MMX Launch Rack

[JAL3]

In checking my club's flight cards for the last 2.5 years, I find that there have been 8 MMX launches. All of them were done by me. I have tried to see if there was any interest in an informal MMX contest of some type on several occasions and there was not. In delving a bit deeper, I learned that MMX was not disdained because of its diminutive size, it was shunned because of the hassel, real and perceived, of flying them. That was an attitude I shared myself. Every time I thought about building or flying one, I usually gave it up as too much hassle.

That is especially true of the ground support equipment. The silo launchers are problematic and I have had only one good launch off of one. The rest of the time I have had to kludge something together, cross my fingers and hope it works. It sometimes even does.

This is not to say that there are not some great MMX GSE ideas out there. There are. They just don't strike me as worth the effort. I finally decided to see if I could design something to take some of the hassle out of it and make it fun. In effect, with a minimum of effort, I want to be able to treat an MMX rocket like any other. Go out to the assigned pad, hook it up, walk away and have reasonable confidence that the rocket would launch. I wanted to be able to do this without lengthy preparation of special consumables. In order to do it, I was willing to invest some time, effort and money into making such a system.

The basics that I wanted to accomplish are these:
Build the project with readily available parts; no machining or milling.
Be able to use any of the common igniter options without having to switch gear
Be dependable; the same ration of successful launches as will the bigger gear.
No hassle, perceived or real.


I have some basic ideas in mind that I will develop over the course of this project but would appreciate advice and comments from those with more experience in this area.

The first thing I would like to hear is what is considered a "comfortable spacing" between individual launch stations. How much linear space to I need to dedicate to each pad so that multiple flyers can set their rockets up at the same time without falling over each other?

 

[brianc]

John - See this tip I submitted to EMRR for a simple answer
to your GSE problem.

https://www.rocketreviews.com/featured/tip_featured62.shtml

 

[JAL3]

John - See this tip I submitted to EMRR for a simple answer
to your GSE problem.

https://www.rocketreviews.com/featured/tip_featured62.shtml

I thought I had found all the articles on EMRR but I was wrong. Thanks.

What do you consider as a comfortable distance between MMX pads?

 

[Micromeister]

John:
I just don't know where to begin!

I've been flying micros since they were introduced. I think I used one of the silo launchers exactly one time before realizing it's the 9v battery and the plug in igniters that were the problem.

There are any number of ways around the silo base problems. The MicroMaxRockets Yahoo group files section is LOADED with a number of ways to either alter the old silos, constructed simple easy alternatives or make Add-on or Slip over launcher bases that attach or slip over a standard 1/8" launch rod allowing the rod to be used normally or with the micro .049" micro rod without changing any other item on the rack.. as a matter of fact at our club some folks use the silpover base as the standoff clip
Jim flis has a spent motor casing slip over on his web site, I've been using something similar for years. it's a spent casing with a 1/8" x 2" Launch lug on one side and a .049" music wire x 12" long micro rod epoxied to the opposite side. allows the model to be suspended over the edge of the casing Works like a dream.

but I've moved Well beyond that, I devised a very simple 2.5" x 4" x about 1/2" alum and Acrylic Micro Launcher base that was originally designed to clamp onto the end of our standard Rack launcher, but as long since been adjusted by using a standard 1/4-20" tap to attach to a lightweight Digital camera Tripod I picked up for 6 bucks. To this base I can thumbscrew any number of accessories can now be added including several types of Tower launchers, Various launch rod combinations for gliders, Pistons, or just used with a single .049" rod for everyday type launching. This base and tripod have become my workhorse launcher.

For the clubs I belong to I've fabricated flat 1/4" alum. Slip over attachments with Z bent .049" x 12" rods that again slip easily onto any standard 1/8" launch rod, have a cut-out that will accept the standard "old time" Plug igniters or hold any other type you'd like to use and a hole the allows the microclip leads from the host launcher to be supported so as to take some of the weight off the igniter leads. These have been used at several Regionals, and I believe were present at the Naram-51.

