Advanced Search

I'm also designed a mesa clone for a Raspberry Pi, currently in the process of testing everything.
Except for the reversed Sserial Pinout it looks like I got everything right.
You can take a look at my schematic for reference: github.com/jstjst/stmbl-fpga-master/blob...tmbl-fpga-master.pdf
Be careful the SPI In Out labels in the 7c81 schematic are reversed compared to the ucf file. Luckily I could fix that in the ucf file.
I routed some signals under the fpga, I see no problem with it. But try to have no completely hidden tracks so you can fix them if you got some connections wrong. In my opinion one of the more important things is the placement of the decoupling caps.

There are some pitfalls with the whole (fpga) programming (especially when using the Ethernet host interface). But with some reading through the forum I got everything pieced together, including recompiling mesaflash and linuxcnc. So it is totally doable (for reference, this is my first deep dive into linuxcnc and mesa/hostmot2, only used the RPi GPIO interface before, didn't use/own a mesa card).

Big thanks to Peter for providing the schematics and all the information that is on the forum!

Have you had any time to give a Dell OptiPlex 7050 a rub yet?
It would nice to get some feedback and recomendations regarding eventual tweaking :0)
Kind regards/Stefan

Can you reproduce this in one of the included simulation configs?
If yes then please provide a minimal gcode example (ie one that can actually be run when loaded) along with a clear description of when you are stopping the program and tell us what linuxcnc version you are using.
If you cannot reproduce this in a sim config then please also attach your zipped config folder.

As it is I cannot reproduce this on either 2.9 nor on master.

91 turns is possible very much so ,

this is just a simple small part so a complex job would very much be way over that turn number.

wrapping sounds right as number does a odd sign change in the feedback counts

Unfortunately not yet, but am looking to get this cataloged for others as I have completed quite a few 3d printed parts to help support the PM728VT machine to CNC.

As such this can help others move across more quickly.

I want to make sure there is a positive ending before releasing the build program, just to make sure others get to a realistic endpoint.

Currently using a laptop, and seems to be Ok. But may need to get a miniPC to run it all so just incrementally addressing each issue.

For the cross slide I oredered a 12mm ballscrew. If I can find room I will mount the ball nut under the cross slide table. If not, the screw I bought is long enough that I could mount the ballscrew on the back side of the cross slide table.

I'll be going out of town for a couple weeks, but when I get back I think I will do some examining for the encoder situation.

I saw a video of somone doing threading on linuxCNC using a missing tooth scheme. I may look into this more when I bored in my hotel room next week.

Thanks again for the comments
 

Leave them at default 5000 till you have everything working properly, then you can decide if you need to mess with timings. Usually there is no need.

www.aliexpress.us/item/3256805790238823.html

I am waiting for the manual from the seller, will add when i receive it.

 

No., unless you need a new component to provide the pins.
(which is not the case here)

If you are learning, I would definitely poke around a bit with halshow
(in axis it's: Machine --> Show Hal Configuration)

 

Greg,

Right now, you have a machine in good mechanical state. The only problem you have with this machine is the controller. My advice, do not remove or dismantle any component at this stage. 

1-Gather the manuals wiring diagrams and any information you can find. 

2-Study the servo drive CONTROL METHOD (analog, digital, industrial communication bus etc …) 

3- Study existing wiring diagrams and determine the number and type of IO’s (sourcing/sinking) 

4- study the type of controller you will need, the type of daughter boards needed and type of PC (pci/pcie/ethernet/Mitsubishi bus communication bus … etc 

5- Modify the existing wiring diagrams to reflect the changes required. Keep in mind that the machine was designed and assembled by highly skilled craftsmen, at this stage you will focus on keeping the modifications to existing components to a strict minimum. 

6- With all the above knowledge and mods you will be ready to configure the controller and choose GUI 


Note: machine integration requires patience especially if you have not done it before on a machine such as vmc. (Bounding, grounding, shielding can be nightmare, modifying the safety control system can become a liability and changing from sourcing/sinking io can be laborious, etc …), keep it simple stupid (KISS) is the answer to a successful project.

Thanks for your reply . Just curios if we need to loadrt something in hal before putting the new command.

Hi
G10 L20 P1 z0 doesnt work if the below program is stopped midway and rerun. Random z values come up and cut gets all wrong. Please guide as what is incorrect.
G10 L20 P1 x0 z0
G01 Z0.5
G01 Z-0.1 F5 ; cut here
G10 L20 P1  z0
Code here
M2

This very quickly is going to turn into a how to destroy some Fanuc encoders thread so stay tuned for that   

I've decided to replace the encoders... this is probably not the answer that future readers are going to want to read, but its the least expensive and most straight-forward approach I can come up with. Either I have a digital problem or a mechanical problem to solve, and the latter is much more manageable with my skill set. 

I'm trying to get better at knowing when to take a different path to the finish line. I once spent months trying to design a DC motor driver (90v 200amps) that ran on 600v 3phase for a Hardinge CHNC lathe based on open source electric vehicle schematics. Long story short, I didn't succeed and blew up a lot of expensive components along the way    Once I finally decided to swap the motor for an AC one and add a VFD, the whole thing was turning in in 2 days! 

More to come! 

timo wrote:

Unfortunately hollow shaft encoders are much more expensive than the required parts

 

One option might be an engine crank encoder:

Do not buy RPI5
www.youtube.com/shorts/qN-1nPGbS3I