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demonx

So this is where the cnc guys hang out?

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Ok, I've taken the plunge. I'm finally entering the world of CNC.

I decided a while back if I was going to do this, I was going to do it properly, so I hired an engineer to design me a CNC suited for one purpose only, building guitars.

Long story short, I gave the engineer the specs of Dougs machine telling him "This guy knows what he's doing" and then the engineer pumped out some specs. I passed them along to Doug who (thankyou) has offered some valuable advice and then the specs were revised to the following:

X-Travel 1700mm.
Y-Travel 1000mm.
Z-Travel 200mm

These might actually be a fair bit larger on the finished machine.

Aluminium & steel construction.
Maximum recommended cutting tool capacity Ø12.7mm.
Fitted with (miniumum) 425oz-in stepper motors on each axes.

X-Axis:
Dual Rack & Pinion Drive System.
30mm linear bearings running on supported precision ground hardened shafts.
Stepper motor pinion drives spring loaded to minimize backlash with rack.

Y-Axis:
Rack & Pinion Drive System.
25mm linear bearings running on supported precision ground hardened shafts.
Stepper motor pinion drive spring loaded to minimize backlash with rack.

Z-Axis:
16mm x 5mm pitch ballscrew leadscrew.
20mm linear bearings running on supported precisions ground hardened shafts.
Stepper Motor mounted to leadscrew with self-aligning coupling.

Controller:
Fitted with Bipolar Stepper Motor Drivers.
48VDC power supply.
Breakout board with IC buffer & 25pin parallel port interface.
Fitted in enclosure with cooling fan.
25pin serial cable for connection between the control box and your computer.
Output relay for switching of Spindle.
Travel over-run limit switch inputs.

Automatic Tool Change (ATC) System:
2.2kW Water Cooled Spindle with ATC.
6 x Collet Chuck Tool holders.
1 x Tool Rack with 6 tool forks.
Includes spindle mount, water cooling system, pneumatic valving system, VFD setup & cabling.

Aluminium T-slot Table, (using 160x40 profile T-slot Extrusion):

The machine will also have a remote hand controller and a dust extraction hood.

Long story short, this thing is costing me an arm and a leg, enough that I've had to take out a bank loan using my house as security and I have no idea what the hell I'm doing, so I reckon you guys are my "call a friend" at the moment!

It'll be next year till the machine is built and delivered, but I wanted you guys to be the first to know.

Cheers

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Sounds like a really great machine. I plan to build myself one once I get moved and settled. I have a little cnc milling machine, but plan to have a cnc router, cnc metal lathe, and larger cnc milling machine within the next 1-2 years. I like the option of making my own hardware as well as the bodies and necks. There is a fairly steep learning curve to cnc, but it's totally worth it, and once you overcome it on one machine, you basically overcome it on all machines save for a couple of small subtleties. Good luck with it and post pictures back when you have it!

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Tool changer. Now that's just taking it one step further. I'm 100% confident in Doug's advice so you should be good. Are you starting out by cutting templates and jigs in order to familiarise yourself prior to committing to real wood?

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Tool changer. Now that's just taking it one step further. I'm 100% confident in Doug's advice so you should be good. Are you starting out by cutting templates and jigs in order to familiarise yourself prior to committing to real wood?

It's not even built yet, won't be for another two months approx.

The tool changer added something like eighteen grand on the price once the machine was upgraded to accept the extra weight and adding the extra control and motor etc etc. The tool changer will also need its own air compressor but I'll just use my existing one to start off with

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What software are you planning on using for your CAD/Cam? It's never too late to start learning how to use it. :)

mk

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Mach 3

Vectric (simply what the machines builder uses)

I've learned 2D Autocad for things in the past, so I tried doing 3D stuff in it but having difficulty. Have got Rhino 3D but having trouble working anything out.

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It doesn't seem much more difficult working in "2.5D" to 2D. I'm working on my first guitar program to rout a slab P-bass. I did all the outlines in 2D and from thereonout it just seems like a series of pocketing and profiling operations. For doing a more involved thing like a forearm contour or a tummy cut I guess you have to deal with more 3D than 2D.