I do have a 36" x 3" x 4" 6 pad Micro Rack. Spacing between the rods is 6.0". This rack has been used at a number of club and regional launches. Designed to be mounted on a single standard Camera tripod and works extremely well with large numbers of fliers and is quite stable in windy conditions. We've had as many 8 or 9 people at or around the rack while loading with no major problem with crowding. IT Is tight spacing but is not a time consuming problem. Below are some photos of these items. I have drawing of some of them if you'd like to make one yourself. The only one that required any really special machinery was the micro rack as I did have to use a 40" sheet metal brake to form the base body channel. Other then that all were completely constructed in my TINY townhouse basement backroom workshop with handtools, a drill press and belt sander. If I can do it just about anyone can
If you'd like I can post or send you my working and/or as built drawings for most of these Ground support equipment items.

 

[Micromeister]

A couple more pic of the rack with the old modified silo bases and after modifications at last springs Blue/Grey Regional in Virginia.

Truely John: if you club is currently using a standard 6 or 8 position launch rack system with standard smooth jaw micro clip igniter connector leads, I'd strongly suggest building 4 to 6 slip over rod launchers. Even if you make the support beam out of wood covered with some form of blast resistant Stainless tape, Nomex Cloth or something, they are the quickest and easiest way to make Micro flying easily accessible at club launches. Being flat they can lay in a small space in a given box or have a special place in your equipment tote. Rods can be sized to fit whatever container you have available as just about any length between 9 and 12" is fine for even the heaviest Micro's. the only time I use longer rods is with Gliders that are generally taped halfway up the rod anyway

Those fancy Z-bend rods are not a major problems either; they are done by hand with a pair of pliers and fingers.
a 1/4" offset allows Any size body tube model to be centered over an igniter. Not really necessary if your not faced with the old style plug igniters but a handy adjustment method anyway.
Let me know if I can be in any way of help.







View attachment Eq04-b1_MM-6-Pad-Rack_AsBuiltDrawing-c_12-2000.pdf

View attachment Eq04-c1_MM-6-Pad-Rack_Rack Mods_03-20-06.pdf

 

[Micromeister]

if your worried about losing rods or slipover pieces make up a special box for them. below are a couple pics of a Basswood storage/presentation box I made for two of the flat 1/4" slip-over Aluminum based micro launchers.
Doesn't have to be fitted but is wasn't that big a deal to make. other then getting the sliding top to work smoothly Actually making the box was more fun than building the slip-on launchers

 

[JAL3]

Hi, Micro.

I had a feeling I would be hearing from you before too long.

Actually, a lot of what I'm envisioning is integrating and adapting ideas I've seen here, many from you, and from the MMX yahoo group. Nothing I've seen goes all the way to what I am seeking but a lot of it goes a good way in that direction. I just want to play with the ideas and come up with something that will work dependably for me and my club.

This is going to be a slow process. I'm taking it easy. I started posting last night because I was at Lowe's yesterday and bought the first of the stuff I know I''m going to use and decided its time to start soliciting ideas as I start to firm up my own.

Assuming I get some time today, I'm going to take some measurments and make some detail drawings of various igniter schemes I've run across. Then I can get started on the actual ignition system drawings and post them for comment.

Using the Z bend is actually a big part of my plans. That has been the most successful for me so far and I got the idea from Art Applewhite when he used to attend our club launches. I do have some mods in mind, though.

6" spacing? that's tighter than I had imagined but workable. The fuzzy number I had in my head was 9"

Something I would really like to see is ideas for pistons. That is something I have almost nothing on thus far.

 

[Micromeister]

I e-mailed you some additional info on my micro floating head piston launcher. and though I've had it published in our club new letter Zog-43, posted it to the MicroMaxRockets Yahoo group and given the design drawing to Sport Rocketry so I guess it should also be posted here LOL!

By the way if you notice the Piston launcher is attached to my workhorse tripod/alum launcher base I mentioned earlier.

