Hi Zach -- I'm away from the shop for a week or so, will post when I return. Sorry.
Neil

Hi Niel,

Thanks for all the information you have shared. I like the youtube video a lot.
Your build is very clean and tidy. Very professional. I am impressed.

I have been able to convert your solidworks files to parasolid format. Better than step format in my opinion.
You can place it on your parts list so others can get it. I have uploaded them on this post.

I am thinking of an identical machine. But I would like more Z, at least 180 mm.
I want to machine 200 mm high EPS (Polystyrene) and cut poplar plywood up to 12 mm thick.
Have you tried any foam?
Do you think that making the side plates higher will affect the rigidity of the system?

What cutters are you using?
You should get info on feedrate and spindle rpm from tool catalog, it is the tool manufacturers that know the ideal working conditions for their tools. You could be low on spindle RPM.Normaly wood tools are very specific. I have many clients using artcam on wood, special tools and normaly quite high rpm..

I believe the way the spindle or routers is fixed onto the machines is not ideal at all. I have been machining with routers and robots and the stiffer we attach the spindles the better.

With regards to dust on your V sections. You could attach a simple compressed air tube pointing on the V section where the rollers move, so that it removes any debris or dust. Sounds crazy, but it could work. From my experience, dust will go everywhere unless you have a VERY good vacum on the tool, even with all the dust boot apparatus . I have never seen a router with no dust on it. It sucks but it is the way it is.

At 2 min 22 seconds on your video, is that fastest speed you cut (when you press shift + arrow keys?
What feedrate can you go up to on this machine? or what feedrate are you using for the simulation?

One last question?
On your machine how do you set the length of the tool?
In case you use a different cutter for roughing , and finishing? That is something I am wondering. cause if you zero the part (part datum) with a tool, and use just the one to do the milling, no need to set correct length, as the machine will offset correctly. in other words it will know the height.

I am curious to know how this can be done. as this is important when doing a more complex milling job with different tools.

Thanks again and impressive build.
I have learnt a lot from your project.

Alex

This is the same for all machines. Some people have a conductive plate that the machine touches with the tool-tip and then automatically calculate the length. I don't have one yet so I loosen the collet and let the tool slide down to touch the part. Then move the machine down to where you want it on the tool, and then tighten it and tell the machine that z=0. This way you can change tools many times.

Hi Dude,

I understand the process.
I work with cnc, sell software for a living, so I am ok with all this.

My question was in the line of saving the tool length inside the software, MACH 3. If I have a toolchange device, where the lenght is constant, I do not have to measure everytime I change tool. Is this stored in MACH 3 or any software?

You do this if you have a collect, what about tool change? Meaning when you have a cone and you change the whole lot.

Dude, is there a post for your build?

Take care

Well I don't use Mach3 but in Linuxcnc there's a tool table where you set the tool length. I don't have any builds worth mentioning.

Good stuff!
I am considering linux cnc, but I would prefer to run on windows.

Do you have any idea how they compare ? Linux cnc and mach3?

Thanks

I have a dual-boot with winXP/mach3 and Ubuntu/Linuxcnc. I used windows/mach3 one time to test my parallel port and then never again.

One major difference is that LinuxCNC distro is a real-time operating system and winXP isn't. Another difference is that all the time and energy you put into learning linuxCNC will pay off because you keep using your knowledge even though you can upgrade for the rest of your life. All the files maintain compatibility, etc. With XP/mach3 you are at the whim of the developers. They might completely change the UI every year. The new mach3 might not run on XP so you'll have to buy win8(and get a whole new machine to run it), stuff like that.

XP has a Microsoft and NSA backdoor. Pirated mach3 copies have anybody's backdoor. It cracks me up when all these people invent really cool stuff and then can't figure out how an exact copy ended up on ebay from a Chinese supplier...

Do you have a bit that is 180mm long? The longest bit I can get is one with about 30mm effective cutting length. Unless, of course, all you want to do is make some surface work on the 200mm EPS.

Or 3D carving but then you'll need a fourth axis.

Yep.

I do not need a 180 mm cutting length, but I can get a tool with 180 or more. I am making surfboards, so I am just wanting to
What I want is to place a block of EPS that has more or less that height, a cutting length of 35 mm is enough.
I was also considering using a grinder with a custom build disc cutter, to remove more material in one go.

http://www.bornemann-mb.de/images/pdf/Cylindrical_shank_cutter_Basic-Cut.pdf

I have used this German brand, spindles, hollow and non hollow cutters, and best of all the vacuum system. Best I have ever seen for EPS or PU!

