MiKro

4 hours ago, mistermikev said:

>snip<

I bought a dial indicator and an arm for doing just this (calibration)... but got stopped when I realized I didn't have a way to mound it in my collet (it's too big) and then realized - aluminum is not magnetic (hehe) so can't stick to the bed.  I need to rig up something to overcome this and will do for sure asap.

can you elab a bit on backlash?  I think that would just be an issue if I was running in wood right?  I'm literally running this above my work piece in air and observing it go off course.

>snip<

A dial indicator is help for tramming not really for step length. I use DRO's but they are expensive.

I used to use a digital caliper. Make a straight line cut about 1/8" deep. Say 5" long. Start by moving the mill a short distance in the direction of the first cut as this will load the ballscrew correctly for that measurement.. Then measure the actual length of the cut minus the measured value of the cutter diameter. This will be what it is actually doing or very close. then compare to what the step settings are? Do not do it both ways and use that measurement it will be wrong ( it will have backlash in this measurement). Get this correct first before looking at backlash.

Next with out moving anything other than Z up some for clearance after making a cut as described above. Now make the same cut next to it by moving the other axis only first ( do not unload the first cut movement. Now Go the opposite direction cutting and measure that. Now you will see your backlash amount in the screw/ballnut for that axis. Only do that part after you get the true length correct.

Hope that makes some sense?

MK

Mike,

Mach3 is not your problem unless you have inadvertently set something incorrectly. 

Are you positive that the steps are set correctly? If not sure at minimum run the auto set feature for each axis. Use at minimum a good set of calipers to measure and set this. Go to at least 5" or more if your calipers will allow.

Have you checked for backlash in each axis? If not then remedy that.

Have you checked for squareness of x and y? Also perpendicular Z to each of X and Y (tramming) ?

I hear this all of the time from people. It is Mach3, or it is Aspire, or what ever software. 99% of the time it is a mechanical problem, a setting that is wrong, or EMI electrical issues.  If it is software related, 99% of the time it is the user has made a mistake in the software use.

Just my many years of use and helping others with problems, experience.

Basically my 0.02cents.

Mike

1 minute ago, mistermikev said:

so... n.o.s. chinese fender knecks.... nice. hehe

perfect for a CBG LOL

mk

1 hour ago, mistermikev said:

hehe, nos guitar necks - I'm told they are all the rage... very "in" right now!!  

I think these are some chinese specials that someone had that I got in a buy out. LOL.

I also found a complete Carbon Fiber neck that was in the group. LOL Funny how when cleaning shit you find shit.,

mk

I don't know what I have been thinking? I was going through a bunch of old stuff. Found some old Strat Necks that are already done with paddle heads

I think I will just fixture one up and trim the damn thing to make a CBG neck quick. LOL!!

MK

So back to the CBG neck. I used an old fret board I had laying around and epoxied it to the neck blank after installing some POS truss rod I had laying around.

I got in a hurry and forgot to put a spacer on the top of the truss rod adjustment area. I would usually mount this type being heel adjust but being a 3 string and all I went easy.

I radiused the board to 18" and then the head stock transition. All in all okay. Need to layout markers since I had already slotted the board many years ago and forgot to do it before radiusing. LOL.  Yep stupid me. The booze was good though.

Just sitting  back having a drink doing stupid stuff while the machine ran. With out the insert for the truss rod it looks weird but what the fuck it is a toss around Shop 3 string. LOL

UPDATE: Well when I screw the pooch I do it very well. LMAO!!  I measured the wrong damn fret for the location to set the markers, so you guessed it. Scrap one fret board. LOL!!!

.mk

Starting over with the fret board. LOL

44 minutes ago, ScottR said:

Is Dolly having balance issues too?

SR

Maybe, I think it is age related though.

mk

1 hour ago, ScottR said:

She is starting to develop balance issues.

>snip<

....but apparently she's top heavy.

SR

 

So is Dolly Parton,

mk

Why not just do a swimming pool route?

MK

what is the controller that is being used? Picture of the boards would help adding limit switches at least for just homing should be realitively easy.

Do not use soft stops as they move with your zeros and cause problems .

Edit the XML with notepad if nothing else

See here.

As far as the center is not the best option for X0, Y0  you should use a corner that is referenced from your X0 Y0 machine coordinates.

