Timing belt and critique drive concept please

[mbond]

The idea that Linux has fewer bugs than Windows is a myth. There is far more security research done to try to find bugs and security issues on Windows than on any other platform including Linux. And far more effort put into fixing them.

Having said that, Windows is not a very appropriate platform to run a CNC because of the way that the scheduler works.

 

[jcdammeyer]

LinuxCNC.

Free and works great. I love the way you can customize if desired. I'm not sure what other software lets you close the loop with linear scales?

My initial thought was that Linux would require a lot of specialized "Linux" knowledge but my experience is that it's actually a lot like Windows, without the; bloat, spyware and countless bugs and upgrades. It just works!

My old Mach setup even with backlash compensation was often out 0.002-0.003. No longer an issue.

I'm using the AXIS user interface. The QtDragon looks interesting but I'd have to get a larger monitor for it. I'm still running 2.8.1 with the MESA 7i92H. And now 2.9.3 has been released. Upgrades, regardless of Windows or Linux seem to be a never ending story.

I've also been playing around with the idea of using a Pi4 with the MESA 7i92H and a couple of cheap Break out Boards.

 

[slow-poke]

When I decided that I would go the LinuxCNC / Mesa route, I called Mesa and asked them them for recommendations for a PC. Fellow explained that people are using pretty much everything including little Raspberry Pi boards, however he recommended getting a used HP desktop (he listed a few models) as they are dirt cheap and readily available. He stated that these had proven low latency and good video support. Quick look on Kijiji / Marketplace and found several available around $50-100, so that's what I'm using.

I would have to look at my notes but IIRC I have had that PC and Linux up and running for about a year and no updates that I'm aware of. Initially I was going to treat this machine as an island ( that's what I did with my old Windows machine running Mach for my old mill because I was paranoid Windows would randomly decide to upgrade the OS and break what was working). The strategy worked but was inconvenient.

Fast forward to the new system and decided to connect that PC to the outside world via a plugin USB-WiFi dongle so an island until I plug in the dongle. Handy because I can access the LinuxCNC forum for help directly from that PC, and easy to share screen snapshots, copy/paste configuration files etc. I think when you add up all the little extras required for the PI route (power supply, enclosure), its hard to complete with the $50 used PC route. IIRC the HP I'm using has 8 USB ports and they sure come in handy.

I enjoy having the ability to customize even if that requires tweaking HAL files. That being said for those that get nervous opening a Windows CMD prompt then some canned Windows software might be a better choice.

 

[jcdammeyer]

When I decided that I would go the LinuxCNC / Mesa route, I called Mesa and asked them them for recommendations for a PC. Fellow explained that people are using pretty much everything including little Raspberry Pi boards, however he recommended getting a used HP desktop (he listed a few models) as they are dirt cheap and readily available. He stated that these had proven low latency and good video support. Quick look on Kijiji / Marketplace and found several available around $50-100, so that's what I'm using.

I would have to look at my notes but IIRC I have had that PC and Linux up and running for about a year and no updates that I'm aware of. Initially I was going to treat this machine as an island ( that's what I did with my old Windows machine running Mach for my old mill because I was paranoid Windows would randomly decide to upgrade the OS and break what was working). The strategy worked but was inconvenient.

Fast forward to the new system and decided to connect that PC to the outside world via a plugin USB-WiFi dongle so an island until I plug in the dongle. Handy because I can access the LinuxCNC forum for help directly from that PC, and easy to share screen snapshots, copy/paste configuration files etc. I think when you add up all the little extras required for the PI route (power supply, enclosure), its hard to complete with the $50 used PC route. IIRC the HP I'm using has 8 USB ports and they sure come in handy.

I enjoy having the ability to customize even if that requires tweaking HAL files. That being said for those that get nervous opening a Windows CMD prompt then some canned Windows software might be a better choice.

Totally get that. I have a Lenovo PC (and a spare) bought for about $50 from BC Government Surplus. I like the Pi approach maybe for my CNC router rather than the mill. The MACH system for it is getting a little long on the tooth and I have the second MESA board.

Here's the LCD Touch Screen I bought for this package. This time with the CANUSB which talks to tool changer and other stuff. Python Software to gather the CANOpen protocol messages and do things with them. Currently, this is just a lab bench play toy.

 

[slow-poke]

I agree a Pi is very appealing for something like a router or any smallish machine. It sure is nice to have options. For us "techies" it's like living in a candy store.

