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greenscoe
09-24-2014, 07:40 AM
New builders may find making a mold a daunting task. I dont know what other hobby makers do, but this is how I go about it.

First I decide on the box shape and make a paper/card pattern which I transfer to wood. Here I've used an old drawer side -others might use a new piece of plywood: I sprayed paint to get a shadow on the wood rather than drawing around my paper pattern. I then cut out the wooden master pattern -use a jig saw or bandsaw-and cleaned it up with hand tools until I was entirely happy it was the shape I wanted. My master pattern is a little more than half the box shape with the half way clearly marked-I'll explain later.

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My master pattern is then used to create a number of half mold slices. Again I used scrap wood, plywood would be better. The master pattern is copied onto the wood slices and again each is sawn out roughly with jig or band saw. I made 8 slices in total -only 2 slices shown here.

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Now for the clever part. The master pattern is then screwed to each roughed out half mold slice in turn. Then using a router (with or without router table) and a bearing guided template profiler bit, exact copies of the master pattern are made to be half mold slices. The reason the master pattern is slightly more than half the mold is that the profiler bearing needs the extra shape to follow in order to cut each end of the half mold slice accurately. I recently bought this router table for 30 from Aldi but its not necessary: holding the wood and moving a router achieves the same result. In the photos the master pattern is the old drawer side, the half mold slice is the yellow pine-notice the bearing which follows the master pattern.

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The 4 per side half molds slices are glued/screwed together in a thick sandwich. The 2 halves of the mold can be joined at the ends with wood as here or other means such as quick release clips. Its necessary to separate the 2 halves to extract the box after gluing on the back and top.

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In theory it should be perfect but checks should be made to ensure the the mold is true/square. In practice a little cleaning up/adjustment may be required. I use car body filler for this. The overall size of the mold can be reduced to ensure your F clamps reach the box whilst retaining its structural integrity. Finally the mold should be sealed with several coats of varnish.

This mold is 13.25" long for 20/22" scale length instruments. It took me about 10 hrs to complete-my material costs were negligible.

See next post for first use of the mold this morning and a photo of my tenor mold, made in February this year by the same method only without a router ie entirely with hand tools.

greenscoe
09-24-2014, 07:53 AM
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Here is the new mold in use this morning. The sides are sapele and bent well on my homemade electric pipe bender. The clamps are not exerting any pressure-they are just to hold the sides in place/shape overnight before end trimming/ fitting the end blocks -maybe tomorrow.

For those interested in the shape, it was inspired by 'Allens' beautiful instruments, somewhat less square than my tenors.

The other mold is for my tenors-7 to date: it was made with a jig saw and hand tools and probably took about 25 hrs.

Huke60
09-24-2014, 11:00 AM
Hi Alan
Some good ideas there which might be helpful
I might need to adjust the height on my mold as when I bend the sides they are two tall for my mold
I have a great idea which worked well with my last tenor which helps to glue the top and back on.
I will show you on Saturday and might post on here some time soon

gspears
09-24-2014, 01:27 PM
I build using a Spanish heel design. I wonder if others have made similar molds for Spanish heel construction? I would like to see a few..ill start looking now..haha.. very good ideas.. thanks for sharing.

ericchico
09-24-2014, 02:20 PM
I build using a Spanish heel design. I wonder if others have made similar molds for Spanish heel construction? I would like to see a few..ill start looking now..haha.. very good ideas.. thanks for sharing.
Heres my Spanish Heel mold ;)

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and my solera
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gspears
09-24-2014, 05:14 PM
Thanks Ericchico. I have similar molds based on the Hana Lima book designs. Your mold for holding the sides is much nicer looking then the one I built. LOL. But it does the job. Thanks for sharing!

Timbuck
09-24-2014, 09:24 PM
I started off with moulds (English spelling) almost identical to those..The design of the one i'm using now has evolved over the years with some of my own ideas mixed in with others that I stole...It's a sort of a mould built onto a Solara ...I made slide show of it showing all it's parts, including the back template indexing beam..this makes sure that the backs line up perfectly every time...this is the slideshow.
http://s219.photobucket.com/user/shiregreenbod/slideshow/New%20Mould/?albumview=slideshow

LesterPolfus
09-24-2014, 11:48 PM
I build using a Spanish heel design. I wonder if others have made similar molds for Spanish heel construction? I would like to see a few..ill start looking now..haha.. very good ideas.. thanks for sharing.

I too use the spanish heel design and I made a similar mould using the same process.
Mine though is designed to be fixed to the solera with dowels, keeping the two parts of the mould from opening (the neck side is open, being the width slightly more than the width of the neck, and there's a hinge on the tail side). The dowels are glued to the solera and they go through a slightly bigger hole in the mould so I can take the mould and the solera apart without effort when I need to.
I have no photos of it, hope the description is clear.

Michael N.
09-25-2014, 12:31 AM
It's also possible to do a half mould, clamp a Side to it and glue on both top and bottom linings. On release the Side will hold it's shape remarkably well, such that a full mould is not needed for assembling the rest of the instrument. It works well for any Neck joint including the Spanish heel.

Timbuck
09-25-2014, 03:57 AM
It's also possible to do a half mould, clamp a Side to it and glue on both top and bottom linings. On release the Side will hold it's shape remarkably well, such that a full mould is not needed for assembling the rest of the instrument. It works well for any Neck joint including the Spanish heel.
That's very interesting Michael.....I'd never thought of that way of building before...it sounds as if that way calls for solid or reversed kerf linings.

