ES2 - Big LP and LP4

[Bizman62]

Is the speed controller some sort of a current adjuster, dropping the AC to a lower voltage? There was some interesting palm routers for next to nothing at a Chinese shop but they had no speed control. Then again my trim router is of the smaller sort and the Lidl (a German chain shop) seems to have an even smaller one as a campaign article - and they have a 3 year warranty!

[curtisa]

3 hours ago, Bizman62 said:

Is the speed controller some sort of a current adjuster, dropping the AC to a lower voltage?

It'll be a generic SCR chopper speed controller. Cheap as chips but not very reliable and of questionable safety. Note you can only use them on brushed motors (hand drills, routers etc); they're not compatible with larger induction motors such as used in drill presses or jointers.

[Crusader]

8 hours ago, Bizman62 said:

Is the speed controller some sort of a current adjuster, dropping the AC to a lower voltage?

I don't know exactly how but its to give the router variable speed. It keeps the noise down and the router bits I use are over 2 inches wide which are scary at full speed! And by the way something I might have not mentioned is the new router has variable speed built in. I am notorious for leaving out bits of information like that!

 

 

4 hours ago, curtisa said:

It'll be a generic SCR chopper speed controller. Cheap as chips but not very reliable and of questionable safety. Note you can only use them on brushed motors (hand drills, routers etc); they're not compatible with larger induction motors such as used in drill presses or jointers.

The first one I had was something a friend picked up in China, and the one I just bought was from Jaycar, made in Germany, and yes the instructions do point out their limitations just as you said

[Bizman62]

7 hours ago, curtisa said:

It'll be a generic SCR chopper speed controller. Cheap as chips but not very reliable and of questionable safety. Note you can only use them on brushed motors (hand drills, routers etc); they're not compatible with larger induction motors such as used in drill presses or jointers.

Thanks! Now that many power tools are becoming brushless I guess a built-in speed controller is worth the extra price.

A bit tangential, that kind of thing may be the gadget a friend uses to make an old deep freezer suitable to keep his beer tanks cool.

[curtisa]

1 hour ago, Bizman62 said:

Thanks! Now that many power tools are becoming brushless I guess a built-in speed controller is worth the extra price.

No. Brushless DC motors are different beasts entirely and wouldn't be compatible either. The SCR choppers are old-school tech - think more along the lines of a light dimmer for incandescent globes.

 

1 hour ago, Bizman62 said:

A bit tangential, that kind of thing may be the gadget a friend uses to make an old deep freezer suitable to keep his beer tanks cool.

You mean...like a thermostat?

[Bizman62]

5 hours ago, curtisa said:

You mean...like a thermostat?

Nope. Like something that lowers the current so that the compressor doesn't work on full power. Deep freezers don't have a thermostat setting for above freezing point temperatures. At least not here.

 

5 hours ago, curtisa said:

No. Brushless DC motors are different beasts entirely and wouldn't be compatible either.

 I understood that they wouldn't be compatible with the external gadget, but brushless tools do have built-in speed controllers, don't they? I meant that investing in a brushless tool that has that controller knob is worth the extra cost compared to a single speed one.

[Crusader]

16 hours ago, curtisa said:

It'll be a generic SCR chopper speed controller. Cheap as chips but not very reliable and of questionable safety.....

Yes the reason I bought a router with built-in variable speed is because I thought an external one might not be good for the motor, cost quite a bit!

 

Well I got my washing and vacuuming done today and also had time for guitars!

A lot of mucking about but I got the mahogany back shaped (still have the inside to go)

Tried to figure out a way of making it the same as the QLD maple and did something like this but with 1mm rises

Maybe I should have taken a pic before sanding...

Edited April 9, 2022 by Crusader

[Crusader]

Latest developments, converting my depth gauge into a drill press

There's no 'love-heart' on this one, and the Tap-tone has gone from A2#-30 cents to G2+40 cents

 

[Crusader]

Need to come up with a better idea for my "drill press", flexed more than I thought and went too deep. Some areas are 3mm and still leaves dimples leaving it on the cusp of disaster

Also I added a piece of measuring tape to my callipers to help read the depth

 

I tidied up the inside a bit and cut the Neck Block along the nodal line

 

 

Body jig is out of shape, I will need to put Binding on the back of this one probably

[Crusader]

I've been stewing over this mahogany back thinking its too thin, and shaving the dimples out would make it even thinner. So I googled it tonight and apparently some backs and tops go down less than 2mm so that makes me fell a bit better. I think I will have to bind it, just another un-planned pain in the neck

Also not sure about the thick strip down the middle, wondering if it causes the tap-tone to be "confused" It doesn't ring out a definite single note. Maybe one half rings one tone and the other side another. Maybe better to stick to tradition and glue a strengthening strip down there. The laminating effect may be stronger after all

Any comments or suggestions are very welcome

So that's my ponderings at the moment and hopefully I will get onto it in the morning

[Bizman62]

4 minutes ago, Crusader said:

It doesn't ring out a definite single note.

