MiKro

Looking good.

mk

https://www.shars.com/products/cutting/end-mills/1-4-se-2-flute-4-oal-long-solid-carbide-end-mill

5 minutes ago, ADFinlayson said:

Thanks Mikro, I've had what you describe before but they've been visable prior to sanding - I don't think this is anything to do with the spraying process, when it was levelled prior to buffing, it was silky smooth, no lumps or dips 

If all was good before buffing, then definitely check your buffing pads/wheels for residue or maybe even your polish is contaminated.

mk

8 minutes ago, ADFinlayson said:

So I noticed something when I was inspecting the finish. There were some white marks/small specs - my first thought was f$%k I've burnt through the finish, but I noticed they were raised like bumps. I took a bit of wet 1200 too them and they disappeared back to smooth matt and I don't appear to have burnt through (I think). Annoyingly I did not think to take a photo before I sanded the marks off.

Could this be some residue building up on the surface?

Could I be staying too long in one place? I never let the surface get hot though.

Do I need to rake clean the mops on the buffer?

I have the same thing on my last lacquered build, I just assumed that I'd burnt through and I figured I'd just refinish it some time. Now I'm doubting that I've burnt through the finish on that one at all.  

Sounds more like your gun is not clean and spitting out atomized droplets. Check tip and parts for any build up also make sure that your filter is clean as well. I will assume you are using a filter cone for the clear coat before it goes into your gun? Also make sure you are thinning your clear coat properly. Also could be over spray?

mk

15 hours ago, killemall8 said:

I say ir very year, but I'm making a commitment to taking more in progress pics this year. But here is where we are at for now. 

 

Turkish Walnut.

Looking good Luis.

MK

@Jolly,

I had a thought about this in one of those waking moments. YOU are going for HIGH VOLTAGE on this one. That all sounds cool but I question the safety of it.

Since the player is the only true earth ground and  if you have any short that would feedback voltage it will go through the player to ground. Just as a properly grounded chassis is done to prevent a deadly shock. The player becomes the chassis ground. I would be very hesitant to go this route unless you can some how isolate the high voltage from the player.

Just a thought about safety from my view of things.

MK

So what you are saying is use the 12th fret as the perpendicular and pivot point. Move the nut and the bridge accordingly. I would maybe suggest doing a mock up using lesser woods and your cnc and see how it works first. Also make the neck bolt on for the mockup as this allows you to make changes easier I would think?

Just my thoughts out loud Mike.

MK

On 11/20/2021 at 11:45 AM, Clintoncraft said:

I started a project 9 years ago that has just been sitting since I don’t have the knowledge base to solve a problem I’m having:  I have wound pickups for individual strings on a project guitar.  I want to be able to mix these pickups from both of two pickup positions into a one-both-one, two channel output (so I can send the output from any string to one of two amps, or both).  I built in a passive mixer with resistors in series with the pickup output into the 3 way switches to isolate the pickups from each other, but I was, and still am operating from relative ignorance to the value of these resistors that would work.  When I built it, the output is super low, so I’m wondering if my idea is failed at the outset, or whether it’s just a question of using the wrong resistors.  Any help in progressing my question to the point it’s understandable to you knowledgeable folks, and even to the point it’s successful would be greatly appreciated.  Thanks in advance.

Welcome to PG,

What you have appeared to do is similar to what Boss/Roland did on the GK series pickups for midi. Since these are a single string pickup, less windings are available therefore less output. First look at summing boards. These will give you some idea how to mix and match the signals. Also you will most likely need a pre-amp of some sort. Another avenue to look at is Cycfi research and there Nu pickups and  there Nexus electronics, this may give you an idea as well.     There website is here      Cycfi Link.

I hope this helps.

MK

1 hour ago, MiKro said:

Ah, I will look into that thanks for the extra eyes. I do miss things at times. LOL

MK

@curtisa, Yes you are correct I some how moved that over. it should look like you drew it. . The cap to ground and no connection between I and A except at ground. Thanks for catching that. easy to change.

