Re: Hobbyist CNC - is it worth it?
#CNC
#CAD
Hello, All,
I have been considering a conversion of my mini-mill to CNC.? I don't do any commercial machining, only my own projects, many of which are tools and accessories for other machine tools.? Do you think a mini-mill CNC conversion is worthwhile, and what would you do with it???
I also realized that I am not fully aware of what the finished CNC mill consists of, or HOW you use it.? For example, when wishing to do a simple machining operation, I know there is an electronic control box that is used; no more cranking the handles.? But how do you get your CNC-machined part to, well, machine?? Let's say I draw up a 3D model.? I know how to do that because it's necessary for my 3D printer.? But if I now want to machine this part, what do I do?? I think?that there is some kind of CAM (Computer Aided Manufacturing) program in which I define which end mills and such to use, and then define "tool paths" of where the tools will actually move, but I am not sure.? Is the CAM program completely independent from the CAD system?? Or must they be related?? Can I draw a 3D part with Fusion 360, for example, and then use a separate CAM program to specify the end mills and define the tool paths?
You pretty much have it nailed. CAD for design, CAM to actually tell the mill what to do. Fusion 360 has a CAM component built in.
Here is a listing of free and OSS software for CAM/CNC I found?
And another:
I do know LinuxCNC is well supported.
Any enlightenment would be appreciated.
--
Regards,
Charlie
New Jersey, USA
MURPHY'S CONSTANT:?Matter will be damaged in direct proportion to its value.
--? Bruce Johnson
"Wherever you go, there you are." B. Banzai, PhD
|
Hobbyist CNC - is it worth it?
#CNC
#CAD
Hello, All,
I have been considering a conversion of my mini-mill to CNC.? I don't do any commercial machining, only my own projects, many of which are tools and accessories for other machine tools.? Do you think a mini-mill CNC conversion is worthwhile, and what would you do with it???
I also realized that I am not fully aware of what the finished CNC mill consists of, or HOW you use it.? For example, when wishing to do a simple machining operation, I know there is an electronic control box that is used; no more cranking the handles.? But how do you get your CNC-machined part to, well, machine?? Let's say I draw up a 3D model.? I know how to do that because it's necessary for my 3D printer.? But if I now want to machine this part, what do I do?? I think?that there is some kind of CAM (Computer Aided Manufacturing) program in which I define which end mills and such to use, and then define "tool paths" of where the tools will actually move, but I am not sure.? Is the CAM program completely independent from the CAD system?? Or must they be related?? Can I draw a 3D part with Fusion 360, for example, and then use a separate CAM program to specify the end mills and define the tool paths?
Any enlightenment would be appreciated.
--
Regards,
Charlie
New Jersey, USA
MURPHY'S CONSTANT:?Matter will be damaged in direct proportion to its value.
|
#3D using wood impregnated filament pt 2. calicat.STL
#3D
Printed a couple of calibration cats.Basically the STL is for calibration. STL is available off the web, any problems I can send it from here. First a standard size basically 20 mm square 30 mm tall.second at 300% scale. I checked my print and the X Y Z dimensions, X 59.85 Y60.15 X 90.2.mm Good enough for using wood impregnated filament I think.Suggest that you calibrate 3D printers on a regular basis.? But this is a fun project to do, and make good gifts for small kids. I printed one about a year ago, and gave it to my local bar owner Diego?s niece of 6 years old. She came back with it 3 months later nicely painted. Diego offered the calicat Olives in the photo? LOL. The finish can be improved by slow feed rates and lower Z steps.It can be sanded and looks like your typical fiber board. The wood impregnated filament must be kept in a warm store area and very susceptible to attracting moisture. Truly recommend to members too by a spool and have fun.    -- John
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Re: Arduino based DRO using cheap Calipers
#ARD
#DRO
Me - I would vote for the less useful units - links, chains, rods, parsec, astronomical unit, light-year - <g>
But, for a lathe, I could see pitch being useful, you would program the threads per unit and the readout would be a thread count...
Another useful thing, playing on the pitch idea above, would be a digital divider - knowing the distance between marks as the unit, set to zero at a point, drive till you get to 1.00000, then 2.00000, etc. You don't have to do the math for evenly spaced things.
