38mm steel tube for US market

[colemanomartin]

In the US market 38mm square steel tube is standard. Is it possible to reduce the dimensions of the steel tube mounting points from 40x40mm to 38x38mm (by only moving each wall in by 1 mm) without altering the other mounting points for the carriages and ball screws? If so, a second set of STL files sized for mounting the Y and X rails would expand the reach of this project without significantly reworking the design.

[colemanomartin]

As I'm looking at this, decreasing to 38mm square tube will reduce the distance between the two halves of the carriage. By my calculation the distance decreases by 2.83mm. This changes the placement of half of the carriage mounting holes on the side panels and the Z axis wood panels. In theory, the upper or lower line of those carriage mounting holes could be changed to slots to accommodate for the two different widths of the carriages. Not sure how people would feel about that. It could make things a tiny bit less stiff. The other way to do it would be to change the mounting hole positions for the XY carriages and have s separate STL file for those pieces to be used by the 38mm people.

[RootCNC]

I think my preference would be to keep the side and front/ rear panels the same between the two configuration and have the 3D printed parts change in size. This should be easy to configure in the software.

[RootCNC]

The updates files can be tracked here - https://github.com/RootCNC/Root-4-CNC/tree/38mm-Dev

[RootCNC]

Here are the files I expect to be impacted by the change:

• X_Axis_Mount_FF
• X_Axis_Mount_FK
• Y_Axis_Mount_FF12
• Y_Axis_Mount_FK12
• XY_Carriage_Coach
• XY_Carriage

Please note - I have no plans of testing these parts, I will require some sort of feedback from the community :)

The files will be in the 38mm-Dev branch of the project until I have feedback on the parts.

[colemanomartin]

Thank you. I have a friend also starting a root 4. I'm sharing this with him. One of both of us should be able to test.

…

________________________________ From: Pete <notifications@github.com> Sent: Sunday, November 15, 2020 5:02 PM To: RootCNC/Root-4-CNC <Root-4-CNC@noreply.github.com> Cc: colemanomartin <colemanomartin@hotmail.com>; Author <author@noreply.github.com> Subject: Re: [RootCNC/Root-4-CNC] 38mm steel tube for US market (#2) Here are the files I expect to be impacted by the change: * X_Axis_Mount_FF * X_Axis_Mount_FK * Y_Axis_Mount_FF12 * Y_Axis_Mount_FK12 * XY_Carriage_Coach * XY_Carriage Please note - I have no plans of testing these parts, I will require some sort of feedback from the community :) The files will be in the 38mm-Dev branch of the project until I have feedback on the parts. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub<#2 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AJ7NBHNWMMM3LJHQCCXCH5DSQBMX5ANCNFSM4TFJWVPQ>.

[THUNDER351]

I only see 2 of the 6 part that you expected to change.

[RootCNC]

Please see the update - please can you give me feedback on these parts? once I know they work i'll move the out of the DEV folder

[RootCNC]

Link to the files are HERE

[THUNDER351]

I will get them printed soon. Been printing the other parts. I will let you know how they work. The first two parts you made the changes to worked on the 1-1/2" x 1-1/2" tube I plan to use. Thanks for get these parts made. I was watch a video on making changes to STL in Autodesk Inventor and going to give it a try this week.

[BayouBurner]

Printed the y-axis mounts and they are too tight to use. My stock is exactly 1.5"m(38.1mm) but the part is a bit under. Could be shrinkage? Printed metric versions and they fit fine, I may add a tape sleeve to perfect the fit but its fine as is.

[colemanomartin]

With what material did you print?

[BayouBurner]

Black PETG. I may be heading in the wrong direction, but I'm printing and using the std 40mm parts with 38.1 tube and its all fitting together fine. My biggest worry was the carriage sets fitting on the side plates and still being adjustable but it was perfect.
Same for Z panels, fit is great. There is some play in the y axis mounts, but I plan to use the hold down bolts to make the fine adjustments. Time will tell.

[RootCNC]

It might seem your printer isnt printing to scale perfectly?