cnc inlay first job routing now...

i know you all think cnc is for sissys so for all you sissys out there pict attached.

i am making the kids tea while the router performs a routing job unaided and makes a good job!

1mm router cutter and niceeeeee!



this design will be called my zipper! tenor uke with spanish type neck joint.

CNC still requires an imagination, a design, a tool path, and proper setup. There is nothing wrong with that. If you can make art by hand, more power to you. I have admiration for skill in many forms.

ah thank you Gary... it sure takes some working out but once you get the machine and software then possibilities open up design wise. I also bought the router machine flat packed so the joy of putting it together was truely endless! I am actually a jewellery designer and cad modeller for 3-d printing by trade. I thought the cnc would be good to have a go to see the possibilities as the cad side is simple given my background. I thought maybe I d have the tear out problem or that the radius in the corners would make it look rubbish or for the circles on a cheaper range cnc could look a bit wobbly. However I ve attached a close up of the first job that had a few differing tool paths. The cutter was a 1mm so the corner radius is only then 0.5mm so not so bad! The router makes a small like metal would have bur type effect on the surface but once sanded for a second or two comes off cleanly leaving non chipped crisp edges as seen in the picture. On my test parts the male inlay part fits so tightly that you have to position it exactly straight from the top and push it in and has no gaps at all which to a jewellery guy is very satisfying. For this design the uke has darker bocote wood sides I ll inlay the the zipper pattern with bocote then cut the over hang edge off completely so then when attached to the body will I hope its breaks the outer edge up visually so the side wood continues onto the sound board. Fingers crossed it will look nice.

As for the skill in many forms comment I say work to your strengths and find find your own route. I hugely admire the work on here and also surprised at the quality of craftsmanship even by the non pro uke makers. I have adopted this hobby rather late in life as heading towards 50 soon so I ve some catching up to do! I hope to simple make beautiful ukes that will be around long after I ve parted this world!

If you want tighter corners then go with a "rest" machining operation that will clean them out with a smaller bit after the first operation is complete. This is a very common CNC machining operation.

If you go with a 0.5mm bit then the corner is going to look for all intents a purpose as square. Especially if the part that you are fitting in has a square corner.

You will most likely find that you will need to make the inlay parts slightly smaller to fit the pocket. Humidity, tension release in wood, glue swelling will make for a fit that is so tight you will struggle to get them to fit.

Oh, and what ever you do, remember that Super Glue and softwood tops don't play well together.

robinashby said:

I hope to simple make beautiful ukes that will be around long after I ve parted this world!

Click to expand...

Yes we all probably secretly hope that a hundred years from now our works will still be going strong as in "Oh my God! I can't believe I found a rare one hundred year-old RobinAshby ukulele in perfect condition at this yard sale! I'm rich!"... Ah, yeah.

I don't have any problem with CNC nor do I think it is for sissies. It is just another tool. However, I will point out that while you are letting the CNC do its work and are off drinking tea with small children, I am happily working with wood in my workshop and there is no tea (an inferior beverage if you ask me) and there are no children (yea!), just me and the smell of sawdust (cough, hack) and the quiet sound of my plane tearing out a hideous splinter from a priceless piece of African Black Buwannawanna wood.

Thanks Allen for the advise...the parts I didnt make any smaller I actually thought I might have to.. maybe the cutter is so small that it bends about a tad at high speed as the part push fit in pretty well.

However the rosewood was the second attempt as the first piece started to curl upwards dramatically when only secured in the centre with couple of screws so was scrapped! I am new to working with wood on this scale and supprised at just how bent and twisted it became maybe its the heat from cutting or just making tensions but hey was shocked!

This one was screwed the centre plus tiny pins the corners and even then it wanted to curl but ended up okay. I think theres play in the machine as it was about 0.1mm different in one direction which is about the tolerance given for this type of intermediate cnc router bed.... that said I think it seems okay... i ve never used super glue for wood working so it was titebond and sanding and outcome is pictured here. Think theres tiny bit of tear out but only couple of fibres which hope when taken down with a scraper once the outers parts are in place also. I ve tried the hot glue at times but think maybe my workshop in the uk just cold for it!

As for sequoia's outrageous comment about tea! That's fighting talk to an Englishman! Though tea has to be made with the right water and full fat milk of course or it is rubbish! But tea in england actually means also your evening meal also so thats what I was doing with the kids.... think with cup of tea my kids would be even more crazy than they are now (5 year old twins).

And I agree about the hand tools and quiet calm of using them and I even use a hand drill when I can as don't like the noise or the dust when making stuff. Good thing about this router is its enclosed with extraction so the dust is fairly non existent in the air so no cough or hack thank god as I have enough coughing from my bio hazard twins.

Anyway I am interested in design feedback also along the way...... I think decoration on ukes are like tattoos on people they have to be done well and done to fit the body shape not just plonked on with no relationship to the form. I will try to make my ukes like a sharp smart tailored suit rather than a fashion fad product.... thats the aim, hope I dont miss!

I d like to see a few more pics of stuff being made on here rather than the finished thing as the process and problem solving holds the fascination for more me along with the outcome!

I d like to know if its the challenge of making and problem solving along the way that other find interesting or the outcome of the luvly ukes?

What CNC machine is it, where did you get it, how much. I'd love to have one.

this is the model : stepcraft 600

https://www.stepcraft-systems.com/en/cnc-3d-systems/stepcraft-2-600

i made an enclosure for mine as its in my house..

Would only advise if you were good on a cad program to input the design though.... learning the cnc bit and the cad also plus putting this thing together would for me be a bridge to far!