For what I've seen some top luthiers do on acoustic tops is that they're trying to get as many different notes as possible. They do that by honing the braces.

A laminated strip may or may not be stronger, it depends on the wood used. On acoustics the center strip is there mostly to keep the halves together and the grain direction is perpendicular to that of the bottom for the same reason. And it's not very tall, only a few mm. And it's often made of several short pieces. That ridge looks way taller so it should stiffen the bottom sufficiently compared to those.

[Crusader]

9 hours ago, Bizman62 said:

For what I've seen some top luthiers do on acoustic tops is that they're trying to get as many different notes as possible. They do that by honing the braces.

A laminated strip may or may not be stronger, it depends on the wood used. On acoustics the center strip is there mostly to keep the halves together and the grain direction is perpendicular to that of the bottom for the same reason. And it's not very tall, only a few mm. And it's often made of several short pieces. That ridge looks way taller so it should stiffen the bottom sufficiently compared to those.

Thanks for your comments, I think I worry too much and just need to get on with it and accept things don't always go to plan

[Bizman62]

Adding to my previous comment, the reason behind trying to maximize the notes on a guitar top is to emphasize every strummed note, add richness and loudness to all of them. And maybe trying to prevent wolf notes.

Don't know how much the back actually affects the acoustic tone other than to bounce the vibrations of the top out of the sound hole. That's the logic behind the top on acoustic instruments often being of spruce as it vibrates well and the backs are maple as it's stiffer and bounces the vibrations instead of absorbing them.

In your case, as you're building an electric without sound holes the acoustic properties may not play that big a role but they may affect sustain and maybe also harmonics. Interesting to see how this turns out.

 

[Crusader]

Had a little win, it turns out my "callipers" were reading 1mm less than actual, so what I thought was 2.5mm is actually 3.5mm. So I went over the back making it a more uniform thickness with a minimum of 3mm and max of 4mm and I'm happy with that. I think if I try to get too fussy I will stuff it up

 

On 4/23/2022 at 2:02 PM, Bizman62 said:

Adding to my previous comment.....

Good comments, yes my aim is to avoid wolf notes and so forth not so much for accoustic properties (although I believe what's good for the goose is good for the gander) On the first hollow guitar I made, the top and back are flat inside and I theories that it causes "standing waves" resulting in a wolf note. So that's the reason for scooping this one. And by the way I almost ditched the Mahogany back to make another out of Maple!

Its been a pain in the neck working on this back but having all these dramas unfolding has brought my attention to other aspects of the construction which I might have otherwise overlooked. The top has a lip around the edge which has turned out to leave gaps, and the sides are of uneven thickness, so I did some work on this today. I also aimed at eliminating any loose ends that would cause lost vibrations. Tomorrow I will go right round the edge of the top and take out that lip and its gaps

 

[Bizman62]

48 minutes ago, Crusader said:

Had a little win, it turns out my "callipers" were reading 1mm less than actual, so what I thought was 2.5mm is actually 3.5mm.

Yay! That's good news!

[Crusader]

The latest thing I've done is to remove the built-in lining on this guitar. When I glued it up I think the sides shifted and left gaps and that would mean a lot of vibrations would be lost. Its also unnecessary because the sides are plenty wide enough but it was a good little experiment. I was able to work on the top without it being glued on

 

[Bizman62]

I had to search back to the first page to see what you did. Definitely yes the sides are thick enough for a solid glue joint. After all the linings on acoustics are only some 5 mm wide and even that may be partially routed off for binding. And in my thinking a plastic to wood glue joint is never as strong as a wood to wood glue joint so binding most likely doesn't add more strength than what has been routed away for the channel.

[Crusader]

I decided I want the top to have a more even thickness all over so I redid the depth drilling and bought an attachment for the Angle Grinder. I found it grabs too much and although its length enables me to get into deeper places I can't feel how much its taking off. On the upside, the cutter can be swapped out for a sanding disc and that did quite a good job with a 40 grit pad

Also just for the record the top was even thicker than I thought it was before. Not so worried about that little area between the pickups

 

[Crusader]

A bit more done today shaping the inside of the Top, rounding off any square edges and thickness is roughly 4mm all over

 

[Crusader]

I finally glued the Back on today. Its a bit small in a couple of places but I can fix that with binding or just sand the difference out (yeah I think I will do that)

First up here's a smart idea, glue the pot washers on! - Second photo, this is the first time I haven't used a ton of G-Clamps, would be better if they were round

