Yes you can do that. Check "stop CV on" setting.
It switches from CV to exact stop mode depending on the approaching angle in next line of code. Set the angle here :)

Welcome to the club Ries, you have built a great looking machine.

I am looking forward to seeing some of your projects.

Ries, how did your leadscrew pitch setting went?

Anil,

I am not sure I have seen that setting, is this a Gcode function or a Mach3 setting?
Come to think of it, when I issue G64 P0.1, it should follow my lines within 0.1mm and also carve me letters smooth enough, I need to experiments a bit I think...

@Wayne, thanks.. I indeed have that club feeling and very happy with the number and the machine, I got my first RFQ already... and this is just a hobby!

@Ken: I didn't change it yet, My main problem is that my supplier didn't gave me to much specs but it's Module 1, 22 tooth pinion and my teeth are 6mm apart.
From the spreadsheet you send me I cannot makeup in EMC what I should fill in because when I fill in the value the spreedsheet creates, I am simply way off. In this case it usually means I have no idea what I am talking about :D so I will properly put a bit more trial and error in calibrating the machine rather then doing this scientifically.

Ries

did you divide the values of step/mm by step/Rev?

Ken,

in EMC I need to fill in how much the gantry will move per revolution, and from the current pinion I have no idea how to calculate that, and it doesn't match well with the sheet of gerard, I have properly some weird module, but not 1.5. I did a rough estimate once and based on that I did a bit of trial and error to get closer and closer to the final number, top of my head I set it to 92.xx mm/rev.

If I have the outer diameter of the pinion, and I know the distance between each teeth, wouldn't it then be possible to calculate the movement of my gantry per revolution, this would possible even depend on the type of teeth?? Gosh......

Ries

Ries,

(Step/mm) / (step/rev) = rev/mm
Which is what EMC2 stepconfig wants to know.


but since you don't know what gear you are using, then I have the Gear dimension formular, hope it helps.
Attachment 8466

That is a setting/function in mach3 .
I was using a simple program "Turbocnc" in past and just now installed EMC on my machine.

I'll post as soon as come across any setting (or another way to do it) that do the same thing as "stop CV on angle" in EMC.

Anil,

the guys from EMC did start implementing something like 'stop CV', the idea was to switch to G61 or G61.1 when some angle where sharper then XX degrees. However, this turned out not so reliable because when you have designs with different angles the final output can look weird because of the decisions the machine made during cutting.

What I am planning to use is G64 P0.1, for my letters that gave me very nice results while maintaing cut speed. G 64 p0.1 (in metric mode) simply means follow the line while keeping your velocity but stay accurate within 0.1mm.

The accuracy highly depends on the accel/deacceleration settings of the machine with the maximum speed taken into account. if you don't allow your machine to go fast and acceleration and de-acceleration values are low, then you will not notice this. However, when you have high velocity, then you will see the effect.

Here is the G-Code:
G21
G17
G40
G90
G94 F16000

G61
G0 X0 Y0
o100 call

G64 P0.1
G0 X10 Y10
o100 call

G64 P1
G0 X20 Y20
o100 call

G64 P10
G0 X30 Y30
o100 call
G0 X-10 Y-10
M2

o100 sub
G91
G0 X75 Y0
G1 X-75
G1 Y75
G90
o100 endsub

Also remember, to cut a sharp inside corner is different from a sharp outside corner. (On an outside corner, the toolpath is allowed a radius movement and the corner is still sharp)

Gerald,

you mean during cutter radius compensation, G40, G41 and G42, right ?

I created a little movie with CV mode on and cutter compensation left with a tool diameter of 5 mm, the speed of the tool is not realistic, aswell as the compensations in question for a real machine, it just shows what gerald is mentioning. The white lines do have rounded corners, while the part in question if cut out on your machine will have sharp corners.
The 4 corners still shows with no cutter compensation (left) to 0.1, 1 and 10mm settings.

Movie

note: The blue/green lines show the 'part', the white line shows the planned path, and the red line shows the actual cut path.

PS: It's a nice exercise to understand what's happening and how the machine + control software behaves. I can encourage you all to play with gcode and settings within for some time to get a better understanding.

Ries

Small update,

I decided to add an additional ventilator in my control box to suck in some fresh air through a filter on the top left of my controlbox, and get it out on the bottom right. I had two times my computer shutting down, only when the control box was closed. It's a bit scary aswel, because my router turns on and off quickly for a split second, don't want to have my hands there. I now turn of the router before I change a bit to be sure.

