I re-cut my bearing edge today

Jankowske

Senior Member
Well, it's past midnight...so yesterday. It was nice out, I was feelin' kinda feisty, I half-recalled reading somewhere about drum builders using sidewalk cement to get a level edge on a shell, and the stock 45° bearing edges on my X7 had been weighing heavily on my mind. My friend the bass player showed up just as I got the reso off my kick, and I said something like "hey, you know the bearing edge...the important part of the shell that touches the head? I'm gonna grind it on the cement."

After he realized I was serious and I learned him up a bit on bearing edge profiles, we found a level patch on the patio slab and we got to grindin', which led to filing, scraping, more grinding, sanding, scraping, etc. I was shooting for a full roundover (half roundover? whatever) and the grinding and spinning was good for removing material. I got a quarter roundover router bit with a pretty tight radius and used it as a hand tool as some sort of shaving scraper thing for going around the outside edge. It was very hard on the thumbs and I don't reccomend it. However, I have pretty steady hands and it did a good job.

I checked it for level between heavy grindings with a large round piece of glass (about 25"; think it was a tabletop). Once I got enough of the old edge off I started focusing more on the scraping and getting the half flat/half angle profile to round. To really get the edge down flat, I got an adhesive sanding disc, about 80 grit, and tore it into quarters. I stuck them evenly spaced on one side of my glass chunk and used it to sand down the edge finer and flatter by spinning it. I kept alternating that with my hand scraping.

Eventually I got to hand sanding with 100 grit and scraping with a smaller bit until I had it really round and smooth and even. I was pretty careful the whole way...careful, not always gentle...and I never got any gaps or dips checking against the glass. I finished it with some 300 sandpaper and rubbed on and buffed off some parrafin wax.

I'm not even gonna be modest. I did a really damn good job. I'd put it up against any high-end factory edge save Guru and the like. Also, I'm pretty sure all of that took less than an hour. Sonically the difference isn't night and day but I am missing (not missing?) some overtones from my fiberskyn dip. There's something more solid about it. I like the way the head fits now, too. It's just all-around better.

I plan on doing the batter edge tomorrow...later today...weather permitting. I'll attempt to use my ape-like photography skills to better show you all the tools and process and finished product.
 

Andy

Administrator
Staff member
Good on you for trying this, but oh man, I've never had my mouth agape for so long when looking at a computer screen! BTW, glass table tops are mostly way off being truly flat. Same with stone kitchen counter tops, etc.

I look forward to the pictures (I think), in a sort of hiding behind the hands kind of way ;) ;) ;)
 

Jankowske

Senior Member
Well it's not raining yet, so the batter edge is looking feasible today!

I remembered reading somewhere not to trust float glass. Pretty sure that's what my chunk is. Anyways, it's the best I had and I figured my spinning technique would help to split the difference of any anomalies with it. Like if it had some imperceivably subtle potato chip thing going on, the sandpaper in the high spot(s) would be cutting a little more, but I was constantly spinning it and I wasn't leaning on it so the weight of the glass provided even pressure.

Anyways, it's got nothing on your Guru edges, Andy, but they're really good, I swear! Router bit hand-tooling and all. And some 300 grit and some parrafin wax goes a long way. And I don't think anyone will fret too much if I mess up my cheap asian tubs, so mod away I shall...
 

WallyY

Platinum Member
Looking out my window, all the sidewalks are curved.

My amateur doctor diagnosis is that you are therefore, insane.
 

shemp

Silver Member
If anyone is in SoCal and needs a bearing edge worked on, I would call FORD drums in Santa Ana..They agreed to do an edge or two for me. They also make stellar kits.

Just sayin'....there is an alternative to sidewalks and sandpaper here in the OC.
 

Jankowske

Senior Member
Well it's raining now, so it might not get cut today, but I got some pictures anyways.

The victim. Cement slabs in background.



My innertube hoop saver pedal clamp thing that I should probably make another thread about.



Head off, and the kickport too since I decided to clean up the old cut. Also I have my tom mount off since they're all on stands and I intend to make a patch for it.



A big nick in the bearing edge. Kinda hard to see in the crappy picture. Not sure how or when it got there...



So it's really hard to take a picture of a curved rim with one of these stupid digital auto-focusing things.



More bearing edge profile. I think we're all familiar with the 45 degrees. I just wonder how I'll get a good picture of the finished edge...



My glass tabletop with sanding disc patches.

 

mandrew

Gold Member
Hey, if these simple methods work, I will try cutting some snare beds with my neighbors chain saw. Should work if I have a steady hand. . .
 

Jankowske

Senior Member
Chainsaw sounds doable.

Are those pictures showing up for anyone? I'm on a different computer now and I can't see them.
 

Andy

Administrator
Staff member
Chainsaw sounds doable.
It must be doable, because I'm certain half the (nearly new!!) drums brought to me for correction had their edges/beds cut with one ;)

BTW, the glass table top with intermittent sanding pads is a master stroke. A fundamentally flawed masterstroke, but a masterstroke nonetheless, lol!!! That said, I guarantee you're getting better results than some new drums I encounter.

