I want to have a go at making some custom handlebar risers for a
motorbike. I'll be using 53mm dia' round bar but I'm having trouble
working out how to drill/bore the hole where the bars seat. It needs to
be split into 2 sections, the bottom section is fastened to the bike and
the top section clamps to this over the bars. The hole for the bars
needs to be approx 22mm (7/8ths) and will have to be reamed out for
accuracy.

If I drill the hole out first then cut it on a bandsaw I'm going to lose
the accuracy of the diameter with the width of the cut, I don't think
that my bandsaw will create an accurate enough cut anyway. Is it
possible to drill through the middle of two sections clamped together or
will I have to drill two holes in the stock, cut, then mate two sections
together?



http://tinyurl.com/yrlo5d

Babba writes:

Is it
possible to drill through the middle of two sections clamped together

Yes, that would be the best way.

Babba wrote:
...snip
Is it
possible to drill through the middle of two sections clamped together

http://tinyurl.com/yrlo5d

Yes, that's how I do it. Its also a good idea to put a packing piece
between the two sections so as to provide a reasonable clearance when
finished.

--
Regards, Gary Wooding
(To reply by email, change feet to foot in my address)

--
Posted via a free Usenet account from http://www.teranews.com

On Thu, 21 Feb 2008 05:22:32 +0000, Babba wrote:

I want to have a go at making some custom handlebar risers for a
motorbike. I'll be using 53mm dia' round bar but I'm having trouble
working out how to drill/bore the hole where the bars seat. It needs to
be split into 2 sections, the bottom section is fastened to the bike and
the top section clamps to this over the bars. The hole for the bars
needs to be approx 22mm (7/8ths) and will have to be reamed out for
accuracy.

If I drill the hole out first then cut it on a bandsaw I'm going to lose
the accuracy of the diameter with the width of the cut, I don't think
that my bandsaw will create an accurate enough cut anyway. Is it
possible to drill through the middle of two sections clamped together or
will I have to drill two holes in the stock, cut, then mate two sections
together?



http://tinyurl.com/yrlo5d

Yes. You can clamp 2 pieces together with a shim, the thickness of the
gap you want, between the two pieces. You could run into trouble with
a drill, however. Unless you have a very ridged set-up. Even so, I
would drill it undersize, and bore it to size.

Matt

We have made thousands of handlebar clamps for motorcycles. We CNC
mill the bar hole 7/8, 1" or 1-1/4" with a 3/4" end mill. Then we
slice it in half with a 0.050" thick saw blade in a horizontal mill.
If you don't have a horizontal mill, set up the saw blade in an arbor
and slice it off that way. I think the saw blades are called Jeweler's
blades. They have very fine teeth, are HSS and only cost a few bucks
each at MSC.

Dave

On Wed, 20 Feb 2008 23:22:32 -0600, Babba wrote:

I want to have a go at making some custom handlebar risers for a
motorbike. I'll be using 53mm dia' round bar but I'm having trouble
working out how to drill/bore the hole where the bars seat. It needs to
be split into 2 sections, the bottom section is fastened to the bike and
the top section clamps to this over the bars. The hole for the bars
needs to be approx 22mm (7/8ths) and will have to be reamed out for
accuracy.

If I drill the hole out first then cut it on a bandsaw I'm going to lose
the accuracy of the diameter with the width of the cut, I don't think
that my bandsaw will create an accurate enough cut anyway. Is it
possible to drill through the middle of two sections clamped together or
will I have to drill two holes in the stock, cut, then mate two sections
together?



http://tinyurl.com/yrlo5d

I used a boring head with an extended cutter holder I made.
The half circle was cut full length from one side.

A couple of pictures of a handlebar clamp I made.
http://varian.net/wayne/hclamp/mvc-010f.jpg
http://varian.net/wayne/hclamp/mvc-025f.jpg
http://varian.net/wayne/hclamp/mvc-038f.jpg

Wayne D.

On Feb 21, 8:53 am, "Dave, I can't do that"
wrote:
We have made thousands of handlebar clamps for motorcycles. We CNC
mill the bar hole 7/8, 1" or 1-1/4" with a 3/4" end mill. Then we
slice it in half with a 0.050" thick saw blade in a horizontal mill.
If you don't have a horizontal mill, set up the saw blade in an arbor
and slice it off that way. I think the saw blades are called Jeweler's
blades. They have very fine teeth, are HSS and only cost a few bucks
each at MSC.

Dave

And they are not hack saw blades! They snap real easy.

Paul

Er, Paul,

And they are not hack saw blades! They snap real easy.

They are round milling cutter blades, hence the "arbor" comment. We
have never "snapped" a single one.

Dave