No matter what method, practice, practice, practice.
How to Cut Chipboard Cardboard (back of a legal pad)
- Thread starter brockrwood
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Four fins created.
Method:
Draw rough shape on cardboard.
Cut out with scissors.
Drill small hole in approximate center of 13 mm motor mount tube circle.
Ream out the hole with the tapered reamer (I love my tapered reamer).
Sand the hole even bigger and clean it up nice.
Keep sanding until the 13 mm motor mount tube fits perfectly.
Next Step - do the other 13mm motor mount tube hole.
Third step - sand down the outside of the motor mount centering ring until it fits into the 29 mm body tube.
Fourth step - repeat all of the above to make another one.
Fifth step - wish you could afford a laser cutter.
Draw rough shape on cardboard.
Cut out with scissors.
Drill small hole in approximate center of 13 mm motor mount tube circle.
Ream out the hole with the tapered reamer (I love my tapered reamer).
Sand the hole even bigger and clean it up nice.
Keep sanding until the 13 mm motor mount tube fits perfectly.
Next Step - do the other 13mm motor mount tube hole.
Third step - sand down the outside of the motor mount centering ring until it fits into the 29 mm body tube.
Fourth step - repeat all of the above to make another one.
Fifth step - wish you could afford a laser cutter.
DES
Well-Known Member
Might want to give a jewelers fret saw a try. Like a coping saw, but one that actually works. The blades are very thin and very sharp. I use them to cut sheet metal, but they would make short work of chipboard, and you can cut right up to your line with precision. Tooth count anywhere from 18 to 60 teeth per inch, something on the order of a #1 with 48 TPI would be about right for chipboard. A little bit of technique required, but easy to use with a little bit of practice. Just keep the handle straight and don't bend the blade. Don 't yank, especially when backing out of a cut.
With patience, you can cut hardened steel with a jewelers saw. Should be able to saw out a chipboard circle in about three minutes.
The fret saw also works well on phenolic, fiberglass, and PCBs.
With patience, you can cut hardened steel with a jewelers saw. Should be able to saw out a chipboard circle in about three minutes.
The fret saw also works well on phenolic, fiberglass, and PCBs.
If you're going that way (which is not a bad idea) buy a pack of blades. You're all but certain to break one or two as you get the hang of using it. They're not expensive, and you don't want to be stopped because of not having one on hand.
Like any skill, building model rockets takes practice. You are going to learn what to do and what not to do as you build your models. What happens is you learn little details - hundreds of them - as you build. Things like, "If a tube and tube coupler have a snug fit, and you are going to glue them together, sand the tube coupler until you get a looser fit. If you don't, then the when you apply the glue, the fit will go from snug to "super tight" and you will not be able to get them all the way together. Then you will be tempted to press too hard and you crease the body tube".
Sigh. That is how I learn everything. By goofing it up the first couple of times.
Your point is valid and correct, that we learn both from our one mistakes and others'. The coupler example, well, that depends on the gl... Never mind. That's a whole other thread. Wait, strike that, it's lots of other threads.
The coupler problem relates to the working time and "grab" of yellow glue.
A glue for paper that has a longer working time without grabbing will solve that, i.e. white glue or epoxy.
For LPR, white glue is less messy, doesn't have to be measured and mixed, and is less expensive than epoxy.
But then again not all white glues are the same.
I better stop now.
PS jqavins glue is not a dirty word, you can say it.
woo woo woo woo woo nyuk nyuk nyuk.
A glue for paper that has a longer working time without grabbing will solve that, i.e. white glue or epoxy.
For LPR, white glue is less messy, doesn't have to be measured and mixed, and is less expensive than epoxy.
But then again not all white glues are the same.
I better stop now.
PS jqavins glue is not a dirty word, you can say it.
woo woo woo woo woo nyuk nyuk nyuk.
Of course it's not a dirty word. I was trying not to start another glue battle.
Glue, glue, glue, glue, glue.
You guys are hilarious!
As for glue, I just use whatever works. I have to admit that I might be changing my mind about Original Titebond versus Titebond II. I used to swear by Titebond II, but it DOES have some water resistance, which makes it a little harder to get off and a little harder to clean up. Recently, I have started using good old Original Titebond. It seems to have a pretty fast tack, like Titebond II, and it is a bit easier to clean up.
I take it back. I never wrote anything about glue in this thread. This isn't another glue thread, after all, so why would I write anything about glue? I never did!
Fins on. Motor mount ready for sanding.
The fin pattern is from the Estes Astron "Cobra". See these plans at JimZ: http://www.spacemodeling.org/jimz/eirp/eirp_17.pdf
The Astron Cobra was showcased in the Model Rocket News, August/September 1963: http://www.spacemodeling.org/jimz/mrn/mrn_v03n04.pdf. I was three months old.
The fin pattern is from the Estes Astron "Cobra". See these plans at JimZ: http://www.spacemodeling.org/jimz/eirp/eirp_17.pdf
The Astron Cobra was showcased in the Model Rocket News, August/September 1963: http://www.spacemodeling.org/jimz/mrn/mrn_v03n04.pdf. I was three months old.
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Launch lug on. Motor mount sanded and fitting well. Time to put a small launch lug near the top of the main body tube and sand the tube coupler to get a looser fit to the main body tube.
I think the next time I make a custom, cluster motor mount, I will do the motor tube holes in the cardboard first, leaving them in a big square of cardboard. I will get those holes sanded to perfection and THEN I will cut out the big circle around them to make the outer part of the centering ring. When I cut out the outer circle at the same time as the holes for the motor mount tubes, I had a lot of trouble sanding because I had very little material to hold on to while doing the sanding. Live and learn.
Gosh. After all of this work, I hope I don't lose the rocket or crash the rocket on the first launch. It is a rotten thing when the model you have slaved for days to make is lost the first time you launch it.
I think the next time I make a custom, cluster motor mount, I will do the motor tube holes in the cardboard first, leaving them in a big square of cardboard. I will get those holes sanded to perfection and THEN I will cut out the big circle around them to make the outer part of the centering ring. When I cut out the outer circle at the same time as the holes for the motor mount tubes, I had a lot of trouble sanding because I had very little material to hold on to while doing the sanding. Live and learn.
Gosh. After all of this work, I hope I don't lose the rocket or crash the rocket on the first launch. It is a rotten thing when the model you have slaved for days to make is lost the first time you launch it.
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