Your thinking kind of reminds me of this - erm, "pioneer". (note power lines ;)
 

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bobdadruma

Platinum Member
Gee, I guess that I did it wrong when I took my 65 Slingerland shells to my friends machine shop and use a machinists, "True Table" (which is a flat accurate steel slab that is used for detecting warp in engine parts) to use as a sanding table.
All that I needed was a sidewalk and a piece of glass :)

If I found a tiny nick on the edge of my bass drum I would simply fill it with wood filler and sand with a fine sponge sanding block.
I wouldn't attempt to cut the entire edge for such minimal damage.
 

BacteriumFendYoke

Platinum Member
It must be doable, because I'm certain half the (nearly new!!) drums brought to me for correction had their edges/beds cut with one ;)

BTW, the glass table top with intermittent sanding pads is a master stroke. A fundamentally flawed masterstroke, but a masterstroke nonetheless, lol!!! That said, I guarantee you're getting better results than some new drums I encounter.

Your thinking kind of reminds me of this - erm, "pioneer". (note power lines ;)
The man is a genius...

In one fell swoop he can not only get stuff done but deprive us of his stupidity and raise the collective IQ of the World...
 

GeoB

Gold Member
You all seem to forget that drum making isn't exactly rocket science. I think manufacturing would like us to believe that but look back at the essence of the craft and you will find drums constructed by hand with tools made of iron and stone and fire. Constructed by feel and texture. A thinly scraped goat hide, knotted sinew...

This OP took a manufactured, drilled, and equipped shell and ground down an edge. Sheet glass is suitable... this stuff ain't rocket science. I have djembe's that are simple in construction yet they sound better than a highly fabricated drum. Why is that?
 

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GeoB

Gold Member
Gee, I guess that I did it wrong when I took my 65 Slingerland shells to my friends machine shop and use a machinists, "True Table" (which is a flat accurate steel slab that is used for detecting warp in engine parts) to use as a sanding table.
All that I needed was a sidewalk and a piece of glass :)
You altered the edge of a '65 Slingerland? Do you consider that a mistake or an enhancement?
 

bobdadruma

Platinum Member
You altered the edge of a '65 Slingerland? Do you consider that a mistake or an enhancement?
I trued the edges on a precision sanding table. Then I fine sanded them by hand. I did it properly. I didn't do a recut. There was no need to. There were some high spots that needed to be fixed.
Yes, it is an enhancement. Kits from this era weren't as precise as the kits of today. Places like Steve Maxwell's do this sort of thing all the time for clients that wan't a vintage kit to be truer than stock.
 

wildbill

Platinum Member
Chainsaw sounds doable.

Are those pictures showing up for anyone? I'm on a different computer now and I can't see them.

The pictures come through fine.

You learned something, accomplished something, and are satisfied with the results. Good job.

Ya - you could take it to someone for work to be done on it with the highest levels of technology available. But where's the fun in that? LOL
 

Jankowske

Senior Member
Hey, thanks for all the interest, guys! I just got done with the batter edge and I'll try to get pics up tomorrow.

To clarify, I didn't recut my edges with ghetto tooling to take out a few little nicks. I wanted a whole new bearing edge profile, and I wanted to see if I could do it myself. I've read about different cuts and their effects on a drum's sound, and the logic behind it seemed to make a little sense. I didn't think it would be a super huge difference on my PDP shells, but the idea intrigued me and I like doing hands-on stuff.

I'd love to have an actually-flat table and make up some jigs to do things properly, but I definitely wasn't about to pay anyone to do this and I'm not going to pretend that my X7s are too important to be off a few thousandths here and there...especially since they already were. The batter took a lot longer since there was a substantial low spot by where the pedal clamps. The spot was around a foot long and I'd guess about a millimeter low. Now I know why that spot always threw me off when trying to tune JAW. My cutting surfaces weren't perfect so they still did some cutting there but not as much. On the glass the spot is still percievabe but less than 1/3 of what it was.

Anyways, it's too late to drum now so I'll have to wait until tomorrow to hear if there is any real difference. Probably not much but a significantly flatter edge + a nice new roundover + some parrafin wax = a definite improvement in my book, and all it cost me was some sandpaper and sore fingers.
 

Jankowske

Senior Member
Well, I've been my usual punctual self. Out of those pictures I took, this one turned out the best. Tried getting the camera to focus on the cardboard so you could see the bearing edge's profile. I've had worse ideas. Also I figured out that this camera is taking pictures as .jpg files...I should probably change it to raw to spare everyone the twice-compressed resized finals. Where's cbphoto when I need him? Anyways, I might try again at a good picture, but in the meantime, you're all invited to come over and admire/cringe at my handiwork in person.

 

john gerrard

Senior Member
It looks like you have done a pretty decent job. Glad to see that you had the guts to try to do it yourself. Hope you are satisified with the outcome. Good luck. John
 
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