You are directed to draw a line down the entire length of the BT-101 tube.The instructions show a line drawn using a door frame.
This tube is wide! I found it hard to fit the tube into a door frame.
This wouldn't be any problem with a 1" diameter tube, but this thing is 4" in diameter!
I had better luck using my handy aluminum angle.
In the picture you can see two lines. the pencil line closest to the angle was drawn using that angle. The line to the right side was drawn in a door frame.
Enlarge the picture and you can see the difference between the two. The door frame line wavers a bit and isn't straight from end to end.
There's really nothing very special about the engine mount stuffer tube. I won't be covering much of it's construction here.Simply slit the tube then insert the forward end of the engine hook in the slit.
To the left side of the picture is the brown retaining tube. It's very thick and holds the hook very well.
The centering rings are another story.
The fit around the internal BT-50 motor mount tube was perfect.
The outside edge of the large centering rings was pretty loose in the BT-101 main tube.
Around the outside edges I build up the diameter slightly with two applications of a white glue bead.
This was just enough to give me a better slip fit of the centering rings.
Time spent on build: 1:45 making engine mount and marking tubes
Total time on build so far: 3:15
Drawing a perfect line on a large/long tube is a difficult proposal indeed. If you hold the tube too loosely it can slip, if you hold it too tightly it can warp the tube and mess up the line. The aluminum angle is the best way to go, and you don't end up with pencil lead on your doorframe.
ReplyDeleteThe instructions say to shove a small ring of cardboard tube inside the stuffer tube using another yellow tube as a depth guide, and you're supposed to have glue inside the stuffer tube for the small ring to pick up on the way in. I can't see how this leaves enough glue on the small ring, and I wanted to add a fillet of glue to the ring, but it was way too far inside the small stuffer tube for me to reach with my glue or finger.
ReplyDeleteMy solution was to pour the glue in, watching where it landed to make sure it got on the ring shoulder correctly, and then I used the back end of a small paintbrush to make the fillet. The small diameter of the brush, the rounded end, and the length of the brush handle, made a perfect tool for this.
Several times I pulled out a lot of glue and wiped it on a paper towel, but it did the job better than I could have done using a finger tip even if I could have reached it.
Hi Mushtang,
ReplyDeleteYou've got to be careful how much glue you use on the internal fillet. A heavy glue ring will shrink and pucker the outside making a recessed ring around the tube.
Next time, intead of pouring glue in, try transfering a drop on the back of the brush end onto the joint and smooth it out with the back end of the brush. You also remove any excess with the back end of the brush and wipe that off.
Keep repeating the one-by-one drop transfer of the glue until it is all the way around the ring joint.
Good luck with the rest of the build.
I'd read that on one of your posts, but since this was the stuffer tube and not the body tube I wasn't that concerned with how the outside looked. But I'll definitely be careful gluing the engine mount to the inside of the BT.
ReplyDeleteI've already built up the outer diameter of the rings with glue like you recommended, and they fit much better now.
I'm in the middle of filling the grooves in the body tubes, and will glue the engine mount next.
I can't imagine how badly this would look without your blog to guide me. Thanks again!
What size aluminium angle did you used?
ReplyDeleteHi Admin,
ReplyDeleteThe aluminum angle is about 1/2" high (each side of the "V") and about 18" long.
I use it on all tubes.
It's a little large for BT-5s but still usable. It's almost too small for the BT-101 (on a Saturn V) but can still be used to mark the tubes if it is held steady.
I only have the one aluminum angle.