Here is a little video I made during cutting the channel for my hold down system on my spoil board. video
I decided to create the same hold down system as Mark has. Link

Given the a mouth of dust I have seen last Wednesday, next project is going to be a dust foot and dust management, not sure yet if we are going for a cyclone or a bin/bucket cyclone.

Ries

What sort of ambient temp in Quito? I know its 2000ft above sea level, but is it any cooler then near sea level? I'm asking because I want to know if I must cut a hole on my control box for the fan.

Ries, you have the computer inside the control box?

The router should not switch on/off if the the PC start/stops - in Mach, the "charge pump" takes care of that. There must be something similar in EMC.

There is a charge pump function you can configure in EMC. You'll want some lines in your config file similar to these:

@Ken,

we are at 2400 meters (7200feet) average temperature during the day is like 24 celcius at 2PM, at the coast it's much warmer (32-35).

@Gerald: my CPU is mounted inside of my controlbox. This works fine untill the temp goes up. When my computer shuts on/off my router goes on for a split second, the router doesn't have time to go to full speed.

@Brad: I do have the CP enable, I am pretty sure of that, but I will check next Saturday to give this a other inspection. I did some test here with my kitchen table project and for example I couldn't jog in stepconf, but it worked fine in Axis.

Theory:
The CP protects you when the computer goes on and off while EMC/Mach3 is not running. THis because the software can properly shutdown and startup the CP
However not during a computer/software crash. I tried to find the CP circuit in the manual, but it's only written is a block diagram. The documentation states "100 Hz minimum square wave on pin 17." I can only imagine the CP is implemented using capacitor/resistor circuit with a hold time of roughly maximal 10ms. So when a computer crashes, or shutsof while EMC/Mach3 is running, it might switch a output for max 100ms because the CP is active.

Tomorrow I give it a quick inspection on the jumper still, can't be sure enough.

Ries

Yes, there is a short time delay for the capacitor to drain via the resistor, but I thought it was too short to energise the router and the contactor/relay switching the router?

Gerald,

I do hear the relays switches very fast, given the nature of a relay (mechanics), this might be just enough to switch on/off very fast. With a solid state relay I might not have this problem because they can switch much faster.

A relay tend to hold itself for a brief moment, something with flux.. Don't remember the terms anymore. But when a coil get's released of it's supply, then the coil lends to hold itself for a moment longer. This will make my router turn, even though the pulse to the relays is only around 10ms.

Ries

Small update...

the ventilator and filter in the control box really helped well, the machine has been on for the whole day and didn't shut off, without the extra ventilator and the control box closed this would take around 30-45 minutes and it would shut down, so I think I am good there.

Given the amouth of dust cutting the T slots for the hold down system generated, my next project was creating a dust feet connected to my little vacuum cleaner to see if the initial design worked. I work with a 'iron man', so you see a bit of iron there :) We where in for a nice surprise, because we forgot how much air the router pushed downward, at first we generated more dust then we sucked up. We solved it by redirecting the air of the router back up with a small 1mm plate directly under the router and opening teh wood. I am going to design a new dust feet now we know that this setup worked. Also notice that the front of the feet can be removed and currently hold by a elastic. THis is going to get changed by a system that I can open and close, so I can start the MM, and if everything looks good I close the dustfeet.
As you notice I use a small hose for the dust feet instead of a big one, the rationale for this is that I wanted to create fast airstream rather then a slow one with a big pipe. I also mounted it on the side instead of the middle to make sure the air swirls around in the dust feed. The size of that pipe is subject to change, but given the <1HP vacuum I have, I though a bigger hose would be less effective here. There is no science behind it, but I just thought this was a good idea.

Also going to make a mini cyclone, size of it would be around 30x48 cm, same smaller size to make sure that the internal airspeed is fast enough for my size vacuum so I can separate wood chips from air effectively, bigger is not always better :)

Attached some images showing:

1) 15mm MDF close-up to show off cut quality, very happy with that...
2) Dust feet created, this going to get replaced...
3) For Ken I promised a image of my M1 30 200 A A
4) Image of the T channel I created for my hold down system
5) Basic design of the cyclone...

