Ellis motors

[Brian62]

Going to try a J228 ellis Sat. Will be the longest burn I have ever tried. I do not even know what type of flame burn this has. Anybody got some pics of thiers?
Brian

 

[cjl]

Umm..

You may want to rethink that. I believe the Ellis J228 was decertified due to a high failure rate.

 

[tfish]

From TRA's web page...

Ellis Mountain M1000, L600 Entered on Burn list as of 31 Aug 2005, Manufacturing for sanctioned use expires 31 Aug 2005

J228 immediately decertified for sanctioned use.

 

[denverdoc]

Brian,

Thats a killer motor, when it works, and when it doesn't. If you don't fly it and wish to dispose of it, PM me. We have special occasions here in colorado for motors like these. If you do decide to try, igniter 1/2 way up.
JS

 

[Donaldsrockets]

If it does work, it will have a bright yellow/orange flame and a moderate amount of white/grey smoke, very similar to ProX Classic propellant.

But like others have said, TRA decertified it for quality issues so you would not be able to use it at a TRA sanctioned launch, an EX launch maybe.

 

[just rockets]

The J228 is an awsome motor when and if they work. The failure rate is very high like 1:1 at best. TMT testing has had it decertified for over a year. If you decide to try it don't place your igniter more than 1/3 past the nozzle. The biggest problem that we have seen is blowing the forward closure. The motor is like we like it, Right on the edge of extreme. If they fix that problem it will be one bad *** single use. Good luck, Scott TRA 9279 L3

 

[Chuck Rudy]

Originally posted by Tfish
From TRA's web page...

Ellis Mountain M1000, L600 Entered on Burn list as of 31 Aug 2005, Manufacturing for sanctioned use expires 31 Aug 2005

J228 immediately decertified for sanctioned use.

You may want to recheck your expire date.

Chuck

 

[Brian62]

After I found out that this motor was de-certified, I very disapointedly pulled plug. After seeing the input from some of you who have personaly seen this be a problem child, I am very glad I did as I only have this one 38mm,Voo-Doo rocket. no other 38mm.(DenverDoc I will let you know)
Brian

 

[Flamboyant]

Does the G20 have a high failure rate too?

 

[robfire820]

I flew an H50 at AirFest in an LOC Weasel for a very awsome flight, it went up and up and with the wind(or lack there of, for once) it landed with-in 200 yards of the pad, on a streamer. These are awsome motors when they do what they are supposed to do. I would not fly one in a rocket that you have spent a lot of time on though, just in case. Rob

 

[Donaldsrockets]

I have flown three Ellis motors, two G35s and an H48. All performed normally.

I have never heard of a G20 CATO but I have seen the 24mm G37 blow it's forward bulkhead out and I've also heard that the failure rate of the 24mm E12 is very high.

I would really love to try the G20 in my 29mm saucer.

 

[Fore Check]

Granted, the following observation is completely unscientific, so take it for what it's worth.


At Midwest Power 4 (about a month and a half ago) and recall about 10 launches (or attempts) on Ellis motors of various sizes.

Only ONE launched as planned. Over half of them CATO'd in some way. A couple others just spit igniter after igniter after igniter after igniter until the owner just gave up in disgust.

 

[Flamboyant]

Originally posted by Donaldsrockets

I would really love to try the G20 in my 29mm saucer.

Exactly what I'm doing for its first flight.

 

[Donaldsrockets]

Originally posted by Fore Check
Only ONE launched as planned. Over half of them CATO'd in some way. A couple others just spit igniter after igniter after igniter after igniter until the owner just gave up in disgust.

I will second that the Ellis propellant is hard to light.

For the G35s, I used Quickburst Twiggys, took a few seconds to come up to pressure but that 4 second burn was just sooooooooooooooooooo cool.

For the H48, I used an ignitor made from thermalite, made for me by a club member which worked great but still took several seconds to get the Ellis propellant going.

That motor burned for about 5 seconds or so, really awesome!!!

 

[kiheimer]

About a year ago I launched a rocket on a Ellis Mountain J110.
The motor never came up to full power. At about 200 feet the rocket started doing loops, landed on he ground, and land sharked about 75 yards. I wasted $75 on the motor and the rocket was ruined. I'll never buy another.

