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Cutting precise angles

9.5K views 20 replies 9 participants last post by  bendrum  
#1 ·
I want to make a stave drum and I'm not sure how to cut the angles. I want 12 staves which will mean a 15 degree angle for each cut. I have a choice of a router and a hand saw.

I have nothing to measure angles at the moment, I was planning on using trigonometry and measure things. I was going to make an angled jig to clamp my wood to and then run it along my router table. I'm not convinced that the router bit is completely perpendicular to the table though. The other option is a hand saw, but I think that will probably be less accurate.

What would you recommend?
 
#2 ·
Peter,

Comparing accuracy of cut with router table versus "hand saw" is like comparing a sniper rifle to throwing a rock. You can buy a protractor to measure angles for $1.00 at Wal*Mart. A good quality protractor or angle gauge for woodwork can be had for $15.00 or less...

Otis Guillebeau from Auburn, Georgia
 
#4 ·
Hi, Peter; welcome!
You didn't fill out a profile, so other members wouldn't know whether or not you have access to a tablesaw(?).
For what you want to accomplish, sure, you could cut the staves out oversized, and hand plane them down to a perfect fit, but that assumes a lot of hands-on experience on your part. Might be a fun learning project, but don't expect a perfect fit first time out of the gate; that's going to take practice. But as I said, a great learning experience.
I've been working with wood since my teens, but that'd be a challenge for me.
Begging the use of a tablesaw is your best short term answer.
 
#8 · (Edited)
Build a jig to hold the wood at a 15 degree angle. The jig should be adjustable. Then use a straight bit.
Use cheap wood for the staves until you have dialed in your jig.
Great project. You will learn the difference between theory and practice. (Practice wins)
 
#9 ·
I started making a jig today but got the sizes completely wrong.

What's the best way to cut the pieces to size (not angle them, but just do the lengths and widths)? Would it be best to do one, and then use it as a template with the router? The lengths aren't as important (as the ends will be cut off later), but the widths must be the same.

What's the best way to make the jig adjustable? Nuts and bolts to adjust the height at the end of the ramp?
 
#14 ·
Peter; owning one may not be in the program but can you get access to someone else's?
Perhaps a neighbour, or someone at work? The angle is important but even more critical is getting the long sides parallel, and each piece the identical width.
Any other tool is a poor substitute for what a properly set up TS can accomplish for those factors.
 
#17 ·
More to the OP that to you Neville--

No one asked about the dimensions and shape of your finished barrels... So I'm asking.

Straight sides, like a tube? (not really a classic barrel shape, but good to start out with...)

Or a classic barreled shape with larger diameter in the center than the ends?

That would change what people are recommending for tools.

For instance- Charles was spot on with an angled jig to hold the barrel staves to take acre of those angles for tooling. That would take care of holding those angles, even with bowed staves.
 
#19 ·
Hi Peter, I'm in the middle of a stave drum building project myself. I just did a search for "angle jig" on the forum after spending the day designing and half finishing a 9 degree angle jig and found this thread. I'm glad to see it's recent. I've ruined 3 shells and my 4th is a success (3rd shell almost was until it hit the floor) but I wanted better accuracy every time so I bought a cheap Chinese made (sorry purists I unfortunately can't afford USA made or even Japanese made) angle block set to use as templates with a flush trim bit for whatever angle I need up to 55 1/2 degrees. Is anything 55 1/2 degrees? They come in sets of 1/2 - 5 degrees and 6 - 10 degrees and they can be combined so you could use the 10 and 5 degree block to get your 15 degrees. I got both sets for about $27 off of Ebay with free shipping. The vendor selling them was called Proline but there are a few others selling the same product. I don't know what shipping to the UK would be. They're not very pretty but they're accurate. I got those yesterday and I also got a Craftsman Digital Torpedo Level (which is very cool with lots of neat features) last night to double check the blocks and also used it to double check my finished angle pieces after flush trimming them on the router table. I'm using 3/8" baltic birch plywood for the angled supports and the ramp and 1/2" bbp for the base. I briefly checked your other posts and see that you now have a table saw so that'll be great for making your cuts. I've been using a radial arm saw so far to do all of my cutting and while that has worked, it's a lot of tedious set up time (even though I do have fun with that …especially when I finally nail it) to get it just right. A drum builder named Lee Wright was kind enough to share his stave cutting jig on Youtube and I've pretty much based mine on what he designed, however, his is machined steel or billet aluminum. Not sure which.

As Charles said, you can get a 15 degree chamfer bit to get a perfect bevel but the angle block set will give you more options. For 20 sided drums or tubs or barrels it requires a 9 degree angle and despite endless searching, I have not seen a 9 degree chamfer bit so the use of the angle block set to create a jig is the way to go unless you can afford a custom bit to be made. There are also other angle block sets under $50. that include a 1/4 degree which you could use to get 11.25 degrees for your 16 sided shells.
 
#21 · (Edited)
No I didn't mean Primeline. (spoken nicely and respectfully) The Ebay vendor is called Prolineparts, I had just written Proline previously, but the block set is actually made by or distributed by, (not sure which) Shars. Shipping was very fast, too. I ordered them on Wednesday and got them Saturday California to Boston. I took some pics last night so here they are. Please pardon some of the fuzziness as my photography skills were not at their best when I took these. My jig is obviously not complete but this is an idea of where I'm going with it.
 

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