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SwedishLuthier

Old Mcdonald Had A Radius Block

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I have used my old StewMac radius blocks like forever. Never any problems. Recently I (more or less consciously) destroyed the 12” block by using it as a clamping block for a tricky repair. It was old and I had an order for SM plannes so I incorporated the cost in the repair and said what the…

Anyway, the new block arrived and I put it in the same place as the other. As I haven’t made any 12” fretboards in a wile I only recently took it out for use. After sanding an ebony fretboard into shape I discovered a thing. The block was not very uniform. The radius part had very obvious flaws The harder winter parts were protruding and thus making a very visible grove along the fret board. Most likely this is because SM have used sub standard, not dry enough maple for the blocks, machining them “in the green” and the blocks have dried out in my workshop. So being a long time since I ordered them I thought that there were no way I would get a refund, and always curious for new tool, I bit the bullet and ordered their 18” long, 12” radius sanding beam. It arrived and I noticed that the radiused surface had small but very noticeable and sharp aluminium chips from the milling process. It took me a while to clean all of that away. Also the corners were pretty sharp and would easily dent a board. Had to file them away. But I have saved the best for last. The business end of the beam isn’t dead flat!!! It is slightly curved and therefore rendering it unusable for fret work, which is what it is advertised as being possible to perform.

I must say that the QC department at SM seems to be asleep at the wheel lately

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You mean the SM QC guys have a wheel? I thought they just reinvented everyone elses ;-D

I really would like a radius beam from SM but the thought of paying shipping on top of receiving a potentially substandard item dissuades me. I'd rather pay money to build equipment to make my own!

Thanks for the heads up - let us know what SM's response is if you contact them about this.

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Whilst the problems are worrying, I can tell you in advance what Stew Macs responce will be;

'There's another one in the post, no charge. Sorry for the inconvenience'.

They have a justifiably stellar repuation for making it right if they drop the ball.

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That's more reassuring, although I may still just go down the road of making a bunch of long radiused sanding beams this end of the pond anyway. Costwise, it won't be much different. That and it's fun. There's something about buying out of catalogues though....

....and I don't mean Grattan....

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I wonder how perfect one like this really is

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Not very? The tension doesn't look like it would be even across the radius, perhaps even much flatter in the central apex of the radius. The use of bottle buckles are a great out-of-the-box idea.

Perhaps using this concept, and taking a cylinder of the desired radius and using it to sand the inner face would work better. I'm sketchy on how accurate this would be. Interesting idea though! Good link.

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Didn't LMII have a tool lie that but with only two turnbuckles?

I have already mailed SM about the issue, but it is really anoying that they depend on their "replace anything that is substandard policy". It cost me a lot of time, waiting for the better tool to arrive. And I really hope that they don't want me to return the bad beam. The cost in returning it and the problems I get with customs... They charge med import VAT even if I recieve an item free of charge. I will have to pay 25% of the value of thet free item. To get a refund I have to EXPORT the bad item and that will not only cost me shipping but also customs handling... So even if SM replaces the beam with a better one it will cost me more money.

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I was thinking about the import duty/VAT issue this morning myself. I've had items labelled up as "item returned under warranty repair" which managed to get my ESP Explorer through customs :-D

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I feel your pain. :D One of the first non guitar projects I have slated for the CNC is a combo 12" set consisting of a long sanding block, and fretboard glueing caul. I hate using my Stewmac sanding block for glueing radiused boards on. I have acess to scrap Corian material. It will be heavy, but I think it will work well.

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As for gluing cauls, take some MDF, set your table saw to tilt (can't remember the angle), put the fence on the opposite side of the blade than usual and send the MDF through. Then slot the MDF where frets for your favorite scale length would be (or don't if you fret after gluing on boards) and voila. I know that's vague, so what you should end up with is an MDF piece with a shallow triangle cut from the bottom. Not it's not a radius, but if you get the triangle right it should put a lot of pressure on the edges of the fretboard where you really want a tight joint and enough pressure on the 2nd and 4th fifths of the board (if talking left to right; ie: not edges and not center), and as for the center... who cares, you don't want the fretboard glued to your rod (not that it even matters with wood glue). It's what me and the guys I know use and there hasn't been a single issue.

Chris

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Thats a cheap and simple tool Chris. Thanks for charing.

Currently you can get a sweet deal on one of these I have one of the "second grade" and it is perfectly all right.

No reply from StewMac yet...

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There's also a tutorial around here somewhere (I did a quick search but couldn't find it) about making your own radius blocks with a drill press and a Safe-T-Planer. It's a great method; I've made 12'", 16" and 20" blocks.

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Didn't I see a jig somewhere where you could make your own with your router on a pivoting arm? Someone should make up a dozen or so and put them in the "for sale" section. If they resonable cost, I would purchase one to save me the trouble to building the jig.

