what is the speed of Cw in Inches per minute

[benluz]

I'm trying to find the specs for feed rates for the cw ballnose bit: feed rate, step and so on. Any help would be greatly appreciated.
Thanks,
Ben

[Dan-Woodman]

Look on page three of your owners manual.
Length axis--2" per second
Width Axis---12" per second
Up/down Axis--12" per second

These are feed rates for the machine , not specific bits.

[Lin]

Ben, I don't know if this will help you or not. One of the programs I wrote for a CNC where I work I used a carbide 1/4" ball nosed E/M. I ran a speed of 5000 RPM on it. Cutting an arc with it. Cutting aluminum with coolant on it...taking off aprox. .045" in metal in two passes. .025" the first pass and the rest on the second pass. Finish did not have to be extremely smooth.
Lin

[Digitalwoodshop]

When I worked at Sony I did some programming of some Fanuc Robots for painting liquid carbon on the outside of the picture tube. That was very much like the CNC you are using at work. With THAT program "at work" you can select different feed rates to optimize the bit performance, cut quality and job completion time.

At this time with Designer, you select the bit in the tool section and the software is already set to a pre determined (by LHR) feed rate that WE, at this time, have NO control over. Suggestions have been made for future program updates that a slider type software control be offered to allow USERS to adjust the feed rate up or down based on cutting sign foam or solid oak.


How it works from what I am seeing without the benefit of schematics, block and wiring diagrams is the Cut Motor has a Closed Loop Feedback System.

It is my belief that the Carve Machine uses the Cut Motor RPM detector and the PWM or Pulse Width Modulator to control the motor speed. Almost like a governor on a gas engine. The way closed loop feedback works is that it monitors the cut motor RPM speed and the PWM output to the cut motor and calculates the difficulty level in cutting within the program. TO help the machine deal with a difficult in cutting oak, I believe the x, y, and z are stepped SLOWER to match what the machine is seeing on the RPM sensor, keeping that speed within set limits. SO if I am right, it slows the feed rate of the WOOD in the X and the cutter in the Y and Z motion.

The PWM is a speed control device that varies the voltage to the cut motor, changing the amplitude and pulse width. I mentioned to Jeff that I was going to put a relay on the Cut Motor power to control my dust collector. Jeff quickly replied back saying to be careful.... The change in "impedance" could burn up the PWM or Motor. Scratch that idea.... He is correct.

Like a lit flashlight bulb, then add a second bulb in parallel, they both become dimmer.... Change in impedance for AC Power or Resistances in a DC powered circuit.

We do not have control over feed rate. It's a "nice to know number". Sorta like a trick question from your fellow co workers. Hey, what's the feed rate of that thing? MY CNC can cut.... Blah, blah, blah.... Like the guy asking how fast your CAR can do the 1/4 mile....? MY car is better.....

This is a HOBBY MACHINE....that some like me, use more like a commercial unit.

It's like "Fuzzy Logic" in electronic circuits. Some have heard of binary logic circuits or programs running everything from your dish washer to your DVD player. Logic programs respond to inputs and outputs and based on that, the program responds. If you wanted to write a program to balance a upright pencil in the palm of your hand, the Logic circuit and program would be HUGE to cover all the possibilities.

Fuzzy Logic was developed in Japan to be a "Responsive Program" and respond to variables like the pencil starting to fall to the left, correct the hand position, now it is falling to the right, correct the hand.... A Closed loop logic program called fuzzy logic. Or as I call it, a program that the instructions and rules are not written in stone like logic circuits. And they do it with a much smaller program and less hardware just to save MONEY.

So.... Off my Soap Box....

