A new CNC router in the house

[guitarbuilder]

About a year ago I purchased a 24 x 36 cnc router from a new company just starting up. To make a long story short, it didn't live up to my expectations. The design was nice but the routing was sloppy. I had been producing parts but many of them were bad due to sloppy linear guides. The ones engineered into the design worked, but couldn't produce the accuracy I was looking for. Previously, I had built a couple smaller routers which as it turned out were better than this commercially made one. I started to think about re- engineering the new one with new linear guides but that would have involved having new parts machined and I just decided to move on. I plan on down the road making my own home built again with machined parts but in the interim, I saw that K2CNC had a 25" x14" frame on ebay with a buy it now. K2 is pretty well respected in the home duty cnc router world. They do produce a luthier model too. It turns out that that machine is a bit more than I could afford. Anyway I opted to buy the smaller machine which size wise is more than enough for what I do, and in fact it is bigger than my home built one that I've used for years. I've had the frame set up in my workshed and now it was on to motors and controllers. I searched for pre built kits and ended up ordering a Probotix system with ( 3) 280 oz stepper motors.
Those were delivered yesterday. I now will hook them up and attempt to make the adjustments to get the K22514 up and running. The combined cost is a bit less than 2000 dollars which for cnc isn't that much really. I already have all the software, so I didn't need to order that again. I'm awaiting an email from probotix about hooking up my home switches and setting the steps per inch.

Here is the machine in the shed


Here is the machine from the k2 website:
http://www.k2cnc.com/shop/proddetail...2514-09&cat=26
and the motor/controller
http://www.probotix.com/3_axis_stepp...or_driver_kit/

I ended up selling off a few guitars to fund this. I have a kid in college and well you know the story.

[dholzric]

I'm working on building one as well. Is 25x14 going to be big enough? I'm trying to get mine at least 20" wide so i can so some archtops and have little room to spare.

Originally Posted by guitarbuilder

About a year ago I purchased a 24 x 36 cnc router from a new company just starting up. To make a long story short, it didn't live up to my expectations. The design was nice but the routing was sloppy. I had been producing parts but many of them were bad due to sloppy linear guides. The ones engineered into the design worked, but couldn't produce the accuracy I was looking for. Previously, I had built a couple smaller routers which as it turned out were better than this commercially made one. I started to think about re- engineering the new one with new linear guides but that would have involved having new parts machined and I just decided to move on. I plan on down the road making my own home built again with machined parts but in the interim, I saw that K2CNC had a 25" x14" frame on ebay with a buy it now. K2 is pretty well respected in the home duty cnc router world. They do produce a luthier model too. It turns out that that machine is a bit more than I could afford. Anyway I opted to buy the smaller machine which size wise is more than enough for what I do, and in fact it is bigger than my home built one that I've used for years. I've had the frame set up in my workshed and now it was on to motors and controllers. I searched for pre built kits and ended up ordering a Probotix system with ( 3) 280 oz stepper motors.
Those were delivered yesterday. I now will hook them up and attempt to make the adjustments to get the K22514 up and running. The combined cost is a bit less than 2000 dollars which for cnc isn't that much really. I already have all the software, so I didn't need to order that again. I'm awaiting an email from probotix about hooking up my home switches and setting the steps per inch.

Here is the machine on ebay:
170564598249

and the motor/controller
http://www.probotix.com/3_axis_stepp...or_driver_kit/

I ended up selling off a few guitars to fund this. I have a kid in college and well you know the story.

[guitarbuilder]

The machine can accomodate material up to 19 wide and it is open ended along the length. Although the axis is 25 long, you could do longer work by repositioning. Also you could machine diagonally which would get you up to about 28+ inches. I really want a machine with supported rails and that is what I will build down the road. This has 20 mm rods and it is tighter than my home built one and for sure more rigid than the last commercially made one I bought.
Probotix emailed me back with the information I needed so tomorrow I'll start to install the motors and see what happens.

[Shepherd]

I'm guessing that you've had a duplicator in the past. Any reasons why you would switch to cnc? Sure a cnc is a great tool but by the time you add software and a computer it's a pretty large investment. How many guitars would you have to sell to break even? Plus just learning how to use it is like starting a new trade. I was seriously considering building one and did alot of research but it really made my head hurt . I'd like to build a duplicator so I'm interested your opinion on any advantages or disadvantages between the two.