Update: It has been corrected. Damn how did I miss that one. LOL. Thanks again for your extra look over.

I know how I did that I had removed it once and put it at the Rectifier section, then moved it back using a larger one at the rectifier then stepping down at the module.  I must have just joined it in wrong when I went back. DUH!!

As far as heat and voltage I will most likely use lm317 for all of the LM series. I may also up the wattage of the resistor to the trim pots for those

mk

1 hour ago, curtisa said:

Don't think we're talking about the same thing. I mean this:

Should probably be like this:

Ah, I will look into that thanks for the extra eyes. I do miss things at times. LOL

MK

14 minutes ago, curtisa said:

Some Q's and thoughts for you. Bearing in mind the diagram is a bit blurry, even when blowing it up on my screen:

• Input-side filter caps in the LM3x7 regulators are normally connected across the input and ground. Connecting them to the midpoint of the voltage setting divider will reduce their effectiveness for input-side ripple filtering (I've got a feeling you'll probably also get worse output ripple as loading increases too). Although there are those whopping big caps on the outgoing sides of the bridge rectifier (10000uF and 2200uF? Too blurry...) which will swallow up most of the ripple.
• 2K variable pot on the voltage setter dividers for the two +/-24VDC sections give an effective adjustability range of 1.25V - 11.67V (asuming the R1's of each are 240 ohms - hard to make out), which won't be enough to get you to the +/-24VDC you're after.
• 5K variable resistors on the 12V, 9V and 5V sections gives an effective adjustability range of 1.25 - 27.29V. Is it possible the values of the variable resistors on the +/-24V and 12/9/5V sections have been swapped on your diagram?
• The 5, 9 and 12V regulators will be working up a bit of a sweat with 35V at their inputs. The 5V in particular will be having a hard time as it's trying to burn off significant amounts of power when supplying moderate load (eg, 35V input - 5V output = 30V. Multiply by say 300mA of load and the poor old thing will be cooking up 9W). Bank on a fairly substantial heatsink or maybe consider adding a chunky votage-dropping power resistor(s) on the input side to ease the burden on the regulators. Also note that the LM317 is specified for a max Vi -V0 differential of 40V. 30V as designed does appear to give you plenty of room to move, but if your input voltage rises too much and your 5V output voltage sags too much (or you have it set to a lower value using the 5K variable R) there's a chance you're going to exceed that rating.

Yep I am aware of the ground. I made it a floating signal ground and not chassis ground.  The caps are 1000uf and 220uf. 

Yes I got the Pots bass ackwards thanks for that. Yes I am aware of the input voltages and will be adding current limiting resisters where needed. I am still bread boarding each now.

Thanks for the input.

MK

Hi All,

I have finally finished the schematic for my regulated bench power supply. Now to build it. LOL.

mk

Looking at the specs on that DC buck converter,  I don't see any for frequency.

I might be concerned about the frequency it is running at? The others I have seen that produce that much voltage variance seem to be in the 20Khz range not the usual lower frequencies. Just something to look at for reference and rule it out.

MK

Keep up the work, trial and error are part of the electronics when it comes to being unconventional in purpose. LOL

MK

Jolly,

Glad to see you trying the exciter direction. I too am working on a design that uses the exciters mounted to a plate for speaker. This should give you some flexibility as to tune the output some for better bass response based on location on the plate/soundboard. The problem you may run into though is the feedback, so that will need to be addressed. In some cases though it may also act in some way as a sustainer.    

I think I mentioned in your last build that you may want to look at the Cockroft Walton Voltage multiplier circuit. Using diodes and capacitors you can get a lot of forward voltage that may suit your needs as far as upping your voltage requirements in a light small package.

May I suggest, you also look into using Lipo RC type batteries as a power source. Smaller with as much power and less weight maybe. .

MK

BTW Congrats on the GOTM win.

Hi all,

Been really trying to learn this new tool in Rhino7 called sub-d. I took my LP model that I did in Rhino6 nurbs mesh and converted it to a Quadmesh, then Sub-D model. With a few pushes and pulls here and there, I have refined that even more than what Nurbs can do. I am really pleased with the results of this new tool.