AL

[Lin]

Doesn't Ben have a shotbot also? Figured he ask the question for reference to set that one up. When I program the CNC's at work I have a chart to give me a starting reference most of the time...then I ramp it up as fast on the feed as I can get away with to get "more parts per hour" off the machine.
When I have no reference to go by...the smaller the tool..the faster RPM I can give unless its a long tool. Shorter the better. Less flex. Feed rate is sorta by the seat of my pants...Start slow and work it up till I hear the tool telling me...don't push me no more...lol
I love it when I can run the diamond or ceramic inserts in a face mill...
15000 rpm plus more and 450+ IPM. You can fly around a perimeter cut with those babies. A couple of the older machines cannot run the high rpms so we can not run diamond cutters in them. In reality I have to use metric on all but two of the old CNC's. IPM are getting to be a thing of the past.
I know I would really enjoy if the CW software ever becaome G-code capable.
Lin

[Hawg_man]

My take on the feed rates is that this being a general consumer hobby machine and not an industrial production machine LHR has built in feeds based on averages of cutter size and materials cut. I've worked in maching for over 45 years and would love to have more input into how the machine operates but for LHR and their target market that may cause more issues than it's worth.........just my 2 cents worth.

Bob

[Kenm810]

Good explanation AL, Even I was able to follow along, that the Cut Motor RPM detector and the PWM or Pulse Width Modulator being used control the motor speed and acting as a governor to stabilizing the cutting bit rotation for the cut speed. Most of that type of info is normally out of league. I remember your post about tapping into the machine for power source to operate a relay connected to the dust collector system. My skills and knowledge electronics and modern circuitry is rather out dated, when I was a kid we used to build or own crystal radio sets, back then when I went to school for electronics I had the master using a slide rule first. So luckily I remember just enough to get by, and thankfully enough to keep me out of trouble most of the time. At least for me that’s why I felt safer keeping my power sources for my add on’s independent of the machines circuits.

Buy the way, Barbs says even though I’m still fairly "Responsive” but my Logic is often Fuzzy and I’d probably trip over the soap box trying to find one. http://www.carvewright.com/forum/images/smilies/icon_confused.gif

[benluz]

What happened is Vortex ,where I bought my bits for the shopsabre did not send me a catalog.The catalog has a formula for chip load,etc..for optimizimizing bits and cut speeds vs. material that you are cutting .All the CNC users on here were right ,designing a simple sign is much harder with the cnc software vs. the carvewright,on the good side I can carve about twice or as fast useing a roughing cut and a finish cut,the roughing cut only takes 2 minutes at 400 in/min on sa a 14x 10 deep deer carving I did.I can go as high as 2400 in/min but that kind of scary and you don't want to stand next to it moviing that fast, hard on the machine too.I just have to adjust my stepover on the final cut I could see a few lines.
Thanks,
Ben

[fullmax]

but can we change the speed of the lenght and width

[PCW]

If you are referring to travel speed settings there are no user control. The designer software does all of the travel speed calculations for you. I personally would prefer a little more user control.

I think what the software designers was trying to accomplish was to have the program as user friendly as possible. This is why someone new to the software can design a project and carve it on the first day. They wanted a system to qualify for the KISS theory.

With other programs that you use gcode programing it has a little more of a learning curve but a lot more machine control. This is one of the reasons that this is called a hobby carving machine.

[Digitalwoodshop]

but can we change the speed of the lenght and width

Boy that is a old post above about Fuzzy Logic....

The short answer to your question is NO you can't change the feed rate.

There have been some changes with feed rate in every Designer Update lately.

With the latest, I cut some 2 x 2 inch cut paths in this sign to fit hitch covers in the end of the sign.

What I noticed was the feed rate changed. Normally it cut the square at a constant rate all the way around.

With this latest version it started in the middle of the side as normal then quickly moved to within 1/4 inch of the corner then turned the corner at a slow rate. As soon as it got 1/4 inch away from the corner it took off at a quick rate slowing at 1/4 inch from the corner.

Did this over and over cutting the bulk of the cut path at a rate I believe is double the normal feed rate. I did set the depth of cut to .25 of an inch.

So with a Consistent or non changeable feed rate, our only choice it to control the depth of cut.

AL