Monday, April 28, 2008

How I do it

I made a start on the 15 foot radius dish this evening and took some photos of the setup. Firstly, my dishes are made of two 600mm square pieces of MDF that I glued together - giving me a total thickness of 32mm. I then used a jigsaw set in the Triton table and cut the circle using a centre point.

I then used another square of MDF as a base board and partly drilled a hole at the center point. I put a drill bit or screw through the centre of the disc and then down into the base board. The MDF is smooth enough that it is fairly easy to spin the disc on the board below.

I mounted the MDF rails that I had routed to the radus curve onto some pine boards - giving the curve some strength to prevent it from bowing when suspended above the disc.

I used the corner pieces that had been cut of when making the discs and placed them near the edges of the disc. On these, I places some biscuts t make a slight gab and then clamped down the pine boards.

I ensured that the two rails were only seperated just over the width of my router base, to stop the router moving side to side.

I made the rails so they extended well past the end of the dish and that the curve continued past the centre point, considering the width of my router base.

My router has the ability to have two metal rods fixed into the base - the rods are the only parts that come in contact with the rails.

On the last dish I moved the router in and out, taking small cuts. This time (and I am finding a better result) I am turning the dish to make the cut all around the outside and then moving the router a little towards the middle before making the next cut.

I did however slice the disc with a few cuts into the center, giving me a few finger grips to turn the dish with.

Sunday, April 27, 2008

Dishes are done... almost

Well, it may have taken me something like 15-20 hours of fiddling around trying to work out all the new equipment and develop some skill at using it, but I think I have worked out how to make a sanding dish - or at least a way of making a half decent version of one. I tried a few different methods - this is what I ended up using. I think it works best for me.

First of all I plotted out BillM's calculation of the given radius onto 30mm wide x 20 mm thick MDF strips. From that I used nails to plot out the curve, taking into account the width of my steel rule. I also cut the heads off the nails to try and keep it closer to accurate.

Most importantly, I introduced some form of dust management. If you are going to attempt to make dishes, this is a must. To give you some idea, I changed the bag in my standard household vaccum four times today. My shed is trashed from the previous efforts an I fixing up the old vaccum cleaner was well worth the effort.

Below you can see how the steel rule (flexible) is held up by the nails. I use a bearing bit in the router, usinging the steel rule as the guide. When I push the bearing against the ruler it in turn pushes against the nails plotting the curve. Below, you can also see my hightech dust management system in place.

Here you can see how the bearing runs on the ruler... the ruler is pushed back against the nails.

I got carried away and forgot to take some pictures through the process. I will get some detailed photos tomorrow when I make the 15 foot dish. Below is the 30 foot radius dish. I am really happy, some light sanding and I will be home and hosed.

Time taken : 4 hours
Tools used : Router, vaccum cleaner, pencils, rulers, screws, drill, jigsaw, eye/ear/dust protection, etcetera - all of it.
AU$'s spent : Nil

Sunday, April 20, 2008

If I lived in the States - I'd buy them

Last Sunday I spent about 5 hours in the shed. This Sunday I spent about 8 hours at it – MAKING DUST.

I have been trying to make a set of 15 foot and 30 foot radius sanding dishes and I have come to the conclusion that it would simply be easier to just buy the darn things. I won’t go into the numerous different hoops through which I have jumped, but here is the basics of how it ended…

I used a piece of scrap 5mm thick board to make a template. After plotting the points of the curve I used small nails to mark the curve – then used a steel rule to form the curve, which in turn became a router guide. I ended up with a templates that was reasonably happy with.

I glued two 600mm X 16mm thick square boards together and then cut and routed these into circles.

I used my template to make two rails on which I made a carriage to hold the router. The idea being that the router bit, at its highest point just touched the edge of the circle and the carriage rolls down from there. Hey – it works but it is slow, tedious and messy.

So at the end of all my efforts, I have a one dish that is about 20% complete.

Time taken : 12-13 hours
Tools used : Just about everything
AU$'s spent : Nil

Sunday, April 06, 2008

Mold Making

Okay, I am officially back at it again. I spent all afternoon in the shed, making myself a OM mold… or at least starting one.

First I cut a sheet of MDF into 600 mm squares with a jigsaw and on the Triton. My plan being to make sanding dishes, go-bar deck and the form from the same sized pieces.

To make the form I cut these squares to make (near enough) 300x 600 mm rectangles. I used oven baking paper to trace the OM plan that I got from Australian Tonewoods and then stuck the baking paper to one of the rectangles with tape.

I should clarify here that Tim from Australian Tonewoods does not draw up his own plans. With his kits, he supplies plans from the popular Stewmac or LMI ranges. The guitar that I am making now is the from the OM LMI plan, which suits me as I can follow Robert O’Briens DVD that came with my last kit. It was comforting for me to know that the plan I would be follow was tried and proved.

I used a Stanley knife to scribe the outline of the plan from the baking paper onto the retangles and then took my time to follow the line with a jig saw.

On one of the squared edges, I screwed the curve template I had created. This left me knowing that the centre line was square the curved sides – does that make sense?

I them used a router for the first time ever. After getting rid of the excess, I used a bearing guide bit, to follow the curve and created my final template.

Using the jigsaw, screws (to secure template to next section) and router I created 5 more copies of the template. So now I have six 16mm thick pieces of form which I can glue/screw together.

Making the form was a surprising easy step – One that I was too fearful off last time to attempt – I wish I had off. I don’t think that my wood working skills have improved that much on the last build. It really was not hard.

That said – It helped having my fathers Triton table saw and router at my disposal.

Time taken : 4 hours
Tools used : pencil, rulers, T square, baking paper, Stanley knife, Jigsaw, Router, Table saw, tape, drill, 25mm screws, sandpaper.
AU$'s spent : Pine wood $7.08, Alumminum tube $2.25, Threaded rod $4.09, Washers, .30, Wing nuts $2.96, Two 2400 x 1200 x 16 MDF sheets $27.00

Wednesday, April 02, 2008

What have I done?

Well – I’m back!

At the beginning of every build, I am riddled with the question, “What have I got myself in for?” and this is certainly no different. I’ve spent another 100 hours on the LMI kit wizard and thought long and hard about what steps I can tackle, in an effort to challenge myself and those that I am just not prepared or equipped to have a go at – just yet.

As I mentioned below, I was lucky enough to stumble on an Australian kit guitar supplier. I went down and met Tim from Australian Tonewoods a week or so ago and tonight we put together my next kit.

It was a whirlwind experience, kind of like surfing the LMI kit wizard after having a dozen too many coffees. Tim was pulling out different types, sizes and shapes of wood from all over the place, feeding me the qualities, pros and cons for each sample as he handed me the product. I think he quickly worked out that my knowledge and ability is out weighed by my ambition – I’m sure the constant blank stare was a give away. Let me tell you that the choices are even harder when you are touching the wood.

My briefing to Tim was that I am more interested in the process of building rather than the cosmetics etc. Having had a look around his workshop, I am confident in saying he could have put together a kit serviced to the same standards of Stewmac and LMI but I really want to try a few more of the steps myself this time. Not having the equipment to do it myself, I’ve asked Tim to slot the fret board, thickness the top, back and sides – aside from that I think I am having a go at most of the other steps.

Anyway, it’s time I started making molds, dishes… learning how to sharpen chisels and the other dozen things I have on my to do list.

This one will be from the LMI OM plan. I chose this guitar solely because I have the Robert O’Brien DVD so I can follow his steps without making conversions.

Time taken :
Tools used :
AU$'s spent :