[guitarbuilder]

Well years ago I did make a duplicator from plans on the net called a " fishcarver". It was mostly plywood on hinges. It really was pretty crappy. It would be OK for a really rough carve but not much else. I then started to investigate cnc and made a dremel powered router out of mdf from plans by the name of John Kleinbauer. This whole thing started because of some repetitive motion injury that I sustained and that kept me from hand carving a top. Anyway, the kleinbauer led to my real guitar sized home built machine. When you start looking at the cost of woodworking machines, They can add up fast too. I've been woodworking for 30+ years and most of that was guitars. 10 to 15 bodies alone would pay for this investment, but the education I've received is priceless. Once you do it this way, it is hard to go back to a router and basic machines..... With the CNC it's a matter of drawing in 3d and then prototyping the part. By the way, there is a firm who makes a decent duplicator within 100 miles of me. It costs more than the CNC. You can make a decent homebuilt CNC for under a grand. Software costs depend on what you use. The computer runs XP....just used an old one I had. Mach3 came with the commercially made cnc, so I'm using that on the new one. Rhino3d was $150.... I bought it when I was teaching.
Guys get by on sketchup which is free I think. The beauty of this technology is the ability to visualize and bring a product from idea to prototype stage so quickly. No templates are required and you can change things pretty quickly. I'm not saying it is the be all end all, and I still do things the old fashioned way, but for me it's the way to go.

[guitarbuilder]

Well I got the motors and controller installed yesterday. Now we are onto motor tuning. You have to adjust the velocity and acceleration of the motors for each axis. What a pain......when I think I have it I don't.

[Novatuc]

I am so jealous. My job is aerospace and work I with CNC mills every day. I keep wondering about all the parts (wood and metal) that could be made with a small 3-axis CNC mill. Unfortunately, space and finances will not allow me to go for it. Good luck with your machine.

[Ziggy]

Just curious, what do you use to hold the work pieces?

I would imagine that double stick tape would work since the inherent drift of the tape wouldn't be enough to be worrisome on a guitar.

I am working with some ideas for a vacuum system. However, the system would also have to incorporate either a waste piece or some sort of way to elevate the part off the table. (To keep the cutters away from the table.)

[guitarbuilder]

Don't be jealous.... I just sold some guitars I had fixed up over the years for $ to buy this stuff. I am into this one for just around $2k. I'd love to have a nice rig for metal working too but alas.... not until the daughter graduates.

On my homebuilt, I used double stick tape. The commercially made one by pcncautomation ( if you are bored and want an interesting read...check out the cnczone about them as that is a story in itself) had channels for bolts in the table and came with plywood clamps. The K2 has an extruded aluminum table with clamp hold downs as well.
I thought maybe the HP computer I was using was iffy, so I swapped with a newer one and that seems to help out the motor tuning. Of course, then we had an area wide power failure for an hour. The winds are gusting to 45 mph here. I'm getting ready to attach the router and attempt to hook up my home switches.

[joe desperado]

I too would love to build/own/use a CNC for some parts making. I have the buisiness justification for it, but I just don't seem to have the time it takes to incorporate it into my process. The serveral weeks you have spent getting yours up and running...would have cost me more business than what the thing will bring in...(I think).

What did you do with your older units? Are they still useable? I'd like to at least find one that can help me with inlays.

Joe

[guitarbuilder]

What did you do with your older units? Are they still useable? I'd like to at least find one that can help me with inlays.

They are here on their respective work surfaces. My homebuilt one I'll probably take apart and sell the metal parts and motors/ controller on ebay. It was skipping steps due to software, hardware, or the electronics... I swapped computers and it had the same problems. That was costing me money as it would make a first quality body a second in less than one. The PCNC I was thinking of donating to my old school and taking the tax writeoff or selling it off.... but I need to get the new one up and running first. It works fine, just can't carve a neck perfectly. For other tasks it would be OK.
If you are talking inlay, you don't need anything this big.


If you know cad, most of the stuff I did was 2d. That has a shorter learning curve than 3d. For bodies 2d will do most of what you want. LP tops you probably want 3d unless you scan a top with a digitizer.

This is my home built one:
Aluminum, HDPE, Drill Rod, and some MDF.

[joe desperado]

I wouldn't mind discussing this more off line. If you have time can you send me an email? jre_productions@yahoo.com

Fingerboard and headstock inlays are a major pain in the butt for me. The time it takes me to do them by hand makes it almost cost prohibitive for perspective clients. And to be honest, the end result is not that fantastic. Not bad...but not fantastic.

