Bearing edge

[michi]

I shape mine to look similar to the Ivory Coast shape, with a bevel on the inside. However, I don't have any flat bit on top of the bearing edge next to the inside bevel.

Here is the bearing edge of one of my drums. You can see the inside bevel.

Bearing edge with bevel

IMG_1850.JPG (203.52 KiB) Viewed 461 times

Here is a close-up of the profile.

Bearing edge profile

IMG_1859.JPG (88.52 KiB) Viewed 461 times

Cheers,

Michi.

[Djembe-nerd]

I have a Guinea and a mali djembe (this weekedn I will take pics and put them on show your axe) which has the exact bearing edge as the diagram shows. The Guniea is hard on the hands if played longer than 1 hour, Mali is more comfortable.

I am waiting an Iroko from RHD, and probably, probably will be the easiest on the hands looking at the profiles, SO MY QUESTION to the experts is "What if I put a "Carl style edge" something between Mali and Iroko in all the djembes for easy playing, will this affect the sound. Theroritically it shouldn't.

BTW, Carl, your in between edge will be good for most hands, ergonomically, I don't know about the other aspects, sound etc.

[Djembe-nerd]

Michi has got focus issues

Thats looks a good edge for hands. I saw Famoudou in a vedio and have changed my technique. His hands come over the edge and knuckles are on top of the bearing edge instead of landing on the bearing edge. Its a little easier on the knuckles this way for me.

[buttafingers]

Thanks, michi, that was precisely the angle I was looking for on shot #2.

[michi]

Michi has got focus issues

Yes, true--occasionally I lose focus and do something that isn't djembe-related

But, seriously, I did this very close up with a not-so-fancy camera and wide aperture, so there isn't a lot of depth of field.

Thats looks a good edge for hands.

It's comfortable to play, yes (which was the idea, after all).

I saw Famoudou in a vedio and have changed my technique. His hands come over the edge and knuckles are on top of the bearing edge instead of landing on the bearing edge. Its a little easier on the knuckles this way for me.

Mamady plays the same way and recently got me to change my technique to match his. He did say though that he wouldn't give this advice to every player--it applies in his and my case because we both have small hands with shorter-than-average fingers, so it's necessary to reach into the drum a bit more.

Cheers,

Michi.

[Djembe-nerd]

Thanks Michi,

That clue with small hands is helpful. I have small hands too.

[buttafingers]

Spent a little time in the shop today. I'm moving a skin from my first project, a 10" festival drum, down to a 6" $19 Coat Factory model. The 10" had been reworked when I did it 5 years ago and was much lower than I wanted it. Upon removing the skin I remembered how I was disappointed with the sharpness of the rim after I first completed it.

My tools have been scattered between projects and I was without any coarse sandpaper. After some digging, a sharp plane was unearthed. In the mean time I had been playing with power tools. I wanted to see what the jointer could do for the bearing edge that was much to thin. Since there was a lot to come off,it wasn't too nerve wracking giving it a try.




Here is the result before shaping. The table was set to take about 1/64 off each revolution, so it was pretty forgiving.



The flatness was outstanding and there was no need to do any sanding on a piece of glass or
concrete. This method, combined with RHD's of using a roundover bit on the router would make quick, uniform work of bearing edges. The results would be repeatable and tweakable.

[michi]

I wanted to see what the jointer could do for the bearing edge that was much to thin. Since there was a lot to come off,it wasn't too nerve wracking giving it a try.

Wow, I'm envious! I wish I had access to a tool like that. I just spent the past 2.5 hours redoing a drum shell for a student of mine. The bearing edge looked like a roller coaster, so I decided to bring the whole thing down to a plane and reshape the edge from there. But all I have is a small hand-held planer and an orbital sander (plus assorted rasps). Doing the job by hand is time consuming, and it takes a lot of patience to get the edge perfectly on plane.

Your jointer makes very short work of that, by comparison!

Cheers,

Michi.

[buttafingers]

Try looking for a used benchtop version. I was quite surprised and pleased with the outcome so I thought I might share it since you guys have been so helpful.

This makes me want to finish cutting out the hole in my router table and get the lift put in it. It would be much easier to rout the profile with the drum in the same position as on the jointer.

My attempts to hog off some of the radius were a failure, though. After experimenting with tilting the fence and a stop block, I realized this wasn't the best idea. I couldn't see any reasonably simple way of jigging it so that I could take off a preset amount. Every way I tried came out such that it would continually shave off depth, like a pencil sharpener. Probably best left to the block plane.

I got the best results by skewing the plane and sweeping it around the rim, turning the drum as I went. By holding a constant bevel and making a full circle, it wasn't too difficult to get a uniform curve all the way around. Once I made a round, I would tilt the plane a few more degrees and make another lap. This is repeated until you have a rough approximation of your profile. Watch the width of each "facet" you cut and try to keep it the same at all times. Once you get all the way to the top where the skin rests, simply adjust your plane to take a lighter cut and shave off the points between each initial facet made. Tomorrow I may take some pictures just for anybody in the future that might have trouble seeing this in their head.

[Djembe-nerd]

I found this somewhere on the net, can't remember where.

So how does this stand compare to the traditional shapes that RHD posted earlier.

[michi]

I prefer the shape shown in the second image at the top. Widest possible radius makes the edge more comfortable to play, and a small bevel on the inside provides for a clean transition onto the playing surface, so there is no buzzing.

Cheers,

Michi.

[Djembe-nerd]

Michi,

Isn't that too much round if you consider the thickness, because the thickness is the radius. Usually, I have noticed that the bearing edges from the drumbuiders are a little flatter on the top, not completely flat, but less round in the beginning and then round off towards the outside.

[michi]

Isn't that too much round if you consider the thickness, because the thickness is the radius. Usually, I have noticed that the bearing edges from the drumbuiders are a little flatter on the top, not completely flat, but less round in the beginning and then round off towards the outside.

Well, the idea is to make the bearing edge as wide and as round as possible, to make it comfortable to play. I don't see the point in having a flat bit at the top. What would it achieve? It would only reduce the radius of the bearing edge for no good reason, as far as I can see.

Cheers,

Michi.

[Rhythm House Drums]

My original image on this... I think has confused some. It's not flat... but slightly curved. Maybe I should have done a line over top to emphasize this. The highest point on the Iroko (Ivory Coast) model is right before the bevel on the edge. It looks flat, but actually is not.

A flat area would be problematic... just for clarification.