A few design changes

[Chuckles182]

Hi I'm super excited about this project! While waiting for parts to come in from AliExpress I decided to change a few models to use parts from my old Ender 3. One thing led to another and I've made quite a few changes. I am still waiting on my control board and have never used RepRap Firmware before, so I have no idea how my changes will work.

Screen shot of printer in Fusion

Base Frame Support
Added a little more support to help lock things in. I also have the vertical 20x40 extrusion on top of the horizontal 20x40 extrusion so I could use Ender 3 threaded rod and extrusions.

X Axis motor and pulley/idler assembly
I changed the way the idlers and motors are mounted, now a single M3x40 holds the F695 2rs idlers and the stepper motors. I think it makes assembly a little easier. The angled piece is one solid unit.

X B Cable Relief
I need to add slots for zip ties to go through, and cables...

X B Motor mounts
I changed quite a few things with these. I adapted the threaded rod screw to fit the one from an Ender 3. I Added atachment points on the outside to use heat set inserts instead of M3x40 as they're harder to source. This let me make the walls a little thinner for heat management and print times. I added a honeycomb pattern for airflow and cause it looks cool. On the rear cover, there is a spot for a cable relief mount, the right hole accepts a M3x40 for additional support.

Z Axis Motor Mount
I changed this to be able to use the threaded rod and coupler from an Ender 3.

Z Stop
I made and printed two of these, originally the top one butted up against the Z motor mount to use as a reference point. They help assure that both linear rails are parallel with each other.

X B Belt Tensioner
I remixed a Ender 3 X axis tensioner design from Printables. This uses the Ender 3 idlers so I think belt clearance shouldn't be an issue.
https://www.printables.com/model/1137828-4-axis-x-axis-tensioner

Wow! That was a lot more than I had anticipated! I'm still modifying the B Axis and hot end mount so it can use a Phateaus hot end I have from previous build and an orbiter v2 extruder set up to use a bowden tube. I'm still debating on what I want to use as a print bed. I found some on Amazon, combined with a slip ring I think a heated print bed would be possible. If there's interest I can work on uploading .3mf and .STEP, but I wanted to wait till I was done with all my plans.
Oh yeah and I have to actually wire it up and get it moving! That is what I am most concerned about, as I am much stronger in modeling than I am in software/firmware.
Let me know what you think! Thanks!

[TheOnlyMann]

this was made from all Ender 3 V3? thats awesome.

[jyjblrd]

That's incredible, would happily accept some contributions to this repository when you're happy with your design. Feel free to post on here if you need help with the wiring / configuration stuff

[xobes]

This is looking nice. I can't wait to swap out some parts for your designs. :-)

[Chuckles182]

They are 20t pulleys.

[TheOnlyMann]

interesting, been making up the BOM list so wanted to know

[Phizy99]

@TheOnlyMann Have you found all the necessary parts for the BOM list you said you were making? If so, could you share the list with me? It would be incredibly helpful and time-saving for my build.

Thanks

[TheOnlyMann]

my search has mostly been finished, however it is based on SEA(specifically, South Korea)- as such some of it would be outdated on your end.
However, currently in pursuit of making said BOM accessible all around the world, I'd be glad to take some help from others.

My search also has some undocumented changes such as looking at 5015 fans for replacement of the air pump, etc, however most things should be in their "proper" names.
Hope it helps.
I'll link the BOM later, or visit my fork to see the stuff.

[TheOnlyMann]

@Phizy99 here is what i will settle with, however note that some of this is not optimal- i have replaced most of the lsting with more trustworthy vendors, or found my own replacements.
https://github.com/TheOnlyMann/Core-R-Theta-4-Axis-Printer/blob/main/markdown%20files/BOM.md

[ehegenberger]

Looking forward to putting on these extra parts!
I had my first order for my new 3D print farm (OK, more like a herb garden at this point) this week, so I've been busy with that, but my last linear rail finally arrived, can hardly wait to see it in action!

[TheOnlyMann]

Improving Durability Section

now that @Chuckles182 has made changes to use F695 bearings for replacing the easy to break idlers.
Similarly, would it be better to replace the small mr85 bearings with 625 bearings(5mm ID, 16mm OD) or 605 bearings(5mm ID, 14mm OD) for increased bearing longjevity? this could also thin the walls enough that it might break, so i'm not entirely sure.

[xobes]

I've taken some inspiration from these ideas that @Chuckles182 provided, including the awesome hex pattern, and over the last couple weeks, between life, I modelled some updates. I want to test them out, but they are all available on my fork as FreeCAD files here:

https://github.com/xobes/4-Axis-Polar-3D-Printer/tree/beefy

e,g,:

Not tested, but the idea I was going for was to simplify the box design (haha, simplify, with all those patterns) so that each panel can be printed individually, and everything tied together with screws (size TBD, 10mm plus given the nut location).

Oh! Another change I added in my design was to make it so that the entire cage is't being held up my the screw threads of the threaded rod "T8*8 Lead Screw Nut" ...

[jyjblrd]

Looks great! I love seeing people's takes on my design.

One thing I would note: the "box" structure that encloses the X/B axis motors is actually quite structurally important. It needs to be rigid, as it connects the front and back Z axis linear rails. That's one of the reasons my design only used two pieces for the box and has long screws going through the part. So I would test to make sure it is stiff enough.

[xobes]

Yeah, and changes could be made to further allow for some protrusions into the box to sturdy up the corners if necessary; However, it seems pretty sturdy upon first impression:

| | |
|P.S. Connect the wires before you assemble this cage.| |

Here's a close-up of my broken original (I must have some really crappy PLA because I keep breaking stuff and I haven't even assembled everything yet 🤦‍♂️, this got me thinking further about the Lead Screw Nut holding up the entire printer via just the two screws.

I need to re-print a variation of the pulley supports that offers a little offset for the bearings in the timing pulley, as the current combination of timing pulleys and plastic parts allows has a bit too much friction (pulley is wider than bearing).

[Chuckles182]

I like moving the lead screw nut to be more supported by the frame. My X/B arm has been holding in place for a few weeks now, but it'd probably be better to have more support. Your approach to the motor carriage is pretty clever too (more honeycomb is always cool), but I'm with @jyjblrd I wonder how stiff it'll be. Since you've already hade some parts break and now there a lot of spots for a nut/bolt to break through a wall.
I have one more wire to make for the end stop switch and power cables. After that I'll be able to power it up!
Planning on adding newer photos this weekend along with making a fork with all my print files and a write up if I'm feeling really motivated.

[xobes]

I don't know how to prove that it's stiff. Hurt my hands to try and deform the cube 😛

[TheOnlyMann]

the new design would also enable you to install a anti backlash nut if you wanted to, hm. very interesting!

[the-Geeson]

have you put these up for download yet Chuck, I cant see any of these on your fork, but then again I might be blind

[Chuckles182]

I have put a few on printables. You are not blind, I just do not know how to put files on my fork. Nor did I know I even had a fork. I got distracted and discouraged from this project. I’ll figure it out!

[the-Geeson]

ah, cool. I only really want the base frame support bracket (reddish brown print). as Ive got some wobble in the upright and I think this will slove it. Im also doing an [ender3 conversion] (#40 (comment))