3/8" and smaller is great. I'm shying away from 3/4" anymore unless it's 11 or 12" or more diameter. I used 1/2" on my 9" Patriot. Whether I fly an N motor or crash it, bigger rings won't matter.
I made this yesterday, since no one else seems to make one and I need one.
A quality metric rule mated to an 1"x36"x1/8" aluminum angle.
Tube marking and cutting slots will never be the same!
I used the ultra-thin double sided tape that I use to put shrink plastic on my windows in the Winter. That way it can be removed if necessary, or I can re-think the whole thing if I need to change it.
I could not find any Incra Angled Rules in metric of suitable length, since they don't make one.
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I made this yesterday, since no one else seems to make one and I need one.
A quality metric rule mated to an 1"x36"x1/8" aluminum angle.
Tube marking and cutting slots will never be the same!
I used the ultra-thin double sided tape that I use to put shrink plastic on my windows in the Winter. That way it can be removed if necessary, or I can re-think the whole thing if I need to change it.
I could not find any Incra Angled Rules in metric of suitable length, since they don't make one.
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For measuring/marking I turn to Incra. Far more accurate than I'll ever need to be (whether metric or imperial).
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Would it be possible for some backstory on these instead of just "jig-porn"? I'd like to see how some of these are used, particularly Dave A's scroll saw circle cutter.
They are why I had to make this. They only offer a 300 and 600mm version, and they are out of stock at the couple of places I would order one from. I was going to settle for the 600mm version, but Amazon says it's no longer available.
I have and like their 12" Rule.
Yup, just checked their site again and they NO LONGER MAKE THE ANGLED RULES.
I see imperial bend rules on Amazon. 6", 12", and18".
The circle cutter you are referring to I believe may be the one I posted, when I get home this evening I will see if I can get any photos of it in use. Also feel free to ask questions about it.
Great! Sorry for the misattribution, but I'd love to learn about your tool- cutting circles is a pita!
The process goes like this and there are two options to get the Outside Diameter
Option One:
1. Cut the blanks square to about +1/8" radius the size of the finished circle OD, mark the center and drill the center with a 1/8" brad point bit.
2. Place the center hole over the pivot pin on the scroll saw and carefully cut the circle to larger than the tube it goes in.
3. After circle is cut move to sanding jig ( 6th picture from left) drop the center over the pivot pin and lock the circle sander down and turn disc around pivot, adjust as necessary until a perfect fit is acheived in the airframe tube.
4. After the OD has been sanded to the correct size I move the disc to a drill press set up with a General Tools circle cutter (the one on right in last photo) and cut the center hole out, it may be necessary to adjust the center hole a small amount with a drum sander or dremel.
Option Two:
Everything above except step 2, instead I use the bandsaw or the scroll saw (without jig) to cut close to an circle drawn with a compass, drill for the pivot and sand to size on the disc sander (side mounted sander in the 5th photo). Generally this method is faster for thicker CR's and fewer blades get broken on the scroll saw. The disc sander uses a 60-80 grit disc.
Safety tip with the ID circle cutter: tack the CR to a waste board big enough to keep hands clear of the circle cutter and that can be clamped to the drill press table, I use 18 gauge brad nails for this purpose.
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The brass pivot pin is visible near the scrollsaw blade and near the sanding disc, it is simply a piece of brazing rod with the flux removed and cleaned up. Depending on the size and complexity of the CRs I can cut all the rings and bulkheads for a dual deploy rocket in about an hour, thats 3 CR's, and the AvBay bulkheads (each bulkhead is made of two pieces to get the step effect), and usually in the same hour I can cut the parts to include a nosecone av-bay conversion.
Awesome, thanks- I'm working on some av bay bulkheads now that I just rough cut with my cheapo-harbor freight fly cutter. Is there anything more to your sanding jig? Are the two boards interfaced in some way, or is the lower board simply a resting surface on which the upper board with pin rests?
The lower plywood board is a base for the 3 pieces that are on top. The of the 3 pieces on top the outer 2 are glued/screwed on (screws from backside), the center board is free to slide via the dovetail angles. The boards on the sanding jig are literally identical to the ones on the scroll saw jig since I cut them all at the same time from a single piece of 1/4" Poplar wood. To lock the sliding center board in place I use a spring clamp (kind of like a big close pin). The dovetails for the three boards are cut on a table saw set at a 7 degree angle or so the board is roughly cut into long strips each 1/3 the width of the original board. When setting the gap between the boards I use a piece of posterboard so everything remains fairly loose, and the outside boards only get secured to the base. The base does have a guide board on the bottom that matches the slot in the sander table for positive alignment with the disc and it also allows the jig to be clamped in with a single clamp to the table. The diameter of the guide pin is arbitrary, the next sanding jig I build will most likely have interchangeable pins in 1/8" and 1/4" since my OD circle cutters use 1/4" pilot bits.
I hope Incra brings back the metric bend rule.
I'll jump right on it if I ever do find one.
Til' then, I'm still working on designing a better 460mm bend rule of my own. That one was just my first idea.
I need to find the nicest yet thinnest steel rules that I can in that size, then take them to a machine shop to get properly put together.
Table was $99 and so was the router. Get these bits from the Woodcraft store. I believe it was a 70 deg bit, 1/2" collet
One continuous fence keeps the piece moving smoothly. On these cheap router tables, even when you shim the 2 fence halves, it is difficult to keep the piece moving without jumping during the cut.
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2HP Ryobi Router mounted under the table
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Move pieces slowly through the machine, I run all bevels twice to get a precise bevel.
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The finished fin from 1/2" birch.
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So simple and easy--why didn't I think of that?! I tell you, I am really "tool challenged" and just barely get by; I have to learn these things from others.
That's a nice clean setup- I tried a slightly different approach with limited success: I cut a beveled fence (~10 deg, I think) with a recess for a 1/4" straight cut bit. It did an okay job, but had a good bit of chatter. I probably broke some rules by running the stock between the bit and the fence, I'm not a skilled craftsman in any sense. Will try your technique with a beveled bit and square fence.
So simple and easy--why didn't I think of that?! I tell you, I am really "tool challenged" and just barely get by; I have to learn these things from others.
Table was $99 and so was the router. Get these bits from the Woodcraft store. I believe it was a 70 deg bit, 1/2" collet
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