Lil- Rascal- from components to the Launch Pad

[Rrwjr]

I decided it was time to try and do my first build thread. I have read many peoples build threads and learned lots from them. So here is my attempt at a give back to the rest of you TRF'ers. I will try to include as much detail and as many pics (cuz- that what we all like) as I can. One of the things I enjoy in peoples threads is when they explain why there doing something, I will also attempt to do this. I will look forward to your feedback as to what you like or don’t like about the style I use for this build thread

One of the things I feel is important is to determine what your intended use is for the rocket. There are many different things you can do with this kit and here are my plans for it.

It will fly with 38mm motors up to 3 grains
It will fly with 54mm motor up to 2 grains
It will fly with a transmitter in it
It will carry some sort of altimeter in it


About now someone is asking “Why not stick something bigger in it?" As I have mentioned in some other posts, I am enjoying the journey thru model rocketry and I am working my way up to the really "big stuff".

One of the better investments I have made in model rocketry was to purchase roc-sim. I have found that it allows me to think thru my builds a bit more before actually starting them. So for me step one was to make a Roc-Sim file that matches what I have for components in the kit. I would like to enclose the Roc-sim file but i cant seem to figure out how to attach it. It appears i may need some permission, i havent earned. So my first request from you guys is a bit of guidance on how to attach it. The standard components I received from the kit are within ½ of an ounce of my Roc-Sim file so I see it as a good starting point.

Here is the first picture showing all of the components that came with kit.

I am a big believer in dry fitting as much as possible. When I received this kit it was the first “molded” fiberglass nose cone I had received. There was a pretty big parting line step and I took time to blend the parting line on the main part of nosecone as well as shoulder of cone.


After I had removed the step I made sure cone fit into body tube.



More to come........

 

[Rrwjr]

Well it looks like i figured out how to add the roc-sim file.

View attachment Lil Rascal 4in.rkt

 

[Rrwjr]

I spent a few hours today at the RC track with my son, which meant not much progress has occurred. So back to the build, as I had mentioned before my intent was to use some 38mm motors in this rocket. I had this nice adaptor from Aero-Pak that I wanted to use.


I also had an Aero-pak 54mm retainer.

The down side to Aero-Pak items that I see is the cost of the items. They are very top quality components and I wanted to try them out to see how they perform. The 38mm to 54mm adaptor can also be used on future builds hence spreading the cost out over more than 1 rocket.

I decided I would check out how the adaptor would fit in the motor mount. Good thing I like to dry fit, because as picture shows- we have a problem.:y:


Well the easiest way to solve my problem was to cut a longer motor mount tube. Good thing I had a 5 foot long tube from Wildman. Now how long should I cut it? I decided to go with a 2 ½ longer mount than stock (8.5 versus 6). Let’s see how that looks. with the motor retainer , adaptor , and the main air frame


Well that looks much better.:grin: Now time to do some more dry fitting.

 

[chadrog]

Damn you bought five feet?!? Can I get six inches from ya? Looks good, BTW.

 

[Rrwjr]

The next thing I decided to do was fit the centering rings using my Dremel.


After I got the center of the rings to fit, I decided to do a mock up on the outside of the airframe. As you will see I added a 3rd fiberglass centering ring. I have a tendency to overbuild. What do you guys think leave the 3rd ring in or out?


After seeing how things looked, it was time to fit the outside of the rings to the inside of the airframe. ( Sorry no pic of that).I then went ahead and did a dry fit with rings, motor mount, fins, and nosecone. Please excuse my disorganized work area,


Here is a view from the back with the 38mm mount in place.


Here is a view from the back with the 54mm mount in place. Now that looks awesome


Next its time to mark where rings go- tack in place and mount the shockcord. Stay tuned.

 

[Rrwjr]

Damn you bought five feet?!? Can I get six inches from ya? Looks good, BTW.

Yeah I bought a big piece. I knew I would be looking at using it for a few things I have brewing in my head. No problem. giving you some of it, you sure you only need 6 inches?

 

[JDcluster]

I also added a third CR on mine and it's even the same color!
For motor retention I went with drilling and tapping the rear CR instead.



JD

 

[chadrog]

Yeah I bought a big piece. I knew I would be looking at using it for a few things I have brewing in my head. No problem. giving you some of it, you sure you only need 6 inches?

I have an odd thing brewing as well, 6" is all I need. It's funny this came up, I was going to order some from Tim tomorrow - along with a couple other things. Thank you.

 

[Rrwjr]

I have an odd thing brewing as well, 6" is all I need. It's funny this came up, I was going to order some from Tim tomorrow - along with a couple other things. Thank you.

Well based on some of your prior projects, your "odd" thing will probably kick my ideas _ss. What else you need, maybe I have extra of those as well? I got your tube ready for you. Do you want me to bring it to Sod Farm next week or do you want me to mail it to you? PM you address to me if you want me to mail it.

