Re: [Emc-users] Lost fractions of a step

,I too have a similar problem. Built a rotary table (small, about 4" dia). Ordered a worm and wheel pair from Boston Gear, thought I ordered a 72 tooth worm wheel, which moves 5 degrees per one rev of the worm, divided by 400 steps, resolves to 0.0125 degrees per pulse Can't accurately read

Re: [Emc-users] Debian Wheezy monitor problem(s), new install

On 4 January 2016 at 00:27, wrote: > I sort of know what the issues are, I just need help in extracting myself > from the hole I am in. In the my previous build, which was under Ubuntu, I > was able to add some xrandr commands that I had found that worked to a file > in gdm.

Re: [Emc-users] Lost fractions of a step

Great explanation Peter! Happy New Year. John Dammeyer > -Original Message- > From: Peter Homann [mailto:gro...@homanndesigns.com] > Sent: January-03-16 5:36 PM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] Lost fractions of a step > > > It depends on the drive that

Re: [Emc-users] Lost... - New Haven Clock Screws

On Sunday 03 January 2016 14:35:53 Kirk Wallace wrote: > On 01/03/2016 11:18 AM, Kirk Wallace wrote: > > On 01/03/2016 11:11 AM, Kirk Wallace wrote: > > ... snip > > > >> Here is one of the pillar screws that should work for the left > >> hole. The right has a smaller thread which I haven't

[Emc-users] Debian Wheezy monitor problem(s), new install

I have a few monitor issues in Debian Wheezy after updating a machine to the latest Debian Wheezy and Linuxcnc 2.7.3. I sort of know what the issues are, I just need help in extracting myself from the hole I am in. In the my previous build, which was under Ubuntu, I was able to add some

Re: [Emc-users] Lost fractions of a step

It depends on the drive that you have. Geckodrives morph from 10 microstepping to full stepping by the time the motor reaches a few revs per second, so no torque is lost. You get the best of both worlds, very smooth slow speed movement and the torque of full stepping. Also, a lot of people do

Re: [Emc-users] Lost fractions of a step

Thanks to everyone for their input. John answered the right question. The bottom line appears to be that Linuxcnc does "round" both up and down to the "nearest" step as opposed to just dropping the "leftover" So it already does what I was proposing to do with the MOD operator. Apparently the

Re: [Emc-users] Lost... - New Haven Clock Screws

It's easy to determine the size of a metric screw, just measure across the threads with a caliper. M3.5 is unlikely, because that size is not listed in bold print in the DIN list (as is M4.5, M7, M9, M14, M18 etc.). It is, AFAIK, only used in low current (<16 A) electric equipment such as wall

Re: [Emc-users] Lost fractions of a step

On 3 January 2016 at 21:35, wrote: > ,I too have a similar problem. Built a rotary table (small, about 4" dia). > Ordered a worm and wheel pair from Boston Gear, thought I ordered a 72 tooth > worm wheel, which moves 5 degrees per one rev of the worm, divided by 400 >

Re: [Emc-users] Lost... - New Haven Clock Screws

On 3 January 2016 at 19:50, joseph perry wrote: > Almost looks like metric but I can't find an M3 x .6 My 2 cents M2.5 x 0.6 is a size. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto

Re: [Emc-users] Lost... - New Haven Clock Screws

M3.5 x 0.6 is also a size, as are M3 x 0.5 and M3 x 0.35. If the diameter is a full 3mm, I would guess M3.5 x 0.6 because the OD across the crests on a metric thread is always slightly smaller than the nominal OD. It could also be 1/8 x 40TPI which is a commonly used thread on pendulum rods

[Emc-users] Debian Wheezy monitor problem(s), new install

Tom, I can't be of much help, but I can tell you I had the SAME problem w/ the _none_ selection. I suggest to anyone not to click that! You appear to be much more linux versed than I am, but I could at least get a terminal by typing: The Ctrl-Alt-F1. However, I struggled from there. I did

[Emc-users] ATBF saw blades Re: Lost fractions of a step

On 1/3/2016 9:19 AM, Gene Heskett wrote: > That blade was of a > tooth style no longer marketed by anybody, a CMT with an ATBF tooth > sequence, a high angle tooth to the left, one just like it to the right, > and a flat topped tooth that ran about a thou lower than the high angle > tooth's tips.