What made you go for a toolchanger? Surely that is a significant overhead on the CNC project. Not to criticise your choice but it surprised me seeing that listed on your first CNC. I presume that you are aiming to take wood straight from a blank to finishing sanding then?

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Yes. I'm wanting to take a body blank and have it ready to sand, pilot holes and everything drilled ready for assembly. I'll still have to drill tuner holes and elec holes and manual route truss slot. Pretty much everything else will be automated.

About the 2D to 2.5D, things like pockets etc aren't a problem, I just cannot get the curves of a carved top, another example is I drew up a bolt on neck, I got the main profile, got the headstock, got the heel, I just cannot join the three together with the complex curves.

Reason for going a bit more full on with my first machine is I'm sick of buying tools and then having to upgrade. Its a waste of money buying things twice and there's been a lot of that over the last year or two.

Then seeing RADs issues with his machine, Doug has recently upgraded himself, I decided to get the upgrade and save the headaches of an entry level machine. It'll certainly be a massive learning curve, but I just want to do it right.

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I agree on the pains of upgrading. My concern is the length of time before you see return on the investment. I guess if you can do the simpler stuff whilst ramping up it'll all help.

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This was something that was discussed. We talked about using MDF rather than T slot and upgrading in the future. We talked about not having the tool changer. We talked about all sorts of options.

Problem is, the tool changer is a heavy item, so the machine had to be upgraded to thicker materials and a rack and pinion setup to accommodate. If I wanted the option of the tool changer in the future, there was all sorts of things I couldn't cheap out on for the initial build. Then, going rack and pinion meant I had to pay for double the electronics as it has a motor on both sides. But, I cannot cheap out on that either in case down the track I ever did want the tool changer.

Then there was the idea of paying for things twice. I could buy a cheap spindle that I need to replace often, or I could buy a water cooled spindle for $1500 and then its wasted money if I upgrade down the track, or I could just put that 1500 towards the tool changer and not waste money.

So I had my brain stewing over all these options for a long time and decided all in or not at all.

The computer I bought to run it all just arrived today so I have to find the time to sit down and set it up with all the software. Think that'll be a job for tonight since I cannot go to work (torn shoulder)

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You will likely end up covering the bed with an MDF spoil board anyway. You loose 3/4" of clearance to the gantry, but there are advantages are worth it. I machined slots in my MDF board that line up with the T-slots, so you can still access them. Once the board is mounted, I surface it with a fly cutter. This ensures that the surface of the board is exactly flat to the gantry. T-slot tables are rarely flat from the factory. You can machine locator pins in the spoil board for specific jobs, and screw workpieces directly into the MDF if needed. One big advantage is if you have a corrupt file, or if you programmed the Z on your toolpath wrong, it doesnt ruin your T-slot table. When the surface gets all boogered up after use, you simply re-surface it and you're good to go. Doing it this way gives you the rigidity of an aluminum table, and the machine ability of an MDF table.

You'll be glad you have a water cooled spindle. They are much quieter. I have a PC892 router on mine. I have to wear headphones hooked up to my iPhone to keep from going deaf.

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You'll be glad you have a water cooled spindle. They are much quieter. I have a PC892 router on mine. I have to wear headphones hooked up to my iPhone to keep from going deaf.

Doug, Add a Super PID speed control then you can run it at 11k to 14k with no power loss and much quieter, plus MACH3 integration as well. :)

mk

http://www.vhipe.com/product-private/SuperPID.htm

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Only updates I have at the moment are that I learned a couple tricks on the weekend with autocad which have lifted one of my major brick walls for drawing 3D arcs. Still getting nowhere slowly! But it's more progress than before.

Also heard that the spindle is in production and will hopefully be ready early in the new year. It's being custom made to order in the USA. Then they'll hook it up to a CNC and do a test video before shipping it out.