Another idea would be relative measurements - set a point as the start, drive to the next point, showing absolute and relative at the same time - all pretty simple with the little controller.
On Sat, Nov 30, 2019 at 12:59 PM Chuck Pickering < chunk07@...> wrote: I added a 20x4 lcd using Ic2. Now I have 2 sketches that display either mm or In, based on the mm/in mode switch, and calculate the other unit and display it on a second line. I'm going to play with adding another scale and displaying it also, then a third.
|
Re: Arduino based DRO using cheap Calipers
#ARD
#DRO
I added a 20x4 lcd using Ic2. Now I have 2 sketches that display either mm or In, based on the mm/in mode switch, and calculate the other unit and display it on a second line. I'm going to play with adding another scale and displaying it also, then a third.
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Re: Arduino based DRO using cheap Calipers
#ARD
#DRO
You are correct of course, I have been reading too many bits of code the
majority being 24bit.
Richard
toggle quoted message
Show quoted text
On 30/11/2019 18:59, BuffaloJohn wrote: The code is written for a 20 bit value and a 1 bit sign. If you look
at the code, you will see this. The 21st bit is the sign. Then the
rest of the bits are ignored. All the chinese inexpensive calipers
seem to use the same format.
Again, if you read the code, you will see he creates an unsigned
integer [value] and then he converts it to a float with a divisor,
which for mm is 100 and for inches is 2000. So, that means the output
is 0.01mm per bit for mm and 0.0005" per bit for inches.
Yes there are caliper data formats that are as you have said, this is
not one of them. His code works - his is not a 23bit signed value.
On Fri, Nov 29, 2019 at 11:55 PM Richard <edelec@...
<mailto:edelec@...>> wrote:
?From what I have seen a scale will be read as 24bits ones compliment
therefore having 23bits of data plus a sign bit. It will typically
have
a raw unit of measurement of 1/20480 of an inch. Having read the raw
value it would be displayed in inches by multiplying by 125/256
and for
millimetres by 127/1024. As the bit value equates to a probably very
noisy 0.000048828" it makes sense to lose some of the lower bits.
I intend having a play with some hardware and software.
Richard
On 29/11/2019 22:53, BuffaloJohn wrote:
> Interesting to look at where all this came from, I found you code
> matches another I found, and there were lots of other references.
>
> It seems that your calipers use the chinese protocol. That protocol
> does not have a bit that indicates units as far as I can tell
from the
> other sources, so unless you see something in the bits above the
sign
> bit, you would be better off picking mm or inches and doing the
math.
> If, per chance. you find something in the bits above the sign,
and you
> see that one of those bits change when you change units, you have
> found the units bit.
>
> Remember, most of these devices have +/- 0.001" accuracy. Some
of the
> calipers I found have 0.001" (0.025mm) listed, some say 0.001"
> (0.03mm). In any case, the calipers are not accurate to LSB of the
> readout, so a numeric conversion of units is fine:
>
> Resolution
> 0.01mm = 0.00039"
> 0.0005" = 0.0127mm
>
> Accuracy
> accuracy 0.001" = 0.0254mm
>
> Buffalo John
>
> On Fri, Nov 29, 2019 at 11:22 AM Chuck Pickering
<chunk07@... <mailto:chunk07@...>
> <mailto:chunk07@... <mailto:chunk07@...>>> wrote:
>
>? ? ?I can't seem to get the two sketches combined to read the units
>? ? ?bit and calculate the measurement based on that bit. Here is the
>? ? ?two sketches that work, one for mm, one for in. Both depend
on the
>? ? ?mm/in switch be set to the measurement unit you want
displayed. Am
>? ? ?I missing something thinking I can do this? The only
difference in
>? ? ?the two sketches is how it converts the data to inch or mm. I
>? ? ?think I might need to input the value of the units bit
instead of
>? ? ?reading it from the data.
>
>
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Re: Arduino based DRO using cheap Calipers
#ARD
#DRO
The code is written for a 20 bit value and a 1 bit sign. If you look at the code, you will see this. The 21st bit is the sign. Then the rest of the bits are ignored. All the chinese inexpensive calipers seem to use the same format.
