Bushing Sizes

[Randy_]

I was just measuring up some bushings for cwasil's pen kit spec information project and got a little surprise. Miked a new set of Statesman Jr. bushings from CUSA and found them to all be 0.004" over the sizes stated in the instruction sheet. I need to mike the actual hardware, now, and see if the bushings match the hardware or not. I know there has been a problem in the past of bushings and hardware not matching; but I'm wondering if anyone has actually taken measurements to determine what kinds of differences we are seeing???

 

[patsfan]

MY problem is generally the opposite: I have either turned or sanded down my bushings.

Give 'em to me for a while, and I'll take care of it for you. []

 

[JimGo]

Randy, how's that project going? I've managed to mix up a few of my bushings now, so I may need it as a reference!

 

[Fred in NC]

My most useful tools are both calipers.

A dial caliper for general measurement.

A plain old fashion caliper with set screw.
I set it to the final measurement, and use
it to gauge the barrel when I get close to
final size.

Much better than relying entirely on the size
of the bushings.

 

[Old Griz]

A sheet of paper is .003... I think that the bushing being .004 oversize is not going to make a noticable difference in the creation of the pen... especially after you make one or two pens out of them and have touched them with a tool or sandpaper...

 

[wayneis]

Bushing have always been a guide to just get you close. I have always used a caliper because even the parts sizes change occasionally, I think that it due to different thickness of plating. Then like Tom says, bushings themselves get smaller as they are used.

Wayne

 

[dougle40]

I agree about the bushings being a guide only but having a bushing that is 0.004 O/S isn't much good . I still prefer to use a micrometer to do final measurements , I just find it easier to use .

 

[nilsatcraft]

Generally speaking, bushings can be slightly oversized. Otherwise, those who turn down to the bushings and then start sanding would immediately make the blank undersized. I realize that the group here is full of turners who wouldn't do that, but many penturners do. There are also a lot of variables when you get down to a couple of thousandths of an inch. It is recommended that you use micrometers if you're going for a perfect joint from the blank to the pen part.

 

[Randy_]

Originally posted by JimGo<br />Randy, how's that project going? I've managed to mix up a few of my bushings now, so I may need it as a reference!

Jim: The project actually is Chad's(cwasil) and Mudder is helping out. I'm just measuring a few kits to fill in some of the missing information. Haven't seen a post on their progress since April 1 so I don't know how they are doing. I would guess it is a little difficult for them to get information as I suspect most pencrafters don't have either a vernier or a mike or both and of those that do many are probably too busy to find the time to measure kits. That's why I am trying to help out.

As to the comments by other posters, I agree with everything that has been said about using bushings as guides and measuring your work if you want a really tight fit!! I only raised the subject to make folks(mostly newbies) aware of the need to measure their kits and to get some idea for myself of how much variation there really is.

 

[mick]

I've got a similar problem ..not with bushings, but with tubes...somehow some kits got opened and the tubes mixed up ...believe it or not Baron lower barrel tubes and cigar lower barrels tubes look very much alike...Had no way to measure em last night, so at work today I looked em up. 25/64 is 9.9212 mm or .3906 inches. 10mm just a frog hair over .3935 inches (.394in is 10.0076mm)We're talkin .008 difference here I doubt that either kits tolerances would even go that low. Last night I test fit both tubes with both nibs and couldn't "feel" a difference. Any thougnts on this? One thing I'm quick finding out ...I gotta stop by HF and get a set of digital calipers...lol. Specially after dumping out the storage bin containing all my bushings over the weekend!