Beau Hannam Ukuleles
09-25-2014, 04:17 AM
buy one of these

http://www.harborfreight.com/14-in-oscillating-spindle-sander-69257.html

Michael N.
09-25-2014, 05:23 AM
That's very interesting Michael.....I'd never thought of that way of building before...it sounds as if that way calls for solid or reversed kerf linings.

No it works with normal kerfed linings too. It's surprising how solid they feel after the linings are glued, and that's on Guitar sized ribs too. I've only tried it on that size. I also make a Guitalele sized instrument but I use a different method for that. I'm thinking of switching to the half mould for the Guitale as well. For a Guitalele or Uke I should imagine that they will end up very rigid.
You need to finalise the rib shape and incorporate any side taper before gluing on the linings. One thing I have found is that using C or G clamps to hold the side to the mould is a bit cumbersome/heavy. I use 5 clamps - 2 at the extreme ends, one at the waist, one each on the bouts. In future I'm going to try and spot glue the rib to the mould, then remove the clamps before gluing on the linings. That way the Clamps won't get in the way when attaching the linings.
Of course you still need some form of work board. . . or maybe not, if you are feeling very brave.
Torres supposedly glued his linings on to the sides, without any form of mould at all. He made his sides frighteningly thin though, which obviously gave them a lot of flexibility. I suppose that allowed him to adjust the ribs to the pencil line as he glue the whole thing to the soundboard. I've tried that method too but there's always a strong chance that the Sides will end up twisted or racking as I've heard it called.

greenscoe
09-26-2014, 08:52 AM
Its interesting to see what posts this thread has generated!

I started the thread in the hope it might encourage would-be builders to have a go by seeing that mold (mould) making isn't that difficult. I wonder how many first builds (excluding kits with preformed sides) result in instruments that either are not symmetrical or have sides which are not square with the top?

ericchico
09-26-2014, 09:24 AM
Its interesting to see what posts this thread has generated!

I started the thread in the hope it might encourage would-be builders to have a go by seeing that mold (mould) making isn't that difficult. I wonder how many first builds (excluding kits with preformed sides) result in instruments that either are not symmetrical or have sides which are not square with the top?
My first one I struggled with getting the butt joint to line up and trimming it caused the shape to be a little off than the original template. The Spanish Heel way of doing it gave me room to adjust that shape at the last minute. The edges of my sides I got right. Since the top was flat I just had to make sure the edge of the sides were true before I bent them and when glued down they came out fine. Then after the lining was installed I trued the edges of the sides for the back with a long sanding board and checked it with a straightedge until I could see no gaps before gluing. I have a mold built for bolt ons but Im still doing Spanish Heel a few more times and cured my butt joint problem by gluing the tailblock to the sides first instead of gluing it to the soundboard first

Timbuck
09-26-2014, 09:50 AM
Its interesting to see what posts this thread has generated!

I started the thread in the hope it might encourage would-be builders to have a go by seeing that mold (mould) making isn't that difficult. I wonder how many first builds (excluding kits with preformed sides) result in instruments that either are not symmetrical or have sides which are not square with the top?
My first 12 were all over the place...One was so bad i did this with it..and someone bought it :o
http://i219.photobucket.com/albums/cc143/shiregreenbod/halfuke_zps0a617069.jpg (http://s219.photobucket.com/user/shiregreenbod/media/halfuke_zps0a617069.jpg.html)

DazW
12-31-2014, 03:46 AM
Just a quick one, is there any reason each side of a soprano mould cant be made from one piece of wood instead of sandwiching a few pieces together? I have made a template of my soprano and to begin I was planning to use a jigsaw to cut the shape on some 4cm thick pine , then sand the insides smooth and varnish. Thanks in advance

TjW
12-31-2014, 04:10 AM
My first 12 were all over the place...One was so bad i did this with it..and someone bought it :o
http://i219.photobucket.com/albums/cc143/shiregreenbod/halfuke_zps0a617069.jpg (http://s219.photobucket.com/user/shiregreenbod/media/halfuke_zps0a617069.jpg.html)
If they ever sell it, I can imagine the advertisement:
Tim Buck ukulele with cutaway. Half off.

Beau Hannam Ukuleles
12-31-2014, 06:52 AM
nice

I now taper my molds to mimic the back. I fully complete the mold to a bit less then the depth of the end block, then roughly bandsaw about 3/4" off the upper bout fading into the waist

Timbuck
12-31-2014, 07:01 AM
Just a quick one, is there any reason each side of a soprano mould cant be made from one piece of wood instead of sandwiching a few pieces together? I have made a template of my soprano and to begin I was planning to use a jigsaw to cut the shape on some 4cm thick pine , then sand the insides smooth and varnish. Thanks in advance
I try'd that on one of my first mould attempts and found it difficult to sand, and it wasn't too good :(..But I didn't have a spindle sander in those days. ;)..I got a more accurate job by adding the slices one at a time doweling them in postion and template routing from one master slice. :cool:

DazW
12-31-2014, 07:16 AM
I try'd that on one of my first mould attempts and found it difficult to sand, and it wasn't too good :(..But I didn't have a spindle sander in those days. ;)..I got a more accurate job by adding the slices one at a time doweling them in postion and template routing from one master slice. :cool:

Thank you. That's saved me a lot of time and effort, I was also planning to do a sopranino mould using the same method so glad I asked for advice before starting them. Cheers

Underling
12-31-2014, 08:31 AM
I wonder how many first builds (excluding kits with preformed sides) result in instruments that either are not symmetrical or have sides which are not square with the top?
MY first ukulele build is currently on the kitchen table In that very state. I went to glue the front and back on last night and discovered just how far off it was. Today I get to rip it apart and start over :(