Question on Aerotech Arreaux build

Specifically, regarding the "permanent cooling mesh" and ejection gas baffle...I think I have read people stating that their Arreaux's (and other Aerotech kits) have lawn-darted or had other problems, with the suspicion that the "permanent cooling mesh" was getting clogged with engine ejection debris over time.

Have people here found this to be the case? If so, would I just be better off not installing the mesh, but instead using a nomex chute protector? Or are there other work arounds? Or is the mesh not a problem?

TIA!

Definitely avoid using the baffle and use a nomex, you may also want to use an estes retainer not the supplied engine hook and block, so you can use larger motors.

If I had to do my AeroTech Initiator over again, I would remember to put on the red cap with its wonderful contents on the forward closure.

That said, I would also ditch the motor hook, thrust ring, baffle/mesh system and go with an Aeropack retainer (or Estes, if they fit).

Greg

SCrocketfan said:

Definitely avoid using the baffle and use a nomex, you may also want to use an estes retainer not the supplied engine hook and block, so you can use larger motors.

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GregGleason said:

If I had to do my AeroTech Initiator over again, I would remember to put on the red cap with its wonderful contents on the forward closure.

That said, I would also ditch the motor hook, thrust ring, baffle/mesh system and go with an Aeropack retainer (or Estes, if they fit).

Greg

Click to expand...

Ok, consensus is ditch their mesh thingee and go with nomex...

Re: the motor retainer...wow, blow my mind, I hadn't even thought of that! Since the engine hook is integral to their Fin-Lok system, it never occured to me...would I still install the engine hook upper part, but cut off the bottom bit (enough to JB Weld the motor retainer on) and go forward with that?

Mr. GregGleason...you speak in riddles, what do you mean by the "put on the red cap", etc.? I was doing my Arreaux first, and my Initiator second, so if there is any potential pitfalls ahead, I would like to avoid them!

Thanks for the speedy replies, btw!

I stopped flying my Arreaux years ago. because I went on to bigger things. However, it flew great on G80's and I never had any trouble with the mesh. My biggest problem was that it flew too high on G80's and I spent too much time looking for it in the sage brush.

The_Lone_Beagle said:

... Mr. GregGleason...you speak in riddles, what do you mean by the "put on the red cap", etc.? I was doing my Arreaux first, and my Initiator second, so if there is any potential pitfalls ahead, I would like to avoid them!

Thanks for the speedy replies, btw!

Click to expand...

Sorry to have been so cryptic.

The AeroTech Hobby Line 29/40-120 RMS case is designed to house the ejection charge in a plastic, red cap that sits atop the forward closure. When inadvertently left off, it turns a G64-7 into a G64-0.



The result was that my Initiator did what I thought was an amazing imitation of a V-2 "landing". :blush:

Greg

The_Lone_Beagle said:

Mr. GregGleason...you speak in riddles, what do you mean by the "put on the red cap", etc.? I was doing my Arreaux first, and my Initiator second, so if there is any potential pitfalls ahead, I would like to avoid them!

Click to expand...

I think he's referring to the red ejection charge well cap on aerotech reloads. (The "wonderful contents" being the black powder ejection charge)

edit: he beat me to it - curse my stupid typing fingers, they weren't fast enough

GregGleason said:

Sorry to have been so cryptic.

The AeroTech Hobby Line 29/40-120 RMS case is designed to house the ejection charge in a plastic, red cap that sits atop the forward closure. When inadvertently left off, it turns a G64-7 into a G64-0.

View attachment 248203

The result was that my Initiator did what I thought was an amazing imitation of a V-2 "landing". :blush:

Greg

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Oooops, sorry, didn't mean to make you re-live that. If it's any consolation, I can regale you sometime with all the stupid things I've done...but we both probably have better things to do!

I have 2 Aerotech kits that use the mesh baffle and have yet to have any ejection problems. Just make sure there is no debris stuck in the baffle.

The_Lone_Beagle said:

Oooops, sorry, didn't mean to make you re-live that. If it's any consolation, I can regale you sometime with all the stupid things I've done...but we both probably have better things to do!

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It's rocketry. Errors happen. One of the favorite quotes of the current Tripoli president (Stu B.) is "There is a strong correlation between wisdom and scar tissue."

At least I have a few good pics when it was in the stable, like ...



Greg

I think the kit instructions say to keep the baffle clean and it should be fine. I've yet to have a problem. I always put some dog barf or a chute protector in mine just in case.

I have been building/flying AeroTech rocket kits since their beginning. :wink:

I have not had issues with the cooling mesh and/or baffle system. In fact, I use the 'cooling mesh' in kits that I modify.

My Arreaux model has over 40 flights on it. 'E' through 'G' motors. Never had a problem with the cooling mesh/baffle.

My advice would be to keep the cooling mesh and baffle.

Initiator001 said:

I have been building/flying AeroTech rocket kits since their beginning. :wink:

I have not had issues with the cooling mesh and/or baffle system. In fact, I use the 'cooling mesh' in kits that I modify.