Alright back to this build. I want to fly this at the January launch at Bong.

 

[Rrwjr]

I also added a third CR on mine and it's even the same color!
For motor retention I went with drilling and tapping the rear CR instead.



JD

Thanks for the feedback. I'm going to keep the 3rd centering ring in the build as well.

 

[Rrwjr]

I took the motor mount and placed the retainer on the end and drew a circle around tube, then I put the back centering ring on and put a circle around tube where it was. I then measured the amount over for the fin tabs and then drew a circle around tube. Finally I made a circle around tube front of motor tube for extra centering ring. I might also add in here that I had scuffed up the motor tube with 60 grit paper.


I went ahead and also marked where I was going to put the shock cord. I am going with a motor mounted cord. I am using 3/8 kevlar. Probably also over-kill but I would rather be safe than sorry.


With the motor tube all marked up, it was time to go on to the Airframe. I like to try to get rail buttons as close as possible to being centered between fins. I take a piece of cord and tape it on to the airfarame. I tape the edge even with one of the fin slots and then I mark the cord at the end of the other fin slot.


I remove the cord and make a mark in the center of it. ( wow horrible picture)


I re-tape the cord back on to the airframe and marked the airframe in the center of the slots.

 

[Rrwjr]

Then I use the old door jam trick and draw my line down the center of the airframe. I then went ahead and determined where I was going to put the rail buttons as well as a vent hole. I also drew where the nosecone shoulder ended so I could make sure I didn’t have any problems with where shoulder ended.


Speaking of rail buttons, I found these handy items called brad holes at my local home depot. At 69 cents each they seemed like a decent deal.


With all of the layout work done for the airframe and motor mount, it is time to actually start doing some real assembly. I started with the shock cord. I used a bit of CA on the motor tube and attached the shock cord.


Wow- I didnt realize how much time it takes to document and take pictures when doing a build thread. I have a new found respect for all who do build threads.

 

[chadrog]

Well based on some of your prior projects, your "odd" thing will probably kick my ideas _ss. What else you need, maybe I have extra of those as well? I got your tube ready for you. Do you want me to bring it to Sod Farm next week or do you want me to mail it to you? PM you address to me if you want me to mail it.

Alright back to this build. I want to fly this at the January launch at Bong.

At the sod farm will be great, thanks again.

 

[Rrwjr]

Well I got some more time to work on rocket today, so here is what I did next.
After the shock cord had time to set up I notched 2 of the 3 centering rings so they would fit over shock cord.



I then tacked in the centering ring that is at the end of the fin slots. I used CA to tack it in place. I was lucky enough to find a coupler and a centering that added up to the right height where the ring needed to be located. This helps keep the ring square on the motor tube.


While the centering ring was drying, I went ahead and drilled (2) 1/8 holes as pilot holes for the rail buttons. I like to use this set-up as it helps me accurately locate the holes.


I went ahead and opened them up to 5/32 with a regular drill. I also drilled a 3/32 vent hole at this time as well.

 

[Rrwjr]

Next was scuffing up the inside of the airframe. Hard to show in pictures, but if you look close you can see the scuffs. I used 40grit paper and used a cross sanding pattern to scuff tube where fin slots are and where centering rings will be attached to airframe as well as where rail buttons will attach.


I used some tape on the fins to stop where I would scuff the fins. Like the airframe, I used a crosshatching pattern.


The first centering ring had time to set up so I tacked the front centering ring into place. I used 2 other rings as spacers to get ring supported and square to the motor tube.

 

[Rrwjr]

I then used epoxy and put it around the centering rings and let it dry. I put epoxy on both sides of the top ring and only on 1 side of the 2nd ring . I didn’t want to affect how the fins fit in the fin slots with a big clump of epoxy there.


After the CA set up I then used some JB weld to attach the cord the rest of the way. This is the first time I used the JB weld on the shock cord. I had previously just used epoxy. I decided to try the JB weld after reading about it on TRF.


After the JB weld has dried it was time to install the motor mount. I put some epoxy in the airframe where both centering rings contact the airframe and slipped it in.

 

[Rex R]

I like to bundle the shock cord and insert it into the motor mount. helps keep it clean/out of the way.
rex

 

[Rrwjr]

I like to bundle the shock cord and insert it into the motor mount. helps keep it clean/out of the way.
rex

Good point Rex. Not sure why I didn't do that:bang:

 

[Rex R]

the other thing I've found useful(doesn't really apply here), is to feed the cord through the mount, then when it comes time to attach the nylon cord, you can actually tie it on fairly easily w/o needing tiny hands or tweezers .
rex

 

[Rrwjr]

After allowing the motor mount to dry, I notched the corner of all 3 fins to clear area where epoxy had settled on centering rings.


I then tacked the first fin in using CA and let it dry.



Next was the second fin.