 

[Crazyrocket]

I've used about 20 EM G20 in my saucers with great success. Never had a CATO. I always light them with some quickburst twiggies (my supply is running low). I do not know anything about the other EM motors, aside from what has been said here, but hte G20 *seems* to be a good motor.

 

[jsdemar]

I've used about 100 Ellis motors and never had a cato. Maybe I'm just lucky. In the same period, I've flown fewer AT motors and had an F21 blow the fwd closure and crash/burn a scratch-built scale model. And my son had a G80 never fire it's ejection charge.

APCP Motors that have been stored a while are hard to light, especially propellants with metals. That could be part of the problem. Also, you need a good hot igniter to light slower propellants. Remember to keep them sealed and in a cool dry place.

A common problem with the long-burn Ellis motors is improper placement of the igniter. Long C-slots will put themselved out if lit from the top. Or with a huge igniter at the top, it'll blow the casing. A good igniter for these is one that pressurizes the motor, burns longer, and is placed about 1/2 way up the C-slot. I've made my own 16" long 54mm D-grains and it's the same situation.

Another problem with igniters in long motors happens if the leads "accordian" fold at ignition. This is especially true with Ellis motors that have a relatively small nozzle for the length (for the long-burners). There should be no kinks in the wire, and a clear path for it to move when the motor lights.

I'm sure there are some Ellis catos that are legitimate defects, but I think most of the bad rap is from age/storage problems and improper igniter type/placement.

-John D.

 

[denverdoc]

Originally posted by jsdemar
I've used about 100 Ellis motors and never had a cato. Maybe I'm just lucky. In the same period, I've flown fewer AT motors and had an F21 blow the fwd closure and crash/burn a scratch-built scale model. And my son had a G80 never fire it's ejection charge.

APCP Motors that have been stored a while are hard to light, especially propellants with metals. That could be part of the problem. Also, you need a good hot igniter to light slower propellants. Remember to keep them sealed and in a cool dry place.

A common problem with the long-burn Ellis motors is improper placement of the igniter. Long C-slots will put themselved out if lit from the top. Or with a huge igniter at the top, it'll blow the casing. A good igniter for these is one that pressurizes the motor, burns longer, and is placed about 1/2 way up the C-slot. I've made my own 16" long 54mm D-grains and it's the same situation.

Another problem with igniters in long motors happens if the leads "accordian" fold at ignition. This is especially true with Ellis motors that have a relatively small nozzle for the length (for the long-burners). There should be no kinks in the wire, and a clear path for it to move when the motor lights.

I'm sure there are some Ellis catos that are legitimate defects, but I think most of the bad rap is from age/storage problems and improper igniter type/placement.

-John D.

John,

Glad to see you toss your hat in the ring on this one. I like Ellis motors and as anyone who spends time here knows, am a big fan of long burning motors. Talking to Paul H, my understanding was that while the igniter placement improved matters for the J228 dramatically, the rocket was certed on the basis of SOP and decerted cuz that wasn't working with sufficient reliability. Had the motor been submitted to S & T with a specific recommendation for 1/2 placement and even a particular igniter type, the matter might have been avoided. I don't pretend to know the particulars--so if one cares to comment, please do.
JS

 

[Brian62]

I just want the long burn motor, certified so that I may use it.

 

[JoesRocketry]

Makes me glad I turned down the trade of an Ellis J220 for an Aerotech J420. I took a longburn Ellis I motor instead, but our waiver is WAY too low for me to use it at any of the launches I normally attend. That and the lack of a thrust ring...

 

[jsdemar]

Originally posted by JoesRocketry
Makes me glad I turned down the trade of an Ellis J220 for an Aerotech J420. I took a longburn Ellis I motor instead, but our waiver is WAY too low for me to use it at any of the launches I normally attend. That and the lack of a thrust ring...

How about a masking tape thrust ring? Works everytime for me since 1990, up to K1000 EX motor. Should be fine on a low thrust 'I'.

Speaking of low thrust, don't forget to look at the thrust-to-weight ratio. That's a common "user error" with long burn motors, or AT Black Jacks.

-John D.

 

[JoesRocketry]

I have used masking tape thrust rings for MPR, and I never thought it would work safely in HPR. In MPR, I will occaisionally friction fit my motors, but with HPR, I prefer something more solid for both thrust rings and motor retention.