Nice work & thanks for the pix.

hey Guys,

have haven't been active on my thread for a bit, got new clients for my work that keep me buzy.
Good for getting some $$$ in, bad for mechmate work, so only now once a week at my machine for a moment :(

Anyways,
I need to by some bits and considering to buy china/japan. I checked some of the bits in the US, europe but they are way to $$$ for me right now. Given also that I am a newbie, I rater buy something cheap now that I can break and play around with, rather then I break 30USD in a snap...

Anyways,
I want to do plyboard cutting and MDF, and also carving. What sort of bits should I have in stock in general?

Ries

I used to buy carbide cutters, spiral cutters when I could find them. That got real expensive in a hurry. I would break one every couple of days or so. Then I went to carbide tipped, but the finish wasn't what I wanted. Then I found Onsrud.com. I started using their HSS series 40-1xx.

I cut mostly soft wood, and the top edge would splinter, so I now use the Downcut for the first cut and then change the cutter to upcut, now I've cut the finishing at least in half. I do a lot of tool changes, but the end result is faster in the long run.

The HSS cutters last longer than the carbide for me because I can run them longer with out breaking the tool.

You can check their web site, I don't know if they ship world wide or not, but their prices are very good.

They do have carbide cutters as well and I may use them once I get real familiar with my machine, but for now it's HSS all the way.

Dave,
Why not use a compression cutter that finish in one pass giving a clean bottom and top cut?

Dave,

You will get better cuts and the bits will last longer if you use solid carbide bits. If you are breaking so many bits it could be that your feed rate is too fast.

I've thought about compression cutters, I just haven't had the nerve to cut 3/4" wood in one pass. People do it all the time, I just haven't tried it yet.

I'm not breaking cutters because of feeds and speeds, but because of really dumb things that I'm not going to admit to. Solid Carbide spiral cutters are real easy for me to break.

I will start using carbide cutters again one I get to the point I'm really comfortable doing what I'm doing. Until then I'll use the $7 HSS cutters.

As far as the tool changes I do lots of pockets and lots of lettering which requires V Bits. When I do the pockets, I also do the top cut then switch to the upcut cutter. Not all that bad really.

Dave,

What size cutter are you using? 1/4, 3/8, or 1/2 inch? I used to have the same problem but after I went up to 12mm (~1/2"), I haven't had a bit break yet. I'm using Solid carbide two flute up cup spirals. Have not looked back since. I still use 6mm (~1/4) on the occasion for things that really need it. Good luck!

Dave

It is true you can't beat the price of a $7 bit.

I use mostly 1/4" cutters. I use mostly dimension lumber and come as close to nesting as I can, so any cutter than that won't work. I also use 1/8" and 3/16" cutters plus ( v-bit cutters that are carbide ). I have larger cutters that are carbide and I use them when I can.

My problems are mostly g code errors ( trying to make short cuts ) or pushing the wrong buttons on my hand controller.

Looking for a Spindle for Sale in the US, or time to order one from China...
 

Hey All,

in May I am heading for Dallas for a short period of time and I would have a possibility to buy one of the cheap Chinese spindles.

I now that sumbum had one for sale and I was in contact with him about it, but unfortunately he is out of reach at the moment so I am not sure if he still has it or not.

How long would it generally take to import one of these spindles from China? I have a friend that is willing to receive it for me and I am meeting him in Dallas. on the 22th of May.

Or better, does anybody have one of these spindles + VFD for sale?

Ries

Hey All,

here is a little video of my Auto-Z I created yesterday for the Mechmate: http://www.youtube.com/watch?v=s8d1zG0YnIg

The system consists of a little metal box containing a hand full of batteries, a resistor, a LED and a 4n35 opto coupler, this to separate my ground from the BoB's ground to prevent ground loops, high-odd voltages and what not the can be out-there. the PMDX is not well protected so I thought this was a good thing.
The idea was 100% taken from http://wiki.linuxcnc.org/emcinfo.pl?...probe_touchoff and I must say this work just fine!

if anybody is interested in the clp (classic ladder) file, I am more then happy to post by complete config (whish is work in progress... as always :) here.