I'd really have to think about how it could help with my neck building overall. My process is so down pat and pretty smooth, I'd have a hard time thinking how this could improve that portion of the build. Because of the way I cut neck blanks, I am not starting with a pre-determined size/shape. I lay the necks out on a board and place them in such a way that I can get as many necks out of a single board as possible.

[Shepherd]

Damn, you got me gassing for a cnc again. But just too much money for hobby use. Might try to build one of these, doesn't look too complicated.

[guitarbuilder]

Here is a neck off of the pcnc router. This was drawin in 3d using Rhino.
I opt to finish the peghead myself and save an hour of machining with the cnc. I believe I'll get even nicer results with the K2

[mgdesigns]

That neck is looking seriously better than the pineys you've done before. Congrats on your new baby. Green with envy - for sure. I love doing the 3D CAD stuff; I am at the local Community College waiting to get into my CISCO Routers 2 class, and killing time using the plotter to print out some of my jig patterns 1:1. I tend to think in CAD, and would rather do that than just about anything - except throwing wood or metal chips on the floor. Nice Work guitarbuilder.

[guitarbuilder]

Thanks MG . Actually that pine neck came out as nice as this one :-) Not pictured are the ones with the gouges in them that the router made because a deep cut caused the z axis to tilt into the wood. The K2 z axis is solid as a rock in comparison.

[guitarbuilder]

I got the router in and the home switches wired up. It appears I have 2 bad switches out of the 3 that came with it. The X seems to work. They are contact switches. The two show no reading with my dmm. I have an email into K2. I guess I'll try it out tomorrow and see how it cuts with out homing it. I hate the set of mach3 as I have no real clue about what I'm doing besides the trial and error and reading the tutorial. This is why I bought turn key systems before :-).

I just got an email from K2...they are sending out two new switches.

[guitarbuilder]

So I decided to write a little program to mill out a 1 x 1 square with a .5 dia bit just to see what this thing can do. First I get a small hunk of maple clamped down and just mill off a flat section....not too bad some ridges show from the cutting edge, but nothing horrible. The wood, the board is warped and I can see it flex a bit on the table. Today I'll switch to a newer bit that is .5 shank and joint the board first and do it again. My digital caliper measured the 1" square about .983. Just for the heck of it I measure the bit ( woodcraft....old and dull). That was .485....not .5 so I'm thinking if the bit is..... .015 off then that square should be about .985 ish...... and it is .983. Wow that seems pretty accurate.....I'll try it again and compare numbers. I could get excited about accuracy like that. It must be a fluke.....

[mgdesigns]

Originally Posted by guitarbuilder

So I decided to write a little program to mill out a 1 x 1 square with a .5 dia bit just to see what this thing can do. First I get a small hunk of maple clamped down and just mill off a flat section....not too bad some ridges show from the cutting edge, but nothing horrible. The wood, the board is warped and I can see it flex a bit on the table. Today I'll switch to a newer bit that is .5 shank and joint the board first and do it again. My digital caliper measured the 1" square about .983. Just for the heck of it I measure the bit ( woodcraft....old and dull). That was .485....not .5 so I'm thinking if the bit is..... .015 off then that square should be about .985 ish...... and it is .983. Wow that seems pretty accurate.....I'll try it again and compare numbers. I could get excited about accuracy like that. It must be a fluke.....

What G-code generating software do you use? Can't you just change the tool selector to make a custom bit before running the G-code. Instead of using the default 0.500" for the bit diameter, change and make one 0.485" and re-do the the tool paths. The software should compensate for the center of the bit, and you'll end up with the 1.00" square you designed. (That's based upon what I used to do using Rhino 4.0-->Deskproto-->4-axis ModelMaster CNC1000 for the jewelry world - and my models were accurate to .010 mm).

[guitarbuilder]

Originally Posted by mgdesigns

What G-code generating software do you use? Can't you just change the tool selector to make a custom bit before running the G-code. Instead of using the default 0.500" for the bit diameter, change and make one 0.485" and re-do the the tool paths. The software should compensate for the center of the bit, and you'll end up with the 1.00" square you designed. (That's based upon what I used to do using Rhino 4.0-->Deskproto-->4-axis ModelMaster CNC1000 for the jewelry world - and my models were accurate to .010 mm).

I'm using Bobcad for 2d and Rhino/meshcam for 3d. Mach3 runs the program and it can probably do just about anything... the problem is my lack of formal training and the fact that the documentation is embeded on the disk, or you look on the net. I've probably just scratched the surface with what it is capable of doing. I don't have a book for Rhino and that is again in PDF. Not being schooled in cnc, I try to get the stuff to do what I want it to do and if it does it I'm happy.