Also XP is end-of-life in a few weeks. No more updates from Microsoft.

Dude, windows is dead. Accept it. Maybe get some grief counselling. . Maybe one day they'll have retro XP devices like those Atari emulators. Look on the bright side, you can upgrade to windows vista for only $199.99 haha

Actually, it should be considered dead. All those updates exist for security reasons and henceforth microsoft will no longer be attempting to keep it safe. This is okay on a standalone system but any system plugged into the net will rapidly become dangerous.

...But we digress. Let's take the thread back to its original purpose.

So getting back to the thread, I may be making my own motor controller board based around the TB6560 using the parallel port and linuxcnc. If I succeed, I will put it up as an openbuild. It will definitely be able to power an OX since that's what I will use it for and so it will power a frog too. I'll probably incorporate many of the frog concepts into my OX to make a hybrid.

So anyway, yeah that's my plan and it bypasses all the problems I had when I first started like finding a decent controller and software. It has a future. I'm guessing the boards will be around $50 which will bring the cost of CNC'ing down and get more people into it who will then contribute better designs to the community which will improve all of our machines.

Hi Alex and group. Glad to see this thread is continuing in my absence.

Alex, a few comments:

1. The dust removal has been very effective, but I'm still experimenting with different brush lengths and stiffnesses. I will report once I have more data.
2. I agree, the spindle mount could improve, it's on my list of to-dos.
3. Greater z-axis range probably means less stiffness at the extreme extension. It's a trade-off.
4. I run Mach3 on Win7. Seems fine, but I'm leery of updates.
5. I use a variety of tools, mostly solid carbide. All 1/4" shank.
6. The belt and pinion has been a headache, pulleys shifting on motor shafts in spite of flats and loctite. Very small setscrews! I'm changing to 3mm pitch GT3 belts/pulleys now.
7. I'm working with higher cut speeds now than what's in my earlier video. Typically 100ipm or so. Still playing with it.
8. I set my tool height zero much the way Dude does. No auto change on this machine!

I'll be back in town in a couple weeks, will roll up my sleeves then and get back to it.

Regards
Neil

I change most of my setscrews to socket screws. A socket screw of the same diameter as the setscrew uses a much bigger Allen key and is much easier to tighten. I don't do it in places where the screws are in very high revs.

RE #2 I've found that a combination of the routy design which allows you to adjust the height of the gantry, plus mounting the spindle to v-slot, allows me to position both the gantry and the spindle. This is cool because you can reduce the torque when cutting short flat objects(like aluminum plate) and you can have extra clearance for cutting big blocks of softer material like wood.

RE #6 Grind a flat spot onto the motor shaft. The pulley should never move. Perhaps the inner diameter of the pulley doesn't match the motor shaft?

Thanks "Dude", I like the idea of an adaptable z-axis mount, perhaps in my next version...

As regards the pulley shifting, I probably should have been more specific. I did flat the motor shafts -- the shifting I've seen is lateral, not rotational. When it moves far enough it forces the belt to rub against the side of the extrusion groove and wear badly. I'll try putting ordinary screws in (as was suggested) so I can tighten better.

Pictures, we want pictures!
Neil

Neil,

Where do you think the weakest, structurally, areas of your machine are.?You said you were seeing deflection at the drill bit. Can you see the extrusions moving or do they seem weak?.
Also, can you place more pictures of your tables x-axis?

Zach

Another option is to use C-clips... you can use a hacksaw to cut a groove into the shaft while it's spinning and then throw a c-clip on it.

This is the same for all v-slot builds, basically. So there's a little bending that happens in the aluminum Y gantry plates. There's a little flex in the delron wheels. There's a little flex in the extruded aluminum. It all adds up and if you have a very long z-axis, this tiny bending is actually a noticeable deflection in the router bit. On my routy I can just push on the end of the bit and see the deflection is about 1/8" with enough force. On a larger machine like a frog it may be 1/4" or more. If this is a problem for your application you need to reinforce all the parts I just mentioned. Use a double-v-slot on the z axis... Use 1/4" plates on the gantry rather than 1/8". Add more wheels.

Zach -- I'm on the road for a while, not working on the machine just now. Will post as I find out what's up.

"Dude" -- yeah, I need to do something like what you suggest. I may even drill a small recess into the shaft at one of the flats so the setscrew tip gets captured.

Any updates on the progress of this machine and the one Matt is building?