Ries

hey Guys,

today I have been working on my homing squence. I didn't had a lot of time this weekend so I thought it was going to be a nice little project.
I basically followed the instructions here. I am using the second method, where there is a search velocity and a latch velocity.
In short this means that EMC will find quickly (search velocity) the switch position, then goes back under search velocity like 5mm orso. Then goes under latch velocity to find the switch again, but slow and more precise.
This seems to work very nice and I get repeatable results when going back to my touch off location. For my homing switches I used the 'good old' micro-switches because they where really cheap here. I also had one sample of a proximity sensor, and when asking what 3 of these would cost it was 300USD, decision was made fast after that :D.


attached a couple of images of my work of today it will properly not win a beauty contest, but it's very functions and saves me from finding the 0,0 position of my project after a crash in one form or a other :)

Also attached my Mechmate files I use to make that screenshot for anybody that is interested. It's not a drop-in replacement for your current configuration file but it give you a solid idea how to make your own buttons and how to create a ladder diagram for special functions like to pause buttons (single press start/stop), how to use autoZ and how to attach your own buttons to MDI commands.

I hope you like it.

Ries

Nice stuff.
I pop your files in my EMC2 & find your custom panel really interesting, but since I had yet to install home switches so I really can't play with your features.
Question, what is the Rotate Orientation for?
I had a go at the pyVCP & classicladder. its been a while since I started and still climbing the learning curve...

Ken,

the Orientation buttons is a new feature of EMC (supported by G-Code). It simply allows you to re-orientate the CNC files. This can be handy under some situations. For example if you setup the design vertical, but at your machine it turns out that the wood clamps better horizontal. THis is in EMC2 2.4 or 2.5 (I forgot).

Classic Ladder is really cool!! it's amazingly powerfull, the auto-z is designed with CL.

Have you moved on to Ubuntu 10.04?

I can see the use of the position orientation feature it is ground breaking, a part from this are there other significant difference between EMC2_2.3.4 & 2.4 or 2.5?

Ken,

I did follow this with half a eye and I didn't see a need to update yet. Properly partly because I don't use ubuntu but I compiled my own kernel and version of EMC on Debian. And since my MM is in a location without internet which makes it harder to do this task.

I do, however feel that if you have the chance to upgrade, you should do it. De 2.5 version of Axis coems with a patch I created :)

Thanks for your generous offer. I know who to look for when I decided to go that way :)
You made software customisation look so simple :confused:
I have to admit I'm completely useless with Linux (and a lot more systems) after I put my leg into EMC2...I'm still scaling the software learning curve... before I could get comfortable with the version in-hand, many new releases had went by...
IMHO, advantage of sticking to LTS release is that the documentation, teaching aids & forum help are easily available, in such that I don't have to haunt my friends to answers my questions ;)

I get advise like yours from other friends, they did mentioned Ubuntu is overly tweaked... but for now, as I don't even know what tweak is... I will stick with Ubuntu 8.04LTS until either EMC2_2.4 + Ubuntu 10.04LTS realease in live Disc or I feel confident to go Dabien 2.5.
BTW, out of curiousity, does De 2.5 handle multicore processor?

<chuckle> Enthusiasts in any field always disparage the mass-market solutions. It's hard for an enthusiast (myself included) to remember that others just want a tool to get a job done.

Stick with the stable standard release until you have a specific need to upgrade and you'll save yourself some headaches. There will be hot-rodders screaming down the street in sexy looking vehicles, but theirs won't be as reliable as yours.

As for customization, you can do a lot of that without having to be an expert. Learn how to maintain more than one configuration (easy, just create two or more), and you can then play without worrying.

The standard linux kernel has handled multiprocessor systems for well over a decade. Multicores are a variant of multiprocessors with different packaging, and they are also supported by pretty much all Linux flavors. However, if we're speaking specifically of interrupt driven machine control applications like EMC, the benefit gained from the extra cores can be minimal. So, yes, all Debians handle multicore processors seamlessly.

Ken,

I didn't want to make the feeling that you should upgrade, but if you have the change (and also confortable with it) then it's ok, there are no strange bugs or what so ever with EMC 2.4 or 2.5, I thought THAT (are there any bugs..) was the tone of yoru questions. Sorry I did mis-understood you.

I am also just on 2.3 still because it works :) 2.5 only contains apatch I made that will confirm if you really want to re-home, if you pressed that button by accident.

2.5 is only really nice if you really want to rotate you workpiece. It's actually just a g-code, that should also work on Mach3.

Ries

Brad, thanks for the explanation. I admit my knowledge in this thingy that I don't even know what to ask to get to this answer. Now I know. Thousand thanks

Ries, you has always been helpful, the problem is with me, I just don't know enough to ask intelligent questions on the subject... :o
Thanks for being patient with my idiotic questions.

Ken,

not a problem at all... I sometimes have the tendency to be to technical to, stick with the version of EMC you are comfortable with, I am using a 2.3 version without problems at all.

Ries