A SM Rabbet bearing assignment for someone

[Dennis Weaver]

Pg 33 of current Stewart MacDonald catalog has various binding rabbet bearings and lists the size of rabbet you get when you use THEIR BIT. (sized .925")

OK and you can buy sets for enormous prices etc... but separately reasonably priced at 6 bucks each. Well maybe not they are just 50 cent bearings but anyhow.....

A good reference for people wanting to just know O. D. of each bearing so they can figure out which one to buy for their bit to get rabbet depths they want.

Say someone who has these bearings lists the O. D.s for them so people can then say, well with my width of bit (bought from Home Depot or where ever) I need to buy these two bearings for my use. (3/23" and 1/8" or whatever) and only spend 12 bucks!

[Peter Wilcox]

I'm not sure what your question/comment is. The narrowest rabbet I can cut with my cheapo set is 1/8". This is wide for most purposes, so I wrap tape around the bearing to get narrower rabbets.

[David King]

I'm pretty sure that all the major blade companies supply rabbiting kits with all the bearings. I'm not sure what increments you need but there's always a way as Peter suggests. Meanwhile bearings are available in mm and inch sizes or even combinations thereof. Check a place like VXB and your local hobby shop for the smaller bearing sizes.
Amana, CMT, Freud, Whiteside etc would be good places to start.

[Dennis Weaver]

CLARIFICATION- (in order!)
Yea I know I can spend a lot of money and buy sets from many ones. I was saying the SM ones (in tiny increments MANY DIFFERENt sizes) are 6 bucks each. ONLY PEOPLE WHO BOUGHT THEM can say hey this one's O.D. is this. If we made a list then people could spend 6, 12, bucks or so and have the increments they want. If anyone did not buy Stewart MacDonald rabbit bearings Do not reply to the post. You would in no way be able to answer what I want. Yea I guess I could do math and figure them out. Subtract their .9 something bit and the bearing rabbet sizes. Maybe I will just do that.

Some people are replying to post without even knowing what I am talking about.
A. see the Stewart MacDonald catalog.
B. see yea 6 bucks a bearing maybe if people knew O.D.s we can have the 2 or 3 we use for CHEAP MONEY.

Anyhow. I'll probably just do the math.

[Dennis Weaver]

I should just write Stewart MacDonald and say Why do you have to be such money hawks???

List the O.D.s for the bearings so we can easily figure out what size rabbet they would produce with OUR OWN BITS not their 50 buck one!

I get about sick of it. It is a real racket as much as a service.

[Peter Wilcox]

Just do the math: their bearing diameter = 0.925 - 2(binding width). For example, for the .050 binding the bearing diameter is 0.925 - 2(0.050) = 0.825"
You should be able to calculate them all in a few minutes and then buy the ones you need. The rabbet depth is half the difference between the cutter diameter and the bearing diameter.

[Dennis Weaver]

Peter and all - Thanks. I have bits and wouldn't mind spending like 12- 18 bucks to get the exact rabbets I'll ever use.

Maybe like 3/32", 1/8", 5/32", (I have 3/16")
Also the tape on the bearing could be good too for me.

Reason all this occurred is I have bindings that are 3/32" wide and might not do any lines but just use them on the guitar I am making now. Yea I the math isn't too hard the way you explained it.

[Dennis Weaver]

They actually have what I was wanting at their website (not in the catalog though) And all my crying!
You do need to convert the decimal to fractions, well I do.

http://www.stewmac.com/Luthier_Tools/To ... rings.html

Bottom of their webpage-

Find the right size bearing for your binding:
Measure the bearing diameter with a dial caliper and use
this chart to find the size ledge your bearing will cut.

Bearing diameter Size of ledge cut
.925" (23.50mm) Flush
.840" (21.34mm) .040" (1.02mm)
.820" (20.83mm) .050" (1.27mm)
.800" (20.32mm) .060" (1.52mm)
.780" (19.81mm) .070" (1.78mm)
.760" (19.30mm) .080" (2.03mm)
.740" (18.80mm) .090" (2.29mm)
.720" (18.29mm) .100" (2.54mm)
.700" (17.78mm) .110" (2.79mm)
.680" (17.27mm) .120" (3.05mm)
.660" (16.76mm) .130" (3.30mm)
.640" (16.26mm) .140" (3.56mm)
.620" (15.75mm) .150" (3.81mm)
.600" (15.24mm) .160" (4.06mm)
.580" (14.73mm) .170" (4.32mm)
.560" (14.22mm) .180" (4.57mm)
.540" (13.72mm) .190" (4.83mm)
.520" (13.21mm) .200" (5.08mm)
.500" (12.70mm) .210" (5.33mm)

Now I just have to check what a given diameter will do with my particular bit widths.
I have one at 1.5" width that I will probably go with.
Actually I couldn't. I have to use their size bit OR SMALLER to go with these bearings.
Or a little bigger than .925.

It doesn't seem to be gelling with any bits I have.

[Dennis Weaver]

Maybe it will all help someone.....

but I am just going to get a set (Yoniko) that does a 1/8" rabbet, and a purfling strip shoved inside the binding strip will do me fine. I might even get other usable widths because the set I have has a 1 1/2" cutter and this has a 1 3/8" cutter- so we'll see.

Sorry if I got snappy. I find Christmas isn't too cheery except getting days off because lack of family around. Well Church tonight will be good- Carol Singing.

P.S. I ordered green wood strips from LMI to match colors in the rosette!

[Tom Sommerville]

One thing I've discovered is that you can rout a 1/16 " ledge for binding using a 1/2" flush trim with a 3/8" diameter bearing. I think the bearings are mounted on a 3/16" "watchamacallit" (extension? mandrell?)
The tighter radius may be better in minimizing chipping or splitting when routing against the grain--but I'm not really sure or this, as it also travels slower. But, it may be worth trying.

[David King]

Tom the whatchamacallit is often called a "journal" but that's not quite right either because a journal is actually a bearing surface on a shaft that turns in a simple bearing like a babbet or bronze bearing. I guess when ball bearings came around the term stuck.