My Arreaux model has over 40 flights on it. 'E' through 'G' motors. Never had a problem with the cooling mesh/baffle.

My advice would be to keep the cooling mesh and baffle.

Click to expand...

Well, that is good to know. This is my first Aerotech kit, and I don't really want to change things up the first time. Maybe the next Arreaux I buy will be the one I heavily modify...

I'm in the "mesh works as advertised" camp on my two year old, double-digit flight Barracuda. This has been a somewhat hotly debated topic for quite a while; do a forum search on "cooling mesh" for lots of opinions. In the end, I think it's a pick your preference kinda deal.

Initiator001 said:

I have been building/flying AeroTech rocket kits since their beginning. :wink:

I have not had issues with the cooling mesh and/or baffle system. In fact, I use the 'cooling mesh' in kits that I modify.

My Arreaux model has over 40 flights on it. 'E' through 'G' motors. Never had a problem with the cooling mesh/baffle.

My advice would be to keep the cooling mesh and baffle.

Click to expand...

Full disclosure: It is my understanding that Initiator001 (aka, Bob Sanford) was the chief designer of many/all of the AeroTech kits (which I believe is why he supplied the winky emoticon). Bob has already flown more rockets than I will ever fly.

Bob, my main criticism of the mesh/baffle is that you can't use the longer motor cases with the stock build. So my comments are based in my preferences rather than a deficiency. Otherwise, it's a well thought out kit and would have no hesitation recommending them.

Greg

My first MPR was the Aerotech Strong Arm, it has the same motor tube configuration as the Arreaux. I've had no problems with the cooling mesh.

Just follow the Aerotech Pre-Launch Chechout, instructions:

"With the tail of the rocket pointed down and the motor tube empty, shake the rocket to remove any loose ejection charge debris left from a previous flight. Periodically, fluff up the cooling mesh using a bent wire inserted through the back end of the motor tube." I found the cooling mesh alone is enough to protect the chute, no need to add wadding, dog barf or a Nomex blanket.

I also deleted the engine hook & motor block and added an AeroPack retainer. I discarded the elastic shock cord and installed a 15' Kevlar shock cord.

GregGleason said:

Full disclosure: It is my understanding that Initiator001 (aka, Bob Sanford) was the chief designer of many/all of the AeroTech kits (which I believe is why he supplied the winky emoticon). Bob has already flown more rockets than I will ever fly.
Greg

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Yes, that was my understanding, too..

I agree, it is the most well thought out kit I have had yet (I've been on a kit-buying and building binge since coming back as a BAR after a 30 year hiatus); for the price it puts other competitors models to shame, that's for sure!

Reading the forums and other reviews, I did remember hearing some people voice concern over the cooling mesh. Before I started gluing, I wanted to see what the consensus might be. Using the rule of thumb that "the people not experiencing a problem don't write in forums about non-issues" and the other rule of thumb that those not experiencing problems outnumber those who did have a problem by about 90% to 10% or less, this may be an overblown/non-issue.

The_Lone_Beagle said:

Ok, consensus is ditch their mesh thingee and go with nomex...

Re: the motor retainer...wow, blow my mind, I hadn't even thought of that! Since the engine hook is integral to their Fin-Lok system, it never occured to me...would I still install the engine hook upper part, but cut off the bottom bit (enough to JB Weld the motor retainer on) and go forward with that?

Thanks for the speedy replies, btw!

Click to expand...

If it builds like the G-force (which it should knowing how these kits lock together), leave the hook out entirely, it has no use and the forward part is what limits motor size not the back part. You will have a few notches/holes in the fin locks not filled by the hook, but that's just fine. It definitely sounds like the mesh will work, but the motor retainer is probably a more important upgrade if you want to fly 2G and larger cesaroni motors at any point or longer aerotech motors. I built my G-force with no hook, no mesh, and an Estes retainer, and it's flown a motor much longer than stock with no issues.

Let's see if this works....I'm attaching a picture of my dry fit of the fins to my motor mount...anyway as soon as I did this, I had a flashback to ??? 35 or so years, and building my Estes Battlestar Galactica Viper...

I ended up retrofitting an Aeropack retainer and pulling the engine hook on my first Arreaux. On my second one I used the GLR Qwick-Lok slimline retainer, which slightly hangs out the back and looks great, I also left the baffle out all together, as well as made it dual deploy. Well I say "made it" but it is not finished, needs paint...my rocket ADD distracted me and I started working on other kits. And if Wildman keeps having sales it will never get done.

Don't forget that Aerotech just came out with their own screw-on retainers. They are half the price of the Aeropack at $14.99. AT has said they will be soon included in their kits in place of the hook.




Jerome

Those changes/updates would be wonderful for this kit!

However, seeing as I have this (and a mess of other kits to build), and I still haven't really secured a launch site, I'm going to go with the standard build as per the instructions. Maybe in another year or two, if they do get rid of the engine hook and replace it with their own aluminum retainer, I will build another one.