 

[Rrwjr]

After the 2nd fin dried I tacked the 3rd fin in with CA. I might mention here that I was very impressed with the fit of the fins to the fin slots. When the fit is as nice as this fit was, it makes keeping fins square and fin alignment to one another very easy.

 

[Rrwjr]

It’s good to get back to this rocket. I was out of town on business, so I missed out on some building time. I have seen many people use dowels or skewers in the corners of there fin cans. I thought I might try this practice and see how it works.

I started with cutting skewers to length and then roughing them up just a bit.


I then went ahead and used epoxy and laid a fillet in the corners and then placed a skewer in the epoxy. I then added epoxy over the top of the skewer. I did 4 corners at a time.


After all of the skewers were in place and had time to dry, it was time to put in the back rail button before putting on the back centering ring.


I made sure I removed any epoxy residue on the outside of the motor mount and the inside of the airframe where the fins were attached. The back centering ring dropped right in.

 

[Rrwjr]

I put some epoxy on the inside of the centering ring (side towards the fins) and pushed it in. I followed up with the motor retainer. I used JB weld on the retainer and pushed it up against the back centering ring .


A bead of epoxy around the outside of the last centering ring and the fin can is complete.

 

[Rrwjr]

Finally -getting some time to update the thread. I have had a few moments here and there over the last week to do some work and I snapped some pics but just haven’t had time to post.
I decided to start some work on the nose cone. Based on the motors I plan on using on this rocket and using the Aero – Pak 54 to 38mm adaptor, I came up with 15 ounces of nose weight I need to add.

Photo below shows me trying to figure out how many BB’s this will take, this is 1/3 of what I needed


Since this nose cone is a molded fiberglass cone the inside of it is pretty rough already. I started adding Epoxy and BB’s ( 5 ounces at a time) I let the epoxy and BB’s thoroughly set up ( about 6 hours) before adding more BB’s and Epoxy. On the last segment of adding BB’s and Epoxy I didn’t need to add 5 ounces of BB’s based on weight of the epoxy and BB’s added thus far.
Pictured is what it is looking like in the nose cone as I add the epoxy and BB’s



Numerous hours (about 24 hours later) I put the cone on the scale to see that I got 16 ounces of additional weight.


In between layers of adding nosecone weight I decided that I wanted to recess a bulk plate with a welded eyebolt. I wanted to recess it to give me more room for the shockcord, laundry and tracker.

 

[Rrwjr]

I checked location of bulkplate to see if it went down to where I wanted it.


After I got it to where I wanted it, I used epoxy and put it in and let it dry.


Next was the outside of the nose cone. As I mentioned before it had a huge parting line which I sanded down. I have read a bunch of threads where people use a Bondo spot and glaze putty . I decided to try it.


After it dried, I used wet sandpaper starting at 320 then 400 and then 600 to get the cone ready for priming.


Next was primer

 

[Rrwjr]

While the nose cone was drying, I went back to the airframe and fins. I had decided I wanted to try some of the Proline 4500 Epoxy. Having read a number of posts about this epoxy I was a bit nervous on using it. I went back and re-read the posts and decided to give it a try.

I taped up the areas I didn’t want epoxy to get to and I went ahead and put on the epoxy. After it had set up I removed the tape and I thought they turned about pretty good.



I added the last rail button and sat back and looked at it. I think its looking pretty good. Some final sanding and clear coat and hopefully if the weather cooperates here in Wisconsin, it will take to the skies on Saturday

 

[chadrog]

Looks awesome Russ, those fillets are dy-no-mite! Better get a thrusty one for it, looks like it's going to be a bit breezy Saturday.

 

[Rrwjr]

I was able to launch the lil Rascal yesterday. Rare waeather for mid January in Wisconsin. Launch was at our club launch at Bong. Weather was in the 40's with winds from 5 TO 20 mph. Skies ranged from partly cloudy to mostly cloudy. By the time i launched at 2:32 in the afternoon we were mostly cloudy , with winds at 12MPH and 42 degrees. I decided to go with a H123 Smokey sam ( 38mm 2 grain). My intent was to keep the rocket under 1500 feet. I really wanted to prove out the stabilty factor which simmed out at just over 1 caliber of stability. I also wanted to prove out if my build quality would hold up with some of the new things i did. I also wanted to avoid chasing the rocket into the trees or swamps that make Bong a fun launch sight. I decieded to only use a 36 inch chute. Here are the pictures of the launch.
Here she is on the pad.


Here is the start of liftoff:



Here is rocket in flight:


Here is rocket under Chute:



And Finally a safe touchdown about 500 feet away from the pad:



Upon post flight inspection I found no damage and everthing looked good. I was very happy with the flight and the build. This appears to be a pretty popular rocket and I look forward to pushing it further into the air.

 

[cwbullet]

Very nice build and flight. Thanks for sharing. Was it launch with a wilsonfx system?

 

[Rex R]

yes it was.
rex