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I've been getting a little bit of progress in the CAD department. Still cannot work out my main carve, but on the side I've been drawing up some of these simpler carves which are variations of some of my older builds:

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1537861_567850793296759_1790486928_o.jpg

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Ok, so after a whole string of setbacks, mostly due to the spindle company, the majority of the machine is together.

I got to see it moving around yesterday via a wireless remote control.

The Z axis supports in this pic are only temporary ones so the guy building it could work out best positioning to achieve maximum travel etc. The final ones will be much wider at the base and taper up and have bracing to minimize flex.

The final unit is larger than the original specs which is also a bonus.

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10441441_647472102001294_406809434300715

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No - it's too heavy machine for Ballscrews (although the Z axis is ballscrew) so it's needs the industrial style rack pinion on the X & Y axis. In saying that, the engineer stood on the Z axis and it lifted him up and down, so it's pretty solid. The rack & pinion is a much better setup, less flex, can bear much more weight, but comes at a cost. All the framework etc is modelled off a $120k Multicam at a local factory that we spent an afternoon going over and then we upgraded all the specs so its better than the Multicam, took influence from Dougs latest machine, added a tool changer and the engineer also suggested a few other changes and upgrades and here we are. Rather than make the mistake everyone does and go cheap on a hobby machine, I'm investing in a industrial style straight from the beginning to avoid wasting money on upgrades down the track and in the hope **** doesn't break on me..

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fair enough. The real cost starts when you start using it. Its a might head****. And standing around watching it make stuff when you're SUPPOSED to be doing something else :)

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I am not sure your CAD background, but Solidworks and a few SolidWorks courses may be beneficial. I am pretty proficient in Autodesk Inventor, but find that Solidworks can do a lot more. Plus there are a ton a 3d files for guitars floating around online already that you can look at to see how people overcame contour problems. Even if you skip the courses, you can buy the books they uses at the courses online used at low prices and learn the same stuff. Most CAM software is designed to work very well with SolidWorks files.

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Good advice.

As I was getting nowhere with AutoCad, I made the transition to Solidworks last week (thanks Carl for the advice etc)

None of my existing models have imported into Solidworks correctly, but I have been able to edit them in autocad and import 2d outlines to start from near scratch in Solidworks.

Basically over six months has been wasted on autocad and now I'm starting from again, but with a few steps backwards as now I am not even familiar with the Solidworks software so its a VERY slow process.

I had an engineer come around last week who uses autocad every day as his full time job and even he struggled to draw my contours etc, he made the suggestion to try Solidworks.

So after hearing it (Solidworks) from the guys here, from the engineer, from the guy building my machine, I figured it was time to stop being stubborn and just take people's advice, even if it does mean starting from scratch.

I had the CAD engineer come over again last night for a few hours to teach me how to use Solidworks, but it turns out he hasn't touched it since he was a student and being he uses autocad all day every day he'd completely forgotten Solidworks and needs to learn it again himself.

Looks like even if this machine gets delivered in a few weeks, I won't have any models to sent its way. Will be a while till I'm cutting wood.

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I think that maybe the objective of hitting your CNC with good-to-go code cutting complete 3D instruments is a challenge at this stage. I myself am doing what I am able to learn good CNC practice from both the coding and design end through to the physical work and end product.

The first things I cut on CNC was template stuff. Straight up 2D work. Whilst your CNC is very very capable from the specifications, there is nothing better than familiarising yourself with relatively short and simple tasks. I would get my fundamentals down first and pick up problems one-by-one. Doing everything off the bat is a guaranteed way to encounter all of your problems at once or in immediate succession, and also guaranteed to deflate you irreparably with CNC in general.

I can't offer anything other than this because I don't have to maintain or perform setup on the CNC I've been using. Being shielded from that valuable knowledge is annoying of itself because I see it as being a fundamental way of me advancing my skill set and growing. But anyway....enough of my problems.

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Start with the easy stuff. Forget about doing full guitars. Build up to that level over time. Even just doing inlays will do your head in. Clearances, speeds, tooling, how to hold the pieces, etc etc etc.



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