The real KEY to piston launcher is reliablility of continuity thru all the layers, body,floating head and expendable igniter. To that end the .100" Mill-Max Socket connectors have proven to be IDEAL. these interconnecting stackable sockets have provided 100% performance in the shown configuration.
Soldering the 30ga bare nichome into the sockets isn't that big a deal either, I set up a 25watt pencil iron in the living room to assemble about 50 igniters in a little over an hour while watching TV one night.
Hope this helps.

 

[JAL3]

Well, its not much, but I got started by taking out a stock MMX igniter, measuring it and drawing it on AutoCad so that I could use it as a block for further work.

Its not pretty but should be good to within 1/32", at least according to my eyeballs. I'm posting the file only because it might save somebody else some eyestrain some day.

View attachment MMX igniter.dwg

 

[BobH48]

In your first post you said this was your goal:

with a minimum of effort, I want to be able to treat an MMX rocket like any other. Go out to the assigned pad, hook it up, walk away and have reasonable confidence that the rocket would launch.

I am assuming that you are taking the igniters out of the plastic holders and using them just like standard igniters.

If so, what I use takes 5 seconds of prep. You walk out to the pad with your MMX rocket already on the launch rod, clip the clothespin to the standard sized launch rod and hook up your clips.

Picture 1: hole drilled in clothespin with launch rod attached. top view

Picture 2: side view

 

[JAL3]

In your first post you said this was your goal:


I am assuming that you are taking the igniters out of the plastic holders and using them just like standard igniters.

If so, what I use takes 5 seconds of prep. You walk out to the pad with your MMX rocket already on the launch rod, clip the clothespin to the standard sized launch rod and hook up your clips.

Picture 1: hole drilled in clothespin with launch rod attached. top view

Picture 2: side view

I appreciate the input and the clothespin you show is actually a part of the plan at this point.

As for the igniters, I want to be able to use the stock MMX igniter in the plastic, the MMX igniter busted out of the plastic and the Quest Q2 igniters without having to change hardware setups. I think I can do it. Time will tell.

 

[billspad]

I appreciate the input and the clothespin you show is actually a part of the plan at this point.

As for the igniters, I want to be able to use the stock MMX igniter in the plastic, the MMX igniter busted out of the plastic and the Quest Q2 igniters without having to change hardware setups. I think I can do it. Time will tell.

Take a second clothespin and glue it to one side of the clothespin in Bob's gadget with the end that opens on the same end as the rod with the z bend. Use this to hold the old plastic igniter or that little cardboard tube that comes with the Q2 igniters.

I haven't tired it but works in my head and I think it may work in reality.

 

[MarkII]

It will be very difficult, if not downright impossible, to connect microclips to the igniter leads of the QMX igniters if they are still housed in their plugs. Too little of the leads is exposed. That's why we all started the now-routine process of removing them from their plug housings before using them.

MarkII

 

[JAL3]

It will be very difficult, if not downright impossible, to connect microclips to the igniter leads of the QMX igniters if they are still housed in their plugs. Too little of the leads is exposed. That's why we all started the now-routine process of removing them from their plug housings before using them.

MarkII

I have a solution, I think.

Time will tell.

I have to travel out of town in the morning to another church. Depending on when I get back, I may get a little more work done on this project.

 

[JAL3]

Today's miniscule contribution was to draw up an MMX igniter stripped from the plastic casing.

It is less precise than the other because my poor old eyes have a worse time looking at those little tiny hash marks. Besides, I figured there would be more flexibility with this one.

View attachment MMX stripped igniter.dwg

 

[GuyNoir]

In your first post you said this was your goal:


I am assuming that you are taking the igniters out of the plastic holders and using them just like standard igniters.

If so, what I use takes 5 seconds of prep. You walk out to the pad with your MMX rocket already on the launch rod, clip the clothespin to the standard sized launch rod and hook up your clips.

Picture 1: hole drilled in clothespin with launch rod attached. top view

Picture 2: side view

Utterly brilliant.

Thanks!

:clap:

 

[Micromeister]

It will be very difficult, if not downright impossible, to connect microclips to the igniter leads of the QMX igniters if they are still housed in their plugs. Too little of the leads is exposed. That's why we all started the now-routine process of removing them from their plug housings before using them.

