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All,

Does anyone use a cutter with large diameter of 1.25"? I could only find one cutter with a 1" diameter and it happens to use metric bearings which are more expensive.

Does the larger cutter pose any problems? Do you prefer 1/4" shank or 1/2"?

I have access to a lathe and thought I would give it a go.

Thanks in advance and I'll keep you posted on any progress.

_Mike

_________________
_Mike Tracz
MCT Guitars
https://www.instagram.com/mustcreatethings/
https://www.youtube.com/mustcreatethings

Mike, I understand the impulse to make as much of your tooling as possible - it's fun! Probably not cheaper, but who wants cheap fun?

I use the LMI 1" cutter and bearing set, and it performs flawlessly, and I imagine SM's set is as good. Going to a larger diameter cutter should only improve the quality of the cut, if possible, but then you're faced with a small selection of bearing od's, and I assume that's where the lathe will come in, custom-cut bearing sleeves - very attractive possibilities, to precisely size your binding channel. But bear in mind that the LMI selection gives you 0.010" (1/4 mm) steps, for a pretty small cash outlay per step.

Another advantage is the added rigidity of a 1/2" shank, but you're going to be taking very light cuts, so it's a non-issue, I think.

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Dan
http://www.acme-archtops.com

Dan,

Thanks for the reply!

I ordered the supplies today.

1" cutter and bearings that fit it's shaft that I will press into machined sleeves.

Oh I ordered enough to make two sets... Anyone interested?

I'll keep you posted of any progress.

_Mike

_________________
_Mike Tracz
MCT Guitars
https://www.instagram.com/mustcreatethings/
https://www.youtube.com/mustcreatethings

Mike, I hope you don't really mean "bearings that fit it's shaft"? That amounts to a pattern bit, whereas binding bits are flush-trim types that have top-mounted bearings which are intended to reach past the binding channel area to ride against the body. Perhaps by "shaft" you mean the short nipple that is on the opposite end of the bit from the shaft?

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Dan
http://www.acme-archtops.com

yes i meant short nipple. sorry for the confusion.

_Mt

_________________
_Mike Tracz
MCT Guitars
https://www.instagram.com/mustcreatethings/
https://www.youtube.com/mustcreatethings

Having a good deal of machining and engineering experience dealing with machining bearing housings on a daily basis, I am curious as to how you intend to hold concentricity tolerance. Typically on small ball bearings like we are speaking of the concentric tolerance is in the nationhood of +/-.0001” between the bearing bore and the bearing outer race. This is very hard to hold on an NC machine and ten times as hard to hold on a manual lath.

The diameter and bores we will be talking about for such bushing will be very thin walled. If you use tubing to start with there is a fairly high tolerance on the concentric of the bore and OD of the DOM tubing that has to be corrected to begin with. Then as you turn the outside diameter the tube will want to egg due to the thin wall thickness your dealing with. Same thing will happen with round bar stock either on the bore or the diameter. When you press the on the bearing race most of the egg will disappear but not necessarily all. This will lead to an out of concentric guide. I do not mean to be a doubting Thomas here but this is a very difficult task you attempt here, and to elevate a very small issue to begin with.

Truth is metric bearings of equal quality are no more expensive than empirical dimensioned bearings. In fact most bearings used in near all process and designs are metric sized because of the naturally wider incremental range that the metric system covers. And in fact most 1/4” bearings are actually a 6.35mm bearings, ½” are 12.7mm so forth and so on. It is just simpler for bearing manufactures to use metric system to provide a wider range of product with common tooling. That said common sized bearings designed for use by the cabinet and furnishing industry may be less expensive but only because there is a large end user market for them, so the bearing manufactures can make them in larger runs.

Good luck with this project but I am afraid you will find it not to be cost affective at bet and it is likely you will run into tolerance issues while machining.

we have, and still do, machine our own bearings from aluminum, and delrin. But they act as almost collars around internal bearings. Work fine however.

edit... when I say "we" I mean McPherson Guitars.

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John Mayes
http://www.mayesluthier.com

john how small of bearings are speaking of. 12mm or smaller? I did not mean to say this can't be done as we to do the same thing but on larger bearings. just that in a home shop this would be very difficult to pull off and maintain the bearings concentric tolerance.

Michael,

Thanks for the encouragement. Really thanks.

Suffice to say I enlisting the help of my father a journeyman pattern maker and machinist for the past 35 years to help turn the collars (same as John describes) to press on bearings. I really am not scared about tolerances. The are simple collars not piston housing for a f150.

I plan on boring under .002" and heating them up and sliding them on so when they cool they are secure. I have done this on race pulleys for cars and jewelry concepts I've done in the past and it seemed to hold true.

I'll let you know how it works out. I'm sure just fine.

_Mt

_________________
_Mike Tracz
MCT Guitars
https://www.instagram.com/mustcreatethings/
https://www.youtube.com/mustcreatethings