Re: [Emc-users] Lost fractions of a step

On 1/3/2016 8:00 AM, Cecil Thomas wrote: > As I have designed my program there are many more moves in one > direction than in the other so I assume that the "shortness" > accumulates over a large number of moves. My calculations for the > accumulation of error in my system seem to match the

Re: [Emc-users] Debian Wheezy monitor problem(s), new install

Thanks, i’ll see tomorrow what I can do. -Tom > On Jan 3, 2016, at 8:11 PM, Mark Johnsen wrote: > > Tom, > > I can't be of much help, but I can tell you I had the SAME problem w/ the > _none_ selection. I suggest to anyone not to click that! > > You appear to be much more

Re: [Emc-users] Debian Wheezy monitor problem(s), new install

This is a D510 board. I will see what I can do with xorg.conf… Thanks, -Tom > On Jan 3, 2016, at 9:00 PM, andy pugh wrote: > > On 4 January 2016 at 00:27, wrote: > >> I sort of know what the issues are, I just need help in extracting myself >> from the

Re: [Emc-users] ATBF saw blades Re: Lost fractions of a step

On Monday 04 January 2016 00:41:15 Gregg Eshelman wrote: > On 1/3/2016 9:19 AM, Gene Heskett wrote: > > That blade was of a > > tooth style no longer marketed by anybody, a CMT with an ATBF tooth > > sequence, a high angle tooth to the left, one just like it to the > > right, and a flat topped

Re: [Emc-users] ATBF saw blades Re: Lost fractions of a step

On Monday 04 January 2016 00:41:15 Gregg Eshelman wrote: > On 1/3/2016 9:19 AM, Gene Heskett wrote: > > That blade was of a > > tooth style no longer marketed by anybody, a CMT with an ATBF tooth > > sequence, a high angle tooth to the left, one just like it to the > > right, and a flat topped

[Emc-users] Non-rotary gear cutting Re: Lost fractions of a step - Clock Wheels and Pinions

On 1/3/2016 10:37 AM, Kirk Wallace wrote: > I have been looking at clock gearing off and on for a while. So far, I > have found that clock tooth forms are cycloidal, but not really. It > seems there is a British standard which is based on the ideal cycloidal > form but uses a circular arc for the

Re: [Emc-users] Lost fractions of a step

I forgot to mention, I had no accumulated step loss in my tests, I started each test with encoders at 0 and they completed with 48000 and 2, not even a +-1 digit error which surprised me. Dave Caroline --

Re: [Emc-users] Lost fractions of a step

In my experience of watch and clock gear cutting, heating is almost non existent as an error source, for steel one cuts under a lubricant which cools and brass is cut dry with a sharp cutter and often the clamping washers if used will keep it cool. Only one "brass" wheel gave me a problem and that

[Emc-users] Lost fractions of a step

Just chipping in... So on your rotary axis, you have 60 000 steps per revolution. If you set up a dial gauge and do a simple G1 with 600 000 steps, or 10 rev's, is there much residual error? Otherwise, if the accuracy is good enough for one rev, then, in fake code; - home rotary - cut one tooth

Re: [Emc-users] Lost fractions of a step

And another thing, almost all rotaries have backlash, do make sure this is removed in gcode before you start cutting this will result in a single tooth error. Dave Caroline --

Re: [Emc-users] Lost fractions of a step

I suspect that if you were indeed to cut each tooth completely and sequentially you could get the spiral wave of material heat extending that would cause even stranger errors! In the effort to cut a little of each I would use the Fibonacci number applied to 360degrees - as I remember aprox. 137

[Emc-users] Lost fractions of a step

I guess I wasn't as clear as I had hoped about my question. To be more specific: When the commanded value for a move is converted into steps (or microsteps) and that number of steps contains a fractionWhat happens to the fractional part of a step I am not speaking of dropped steps as

Re: [Emc-users] Lost fractions of a step

The internal numbers in gcode are floats there is no rounding down unless you put small constants in your gcode, I calculate the tooth angle in gcode so internally it is as accurate as needed. eg do not calculate yourself use a line such as #=[360/#] I never see your problem and have been using

