembling the motor. Someone who flies L3 stuff exclusively would not be my first choice for showing someone how to assemble a D13 reload. Sorry Kevin.
    Bob Kaplow    NAR # 18L    TRA # "Impeach the TRA BoD"         >>> To reply, remove the TRABoD! <<< Kaplow Klips & Baffle:    http://nira-rocketry.org/LeadingEdge/Phantom4000.pdf www.encompasserve.org/~kaplow_r/ www.nira-rocketry.org www.nar.org
... One nation under surveillance, divisive, with liberty and justice for none.
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Bob Kaplow wrote:

Actually,
The fellow had an article written about him in the newspaper and I wanted to see how a reload was done. Just so happens it was an H load he was doing. I did want to see that size engine loading as I was hoping some time to do that in the future. I didn't at the time fly anything more than SU's. I now know I incorrectly mounted the cap without puncturing it or separating the cylindrical liner. Dave gave me the link to the Aerotech site that shows the reloading process. Interesting that I had the link and saw it some time ago but I had wanted to look at it again and couldn't get it to google up. I see now the link is right out in the open on the Aerotech site. One things for certain, am not going to be doing the same mistake twice. I look at the bright side, at least I had a little angle in the launch rod. If it went straight up and straight down, I might have had my head skewered! :) Man I still was impressed with the noise of that little engine. Quite the concussive experience and most satisfying as I can launch locally and not have to be at a waivered situation.
Kurt Savegnago
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So you put BOTH caps, still mated, on the ejection end of the motor? NOT good...
    Bob Kaplow    NAR # 18L    TRA # "Impeach the TRA BoD"         >>> To reply, remove the TRABoD! <<< Kaplow Klips & Baffle:    http://nira-rocketry.org/LeadingEdge/Phantom4000.pdf www.encompasserve.org/~kaplow_r/ www.nira-rocketry.org www.nar.org
Vulcans believe peace should not depend on force. -- Amanda, "Journey to Babel," stardate 3842.3
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kaplow snipped-for-privacy@encompasserve.org.TRABoD (Bob Kaplow) wrote:

errorteck
:)
--
Jerry Irvine, Box 1242, Claremont, California 91711 USA
Opinion, the whole thing. <mail to: snipped-for-privacy@gte.net>
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In article snipped-for-privacy@corp.supernews.com, Jerry Irvine at snipped-for-privacy@gte.net wrote on 6/13/05 8:33 PM:

U.S. Rackets
:)
BTW the instructions clearly state to separate the plastic caps. There are even some nice pictures showing how the ejection cap is snapped onto the end of the motor.
http://tinyurl.com/a8tlx
Gary
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ROTFL!
    Bob Kaplow    NAR # 18L    TRA # "Impeach the TRA BoD"         >>> To reply, remove the TRABoD! <<< Kaplow Klips & Baffle:    http://nira-rocketry.org/LeadingEdge/Phantom4000.pdf www.encompasserve.org/~kaplow_r/ www.nira-rocketry.org www.nar.org
Timid men prefer the calm of despotism to the boisterous sea of liberty. -- Thomas Jefferson
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On Tue, 14 Jun 2005 05:31:30 GMT, "Gary C. Rosenfield"

Now THAT is truly funny! Thanks, Gary!
- Rick "Had to happen, eventually" Dickinson
--
"The radio business is a cruel and shallow money trench, a long plastic
hallway where thieves and pimps run free, and good men die like dogs.
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Bob Kaplow wrote:

You assume I have way more "rocket money" than is the case, Bob. My average over the past year was a G, I believe, with the biggest motor burned being either a J or a K.
I built a couple of 24/40 reloads last year; problem is it's been almost a year since I did so.
-Kevin
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