OpenBuilds Style Build

[WoodKnot]

Are all your profiles 40x80? I tried to catch up a bit and went back in history to try to figure out what you actually bought for parts, but to be honest, I failed. I don't know which parts you bought, or if you just bought a drawing or a complete kit with some modifications of your own. Somewhere else you posted a link to this machine from cnc4you:



Is this similar to yours? Now, I have no idea about the dimensions here, but it looks like mostly 4x120. As you can see, the BK/BF of the X screw is placed over one groove, the picture shows clearly that the BK/BF is fixed through drilled holes in the extrusion between the grooves. That is also possible to do as a solution, but if you have only 40x80 all the way then you have bigger issues. Anyway, it is not clear to me at this stage what you actually bought, how the parts are meant to be installed or what the actual problem is, other than the fact that the BF/BF won't fit into the grooves. In any case, if 45x90 is not working, perhaps 40x120 would work. It adds some costs, but surely, not nearly as much as £800 because I am pretty sure you could save and use most of the stuff, depending on the design. Never the less, it would be a good idea if you posted some pictures, it would help a lot in the discussions. Anyway, if you buy new extrusions I can recommend you buy it from DOLD Mechatronic. They have good prices and fast delivery. Some extrusions won't cost you an arm and a leg, and you can easily cut them in your workshop.

I think that the 20 rails are MUCH better than 12, which in my opinion is only suitable for 3D printers, so in my opinion that's a good choice. I also think that using a smaller than 1605 screw is not a very good thing. 1204 may work, but not on such large machine. I am using 1204 on one of my 3D printers. 8 mm ACME is a joke for this sort of thing, it is suitable for 3D printers, but not a large CNC.

If I were you I'd try to make something out of the parts you have, even if in the end it will take longer time. What's been said several times and in several forms is that you must make as a minimum, some sort of plan on how you want the machine to look like. If you do that in a CAD software, that's fine, but it is my understanding that you don't want to do that, so the absolute minimum is to take a piece of paper and a pencil and start sketching, measuring and making drawings. I think Jazz misunderstood my comments, because it sounds like he thinks I am against using software, which I am not. In fact, I do use several, but not for machine design and machine assembly simulation. Even though I am not using any machine modelling software, the mistakes you made would never happen to me, not because of CAD or no CAD, but because I do read specifications, look at technical and mechanical drawings, check dimensions, make sketches and measurements and so on. I think that it is ABSOLUTELY necessary that you do that as well, otherwise your build will be extremely expensive and may end up in the garbage if you just ignore things and assume that it will work out somehow. I don't know what sort of things you have made before, but you seem to have a very large and luxurious workshop, especially compared to mine, so surely, even if you only worked with wood before, you must have made many drawings for whatever you made. I am not a wood worker, and my last wood project was two very simple birdhouses, but I made drawings even for those before I bought the material and started cutting up. So yes, drawings are VERY important according to me, but machines were made long before CAD software was invented, so that is not necessary at all. The type of table CNC we normally build is actually a pretty simple machine compared many others which can be made without and CAD software, so that is not required, but careful measurements and drawings are definitely necessary.

Thanks A Camera

The profiles that virtually everyone on OpenBuilds is using is this - https://ooznest.co.uk/product/c-beam...l-cut-to-size/

A lot of guys in the US purchase from them in the UK.

Never used a drawing for anything i have made.

I measure the dimensions of what i want to make and where it is going to go and then just get on with making it.

So, i need to make a bookcase for an alcove -

Height, width, depth, height of books from large to small, thickness of material being used, allow for rebates etc - all just written down as physical sizes. No drawings

I look at other designs, profile edges, create radius corners, all based on what i think looks aesthetically pleasing!

I will make use of most of what i have - but the ball screws are to short and will cause an issue as they are the exact length of all my profiles.

Were as the others are oversized generally by 40mm or greater to allow them to pass through the plates and be secured.