Does the machine have the ability to home? If so, then home the machine. set everything to zero. Go in to mach 3 choose offsets and and then choose G55 or G56 just not G54 then jog or use MDI to move to a specific location , Let's say X2, y2 for an example. once done. then rezero those. That is now a work coordinate using g55 or what ever you chose.  Make sure to save the settings.

Now you have the ability to always find work offset place from the machine coordinates. when you run a part for it you will select G55 or what ever you chose before running anything. YOU can always edit the Gcode to reflect using that as well if you want. I change mine constantly over a period of time as my locator pins may become sloppy. but it is still a referenced work offset from machine coordinates.

MK

So as far as the tilted pocket you will need to make a jig that places the surface at the correct angle for the body to lay on. As far as Sprues. in your tool path settings go to advanced options in the profile tool path and choose tabs. set these accordingly, then calculate. These will hold the body to the outer piece of cutoff wood so it remains as one piece.

So now I have flipped the neck blank. and resurfaced it just to the point of opening up the heel cut.

Why you ask? This way I can now cut the slot for a truss rod, add the fretboard blank with a rear over hang for a 24 fret. Next will be to radius the Fboard after making the markers. Then I will cut the fretslots with the radius . then scallop the headstock which I already drilled the tuner holes when it was on the other side. last I wil profile the entire thing including  the fretboard overhang. I have already profiled the neck heel from the other side.

2 hours ago, mistermikev said:

>snip<

afa bit... just wondering if you are in fact going down to a tapered ball nose 1/8" bit for finishing.  it appears to be the recommendation but will result in an estimate run time upwards of 10hrs!!

I only use those on very fine work. I have even used 1/16" and 1/32" TBN, Otherwise I use a straight 1/4" or 1/8" BN. One other thing is not to do all of the surface just what needs to be milled using  a vector to contain the area. If it is flat there is no reason to mill that in a finish. it can be easily sanded to transition if needed..

MK

Also the back side ready to flip.

So when you use Aspire and some other types of CAD/CAM software that import STL files mainly. This is the problem you may face with STLs. If the mesh count is not up to par it will introduce triangulation artifacts in your work. Which will show up in the milling as well. Sometmes in Aspire you need to up the visual resolution in order to see it.   There are also two available higher resolution modes, Extremely high (20X slower) and Maximum (50X slower) that are not normally visible. They can be made available in the Model Resolution pull-down menu by holding the Shift key down before selecting Create a new file or Job Setup. This can be very useful when needed.

So to give an example look at the neck transistion to the headstock. One has low mesh count the other high mesh count. Both are the same file only mesh sizes changed in Rhino before export.to STL for use in Aspire.

I experienced this myself by cutting corners in Rhino to make a quick neck model for a Cigar Box Guitar.

MK

14 hours ago, mistermikev said:

wow, that's a lovely piece of scrap.  if I may - what bit do you use for the finished pass?

I was using a 1/4" ballnose with a 6% stepover at 180ipm for this. My finish pass endmills are determined by what I am doing.

So to speed things up just a bit, I tried using a smaller number in my meshes/breps. which in turn creates larger triangulations if converted to STL. This is not good. While it may look good in the software design, it shows up on the CNC as large triangulation and is rough, So I will need to go back and redo this one.

Since it is a one off I will just sand the neck. but it does make me look at my settings in Rhino.

MK

7 minutes ago, mistermikev said:

ima b honest.... kinda blurry but... looks like some nice figure. 

A piece of scrap I found laying in the back of the shop. LOL. This is going to be a neck for a CBG 3 string. 

mk

So here is a neck blank I just finished surfacing both sides before I start the next operation of carving the neck.

MK

This should be a Pbass Vectored PDf file.

OOPS no side profile? look at Neck2 Drawings

51-p-bass-neck.pdf

Neck 2 Drawing Section-1.pdf

19 minutes ago, mistermikev said:

just wood screws into the substrate?  I used to do that with my planer board... and after a while the surface looked like swiss cheese.  I spose on a cnc it's easy 'nuff to replace.

 

No big deal as the holes are not a problem only when they raise up the surface and things don't sit flat. A quick scrape with a blade and that is gone. Resurface every few weeks as the mdf will swell some over time due to humidity. The screws that hold the MDF down are counter sunk so I have about 0.550" of surface I can remove.. Removing approx 0.010"-0.015" every few weeks to keep flat.

3 hours ago, mistermikev said:

noice... what do you use for hold downs?

Screws.

Ha, finally got to it. New Spoil board installed and surfaced. Smooth as a babies butt.

mk