Again, if you read the code, you will see he creates an unsigned integer [value] and then he converts it to a float with a divisor, which for mm is 100 and for inches is 2000. So, that means the output is 0.01mm per bit for mm and 0.0005" per bit for inches.
Yes there are caliper data formats that are as you have said, this is not one of them. His code works - his is not a 23bit signed value.
On Fri, Nov 29, 2019 at 11:55 PM Richard < edelec@...> wrote: ?From what I have seen a scale will be read as 24bits ones compliment
therefore having 23bits of data plus a sign bit. It will typically have
a raw unit of measurement of 1/20480 of an inch. Having read the raw
value it would be displayed in inches by multiplying by 125/256 and for
millimetres by 127/1024. As the bit value equates to a probably very
noisy 0.000048828" it makes sense to lose some of the lower bits.
I intend having a play with some hardware and software.
Richard
On 29/11/2019 22:53, BuffaloJohn wrote:
> Interesting to look at where all this came from, I found you code
> matches another I found, and there were lots of other references.
>
> It seems that your calipers use the chinese protocol. That protocol
> does not have a bit that indicates units as far as I can tell from the
> other sources, so unless you see something in the bits above the sign
> bit, you would be better off picking mm or inches and doing the math.
> If, per chance. you find something in the bits above the sign, and you
> see that one of those bits change when you change units, you have
> found the units bit.
>
> Remember, most of these devices have +/- 0.001" accuracy. Some of the
> calipers I found have 0.001" (0.025mm) listed, some say 0.001"
> (0.03mm). In any case, the calipers are not accurate to LSB of the
> readout, so a numeric conversion of units is fine:
>
> Resolution
> 0.01mm = 0.00039"
> 0.0005" = 0.0127mm
>
> Accuracy
> accuracy 0.001" = 0.0254mm
>
> Buffalo John
>
> On Fri, Nov 29, 2019 at 11:22 AM Chuck Pickering <chunk07@...
> <mailto:chunk07@...>> wrote:
>
>? ? ?I can't seem to get the two sketches combined to read the units
>? ? ?bit and calculate the measurement based on that bit. Here is the
>? ? ?two sketches that work, one for mm, one for in. Both depend on the
>? ? ?mm/in switch be set to the measurement unit you want displayed. Am
>? ? ?I missing something thinking I can do this? The only difference in
>? ? ?the two sketches is how it converts the data to inch or mm. I
>? ? ?think I might need to input the value of the units bit instead of
>? ? ?reading it from the data.
>
>
|
Re: Alternative to anodizing aluminum?
#MISC
Thanks, John!
--
Regards,
Charlie
New Jersey, USA
MURPHY'S CONSTANT:?Matter will be damaged in direct proportion to its value.
|
Re: Alternative to anodizing aluminum?
#MISC
Hi John
What type of oil? (to go with boot polish)
Thanks Prasad
?
On Saturday, November 30, 2019, 01:26:09 AM EST, John Lindo <bechetboat@...> wrote:
Hi Charlie.
Oil and boot polish for steel parts.very much a similar process to gun bluing I think,?
Never owned a gun so maybe I am wrong.
There are some good You tube videos on homeshop colour aluminum anodizing with safe working practises.
Avoid the H2SO4 acid, nasty stuff to have around with pets and kids.I use it very rarely for picking off the scale after brazing.
If needs be, then use the acid diluted about 20:1, add the acid to the water, not the other way round, in a strong glass container.
During mixing the diluted acid gets very hot.
Please be careful.
--
John
|
Re: Arduino based DRO using cheap Calipers
#ARD
#DRO
Which part of the data manipulation are you querying? And in the
sketches you posted?
Richard
toggle quoted message
Show quoted text
On 30/11/2019 12:31, Chuck Pickering wrote: BTW, if anyone knows of a reference that explains the data
manipulation as used in these sketches, please let me know.
Chuck
|
Re: Arduino based DRO using cheap Calipers
#ARD
#DRO
BTW, if anyone knows of a reference that explains the data manipulation as used in these sketches, please let me know.
Chuck
|
Re: Arduino based DRO using cheap Calipers
#ARD
#DRO
I built a DRO-550 for my X2 mill. It works great. The mill was purchased second hand, and the previous owner had a DRO-550 on it. He kept the DRO, but left the scales installed. I built a new DRO-550 and hooked it up. I later added a tach pickup based on a Hall Effect switch.
