Hi guys!

I'm a newbie at the refacing job, so I didn't trust just my hands. I made a simple sanding aid for radial facing. I haven't seen anything like that anywhere, so I'd like to hear if somebody else likes the idea.

I've been playing a tenor and recently bought an Aquilasax C-melody. I have a couple of Le Roc mpcs for it. They are intended for the very short cut Aquilasax C-melody reeds, which I don't find very comfortable to play after the tenor reeds. They are actually shorter cut than Rico alto reeds. So I refaced one of the mpcs for Rico Royal tenor reeds: now the horn feels pretty much the same as my tenor. The sound has a lot of treble now which is kind of a good thing with the dark sounding c-melody, I think, but the reed also squeaks easily if it's not completely wet. So my first refacing job is kind of a succes - well you could call it a limited success.

I did measure the mpc and completed the job by polishing it by hand. The measures seem ok according to the charts found here.

Any opinions? The picture is at the photos section.

Mikko

Nice job!  I'm sure a lot of mouthpieces out there could be improved with this rig.  I think it will only get you so far though.  But it may be far enough for your needs.  

--- In MouthpieceWork@yahoogroups.com, "MojoBari" <kwbradbury@...> wrote:
>
> Nice job!  I'm sure a lot of mouthpieces out there could be improved with this rig.  I think it will only get you so far though.  But it may be far enough for your needs.
>

First of all congratulations for the idea and thank you for sharing it.
In principle it should work but I think precision could be not enough for fine works. There are too much moving parts and each part contributes with its own small error (it is still valid the error propagation law). I work with a custom cnc which of course it is a very expensive item but I am always curious and like simple things (maybe because they usually work), can you tell me more about the clamping system? How it works? 
All the best,

Dan
www.hsm-masterpieces.com

Dan,

I am aware of the tolerance problems - if it was really this easy, nobody would use cnc machines. This is just a poor man's attempt to get it done.

My clamping system is the basic metal ligature that came with the mpc. At first I tried to tighten it around the mpc when in place, but that proved to be impossible to do precisely enough. So after trial and arror I ended up tightening the ligature first really tight with pliers to prevent it from moving and then pushing the mpc in leaning it tightly ageanst a straight angle. It is only the friction that keeps the mpc in place and that alone is not enough when sanding - tried that. So I ended up pressing the mpc into the ligature all the time when sanding and also pressing the moving lever downwards to minimize the unwanted up and down movement.

The sandpaper pad can also be tilted a bit since it's been attached with four screws that can be made tighter or looser indipendently. I also prepared to use those thickness cauges in between to get the right angle but that proved to be unnecessary.

The results were ashtonisgly good: according to my measurements they go exactly along the red 085 line at the "Tenor Link Curves" table. Ignore the green ones, they are from another mpc. They were also straight - same measurements at the both sides according to my home made acrylic glass cauge.

The tip opening is now only 085, because I had to sand down the table quite a bit because of an unsuccesful experiment before this one. Next time I'll now better.

The pictures are again at the Photos section.

The machine could be much better but again: no money was involved at all but still I got some results.

Mikko


--- In MouthpieceWork@yahoogroups.com, "lcchtt" <Letydan@...> wrote:
>
> 
> --- In MouthpieceWork@yahoogroups.com, "MojoBari" <kwbradbury@> wrote:
> >
> > Nice job!  I'm sure a lot of mouthpieces out there could be improved with this rig.  I think it will only get you so far though.  But it may be far enough for your needs.
> >
> 
> First of all congratulations for the idea and thank you for sharing it.
> In principle it should work but I think precision could be not enough for fine works. There are too much moving parts and each part contributes with its own small error (it is still valid the error propagation law). I work with a custom cnc which of course it is a very expensive item but I am always curious and like simple things (maybe because they usually work), can you tell me more about the clamping system? How it works? 
> All the best,
> 
> Dan
> www.hsm-masterpieces.com
>

Sharing ideas is what these forums are about - I've read the other people's ideas to understand the refacing job. What was confusing in the beginning was the 2=1mm and thicknesses are 0.001 inch thing. That's actually why my first attempt was a disaster.

Putting the mpc in and taking it out is so easy with my machine, that my method was to gently sand a couple of sweeps, check the measures and then sweeping again. My "machine" is actually a sanding aid and sanding with it is handwork - you can't expect to put the mpc in and to get a finished product out with it (as you do with a cnc machine). You have to check the mpc many times and mark where to sand more. I followed the Otto Link curves. It says in the table they are circular arc. To my eye they don't look like that but about those things other people have much more experience than me so I believe it.

I didn't use any kind of stopper with the facing machine: at first I tried to use an old reed as a stopper in the ligature, but it messed up getting the straight angle right. Another way to make a stopper would be to place a screw with some softening at the sandpaper face. That would prevent you from sanding too far. I only used a chalk pen to mark where to stop.

