This is a great tutorial with an easily made jig, do you have videos on how to true up the ends after glue up and miling the outside if the drum? Thanks, Rick
Hey this is great! Thanks for sharing! This looks very accurate assuming the outside is pretty well round, and it looks like something you can use and un-use and not require a seperate building, 3 phase service and forklift to operate! Shoot, this is something my 6 year old daughter could operate safely! Cool idea!!!
I just finished the first 2 passes on a 20 inch bass drum shell using this design of jig, it works a treat. The problems I had previously with uneven cuts (on inside and outside machining of the shells) were caused I think because of my jig making being made too slaphazard and loose. But this one works fine. It feels solid and tight while routing, no weird viberations.
+Goldsmithexile1960 Glad the jig is working for you! This jig actually works better with larger shells such as floor toms and bass drums, because the larger and heavier the shell is, the more stable it is when sitting on the wheels!
+Murray Drums I didnt rush this time, and spent a couple of hours setting out the jig parts on the table using a framing square etc to get it as accurate as possible especially getting the wheels all squared up in line. I finished the shell late last night down to 10 mm. I did finer cuts each pass, and still got a tiny bit of tearout, but not uneven grooves and scarring as previously. The shell has segments of honey pine in it (I know not ideal, but I used what I had to hand, recycled bits of scrap) The oak segments worked much better though. And the router bit had already done a lot of work on oAk worktops so not the sharpest tool in the box...I think next time I might add some sort of increment scale so I know precisely how far to move the sled each time, just pencil marks every 10 or 11 mm. Anyway thanks again for the videos Fraser, extremely inspiring
Good questions about the smaller drums. It looks like the Bosch Colt router is pretty small. Maybe small enough for an 8" but you could do a 10" for sure. I may invest in something like this.
Great video and great jig. I know when routing straight boards it is recommended to route in one direction. Is it also necessary to turn the shell in only one direction when milling the inside?
Yep I agree, I tried an end cutter but it was only successful if you went from side to side instead of rolling the shell, it was painfully slow so I went back to a 20mm straight bit again.
+Mike James, I think that method of going from edge to edge would work well if you could get a bit that was ground to the exact radius of the inside of the shell, maybe a bit which was around 30mm wide, but has a 6.5" radius at the end! You do get bits called "bowl" and "tray" router bits, but the radius on the end is usually way too small for a drum shell. Most of the those bowl / dish / tray router bits are only available from the USA as well and I'm in the UK!
George Robartes Thanks from the message George, I will look into your idea. I'm pretty hopeless are sharpening cutting edges etc, so that's something I need to work on. Do you think it would be possible to just modify a normal straight cutter rather than making bits from scratch ?
+Murray Drums Get a machinist to put a 1/4" collet on a P grinder for you, or buy a RA gear drive. I think a Milwaukee D handle drill with the 90 deg adapter should fit an 8". The RPM speed will probably be a bit low for a router bit though, and, well, mounting a D handle 1/2" drill should not be that hard.
G.A. Russell I am wondering the same thing. I thought about making a smaller snare for myself but am not sure how I would mill the inside since the router won't fit.
How thick was the timber to start with, before the outside was routered I mean (total thickness) and then what is the final thickness of the shell you aim for?
What's the solution (if any) for smaller drums, ie 8" Rack tom? I haven't seen a router that's < 8" tall... But that may just be me as a newer woodworker.
Hi, Thank you for uploading your ideas about building stave shells like this. Can you tell me please what's the margin of error with this type of shell making ? How accurate shell thickness can you achive? ( I hope you understand my word.Sorry if my english is poor...)
+retyetye Hi Retyetye, I can achieve great accuracy using these techniques, now that I have made quite a few shells and I know how to set up the jigs properly. Usually the outside diameter of the shell is a perfect circle, if you measure across the width of the shell at a few different positions, the size is nearly always the same. If it is out at all, it's usually only by about 0.5mm between the maximum and minimum dimension, so it might be 352.5mm at the minimum point and 353mm at the maximum point. It is possible to make the shell slightly tapered, so for example the bottom bearing edge might be 352mm in diameter and the top one is 353mm but only if the jig isn't made accurately or not set up correctly. The main thing that can vary a little bit is the wall thickness of the shell, particularly when the outside of the shell isn't perfect, but measuring the shell thickness using callipers at several different spots, most of my shells are accurate to within plus or minus 0.2mm. For example, if I want the shell to be 8mm thick, it will usually vary from 7.8mm to 8.2mm. If it's out by any more than that, I will sand the inside of the shell more at the thickest spots and get it within tolerance.