 

 

 

Next Photo I used a couple of locating pins due to the Back being undersized, it had to be in an exact place (would have preferred a smaller nail but 1/16" is my smallest drill bit)

Then last photo, the Nodal Line was right on the Bridge, then shifted 32mm towards the bridge after the Back was glued on. This is about the same as my LP Studio, but after the hardware is on it might shift again

after learning a bit of German I often use capital letters for nouns

Note the Chamber's Res. Freq. is a bit higher with one pickup hole closed off. That means if I put in f-holes, the RF will be lower than without, but I doubt if it would make any difference using the magnetic pickups or the Piezo's. Its just an interesting thing to note

Apart from that I am just so happy this thing is together now, progress at last!

 

[Bizman62]

57 minutes ago, Crusader said:

after learning a bit of German I often use capital letters for nouns

Seeing capital letters used in English texts often makes me wonder if there's any logic involved. I once did a search and the answer seemed to be that there's no logic, at least not anything as obvious as in German. But sometimes it makes things clearer.

You're about the only person whom I know to keep score of the notes of the build. I've seen builders check the tuning of a separate top or bottom but they never seem to tell if they recheck it after glueing the parts together.  I find your meticulousness very interesting. I'd also like to see some studies made a) about repeating the tuning and b) building a similar instrument tuned differently to see how much that really matters.

[Crusader]

On 5/20/2022 at 2:05 AM, Bizman62 said:

Seeing capital letters used in English texts often makes me wonder if there's any logic involved. I once did a search and the answer seemed to be that there's no logic, at least not anything as obvious as in German. But sometimes it makes things clearer

LOL I don't know why I chucked that in there, just to see if anyone noticed I suppose. In English I'm sure there are some rules but school was some 50+ years ago. I think German is over the top with capital for all nouns

 

On 5/20/2022 at 2:05 AM, Bizman62 said:

You're about the only person whom I know to keep score of the notes of the build. I've seen builders check the tuning of a separate top or bottom but they never seem to tell if they recheck it after glueing the parts together.  I find your meticulousness very interesting. I'd also like to see some studies made a) about repeating the tuning and b) building a similar instrument tuned differently to see how much that really matters.

Yes they probably don't want to give out too much of their knowledge! What I wonder is, should the Top and Back be tuned the same or a harmonic. Should the Res F of the chamber have a relation to the Res F of the wood? The reason I'm keeping track of it all is once the guitar is finished if it has a Wolf note or a dead note I might be able to figure something out

I've googled this to death but I never hear luthiers talk about resonant frequency of the wood (entire instrument) whether guitar, cello, violin. We all know how to get a tap-tone from a piece of wood and you can do the same with a guitar. If you hold it around the first fret, put your ear to the headstock, tap the guitar around the neck/body join you will get its tap-tone. The other thing you can get is a jab in the ear from the string-ends. If you try this, experiment for the best place to hold and tap. I hold the guitar up to a Tuner at the base, and you can get the same result from the Tuner near the headstock

Perhaps the Tap-tone of the entire instrument its too low to have any effect. My BLP is about B1 which is the lowest B on a Bass guitar

This video is interesting they talk about a wolf note at 110 and 220Hz (A) At first it sound like they are talking about the Resonant Freq of the guitars Tap-tone but later it comes out they're talking about the Res F of the Chamber and of the Top. How you determine the RF of the Top once its glued I have no idea. Is that what he's doing with the little hammer in the video? The Aussie guy has a funny accent!
 

 

[Bizman62]

1 minute ago, Crusader said:

I've googled this to death but I never hear luthiers talk about resonant frequency of the wood (entire instrument) whether guitar, cello, violin.

If I remember I'll ask today if our Master has anything to say about that.

[Crusader]

I've just watched the video again and realised at 3:50 he says the first peak is the main Air resonance (110Hz) and the second one is the main Top resonance (220Hz) which are both "A" So that answers a couple of my questions

Another thing is you would not hear the Tap-tone of the whole instrument because its sitting on his lap and therefore muted. To hear this the guitar needs to be suspended at one of the nodal lines, which are somewhere around the 1st fret and the bridge

I think he's actually English

[Bizman62]

7 hours ago, Bizman62 said:

I never hear luthiers talk about resonant frequency of the wood (entire instrument)

So I asked and the Master looked puzzled. Since graduating from the Ikata luthiery school in 1986 he's been in the business, got the Master Luthier diploma in 2011, designed the Flaxwood composite guitar etc. so he should know.

Shortly put, what he said is to try to tune the tap-tone to an out-of-scale tune to avoid boosting certain notes. No opinion about the top and bottom being of different notes. And he sort of confirmed your guess about the low notes of an entire guitar not having an effect.