Re: [Emc-users] Lost fractions of a step

On Sunday 03 January 2016 10:00:50 Cecil Thomas wrote: > I guess I wasn't as clear as I had hoped about my question. > To be more specific: > When the commanded value for a move is converted into steps (or > microsteps) and that number of steps contains a fractionWhat > happens to the

Re: [Emc-users] Lost fractions of a step

On 3 January 2016 at 06:02, Cecil Thomas wrote: > My question is about what happens to the "leftovers" when the > precision of the g code commanded position cannot be met by the > hardware executing it. It should all even out over multiple moves. The commands to the step

Re: [Emc-users] Lost fractions of a step - Clock Wheels and Pinions

On Sunday 03 January 2016 12:37:55 Kirk Wallace wrote: > On 01/02/2016 10:02 PM, Cecil Thomas wrote: > ... snip > > > Several years ago I wrote a program to "generate" involute gear > > teeth by making multiple cuts of the same tooth from differing > > angles with a rack shaped cutter. This

Re: [Emc-users] Lost fractions of a step - Clock Wheels and Pinions

The book which has a selection of standards is Gears for small mechanisms by W.O. Davis, it was reprinted by TEE publishing ISBN 1857610156 Note the correct form has a rectangular root which stops the end mill kludge. We just used the Thornton cutters to get it right. The cycloidal form has a

Re: [Emc-users] Lost fractions of a step

On Sun, Jan 3, 2016, at 01:02 AM, Cecil Thomas wrote: > My question is about what happens to the "leftovers" when the > precision of the g code commanded position cannot be met by the > hardware executing it. LinuxCNC does not work in steps. It uses floating point values for all internal

Re: [Emc-users] Lost... - New Haven Clock Screws

On 01/03/2016 09:53 AM, andy pugh wrote: > On 3 January 2016 at 17:37, Kirk Wallace wrote: > >> I'm also working on a New Haven clock that seems to use custom screw >> threads (#3-40?) that don't appear in Machinery's Handbook or anywhere else. > > I thought it might

Re: [Emc-users] Lost... - Clock Wheels and Pinions

On 01/03/2016 10:13 AM, Dave Caroline wrote: > The book which has a selection of standards is Gears for small > mechanisms by W.O. Davis, it was reprinted by TEE publishing ISBN > 1857610156 > Note the correct form has a rectangular root which stops the end mill kludge. > We just used the Thornton

Re: [Emc-users] Lost fractions of a step - Clock Wheels and Pinions

On 3 January 2016 at 17:37, Kirk Wallace wrote: > I'm also working on a New Haven clock that seems to use custom screw > threads (#3-40?) that don't appear in Machinery's Handbook or anywhere else. I thought it might be a watch pendant thread, or Progress, but I

Re: [Emc-users] Lost fractions of a step - Clock Wheels and Pinions

On 01/02/2016 10:02 PM, Cecil Thomas wrote: ... snip > Several years ago I wrote a program to "generate" involute gear teeth > by making multiple cuts of the same tooth from differing angles with > a rack shaped cutter. This eliminates the need for the different > cutters when making only one cut

Re: [Emc-users] Lost... - New Haven Clock Screws

On 01/03/2016 11:11 AM, Kirk Wallace wrote: ... snip > Here is one of the pillar screws that should work for the left hole. The > right has a smaller thread which I haven't looked into yet. ... snip Oops, forgot the link: http://www.wallacecompany.com/clocks/New_Haven/IMG_2275-1a.jpg -- Kirk

Re: [Emc-users] Lost... - New Haven Clock Screws

On 01/03/2016 11:18 AM, Kirk Wallace wrote: > On 01/03/2016 11:11 AM, Kirk Wallace wrote: > ... snip > >> Here is one of the pillar screws that should work for the left hole. The >> right has a smaller thread which I haven't looked into yet. > > ... snip > > Oops, forgot the link: >

Re: [Emc-users] Lost... - New Haven Clock Screws

Almost looks like metric but I can't find an M3 x .6 My 2 cents On Jan 3, 2016 11:39 AM, "Kirk Wallace" wrote: > On 01/03/2016 11:18 AM, Kirk Wallace wrote: > > On 01/03/2016 11:11 AM, Kirk Wallace wrote: > > ... snip > > > >> Here is one of the pillar screws that