You're right on the 24 bit protocol. I have a sketch that displays the raw data from the scale, and it shows the sign bit changing, as well as the data bits when switching from mm to inches.I'm playing with inputting a choice for units by way of the Arduino serial monitor, and then choosing which conversion formulae to use, but haven't got that working yet.
This project started several years ago, trying to get the HFscales to work with TouchDRO. I had it working then, but it was flaky because I wasn't level-shifting the data, and the caliper was powered by the battery. Now I have breadborded a logic shifter circuit, and a 1.5v regulator circuit using the Arduino's 5 v output. I lost or deleted the working sketch and Youriy's toys no longer supports the Arduino.
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Re: Arduino based DRO using cheap Calipers
#ARD
#DRO
Reading this I don't think I was really clear with this posting. Notice at the end of this web page link that the DRO is an open source project. That means if you want to be able to read different scales the code is there as an example.
I have had my DRO-350 and that it's worked so well that it has delayed my CNC conversion project.
John
toggle quoted message
Show quoted text
I have the DRO-350 and also a DRO-550 that I never did use.
John Dammeyer
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Re: Arduino based DRO using cheap Calipers
#ARD
#DRO
I have the DRO-350 and also a DRO-550 that I never did use.
John Dammeyer
toggle quoted message
Show quoted text
-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Richard
Sent: November-29-19 11:56 PM
To: [email protected]
Subject: Re: [digitalhobbyist] Arduino based DRO using cheap Calipers #ARD
#DRO
From what I have seen a scale will be read as 24bits ones compliment
therefore having 23bits of data plus a sign bit. It will typically have
a raw unit of measurement of 1/20480 of an inch. Having read the raw
value it would be displayed in inches by multiplying by 125/256 and for
millimetres by 127/1024. As the bit value equates to a probably very
noisy 0.000048828" it makes sense to lose some of the lower bits.
I intend having a play with some hardware and software.
Richard
On 29/11/2019 22:53, BuffaloJohn wrote:
Interesting to look at where all this came from, I found you code
matches another I found, and there were lots of other references.
It seems that your calipers use the chinese protocol. That protocol
does not have a bit that indicates units as far as I can tell from the
other sources, so unless you see something in the bits above the sign
bit, you would be better off picking mm or inches and doing the math.
If, per chance. you find something in the bits above the sign, and you
see that one of those bits change when you change units, you have
found the units bit.
Remember, most of these devices have +/- 0.001" accuracy. Some of the
calipers I found have 0.001" (0.025mm) listed, some say 0.001"
(0.03mm). In any case, the calipers are not accurate to LSB of the
readout, so a numeric conversion of units is fine:
Resolution
0.01mm = 0.00039"
0.0005" = 0.0127mm
Accuracy
accuracy 0.001" = 0.0254mm
Buffalo John
On Fri, Nov 29, 2019 at 11:22 AM Chuck Pickering <chunk07@...
<mailto:chunk07@...>> wrote:
I can't seem to get the two sketches combined to read the units
bit and calculate the measurement based on that bit. Here is the
two sketches that work, one for mm, one for in. Both depend on the
mm/in switch be set to the measurement unit you want displayed. Am
I missing something thinking I can do this? The only difference in
the two sketches is how it converts the data to inch or mm. I
think I might need to input the value of the units bit instead of
reading it from the data.
|
Re: Arduino based DRO using cheap Calipers
#ARD
#DRO
From what I have seen a scale will be read as 24bits ones compliment
therefore having 23bits of data plus a sign bit. It will typically have
a raw unit of measurement of 1/20480 of an inch. Having read the raw
value it would be displayed in inches by multiplying by 125/256 and for
millimetres by 127/1024. As the bit value equates to a probably very
noisy 0.000048828" it makes sense to lose some of the lower bits.
I intend having a play with some hardware and software.
Richard
toggle quoted message
Show quoted text
On 29/11/2019 22:53, BuffaloJohn wrote: Interesting to look at where all this came from, I found you code
matches another I found, and there were lots of other references.