My next step on this journey is to do all of this in Sub_D only. Another learning curve with everything else going on as well in my life. LOL

MK

6 minutes ago, curtisa said:

The ridges I'm referring to are the minimum stepovers left behind by the tool in its attempts to approximate a 3D surface at a finite 'resolution', if you will. Akin to taking a digital photo with a low pixel depth.

Got it. Just making sure.

mk

On 10/19/2021 at 6:50 PM, curtisa said:

I'm using a 3D adaptive with a 12mm square endmill to rough out the rear profile and then a 3D parallel with a 6mm ball end endmill to provide a finer semi-complete surface finish. I'm still left with ridges that have to be hand sanded and scraped out, but I'd rather spend 30 minutes doing that by hand than spend hours on the mill going finer and finer. just to get the surface closer to a finish-ready state. I have to go up the grits in order to get to that point anyway, so it makes sense to get the neck to a point on the mill where the labour trade-offs become inconsequential.

Including tool changes and fiddling with work holdings I think I can turn out a neck profile in a bit under an hour. Note that doesn't include the overall 2D outside profile of the neck or anything else; just the rear faces of the neck that the palm of your fretting hand holds on to.

Most of the time ridges are an indication of three things, either flex in the machine, flex in the end mill, or the machine is not trammed correctly. Any at the same time will make it worse.

Just my many years of doing this from an experience stand point.

Mike

9 minutes ago, Prostheta said:

Thanks Mike. I think that modelling in 3D often leads towards treating the end product as a single arbitrarily-shaped object rather than a discrete set of milling operations with context. The work I do in Rhino is specifically geared towards developed a specific set of drilling, trimming and pocketing operations. This project has given me chance to practice producing arbitrary working planes, for example the rear contour. I derived that as being a basic cylindrical section in line with the Y axis, rotated around X slightly. Simple tasks and challenges such as this are helping to build my vocabulary of CNC tasks that are more complex in result but simple and defensible in the desktop product end of things.

Adding tabs would be possible with what I do also, however I've never really gone down that road. The lever holddowns work exceptionally well, and having the workpiece mounted within a specifically-reference auxiliary bed reduces vibration very well. The machine is more than capable of doing what I am expecting of it, and in a lot of ways it is like an athlete practicing away from the competition. This all adds up to making my skills that my employer(s) can leverage that much higher.

I've never liked the idea of taking a ready-cooked model into the CNC programming software as a STEP model or similar. Even though there is good geometry to work from, it feels like a lot of context gets side-stepped. If there's one thing that successful CNCing is built on, and that's defensible, built from the ground up, geometrically/mathematically consistent programming. Everything less than that quickly becomes akin to a poor grainy Xerox/photocopy.

Yep, I definitely agree about how one builds a personal working strategy. I'm still balancing off best practice versus that, and it's a task sometimes since this is entirely self-taught. I do thoroughly enjoy it though, because it's all 100% achievement based on what I put in. Those are the best ventures in learning.

Carl, I agree 100% and the last statement is testament to how you and I have approached this avenue in our quest for knowledge. As far as 2d milling that was my first process in a Mill Shop. What I learned more than anything was the importance of a consistent reference point. Machine coorindinates/home. Fron there the CNC was much easire. As far as the modeling I agree I would rather do it myself than plug in others work. While there is validity to that I still do it all by my hand in the program. Yes, I sell models on Etsy, as this is what others want but it is funny how mine do not sell as well since I only sell a model that does not have the 2d machined areas already there. It is funny how you know when someone buys your model they understand that what I produce is just that and the canvas for the 2 d work.