MarkII

Not really mark:
We've been using standard Plug types as is for years with standard 1-1/8" smooth jaw micro clips in several of the launcher bases i've discribed, particularly the Coiled Clips types and the Slip-on standard rod micro launchers. I'm surprised this is coming up it's never been considered a problem as far as I knew.
Slip-on flat models the igniter sits in the cutout with a clip attached to each side, one of the reasons for the mylar covering to insulate the clips from the aluminum base plate. Excess weight of the microclip wire is held by passing the leads cris crossed thuough the hole in the base plate.
Removing the igniter form the plastic plugs simply makes it easier but lots of modelers don't carry around a couple pair of pliers, preferring to just use the old style plugs as is.

Sorry the only photo I have showing the old plug types used directly in micro clips is this one but all 4 of the models in this pic are using standard old style plugs connected to Coiled Clips added to modified old silo bases on my rack. it's just a matter of positioning.

 

[BobH48]

I gotta agree with Micro on this. Before I started taking the plastic igniters apart, I used a piece of plywood with a slot cut into it glued to a launch lug.

I clipped the wires to the launch rod with a clothespin so there was no strain on the leads.

 

[Micromeister]

I gotta agree with Micro on this. Before I started taking the plastic igniters apart, I used a piece of plywood with a slot cut into it glued to a launch lug.

I clipped the wires to the launch rod with a clothespin so there was no strain on the leads.

Bob's made a slip-on launcher base very similar to the ones i've made for the clubs but made out of wood rather than 1/4" alumimun. Really the only reason I used alumimun over wood was to make them last longer in heavy Open Club sport launch use.

 

[JAL3]

I had liked what I had seen of several ideas that used a slot to support the igniter and that was a part of the idea as well. That being the case, the first thing was to come up with the arm that provided the support. I decided on 1/4" plywood as the basis for the framework. I picked it for dimensional stability and because it is an insulator. Most important, though, it has laminations oriented at different angles so that shear should not become an issue. This was because I planned on a relatively skinny support, for reasons which will later become apparent.

I opened up Autocad and drew up a support arm that had a slot that was just a touch bigger than the plastic encased igniter. At this point I did not concern myself with length, only the part that would support the igniter. I then printed out this simple drawing.

 

[JAL3]

Although the support beam would ultimately be of plywood, I did not use plywood at this stage. I chose instead a scrap of 1/4" balsa since it would be easy to whittle on and adjust and because it happened to be handy.

 

[JAL3]

The template was trimmed a bit and then applied to the balsa with a glue stick.

 

[JAL3]

The rough piece was then taken to the belt sander and the profile was trimmed down to the outer edges of the template.

 

[JAL3]

With the outer edges taking place, a razor knife was used to carve out the igniter slot.

 

[JAL3]

Later that night, it was time to examine the first fruits of the project and I spread my stuff out on the kitchen table after the Mrs. had gone to bed.

 

[JAL3]

I put in the plastic igniter ans was glad to see it fit; with me doing the measuring and cutting, such things cannot be assumed.

 

[JAL3]

I also test fitted the stripped down, paper clad igniter and it fit as well.

 

[JAL3]

One of the problems I had experienced with other MMX systems was the attachment of the microclips. My scheme was to get rid of the "micro" altogether and replace it with "macro". I found a plastic clamp at Lowes that seemed to fit the ticket and tried it on to support the plastic igniter. At first blush it seemed to work.

 

[JAL3]

Looking at it from the top, though, there was a slight problem. The grips on the clamp were just a touch wider than the slot. For the ultimate plan, they needed to fit flat within the slot.

 

[JAL3]

Before doing any adjustment, though, I wanted to try it with the naked igniter. I slipped it into place, oriented 90 degrees from the way the plastic one had been, and made sure the leads extended on either side of the support. The clamp was then placed, much lower down this time, pinning the leads to either side of the support arm. I then spent some time fussing with it. Key to making my scheme work was the degree of stiffness of the igniter in this orientation. It seemed to me that the clamp was sufficiently tight to hold it in place without any wiggling.