Design Help Please

[audioandy1762]

Hi All

I am in the early stages of designing my mill and was wondering if one of the more experienced among you, would have a look at my drawings and see if I am on the right track.
The bearings used are Hiwin HGH-HA 25mm rails and carriages for the Z and X axis, I have 30mm version for the Y axis (not shown in the drawings yet).All the mounting plates drawn so far, are all that I have had given me along with all the bearings which is 16mm thick aluminum and pre-drilled to take the rail and carriages. I should end up with about 700mm of travel in the X and Y axis and would be happy with 200mm in the Z.

I have used Autocad 2004 which again I am self taught through reading books and just using it, so if I have done something that’s not quite right I would be grateful for any constructive criticism.

Thanks

Andy

PS Hope this is in the right forum sorry if its not

[svenakela]

Without looking at the drawing I guess it's a router, so I moved this thread to the DIY Router forum.

Welcome and happy posting!

C'mon out there, give Andy a hand will ya!

[ger21]

When the Z axis is fully extended, you might get a little flex. What do you intend on cutting with this? Also, the spindle mount looks a bit weak.

What you're calling the X axis, I'd call the Y. And you probably don't need 30mm rails for the gantry to ride on. Overkill.

[audioandy1762]

Originally Posted by ger21 When the Z axis is fully extended, you might get a little flex. What do you intend on cutting with this? Also, the spindle mount looks a bit weak. What you're calling the X axis, I'd call the Y. And you probably don't need 30mm rails for the gantry to ride on. Overkill.

Hi Gerry

Thanks for the reply I was hoping that the way I intend to mount the Z axis, bearing carriages fixed, with 320mm of rail supported at full stroke of 200mm it would reduce the flex.

My initial idea for a CNC router was to make PCB’s but after finding this site and seeing all the other interesting stuff people are doing I would like to think it would be ok to use on wood and maybe aluminium. The spindle mount was drawn quick just to show the front face of the Z axis I do intend to beef this up somewhat.

The view in my drawing is looking at the front of the gantry, I thought that left to right movement was the X axis and front to back was the Y, have I got this wrong?

As for the bearings I have had them given to me, they were removed from a piece of redundant kit that had done very little work and was destined for the skip! 4 x 30mm carriages 2 x 30mm rails 2.6 meters long!

After looking at my drawing and me clarifying a few points, am I on the right track to making a half decent router or should go back to the drawing board?

Thanks

Andy

[audioandy1762]

Well I will just carry on the way I'm going and hope it turns out ok.

Andy

[Oldmanandhistoy]

Hi Andy,

Have you got a job in mind that needs that much Z movement or are you just covering all the options?

The reason I ask is you mentioned milling aluminium so you need all the rigidity you can get. Reducing the Z movement will increase the rigidity.

Other than that I see no problems with timber products with your design as is.

Are you designing this machine as a hobby machine or do you want to use it for commercially?

John

[audioandy1762]

Hi John

Thanks for the comments, no job in mind I just thought with those bearings and the ball screw I have I would get the most out of them, what would you say is a practical Z movement.

It is only an hobby machine.

Thanks

Andy

[Oldmanandhistoy]

Originally Posted by audioandy1762 Hi John Thanks for the comments, no job in mind I just thought with those bearings and the ball screw I have I would get the most out of them, what would you say is a practical Z movement. It is only an hobby machine. Thanks Andy

Hi,

As this is a hobby machine I would say go with the Z as is; you could always change it if you have problems or you want more rigidity. The way to compensate in your situation is to reduce cutting speeds which is not a problem for a hobby machine but this may still not be enough for milling aluminium.

I would say have a very hard think about what you will be cutting and reduce the Z height to a minimum. Or you could design in a way to adjust the height of the Z for the rare occasions you need the extra.

Be sure to start a thread in the router project log section when you make a start on the build. I am no expert but there are some very knowledgeable members who will keep you on the right track.

John

[audioandy1762]

Hi again John

I will take on board regarding designing an adjustable Z axis, I was also thinking about maybe lifting the work piece up towards the cutter.

One of the reasons I am building a CNC machine is to manufacture cases/boxes to house my audio projects, it would be nice to have the facility to accurately drill along the edge of a side piece of an enclosure to fit a top and a bottom.

I intend to start a thread once I get going, the electronics side of things is almost complete, I am using Gecko 210’s running Nema 34 steppers at 48v 4amp,( got the above working with help from Jerry CJL5585) as you say a lot of knowledgeable helpful and friendly people on here.

Thanks again

Andy