A plastic straight angle also has tolerance issues but I didn't want to scratch my mpc table with a metal one. I used a metal one when building the support - they also have tolerance issues though. A simple way to check one is to draw a line, turn the straight angle the other way around and to draw another line. If they match, it's ok. If they don't, the real straight angle is in the middle of the lines. Sorry if this is too obvious.

I attached a picture of my home made thickness sander to the Photos section - I use it for sanding mandolin or guitar tops and sides. It's made of a wood lathe. The lathe is not mine but I have access to it. There's no way I can make a satisfying mandolin top without one. There are also tolerance issues but the answer is to change the direction of the mandolin top, so the problems do not add up but cancel each other. 

There you can see an adjustment system: that's needed when you sand 5 mm down to 1 mm - a lot of adjusting. With the mpc we are talking about very small amounts of sanding and that's why I didn't build one for may facing machine.

The reason I show you the thickness sander is: it is a tool needed for guitar making. A commercial one is far beyond my reach - way too expensive. The home made one however works well enough for an amateur builder like me. I've also built a rocking cradle that I use under the sanding cylinder to make necks - with that I use the veneer slice adjusting method and it works. With mpcs you can't use a sanding machine like that because we're talking about so small amounts of sanding - one tiny error would trash the whole mpc. 

So this is how I had the idea of my facing machine. Anybody can build one. It's only a matter of minutes. I'd like to hear if somebody makes one and gets some results with it.

Mikko








--- In MouthpieceWork@yahoogroups.com, "lcchtt" <Letydan@...> wrote:
>
> 
> --- In MouthpieceWork@yahoogroups.com, "MojoBari" <kwbradbury@> wrote:
> >
> > Nice job!  I'm sure a lot of mouthpieces out there could be improved with this rig.  I think it will only get you so far though.  But it may be far enough for your needs.
> >
> 
> First of all congratulations for the idea and thank you for sharing it.
> In principle it should work but I think precision could be not enough for fine works. There are too much moving parts and each part contributes with its own small error (it is still valid the error propagation law). I work with a custom cnc which of course it is a very expensive item but I am always curious and like simple things (maybe because they usually work), can you tell me more about the clamping system? How it works? 
> All the best,
> 
> Dan
> www.hsm-masterpieces.com
>

Thank you,

Dan

--- In MouthpieceWork@yahoogroups.com, "mitali37" <mitali37@...> wrote:
>
> Dan,
> 
> I am aware of the tolerance problems - if it was really this easy, nobody would use cnc machines. This is just a poor man's attempt to get it done.
> 
> My clamping system is the basic metal ligature that came with the mpc. At first I tried to tighten it around the mpc when in place, but that proved to be impossible to do precisely enough. So after trial and arror I ended up tightening the ligature first really tight with pliers to prevent it from moving and then pushing the mpc in leaning it tightly ageanst a straight angle. It is only the friction that keeps the mpc in place and that alone is not enough when sanding - tried that. So I ended up pressing the mpc into the ligature all the time when sanding and also pressing the moving lever downwards to minimize the unwanted up and down movement.
> 
> The sandpaper pad can also be tilted a bit since it's been attached with four screws that can be made tighter or looser indipendently. I also prepared to use those thickness cauges in between to get the right angle but that proved to be unnecessary.
> 
> The results were ashtonisgly good: according to my measurements they go exactly along the red 085 line at the "Tenor Link Curves" table. Ignore the green ones, they are from another mpc. They were also straight - same measurements at the both sides according to my home made acrylic glass cauge.
> 
> The tip opening is now only 085, because I had to sand down the table quite a bit because of an unsuccesful experiment before this one. Next time I'll now better.
> 
> The pictures are again at the Photos section.
> 
> The machine could be much better but again: no money was involved at all but still I got some results.
> 
> Mikko
> 
> 
> --- In MouthpieceWork@yahoogroups.com, "lcchtt" <Letydan@> wrote:
> >
> > 
> > --- In MouthpieceWork@yahoogroups.com, "MojoBari" <kwbradbury@> wrote:
> > >
> > > Nice job!  I'm sure a lot of mouthpieces out there could be improved with this rig.  I think it will only get you so far though.  But it may be far enough for your needs.
> > >
> > 
> > First of all congratulations for the idea and thank you for sharing it.
> > In principle it should work but I think precision could be not enough for fine works. There are too much moving parts and each part contributes with its own small error (it is still valid the error propagation law). I work with a custom cnc which of course it is a very expensive item but I am always curious and like simple things (maybe because they usually work), can you tell me more about the clamping system? How it works? 
> > All the best,
> > 
> > Dan
> > www.hsm-masterpieces.com
> >
>