 

[jcdammeyer]

I agree a Pi is very appealing for something like a router or any smallish machine. It sure is nice to have options. For us "techies" it's like living in a candy store.

The touch screen was a foolish and relatively expensive purchase. May end up using it for a Home Assistant type application instead. Here's what it looks like from behind.
Display controller, Pi4, Touch Screen interface. The short HDMI cable that came with it was a POS so I subbed in a better one even though it's way longer than it needs to be. Normally the Yellow Network cable goes to the MESA board.

From the front it almost looks usable other than the printing on the 1920x1080 screen is really tiny for my eyesight. The BlueTooth Logitech Mouse/Keyboard combo is really nice.

 

[slow-poke]

On my to-do list is to find a better monitor for the mill. I used an old Acer that was laying around measured as 18" diagonal actual screen area. Size is about right, but the image quality is not. Perhaps it's just a really cheap display, or maybe it's old' either way the contrast is just not sharp at all.

 

[jcdammeyer]

Ah. Also the default AXIS user interface.
If, from the command line you do an 'lscpu' command you will see something like this:
[FONT=courier new]Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 2 On-line CPU(s) list: 0,1 Thread(s) per core: 1 Core(s) per socket: 2 Socket(s): 1 NUMA node(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 15 Model name: Intel(R) Core(TM)2 Duo CPU E6550 @ 2.33GHz Stepping: 11 CPU MHz: 2000.000 CPU max MHz: 2333.0000 CPU min MHz: 2000.0000 BogoMIPS: 4655.22 Virtualization: VT-x L1d cache: 32K L1i cache: 32K L2 cache: 4096K NUMA node0 CPU(s): 0,1 Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl aperfmperf pni dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm lahf_lm kaiser tpr_shadow vnmi flexpriority dtherm[/FONT]
I've asked Andy Pugh on the LinuxCNC forum whether it's capable of running 2.9.3 and how easy to update from 2.8.1. I'm also running a smaller screen (1280x1024) and at times it would be nice to have it 1920x1080. Especially since I like the QtDragon screen.

 

[jcdammeyer]

Here's the Pi4 screen showing Axis and the panel on the left. It shows information from a CAN bus module that will control the mist motor and tool changer.

My son had an old HDMI monitor that has a vertical line running through the middle but for fun I connected it to my mill system.
The PSNG screen for the touch probe no longer covers the panel on the right so I don't have to switch it off every time I want to probe.

The PYVCP panel on the right can be customized to have extra buttons gauges etc. But man is that monitor big compared to what I'm used to using.

 

[slow-poke]

Well two minutes of display technology research yielded the following. Displays generally use one of three technologies:
TN: Fast, but poor colour quality and contrast, best for gaming.
IPS: Good colour quality, slow with poor contrast.
VA: Best contrast, not fast.

So for this application I need a VA type monitor. It's on its way.....

https://www.amazon.ca/dp/B086XMFNW6?psc=1&ref=ppx_yo2ov_dt_b_product_details

Hopefully it will make a noticeable improvement.

 

[jcdammeyer]

Well two minutes of display technology research yielded the following. Displays generally use one of three technologies:
TN: Fast, but poor colour quality and contrast, best for gaming.
IPS: Good colour quality, slow with poor contrast.
VA: Best contrast, not fast.

So for this application I need a VA type monitor. It's on its way.....

https://www.amazon.ca/dp/B086XMFNW6?psc=1&ref=ppx_yo2ov_dt_b_product_details

Hopefully it will make a noticeable improvement.

This is the other Monitor my son had. It doesn't appear to have much wrong with it although viewing angle is still not great. The screen is very bright. Don't really like it.

VS247H-P | Monitors | ASUS Canada

www.asus.com

https://www.amazon.ca/ASUS-VS247H-P-23-6-1920x1080-Monitor/dp/B005BZNDS0?th=1

Looking forward to your report on the 1366x768p size.

 

[slow-poke]

This is the other Monitor my son had. It doesn't appear to have much wrong with it although viewing angle is still not great. The screen is very bright. Don't really like it.

VS247H-P | Monitors | ASUS Canada

www.asus.com

https://www.amazon.ca/ASUS-VS247H-P-23-6-1920x1080-Monitor/dp/B005BZNDS0?th=1

Looking forward to your report on the 1366x768p size.

