DIY high soulder CNC with cad model.

More
24 Jun 2021 16:15 #212834 by oficinerobotica
@tommylight you are a hero. Now that you pointed that out it seems so obvious. I just assumed that tandem is just another way of saying generate the same steps on two motors( well it is but it also seems to be allot more)

Having a self squaring gantry and limit switches is definitely on the wish list amd they will happen but atm I'm learning so one step at the time.
Thank you again.
The following user(s) said Thank You: tommylight

Please Log in or Create an account to join the conversation.

More
24 Jun 2021 19:08 #212843 by oficinerobotica
@Clive S neat. Thank you. Limit switches will definitely happen. Bookmarking your reply. I just hope that I have enough inputs on the 7i96. I need to wire in the closed loop steppers alarms as eStop also.
Thank you again

Please Log in or Create an account to join the conversation.

More
27 Jun 2021 16:35 #213029 by oficinerobotica
I finally managed to move on the Y axis by setting a negative home position of -700mm in PncConf. The 2 motors work together only if they are set up as tandem. For some reason, setting up 2 outputs for the same axis on the 7i96 will not work. I can see the leds on the drivers activating both at the same time when doing an axis test but when I try to move the gantry only one motor is driven. It seems that, if i set 2 outputs for the same axis, for a brief moment the drivers are both activated but when actively triyng to move only one motor is receiving step signals.
Anyway, I was able to move it using the tandem option but man....that lead screw curvature is BAAAD.


Now I need the experts advice, is it a bad idea to have different pitch ball screws on X and Y axis? My reasoning is this. I have 2x3Nm motors on the Y and one 3Nm motor on the X. Beacause the Y needs 1000mm lead screws I was thinking about 1610 for reduced whip and 1605 on the X for a bit more torque. What do you guys think? I know that I might hit a linear velocity ceiling but then again these motors seem to behave well even at high velocity.
Any suggestions?

Please Log in or Create an account to join the conversation.

More
29 Jun 2021 21:09 #213271 by andypugh

Now I need the experts advice, is it a bad idea to have different pitch ball screws on X and Y axis? 

It's not a problem. 

My lathe has 5mm pitch on the Z and 5.08mm pitch on X. (maybe not a good example, but the point is that it mixes imperial and metric, and it's no problem) 

 
The following user(s) said Thank You: oficinerobotica

Please Log in or Create an account to join the conversation.

More
01 May 2022 02:06 - 01 May 2022 02:08 #241760 by oficinerobotica
My day work and the general situation have kept me away from this project for quite some time now but I have finally made some progress.
Here is a quick test of the Z axis in motion.



I also made a tut of the modelling process in FreeCAD hoping it might help someone.

Last edit: 01 May 2022 02:08 by oficinerobotica.
The following user(s) said Thank You: tommylight, robertspark

Please Log in or Create an account to join the conversation.

More
01 May 2022 08:54 #241776 by tommylight
I have been watching your FreeCAD videos lately ! :)
Very nice, thank you.
The following user(s) said Thank You: oficinerobotica

Please Log in or Create an account to join the conversation.

More
05 May 2022 06:42 #242023 by oficinerobotica
Not much to be shown but here it is.
I had to machine the ball nut holder in order for it to fit between the Z axis linear bearings. Now I will need to drill the corresponding holes on the plate.
 

I made, welded and drilled/tapped the support lip for the bottom of the Z axis. This has 6 screws that will keep it in place
 
 

 
And finally the first coat of paint
 
 

 
Attachments:

Please Log in or Create an account to join the conversation.

More
05 May 2022 09:21 #242025 by robertspark
Question about freecad.... how do you get it to look for Fusion 360 ish?

Where all the components or assembly items are on the LHS and overlaid over the model and not in a seperate menu box?

Please Log in or Create an account to join the conversation.

More
05 May 2022 09:35 - 05 May 2022 09:36 #242026 by oficinerobotica
@robertspark
To get the same result is a bit of a rabbit hole but highly worth it imo.

First you need FreeCAD LinkStage3 dev branch from here github.com/realthunder/FreeCAD_assembly3/releases

This FC branch has a substantial amount of improvements from the interface to the modelling tools but the highlight would be a improved TopoNaming algorithm (Freecad's Achilles heel)

Follow this guide after you installed FreeCAD LinkStage3


Hope this helps :)
Last edit: 05 May 2022 09:36 by oficinerobotica.
The following user(s) said Thank You: tommylight, robertspark

Please Log in or Create an account to join the conversation.

More
05 May 2022 09:59 #242028 by robertspark
Thanks very much for the tip and direction, off to learn.

It's a much nicer user interface

Please Log in or Create an account to join the conversation.

Moderators: cncbasher
Time to create page: 0.371 seconds
Powered by Kunena Forum