-John

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Didn't I see a jig somewhere where you could make your own with your router on a pivoting arm? Someone should make up a dozen or so and put them in the "for sale" section. If they resonable cost, I would purchase one to save me the trouble to building the jig.

-John

Found it!

http://www.projectguitar.com/tut/radius.htm

I went to google to find it, and it sent me right back here. I should have known.

-john

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Today I received the new beam. I did a quick measurement using my StewMac straight edge and a digital calliper. This one have slightly less "relief" compared to the first one but still 0.16mm at the worst place. This is a far way from what I would like to use for fret dressing. And they made sure that they would measure the new beam before shipping it to me! Obviously we have very different views on what is "dead flat".

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Old MacDonald had some quality control issues

E-I-E-I-O

And one if these issues was that they seemed to check the flatness with the blade off an old reel push mower

E-I-E-I-O

With a neck-jig here, a neck-jig there. Here a jig, there a jig, everywhere some freakin' jig

Old MacDonald had a price increase every couple of months

E-I-E-I-O

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LOL

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This one have slightly less "relief" compared to the first one but still 0.16mm at the worst place.

What ?? So turn it around and give it a hit on the workbench to counteract the relief !!!!!! :D:D

Seriously, I understand that .16mm can cause problems, but you've got to remember that you're putting sandpaper onto that which is less likely to be perfectly exact in measurements either.

And then you've got to have your technique down pat , as in no roll off or pivot at your end stroke.

So all I'm saying is there are alot more variables to consider than .16 of a millimetre relief in a radius block.

Nevertheless it is worrying if they can't produce a 'straight' engineered product. B)

cheers, Stu

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Sure, Stu, you are right. But the tolerance for the beam is supposed to be 0.0015" according to StewMac. 0.16 mm is 0.0406", almost 30 times as much as 0.0015. That is too much from a precision tool. But you got me thinking. So I measured the thickness of some pieces of 400 up to 800 grit 3M Vet'n'dry (what I use for fret dressing on a dead flat aluminium beam) and they deviated with 0.01mm (=0.0004").

Nevertheless I must say that they really do whatever it takes to get things right. They have offered to send a third beam, cover the cost for import VAT and return shipping of the two beams, and the cost for the old, old radius block, purchased a year ago. Their QC might be slipping but their customer relationship department (is that what it is called?) is really top notch.

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They spec 0.0015" per foot (not for the full length of the item) for the straightedges, but I don't see that spec for the radius beam (it may very well be the same). 0.16mm is 0.0063", which is still out of tolerance, but nowhere near what you stated. More importantly, if you checked against the Stew-Mac straightedge, how do you know how much of that difference is the beam onstead of the straightedge? The Stew-Mac straightedges aren't the most perfect things out there either (but they aren't meant to be a Starrett).

Stew-mac has definitely struggled with the quality-control of some of their suppliers at times. At least they have the customer service part right. That's what the prices are paying for after all.

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At least you can explain to them easily the problem: this "straight" thing isn't straight. I'd like you to verify the next one is straight before it is sent to me.

They were always very gracious about returns, but I couldn't find a way to explain to them the difference between a blend pot and a regular dual-gang pot in any way that their folks could understand. (Of course the failure in communication is as much my fault as theirs) And it seems like they've at least for the 500K, they were selling the latter for over a year (I don't know if they ever got it straightened out, last time I tired to get one through them was last year)

But yeah, they were great about taking things back and re-shipping and such, even when I got the impression that the fellow on the other end of the phone had no clue why I was complaining.

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It would be impractically expensive to employ staff that were all experts in every aspect of guitars however :-D

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They spec 0.0015" per foot (not for the full length of the item) for the straightedges, but I don't see that spec for the radius beam (it may very well be the same).

That spec was given to me in an E-mail. And it was for the full length, not per foot. The customer service dep. might have misunderstood that part and the spec really is 0.0015” per foot.

0.16mm is 0.0063", which is still out of tolerance, but nowhere near what you stated.

Really strange, you are absolutely right (1”=25.4mm). I used a calculator that automatically converts between metric and inches but something obviously screwed up…

More importantly, if you checked against the Stew-Mac straightedge, how do you know how much of that difference is the beam onstead of the straightedge?

Easy. The defect isn’t along the entire length of the beam. It is much more prominent from the middle towards one end, a slight S-cure almost. When measuring I double checked it by turning the straight edge 180 degrees and if the error was in the straight edge the problem would be from the middle towards the other end, bit it was still in the same spot. And I double-checked against three different steel machinist’s rulers that I know is pretty straight. The result was exactly the same every time. And the error was identically placed on the two beams I have.

At least you can explain to them easily the problem: this "straight" thing isn't straight. I'd like you to verify the next one is straight before it is sent to me.

But that’s what they promised to do with the second beam they sent! They had actually opened the blister pack and taped it shut again. But then again, they probably used a StewMac straight edge to check against…

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