WoodKnot

[A_Camera]

Thanks A Camera

The profiles that virtually everyone on OpenBuilds is using is this - https://ooznest.co.uk/product/c-beam...l-cut-to-size/

A lot of guys in the US purchase from them in the UK.

Never used a drawing for anything i have made.

I measure the dimensions of what i want to make and where it is going to go and then just get on with making it.

So, i need to make a bookcase for an alcove -

Height, width, depth, height of books from large to small, thickness of material being used, allow for rebates etc - all just written down as physical sizes. No drawings

I look at other designs, profile edges, create radius corners, all based on what i think looks aesthetically pleasing!

I will make use of most of what i have - but the ball screws are to short and will cause an issue as they are the exact length of all my profiles.

Were as the others are oversized generally by 40mm or greater to allow them to pass through the plates and be secured.

WoodKnot

Oh, I see. Well, those extrusions are in my opinion far too weak. I was hoping that you at least use 40x80, but those you went for, I see as 20x20 C shaped. Maybe suitable for some very small, light machine with a small DC motor as spindle, but not for a machine of the size and type of use you are aiming at, even if you'd only work with soft wood, I think that would cause you more pain than joy when using it. I think at this stage I'd byte the bullet and start over, trying to reuse the strongest parts (rails and ball screws), not the weakest ones (extrusions), but in any case, I think it's high time to start sketching on paper or in a computer.

Also regarding CAD, I think you must give up any idea about not wanting to use one. I understand that you don't want to spend a small fortune on a CAD software, but there are very capable and useful software out there even for free. FreeCAD is what I am using and as the name says, it's free of charge, unless you are like me and want to donate money to those developers. There are other free CAD and CAD related software out there, and if you are aiming at ever using your CNC then you simply must learn some CAD software, without that, you will have really no use for a CNC. Even a simple freeware like F-engrave needs some understanding and configuration, as well as the CNC software (whichever you plan to use) needs some serious configuration, input file with some G-code containing the correct setup for the material and the cutters, spindle motor and many, many things. It all sounds simple and looks as a simple work, but it isn't. You can, if you are good at low level programming (like I am), create G-code without CAD/CAM, or any other software, using only Windows Notepad, but it takes time and requires a good understanding of G-code, but it is not practical and it takes time, especially if you are not a professional programmer or have many years of experience and knowledge. I started with manual G-code programming and actually created fairly complex items because I was in a hurry and for me it was easier and better this way, while I was trying to find my choice of CAD which I'd be happy with, but I have over 40 years of experience in programming, of which 15 in assembly and C, and the rest is C++, Ada, Ada+ and so on, so with my background it was the right choice, but if I did not have that background, I would have never started with manually programming in G-code. So, while I still stand for what I said, machines can be designed without CAD software, I strongly recommend you to seriously consider some CAD software because you will need it.

Here is a video about FreeCAD and Blender, the guy uses FreeCAD (just like I do) for designing parts and he assembles those parts using Blender, which is also free. I think that this is a very good idea, so I actually installed Blender and will have a look at it for myself.



I am also not interested in spending a fortune on CAD/CAM and modelling software, but of course, those who work professionally and actually selling machines, these are necessary tools, and commercial ones are expensive for us mortals, so for me the free alternatives are suitable. As I said, FreeCAD is free, but donating is fine, you can actually donate any sum and to be honest, it is a professional software, so those guys and dolls deserve my money every time I update the software. I just installed Blender and that is also freeware (donate ware) and a quick test shows that I like it, but will test more and if I ever use it for real I will donate them as well, just like I donate other software makers. But it is not compulsory, and those software don't have any limitations if you don't donate, so that's good. Many commercial alternatives have free versions, but every time I tried one, I run into limitations, so I gave up on them because even they claim that you get the full version, they are ALWAYS cripple ware, or have some serious limitations in usage time, saving possibilities, maximum sizes or other things which can be frustrating or make life difficult.

In short, you should start consider some sort of CAD and accept the steep uphill it may cause before you get started for real with one.