My First Public Build :-)

after lines marked with a dab from a red ink pen guides removed pic 28

Pic 29 lines drawn 2 11/16 inches long to indicate where the front part of the fin root ends

Pic 30 shows the 1/16 gap with red lines
and the yellow lines show the error of the 1/16 gap being to far to the right
of the original line

Better to erase the outside line and correct it instead of a wide gap between the fins and edge of the BT55

Pic 31 shows where the double lines were erased back till just 2 11/16 inched remained

pic 32 shows all 4 of the BT55 tubes marked and ready for slotting
Pic 33 shows some of the handy tools I have used on the slotting

Normally I use a red colored lead in the mechanical pencil so it can be erased
and not bleed through the paint, but I was out of it

qquake2k said:

Wow, reminds me of drafting class!

Click to expand...

now cutting the slots in the BT55
pic 34 & 35 show the starting of the cut. Use slow and light pressure strokes .
A X-Acto knife with a new sharp blade is a must !

Pics 36 & 37 after a few practice cuts on some scrap and the first cut on the BT55 it gets easy to get straight lines
I did not cut all the way to the end until all 4 slots were cut. This prevents the loose ends from flopping around

pic 38 shows where I placed a centering ring inside the BT55 to give some support as I cut on the tube .
pic 40 shows all 4 slots cut

Pic 41 is ready to mate the BT50 inside the BT55
Pic 42 shows the air gap is a tad to narrow so I had to shave the edge off one side

pic 43 the result of the mating of the BT50 & BT55
Pic 44 shows the Kevlar loop just inside the edge of the BT55 so no zipper.
The elastic shock cord will attach to the Kevlar loop

pic 45 & 46 show the mating of the BT50 into the BT55 from a different view.

Also to reduce strain on my eyes and reduce crooked cut lines I only cut slots on one
airframe per day

No gluing will be done until all 4 of the BT50 are mated inside the BT55

Bobby

before I went to far and glued the BT50 into the BT55 I wanted to try an experiment .
As I posted before on the forum I got some Elmer's Carpenter's wood filler ( CWF ) and tried my hand at
sealing the birch fins . I put the scrap section of the finished BT50 with the fins sealed with the CWF inside a slotted BT55 .

Pic 47 & 48

I applied a small amount of super glue to hold the end section to the centering ring down and applied pressure until the glue set
Pic 49

after masking off 1/16 of an edge with tamiya tape on eater side of the fin joint I
applied some epoxy glue . 12 hours later I will remove the tape to see how the CWF surface
holds up to the tape and epoxy

Pic 50 & 51

The test is to see how well the epoxy holds on top of the CWF. If all goes well I well seal all of the fins with CWF before inserting
the BT50 into the BT55

What I should have done was paint the checkerboard pattern on the left fin to see how the black and white paint sections look through the clear epoxy ?

Bobby

Ok I am back now , Been away dealing with other things and working on getting a color laser printer
The taping the edges of the fin glue fillets didn't come out to good. I will try the tape again but
put it further away from the glue fillet . The result I want to get are on the rocket on the left with the non sealed fins.

Just wanted to add some pointers for the ones who are just trying the slotting technique on thin Estes airframe .
When starting the slot do not cut all the way down one side then the other . Cut a short distance of 1/2 to 3/4 inch on
one side then do the same on the other side. This will provide support as you cut . Using this technique you can slowly
work your way down to almost the end of the slots.

If the slots are to be cut all the way down to the end of the tube ( like on this build ) insert a centering ring to provide
support and keep the loose ends from flopping around

NOTE A sharp hobby knife will make the cutting a lot easier and give a sharp cleaner cut

I have the last 3 BT55 tubes slotted . All I need to do is insert a centering ring
and cut the slots all the way to the end of the tube

Will get that finished tonight

Well all 4 BT55 tubes have been slotted and fitted to the BT50 motor tubes .
The fins will be finished with Elmer's Carpenter's Wood filler before the BT50 motor tubes
are epoxied into the BT55 outer tubes.

You can see where one of the Kevlar shock cord attachments is a tad shorter than the other 3

bobby_hamill said:

Here is a photo of the 3 laser cut fin alignment guides ( Thanks Carl )
I marked the front on all 3 and at the bottom to keep all 3 guides aligned the same way

Click to expand...

Where'd you get the fin guides? Carl? Total noob here...

Thanks

Nathan

Carl is a great person to deal with and does excellent work !

link below

https://dfrtech.com/

If you like I can post the 2 files I sent to him to have the fin guides and fins laser cut ?

Bobby

Normzilla said:

Where'd you get the fin guides? Carl? Total noob here...

Thanks

Nathan

Click to expand...

I finally got back to my build and applied a coat of Elmer's Carpenter's Wood filler.
Adding water to the filler thins it out and makes it flow into the wood better .

After letting the filler dry for 24 hours I will sand and apply a second coat

I had to number the motor tube and outside airframe so I would not have any trouble matching the pairs together

sanding of first coat , wipe dust off fins and second coat of sealer applied.
After first coat is applied all later coats will be very thin coats
NOTE please use a dust mask and eye protection when sanding

Bobby

I have been under the weather last couple of days.
Nothing serious just headache , runny nose , and sore throat.
give me a couple of days and I will be back working on the build

Bobby

well cold is about gone now . Still kinda on the yucky side .
So apples. orange juice, rocketry. and alka selser + cold medicine works wonders

just got through sanding the last coat of Elmer's Carpenter's Wood filler.
I mated the BT50 engine mounts back inside the BT55 to make sure everything still
lined up and fit as required .

I am shooting to have the BT50s inside the BT55s epoxied in place and thin fin fillets
applied . So I can apply the first coat of black paint .Gonna be in the mid 60s on Thursday and Saturday
near border line for applying paint but I am willing to give it a shot

The BT50 tubes have been dusted off and ready for gluing into the BT55s

You multiply well

Keep up the good work!

Got all 4 of the BT50s glued inside the BT55s.
Fillets and launch lugs left to be done, then ready for paint

first session of fin fillets completed

thanks qquake2k