It would be nice if the display manufacturers would advertise the technology being used, seems they use the bullet points to advertise what the monitor does well, "Fast", "brilliant colors" and leaving out "lousy text contrast"

According to ChatGPT...
The ASUS VS247H-P monitor uses TN (Twisted Nematic) technology. TN panels are known for their fast response times and lower cost compared to IPS (In-Plane Switching) and VA (Vertical Alignment) panels, but they typically have poorer color accuracy and viewing angles.

The Viewsonic VA1903h monitor uses VA (Vertical Alignment) technology. VA panels are known for offering better color reproduction and viewing angles compared to TN (Twisted Nematic) panels, though they typically have slightly slower response times than TN panels.

Technology comparison:

TN (Twisted Nematic), IPS (In-Plane Switching), and VA (Vertical Alignment) are three common types of monitor panel technologies, each with its own strengths and weaknesses. Here’s a breakdown of the most important aspects for each:

TN (Twisted Nematic)​

Strengths:

1. Response Time: TN panels typically have very fast response times (1ms or less), making them excellent for fast-paced gaming and reducing motion blur.
2. Cost: TN panels are generally the most affordable among the three types, making them accessible for budget-conscious consumers.
3. Refresh Rates: They often support high refresh rates (e.g., 144Hz, 240Hz), which is beneficial for gaming and smooth motion.

Weaknesses:

1. Color Reproduction: TN panels generally have poorer color accuracy and narrower viewing angles compared to IPS and VA panels.
2. Viewing Angles: Colors and contrast can degrade when viewed from off-angles, making them less suitable for tasks where multiple people view the screen simultaneously.
3. Contrast Ratio: TN panels typically have lower contrast ratios compared to IPS and VA panels, resulting in less vivid blacks and whites.

IPS (In-Plane Switching)​

Strengths:

1. Color Accuracy and Consistency: IPS panels offer superior color reproduction and consistency across wide viewing angles, making them ideal for professional work that requires accurate color representation.
2. Viewing Angles: They have excellent viewing angles with minimal color shift when viewed from the side.
3. Contrast: IPS panels generally have better contrast ratios compared to TN panels, resulting in better black levels and overall image depth.

Weaknesses:

1. Response Time: Historically, IPS panels have had slower response times compared to TN panels, although this gap has narrowed with advancements.
2. Cost: IPS panels tend to be more expensive than TN panels, which can be a consideration for budget-conscious buyers.
3. Motion Blur: While improving, IPS panels may still exhibit slightly more motion blur compared to TN panels, making them less ideal for extremely fast gaming.

VA (Vertical Alignment)​

Strengths:

1. Contrast Ratio: VA panels typically have the highest native contrast ratios among the three types, resulting in deep blacks and bright whites, which is advantageous for movies and content consumption.
2. Response Time: VA panels generally have better response times than IPS panels, though not as fast as TN panels, making them a good compromise for gaming and multimedia.
3. Cost: They are often more affordable than IPS panels while offering better contrast and color reproduction than TN panels.

Weaknesses:

1. Color Accuracy: While improving, VA panels can sometimes have issues with color accuracy and uniformity, especially in darker shades.
2. Viewing Angles: Viewing angles are generally better than TN panels but not as wide as IPS panels, with some color shifting when viewed from extreme angles.
3. Ghosting: VA panels may exhibit ghosting effects in fast-moving scenes, which can be a drawback for competitive gaming.

Summary​

• TN: Fast response times and high refresh rates, but poorer color accuracy and narrower viewing angles.
• IPS: Excellent color accuracy and wide viewing angles, but historically slower response times and higher cost.
• VA: High contrast ratios and better response times than IPS (though not as fast as TN), but potential issues with color accuracy and viewing angles.

Choosing the right monitor depends on your specific needs, whether it’s gaming, professional design work, or multimedia consumption. Each technology has its trade-offs, so consider what factors (like response time, color accuracy, viewing angles, and cost) are most important to you when making a decision.
============================================================================================================================


The issue with my existing monitor is text clarity especially with text as shades of grey on white background. Supposedly this is where VA technology shines at the expense of speed, and speed is not important for the LinuxCNC GUI. Can't wait to try it. I will let you know how it goes.

 

[jcdammeyer]

It would be nice if the display manufacturers would advertise the technology being used, seems they use the bullet points to advertise what the monitor does well, "Fast", "brilliant colors" and leaving out "lousy text contrast"

According to ChatGPT...
The ASUS VS247H-P monitor uses TN (Twisted Nematic) technology. TN panels are known for their fast response times and lower cost compared to IPS (In-Plane Switching) and VA (Vertical Alignment) panels, but they typically have poorer color accuracy and viewing angles.