You can get it it kit form or ready built for extra cost...... with all the messing about it took I think two days to get it to work without play in the lead screws and belt and to home nicely without jamming. It was at times frustrating but end the end worth it i think.

Though maybe now wish I d biten the bullet and gone for the pro version buts its a lot more cost involved.

I ordered the extra thick aluminium base which I think holds the machine more rigid when in position not shown in pic as added later. There's larger area machines but think they may have a little more wobble in them?

Great tool but takes a lot of learning which I like for me...... if others like to learn new stuff then great but if your looking for quick return for effort it will leave you wanting!

thanks,

r

Thanks. I'm very adept at computer graphics, but it's out of my price range for now.

Cool looking inlay idea....hope we can see the finished product
I wish I was a CNC sissy. Maybe someday

Slightly worried its all going well.... i ll probably drop the whole thing once its complete and french polished!

Inlay parts same wood as sides are routed and left thick so I can get a hold of them and drop them in.... theres no play at all so have to go dead str8 from the top.

All but one fitted part exactly why there was one that did nt quite drop in I have no idea but made two extra so all was well.

Will leave to dry and quite a bit to remove but seems to come off okay with sanding.

Thank you for your kind comment ksquine and I too look forward to seeing the finished product! but it seems to take an age to get free time to get it all done!

I am considering my next build also now and may make a smaller uke as this tenor maybe tad large and maybe smaller fraction quicker to complete maybe others can advise?

soprano perhaps..... ?

I think you will find that the smaller the instrument, the more difficult to build well.

So allen smaller uke more tricky to make ....... maybe any mistakes made look larger on a smaller uke?

Its jewellery background liking stuff small I guess has an appeal.



Rubbed the inlay down a little and looks okay I think all fits well with not gaps....! The edge will be trimmed so when connected to sides hope it looks like sides become part of the front and break the edge up visually but we will have to see.

Maybe a more solid toned wood for the inlay look stronger like the center but I am sticking to the idea so will roll with it!

Got to take the thickness down from the back I think... any one advise tenor uke spruce top ideal thickness to go to? the top needs more taking away to I think. But what you think you guys thinner than 1.7mm?

Also read somewhere that bracing needs to be the same or similar wood to sound board (same expansion and all that) is that true or just a soft wood okay or can hard wood be used also i guess need to think of weight a little for this?

Glue wise titebond original is all i have is that the glue to use?

Thanks,

r

It's not really the construction of a soprano that's more difficult. It's getting a good instrument out of such a small package. There is far less "wiggle room" in building something that really works, or just doesn't.

You're the only one that can say how thin is too thin for any particular piece of timber. However 1.7mm is at the very thin edge of a tenor soundboard in spruce unless you are using a lattice bracing pattern.

Yes. Titebond Original (Red Cap) is the one to use in their range. Never the others.

I would say that 1.7 mm (0.062) is getting too thin for a spruce top unless it is severely stiff. 2 mm + (~0.080) is more like it. At least that seems to work for me. Also remember you will be thinning the top more as you do your final sand out before finishing... Yes, Titebond Original (red cap) is what I use. Perfect? Ha ha! Not even, but it does have its advantages and I like the convenience. What bugs me is why they put that yellow dye in there. Dries with a yellow tint which makes it problematic for fixing with sawdust/glue preparations. Why not just leave it white? Sigh...I used to use Titebond II (indoor/outdoor waterproof) until I had to take a fretboard off. Nasty stuff. Many luthiers swear by fish glue as giving a superior acoustic sound. Then there are the hot hide glue aficionados which is forgiving and makes repair so much easier. Then there are the... well, you get the picture. When it comes to glues: Pick your poison. Nothing is perfect.

Then I am glad I asked you guys.....

its currently 2.52mm thick so will take to 2.2 or so then finish the top surface off.

I do have the waterproof tite bond also so will leave that well alone for the uke side then and stick (forgive that one) to red cap like I have thus far.

Never tried the fish glue and not sure where I d get it in the uk not sure I ll make the effort unless others think it worth while... is that applied hot also?

thank you all.

Not heard the fish glue one... it's used mainly for gluing dis-similar materials like felt to wooden hammer in a piano keyboard. I honestly don't know why there is a tendency to beat Titebond with a stick - it is an industry standard that works well for many of us. Hide glue is for the adventurous and ultra precise and epoxy for the reckless Glue is simply what works for you - I tried HHG last year and remain unconvinced that it has any advantage FOR ME over cold glue. The very rare occasions that a ukulele needs to be taken apart... well, go figure. Also if you have a Spanish or slipper heel in the mix plus binding with mitred detail? You might as well remake the instrument.

That said ....Three years ago I reassembled a very badly damaged uke that had abalone border - top separated, side caved in and like the top, splits in several places, sides and top. The only way to put together the part with the abalone was with epoxy - a combination of superglue and cold glue in construction meant that getting a mechanical bond was impossible. The splits however went together fine with cold glue and in some places were 'cleated' with brown tape which has a type of organic glue as its adhesive. The caved in side was glued together with a combination of cold glue and superglue. Carefully done, all this was practically invisible in the end - the filled pin holes which I had drilled to insert a string through and attach a paddle so I could pull the side back into shape were the only evidence of a repair - unless you took a magnifying glass to it!

In all, there is no 'right' glue. One ought to be horrified that Bill Collings glues his fingerboards on with epoxy!!! or the neck joint on a Greg Smallman classical guitar is an epoxied butt joint! Even David Hurd used this method... I use Titebond because its convenient, it works, is stable in my workshop and has a good shelf life.

I use epoxy to glue my fingerboards and head plates on as well. HHG for all the braces and red cap for everything else.