Mike

6 hours ago, Prostheta said:

As mentioned, I tend to get very caught up in ideas and have to remind myself how the hell I got here. Well, this time it's not so convoluted. The principle design was to develop a working method for producing a carved top instrument, and to a degree this is pushing away from that, but not unmanageably so. Financially the hardware on one guitar is a high hit (over €300 on the pickups and tremolo alone) however by comparison to the thousands one pays for a high value production or a name custom, it's better. Being a working CNC operator and programmer with potential capacity to hit the highest levels of production quality comparable to top-end guitar houses, I shouldn't be aiming lower. You don't just dip your toes in, right?

The way this clockspring unwinds is to produce the Invaders guitar (at the very least) and then develop the carved top programming on what has been built via that journey. This of itself has consequences towards what I was hoping to be the last build of this year, the Aria Pro II PE-type guitar. Mainly my thoughts have been centred around pushing myself up through the 5-axis CNC learning curve, which I think (without arrogance) I've managed to do exceptionally-well in 12mths. As far as carved tops go, I am still leaning towards the simpler "contour level map" approach rather than simultaneous 5-axis work. Mostly this is down to it being a more efficient process timewise, plus the end product still needs significant hand-sanding work regardless. Additionally, I feel that a contour map is easier to gauge when sanding than ball-nose endmill tracks. The rear contour of the first body shows significant compression marks along the path of the endmill where the absolute rotational centre does no useful work. That's a lot of sanding work, and in the context of a constantly-varying carved top contour, it could lead to inconsistency through over-concentration of required work in one area compared to another, especially endgrain. A cleaner contour map in the order of 0,25mm - 0,5mm per level sounds overkill, however being done as a pure 2,5D process using a simple endmill produces almost zero compression artifacting.

I do realise that a lot of these issues are rarely considered or discussed amongst builders, and there's high possibility that they're not even as considerable an issue as I describe them (@MiKro?) however when wearing my manufacturing/optimising hat, ideas that are tabled and explored always help rattle out potential gains in efficiency, cost-effectiveness, reduction of labour, base quality off the machine or simple pragmatic rethinks. They matter.

Future explorations will look at better workholding (possibly with auxiliary vacuum hookup) and 3D profiling processes. I'd like to see how far I can drive precision, such as adding 2mm corner radii around non-flat surfaces, etc. The binding around the forearm contour in the Invaders instrument is an excellent step towards that goal.

Hopefully this train of consciousness text wall is meaningful....!

I agree, some are an issue as you have described and each takes that on in there own way. I see many parallels in our thinking as well as many that are not. This is also mindful of a few things that dictate one's situation. Such as machine capability, ones ultimate end task of what % is machine and hand work, There are many variables that must be addressed all at the same time.

I still see so many that think CNC is plug and play. We know better.  Bizman62 is understanding the complexity of it now, as are many others as well..

As far as work holding for instance I use a flanged ear approach using location pins and screws for the body. Like I said we each use and choose directions in CNC that make sense and apply to our application. I prefer to model in full 3d where I can and not worry as much about the 2d parts of that. It is the approach that I use. The 2d parts are my map for the 3d model. Again this is something we could discuss for a long time with most likely no end to a proven or best method. Learning from each other though does at least open doors for more intense review of a process.

Looking good Carl..

Mike

A sample of my holding of a body. This allows me to continue until I am ready for final profile cutout. When I removed the back to open this I then after have to go back and adjust the ears once a new removable back was made. This is an extreme that I normally do not have to focus on.

OMG Not another one of those Hideous PACMAN looking Corvus POSs. I am outta here.

LMAO!!!

mk

11 minutes ago, avengers63 said:

In the last 7 years - divorce, moved, vehicular homicide (ran over a guy), job loss - 2 years unemployed, bankruptcy, career change, lost my house, moved, remarried, I'm really ready for a break.

 

Dude, that's rough. Try and be safe, settle in for slight change.

MK

HI John,

All well in your neck of the woods? This getting old shit sucks.

I don't remember your ever building a Tele? Then again I left for while my self. LOL

Looking good you Gray headed old man. LOL

Mike

4 hours ago, John mclaughlin said:

>snip<

John McLaughlin 

You do realize that you responded to a 16 year old thread? I don't think you will get a response.

MK