As with all motors, I had a friend who CATO'ed 3 AT 54mm motors in a row all due to manufacturing defects in the reloads, meanwhile I was lucky and didn't have any of mine CATO. He of course, got great customer service and that is what kept him flying AT.

Moral of the story... what works for some doesn't work for all... and some may have problems and others not... without any particular reason other than good vs bad luck.

 

[2muchstuff]

Originally posted by jsdemar
I've used about 100 Ellis motors and never had a cato. Maybe I'm just lucky. In the same period, I've flown fewer AT motors and had an F21 blow the fwd closure and crash/burn a scratch-built scale model.

I've not used anywhere near that many, but I have flown a number of EM G20's and G35's and have never had a problem, not even with ignition.

I've had a heck of time trying to light AT D motors in the 18mm case. I've given up on few after several tries, even after all the usual tricks of sanding the slot, using an exacto to create a few curly shavings, etc.

The thing about EM motors, is that they are a very different propellant than the usual AT motor. Lower thrust, long burn. They are not 'plug and play' - an EM G35 is not a replacement for a AT G40. If you look at the thrust curves, you'll clearly see they have very different thrust profiles.



tms

 

[denverdoc]

Originally posted by 2muchstuff
I've not used anywhere near that many, but I have flown a number of EM G20's and G35's and have never had a problem, not even with ignition.

I've had a heck of time trying to light AT D motors in the 18mm case. I've given up on few after several tries, even after all the usual tricks of sanding the slot, using an exacto to create a few curly shavings, etc.

The thing about EM motors, is that they are a very different propellant than the usual AT motor. Lower thrust, long burn. They are not 'plug and play' - an EM G35 is not a replacement for a AT G40. If you look at the thrust curves, you'll clearly see they have very different thrust profiles.
tms

Its a great formula and glad to see the positive remarks--usually when Ellis gets mentioned, turns into a bashing party. I've only flown 5 G-H and no problems except maybe too small a motor BP charge to get it done. Laundry hung up 1/2 way out.
JS

 

[Brian62]

This is just a reminder, this was about a de-certified motor only. Nothing about bashing, or any other motor other than the J228 that I am sure has a valid reason for not being certified. Let us be honest, if it worked it would be ceritfied. The other Ellis motors that are certified I am sure are just fine even with their little issues just like all motors.
Brian

 

[Donaldsrockets]

Ellis also had a K600 SU but it CATO'ed on TMT's test stand and was never certified.

I have seen a video of one that worked. It would have been an awesome motor.

 

[denverdoc]

Originally posted by Brian62
This is just a reminder, this was about a de-certified motor only. Nothing about bashing, or any other motor other than the J228 that I am sure has a valid reason for not being certified. Let us be honest, if it worked it would be ceritfied. The other Ellis motors that are certified I am sure are just fine even with their little issues just like all motors.
Brian

I think you missed my point, my apologies for not having been clearer. Anytime EM comes up there is a flurry of complaints that like mob violence tends to go overboard. Its nice to see a more balanced view. Had the J228 been more properly sampled and submitted to S&T committee, it might not even be an ssue. Would seem, that somewhere between the original cert and later, it had some major issues. There might be a work around. Bob suggested a 1/2 placement igniter strategy. Not sure this has worked always, but an ad hoc after the fact soln doesn't cut it with S&T.
JS

 

[Lucas]

Originally posted by Donaldsrockets
I have flown three Ellis motors, two G35s and an H48. All performed normally.

I have never heard of a G20 CATO but I have seen the 24mm G37 blow it's forward bulkhead out and I've also heard that the failure rate of the 24mm E12 is very high.

I would really love to try the G20 in my 29mm saucer.

I had a G20 fail in my 29mm MD, destroyed the whole rocket

 

[Donaldsrockets]

Originally posted by Lucas
I had a G20 fail in my 29mm MD, destroyed the whole rocket

Interesting!!!

How did it fail, did it just blow the nozzle out or did the casing fracture???

The only SU motors I've ever had fail were three AT G35s. All three blew the nozzle out at the moment of ignition.

 

[Lucas]

Originally posted by Donaldsrockets
Interesting!!!

How did it fail, did it just blow the nozzle out or did the casing fracture???

The only SU motors I've ever had fail were three AT G35s. All three blew the nozzle out at the moment of ignition.

The entire casing failed... I have some pics somewhere, I am just trying to find them now.