The_Lone_Beagle said:

Those changes/updates would be wonderful for this kit!

However, seeing as I have this (and a mess of other kits to build), and I still haven't really secured a launch site, I'm going to go with the standard build as per the instructions. Maybe in another year or two, if they do get rid of the engine hook and replace it with their own aluminum retainer, I will build another one.

Click to expand...

Now all the lowest power options for this rocket are produced with aft thrust rings, so you can use the retainer on all flights. I definitely regret putting the engine block into my old Aerotech kits as I was unable to retrofit. Of course it is your build, though! Also using the hook over a retainer will save enough for a motor!

Having built this and immediately regretted putting the thrust ring and hook in as I decided to make a dual deploy. I will be removing them this weekend. I got a second kit but would rather keep it in the event I fence post the thing and I have to rebuild. The cost of estes retainers doesn't justify a hook for a 29mm build.

The_Lone_Beagle said:

Yes, that was my understanding, too..

I agree, it is the most well thought out kit I have had yet (I've been on a kit-buying and building binge since coming back as a BAR after a 30 year hiatus); for the price it puts other competitors models to shame, that's for sure!

Reading the forums and other reviews, I did remember hearing some people voice concern over the cooling mesh. Before I started gluing, I wanted to see what the consensus might be. Using the rule of thumb that "the people not experiencing a problem don't write in forums about non-issues" and the other rule of thumb that those not experiencing problems outnumber those who did have a problem by about 90% to 10% or less, this may be an overblown/non-issue.

Click to expand...

Overblown for sure. The cooling mesh works perfectly. I, like others, have used it for dozens of flights. Just shake out the red caps after each flight and fluff it up with something pointy every now and then. I made my own version with a Chore-Boy in a coupler tube for use in small diameter rockets where packing wadding or nomex is a pain. I like simple rocket prep, and baffles are good for that.

I've always used the cooling mesh & baffle arrangement, works fine. Ditto for the included shock cord. I do recommend leaving off the motor hook & block, since they really limit motor choices. I prefer masking tape retention or Estes retainers on AT kits, both work great. The Estes retainers don't work so well with AT HPR style cases, though.

My G-Force has the mesh and has flown many times. Since it is cardboard, I will probably stop flying it do to deterioration of the airframe long before the mesh causes any problems.

If you're like me, you get a sense of confidence when you have instructions to follow. Some people can dive right in and scratch-build from the start, but some of us like to ramp up to that.

Build it stock, fly it, enjoy it. I agree with the others that leaving out the motor hook and using a screw-on retainer is a good idea, and is not a scary mod. I wish I had done that with my G-Force.

dpower said:

I've always used the cooling mesh & baffle arrangement, works fine. Ditto for the included shock cord. I do recommend leaving off the motor hook & block, since they really limit motor choices. I prefer masking tape retention or Estes retainers on AT kits, both work great. The Estes retainers don't work so well with AT HPR style cases, though.

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(Cool Cherokee-D avatar...I just downloaded an old Estes 1982 catalog, saw the Cherokee-D, and immediately was transported back 32 years...that was one of the definitive rockets, back then!)

You brought up something I just started thinking about --> with motor selection in general, and reloadable motor systems in particular, how do you put in a motor retainer when the various lengths...vary?

I would assume for the single use motors, there are always various tube adaptors, but with reloadables, I'm guessing you would build it with the particular motor hardware you have, and then you would just use whatever reload you have + the appropriate spacer, or am I completely wrong?

Bat-mite said:

My G-Force has the mesh and has flown many times. Since it is cardboard, I will probably stop flying it do to deterioration of the airframe long before the mesh causes any problems.

If you're like me, you get a sense of confidence when you have instructions to follow. Some people can dive right in and scratch-build from the start, but some of us like to ramp up to that.

Build it stock, fly it, enjoy it. I agree with the others that leaving out the motor hook and using a screw-on retainer is a good idea, and is not a scary mod. I wish I had done that with my G-Force.

Click to expand...

Yes, you bring up the point I finally realized several days ago -- especially since I am restarting the hobby again, now is not the time for improvising. Following the instructions will not only be helpful to begin with, but will provide confidence, and a benchmark for future builds, when I want to try something new but also want to know if I really am improving upon the original design.

Unless I follow the instructions to begin with, I won't ever have that benchmark reference point.

Additionally, some of my Black Friday goodies have been showing up, so now I have Nomex chute protector, which I will probably use anyway, to get in the habit...I just feel better knowing there is a (flame resistant) physical object between my shock cord and chute & chute lines and the ejection gases/charge.

You must leave out the foreard motor retainer ring. All you need is a motor tube with no blockage. Forward retainer rings are only useful for BP motors that have no built-in retention.

Any 29mm motor casing will fit in a 29mm motor tube. AT and CTI casings have a retainer that blocks the motor from going through the tube at the aft end. Your only limitation is how much room you have for length, based on your recovery system.