+retyetye Most ply shells I've bought or refurbished over the years are much less accurate, especially vintage 3-ply shells with re-rings, but even good quality modern ply shells, like Keller / Pearl / DW / Sonor can vary a little bit more than the shells I make myself!
It looks like a coopered construction, so there was never any core to begin with. I guess then what followed with a lot of passes like the ones in the video.
The Bosch laminate trimmers are ideal for the inside jig, that's what I use now instead of this big router. They will fit through any shells 10" or more.
Apologies I saw you're using a straight bit but I would have thought a router bit that cuts from the bottom of the bit would be more ideal, straight routers cut on the side of the blade and not really the bottom?
+Mike James, I find that a half inch wide straight cutter does a pretty good job for the outside and inside of the shells and they are quite cheap to replace when they are dull. I've tried bits with "end cutting" design and find they tend to burn the wood a lot more than a regular straight cutter. The straight cutters do leave a sort of scalloped surface, so there is quite a lot of sanding required to get it all smooth after machining, but that would be the case with any router bit.
what router do you use dor this? size of collets and power? how small can you go in size of drums using this technique? i have plans on trying this out :)
Mike James other than the obvious get a shorter router, you could do it by hand with more staves. Another option would be to just use a router to get about an inch in from the bearing edge and finish the rest off of those guidelines.
Since you're wearing a Led Zeppelin T shirt I know you're a discerning guy. I've been a Zeppelin junkie for over 40 years. I'm sorry to say this but even though your jig is a great idea, the design has a basic flaw. If the outside of the shell is not perfectly round to begin with then even using the jig to reduce the interior wall thickness will not get a perfectly round interior surface. On a lathe, the center of rotation is determined by the center of the chuck assembly whereas with this jig the center of rotation is determined by the four roller AND the shell itself. If the outside of the shell itself is out of round then you can't get the inside to be perfectly round either. The only way to remedy the design flaw is to use the same jig with an additional outside router mounting similar in function and design to the present interior mount and have the additional step of routing the outside of the shell first.and that is assuming of course that the four rollers have no play when they're turning and they are mounted in perfect orientation to each other in three dimensions. If you invented and built this jig you should have no problem with the additional set up and improvement to the design. Good Luck!
+mrfester42 Thanks for your input. I agree with most of your comments, but the other jig I use to round the outside of the shell does produce a pretty accurate cylinder before transferring the shell to this jig to do the inside. The diameter is usually within a tolerance of about plus or minus 0.5mm or better. If my target diameter for the outside of the shell is 353mm, the shell will sometimes vary from 352.5mm min to 353.5 maximum, but that would be the worst case scenario, most of my shells are well within that limit. Sometimes the shell is so accurate you can't even detect any difference in size when measuring with a tape measure, so it's certainly well within acceptable limits for a drum shell. The shell wall thickness is usually accurate to plus or minus 0.2mm, so if the target wall thickness is 8mm after turning, it might vary from 7.8 to 8.2mm (measuring with callipers) but I can then sand it a little more at the thickest points if I want to even out the thickness a bit more. The level of accuracy I can achieve using these jigs is as good or better than a lot of ply shells on the market from the big manufacturers.
Do you have a video off the other jig? The jig you use to mill the outside? I would love to see that one too. I think this is exactly what I am looking for, thanks for the video!!!
+Bjarne Lestander A thinner shell is usually a little more resonant / sensitive and warmer sounding than a thicker one. A thicker shell will have a little more attack / brightness and projection (volume) Thinner shells have a slightly lower fundamental pitch. The thicker the shell is the higher the pitch (of the shell) but the final sound of the drum depends on the type of heads, tuning, shell type and thickness, shape of the bearing edges, as well as the type of hoops fitted. Everything makes a subtle difference.