The Viewsonic VA1903h monitor uses VA (Vertical Alignment) technology. VA panels are known for offering better color reproduction and viewing angles compared to TN (Twisted Nematic) panels, though they typically have slightly slower response times than TN panels.

Technology comparison:

TN (Twisted Nematic), IPS (In-Plane Switching), and VA (Vertical Alignment) are three common types of monitor panel technologies, each with its own strengths and weaknesses. Here’s a breakdown of the most important aspects for each:

TN (Twisted Nematic)​

Strengths:

1. Response Time: TN panels typically have very fast response times (1ms or less), making them excellent for fast-paced gaming and reducing motion blur.
2. Cost: TN panels are generally the most affordable among the three types, making them accessible for budget-conscious consumers.
3. Refresh Rates: They often support high refresh rates (e.g., 144Hz, 240Hz), which is beneficial for gaming and smooth motion.

Weaknesses:

1. Color Reproduction: TN panels generally have poorer color accuracy and narrower viewing angles compared to IPS and VA panels.
2. Viewing Angles: Colors and contrast can degrade when viewed from off-angles, making them less suitable for tasks where multiple people view the screen simultaneously.
3. Contrast Ratio: TN panels typically have lower contrast ratios compared to IPS and VA panels, resulting in less vivid blacks and whites.

IPS (In-Plane Switching)​

Strengths:

1. Color Accuracy and Consistency: IPS panels offer superior color reproduction and consistency across wide viewing angles, making them ideal for professional work that requires accurate color representation.
2. Viewing Angles: They have excellent viewing angles with minimal color shift when viewed from the side.
3. Contrast: IPS panels generally have better contrast ratios compared to TN panels, resulting in better black levels and overall image depth.

Weaknesses:

1. Response Time: Historically, IPS panels have had slower response times compared to TN panels, although this gap has narrowed with advancements.
2. Cost: IPS panels tend to be more expensive than TN panels, which can be a consideration for budget-conscious buyers.
3. Motion Blur: While improving, IPS panels may still exhibit slightly more motion blur compared to TN panels, making them less ideal for extremely fast gaming.

VA (Vertical Alignment)​

Strengths:

1. Contrast Ratio: VA panels typically have the highest native contrast ratios among the three types, resulting in deep blacks and bright whites, which is advantageous for movies and content consumption.
2. Response Time: VA panels generally have better response times than IPS panels, though not as fast as TN panels, making them a good compromise for gaming and multimedia.
3. Cost: They are often more affordable than IPS panels while offering better contrast and color reproduction than TN panels.

Weaknesses:

1. Color Accuracy: While improving, VA panels can sometimes have issues with color accuracy and uniformity, especially in darker shades.
2. Viewing Angles: Viewing angles are generally better than TN panels but not as wide as IPS panels, with some color shifting when viewed from extreme angles.
3. Ghosting: VA panels may exhibit ghosting effects in fast-moving scenes, which can be a drawback for competitive gaming.

Summary​

• TN: Fast response times and high refresh rates, but poorer color accuracy and narrower viewing angles.
• IPS: Excellent color accuracy and wide viewing angles, but historically slower response times and higher cost.
• VA: High contrast ratios and better response times than IPS (though not as fast as TN), but potential issues with color accuracy and viewing angles.

Choosing the right monitor depends on your specific needs, whether it’s gaming, professional design work, or multimedia consumption. Each technology has its trade-offs, so consider what factors (like response time, color accuracy, viewing angles, and cost) are most important to you when making a decision.
============================================================================================================================


The issue with my existing monitor is text clarity especially with text as shades of grey on white background. Supposedly this is where VA technology shines at the expense of speed, and speed is not important for the LinuxCNC GUI. Can't wait to try it. I will let you know how it goes.

Thanks for posting that. Great information. Didn't know all that.

 

[slow-poke]

Update:

The VA technology Viewsonic (pretty cheap), definitely does a better job of displaying text than my old Acer that uses TN technology. Nothing like the three larger displays I use for my PC, but still a big improvement from the Acer that I was using. The original Acer display has a really poor viewing angle, just dipping or extending my knee a bit would dramatically change the clarity of text.

JC, I just learned a little Axis shortcut, Ctrl-Spacebar clears all error messages, no more hunting and pecking with the mouse.