It seems that your calipers use the chinese protocol. That protocol
does not have a bit that indicates units as far as I can tell from the
other sources, so unless you see something in the bits above the sign
bit, you would be better off picking mm or inches and doing the math.
If, per chance. you find something in the bits above the sign, and you
see that one of those bits change when you change units, you have
found the units bit.
Remember, most of these devices have +/- 0.001" accuracy. Some of the
calipers I found have 0.001" (0.025mm) listed, some say 0.001"
(0.03mm). In any case, the calipers are not accurate to LSB of the
readout, so a numeric conversion of units is fine:
Resolution
0.01mm = 0.00039"
0.0005" = 0.0127mm
Accuracy
accuracy 0.001" = 0.0254mm
Buffalo John
On Fri, Nov 29, 2019 at 11:22 AM Chuck Pickering <chunk07@...
<mailto:chunk07@...>> wrote:
I can't seem to get the two sketches combined to read the units
bit and calculate the measurement based on that bit. Here is the
two sketches that work, one for mm, one for in. Both depend on the
mm/in switch be set to the measurement unit you want displayed. Am
I missing something thinking I can do this? The only difference in
the two sketches is how it converts the data to inch or mm. I
think I might need to input the value of the units bit instead of
reading it from the data.
|
Re: Alternative to anodizing aluminum?
#MISC
Hi Charlie.
Oil and boot polish for steel parts.very much a similar process to gun bluing I think,?
Never owned a gun so maybe I am wrong.
There are some good You tube videos on homeshop colour aluminum anodizing with safe working practises.
Avoid the H2SO4 acid, nasty stuff to have around with pets and kids.I use it very rarely for picking off the scale after brazing.
If needs be, then use the acid diluted about 20:1, add the acid to the water, not the other way round, in a strong glass container.
During mixing the diluted acid gets very hot.
Please be careful.
--
John
|
#3D using wood impregnated filament. pt 1
#3D
Photo of a ER 20 collet tray as mentioned previously by members. The finish could of been better and but I just wanted to see the results of high feeds and 0.38mm steps per layer using a .4 mm dia nozzle.  Hope of interest. -- John
|
Re: Arduino based DRO using cheap Calipers
#ARD
#DRO
Interesting to look at where all this came from, I found you code matches another I found, and there were lots of other references.
It seems that your calipers use the chinese protocol. That protocol does not have a bit that indicates units as far as I can tell from the other sources, so unless you see something in the bits above the sign bit, you would be better off picking mm or inches and doing the math. If, per chance. you find something in the bits above the sign, and you see that one of those bits change when you change units, you have found the units bit.
Remember, most of these devices have +/- 0.001" accuracy. Some of the calipers I found have 0.001" (0.025mm) listed, some say 0.001" (0.03mm). In any case, the calipers are not accurate to LSB of the readout, so a numeric conversion of units is fine:
Resolution
0.01mm = 0.00039" 0.0005" = 0.0127mm
Accuracy
accuracy 0.001" = 0.0254mm
Buffalo John
On Fri, Nov 29, 2019 at 11:22 AM Chuck Pickering < chunk07@...> wrote: I can't seem to get the two sketches combined to read the units bit and calculate the measurement based on that bit. Here is the two sketches that work, one for mm, one for in. Both depend on the mm/in switch be set to the measurement unit you want displayed. Am I missing something thinking I can do this? The only difference in the two sketches is how it converts the data to inch or mm. I think I might need to input the value of the units bit instead of reading it from the data.
|
Re: Arduino based DRO using cheap Calipers
#ARD
#DRO
I can't seem to get the two sketches combined to read the units bit and calculate the measurement based on that bit. Here is the two sketches that work, one for mm, one for in. Both depend on the mm/in switch be set to the measurement unit you want displayed. Am I missing something thinking I can do this? The only difference in the two sketches is how it converts the data to inch or mm. I think I might need to input the value of the units bit instead of reading it from the data.
|
Re: Arduino based DRO using cheap Calipers
#ARD
#DRO
Yes, I understand that. I have a second sketch that does exactly that. I want to combine the two so depending on units mode the output is correct. I could add the in code you show as result 2 and display both...
If I remember correctly, TouchDRO just used the mm data and would calculate the units value.
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John Lindo
BuffaloJohn