Let's all make the HEAVY (and V1) better without blowing the budget. What are the weak points in the design. Ok, I start.

1. each Y-Axis has only 2x V-Slot profiles. Maybe bump it up to 4x. More stable and more importantly, you can double the Roller count to 8x. The current situation with only 4x Rollers is bad - the Rollers will wear out quickly.

2. Consider using eccentric nuts to adjustment the Roller preassure

3. There are no axial bearings on the feed axes. The motor bearings are under too much pressure and will quickly fail.

Huuum a topic already exist with same subject, Here was the main answers :

1 - Many maker and me never got any problem after many hours using the CNC, my roller still really good. 8x roller is overkill because all constraints will still on 2 roller on extremity. Or you will need to have extrem counter force to see any difference with 8x rollers, but with a extrem condition like that, your 3D Printed parts will break or your motors will loose steps before your roller drift out ^^
2 - You dont need eccentric nut because you firmly press roller against aluminum rail when screwing both parts together, and eccentric nut tend to move with all machining vibrations
3 - I didnt notice any fail with my motors, even less with the Nema23

Did you made on of the V1 or the Heavy ?
I think you need to got one to see real problems of the machine. You will see that eccentric nut or 8x roller are useless ^^

The main problem today is the 2x Y axis rails, they are a bit to weaks and got some (very small) rigidity issues.

I will probably design Y axis feets with a C shaped rails like on X axis.

I notice this problem with the Nema23 version, Nema17 does not have the power to put Y axis in rigidity issue

Thanks. You probably know better  ;)

Although I still think it would be nice - given the low cost - to integrate into the printed parts some axial bearings on the feed axes.

Also, how about adding endstop-switches? Maybe integrate them with the printed parts or the aluminium profile so its easier to install them?

What is your experience with using T8 Lead Screws? I hear they have precision problems. Does it make sense to spend extra for ball screws?

P.S.:

It would be nice if you made just long videos (no editing, real sound and unlisted on Youtube just for the forum) of:

1. the machine doing work so one sees it more in action, how precise it is and much more.

2. just slow pan-overs of the machine and the electronic so one can see in detail how many small things are put together, etc. (there are many beginners out there like me)

I had thought that the Y axis rails were a little thin compared to the rest of the heavy so I have used 2 x 4040 rails each side of the type Ooznest supply.  They are based on the 2020 format.   I redesigned the feet and am going to fix them to 4040 cross rails then some longitudinal rails to support the bed.  Here are   My feet!

@shoe: I think the videos @Topsie has made, are absolutely fenomenous. If you need to see how the small things are put together, YouTube has a feature to slow down the video, in the case you need.

I'm also a beginner, but we need some "dificulties" to grow and learn more.

BTW, @Topsie is alone and has a lot of work in maintaining all the things. The videos editing, reply to each other in different manners (YouTube, site, forum, social networks...), making tutorials, designs,...

I think he is already at 200% to serve us the best he can. This is volunteer work, he has also professional and personal duties behind this project.

If you need any help, we are a growing community in the forum, and can help you in the dificulties you may encounter. ;)

But this is my personal opinion, let's looking for @Topsie opinion.

@Andme: your link is not working, it asks for an authorization. Can you make a new topic on 3D Design and share it there? It's more easy for you to track our thoughts and problems with it. Thanks ;)

I meant to say that the 4040 gives double wheels top and bottom.  4 per side, a total of 8.  I am not sure it is worth going to more than that unless the middle ones are supported independently or the axles substantially thicker as any slight bowing in the axle due to a small amount of preload on the wheels will allow the centre wheel to cease to have any meaningful contact.  This is the case with the existing 3 wheels on one axis.

@DavidC: I just meant he should put a static camera up if he does some CNC and upload it unedited (and unlisted on Youtube to post the links here). Maybe he does such videos anyways and doesn't upload them ;)

Also in the long run he saves work with answering questions. I just want to help. This is no criticism but merely suggestions :D

@Andme: I was also planning to do a "bed rectangle" made out of 2040s or 4040s. I move my CNC in the cellar and quickly move it outside to avoid dust and get proper air and light. I planned to make the "bed rectangle" easily disassembled from the rest of the CNC. This makes the CNC easiert to carry. For that the "bed rectangle" has to be quickly fixed to the CNC...any ideas? Are there V-Slot quick-clamps or something?

How does your bed-design look like?

> 3 - I didnt notice any fail with my motors, even less with the Nema23

@Topsie: from my experience the problem is not with the motor. But if you don't do proper feed axis support, you will lose torque without knowing it (due to forces that now have to be overcome by the motor and would otherwise be catched by the feed axis support). Especially low-torque motors like Nema 17 have a problem there. In the end a 65Ncm Nema 17 behaved in my case more like a 45Ncm motor.

In what direction do the Y-Axis have rigidity issues? Maybe you could fix it with a B-Profile frame on which you mount your CNC? A B-Profile frame is really genious if you want to use it to fix your work-piece. You can have 2x moveable (running on the frame) 2020 profiles inside the frame with which can clamp rectangle work pieces and add further clampes to the 2020s.

I forgot: endstop-switches are a great idea. Kind of dangerous without them. So far I just fixed them badly to the CNC. Does anybody have modified STLs that already have a "place" for the endstop-switches?

Hello All, I'm printing all the parts now, I will gladly add some STLs for end stops once I get it all together.