NordicCNC's build log

[NordicCnc]

Don't waste your time, the way you have it now will work fine, that's exactly as I do them. It's simple and works. If I was to make a suggestion it would be to move the switch onto the side, fastened to the ballnut bracket and use the top slot for targets. How you have it now leaves the switch wide open to debris when cutting and if you cut steel or aluminium then could get false triggers when blasted with chips. Also the crap from cutting aluminium with lube can build up on the sensor.

Thanks for the suggestion. I will check the feasibility of moving the sensor to the ballnut bracket! I was also thinking that for fine adjustment with this simple setup, one could use a dial indicator when adjusting the target.

Again exactly as I do them and they work fine, the round head doesn't cause any issues. The only suggestion I'd make is to stiffen up the bracket. The one I use are 3D printed, You can just see it between the mass of pipes and wires in this pic.

Attachment 27671

Looks good.I think I could make a stiffer bracket out of aluminium without any problems. That X-axis ballnut bracket looks interesting. If I am not mistaken I would think you are using a rotating ballnut. Any chance I could get a closer look at that?

[NordicCnc]

For users of LiunuxCNC with the option to auto-square the gantry it is essential that the switches cannot overshoot their targets during deceleration and reset themselves before the whole sequence is finished. In this case you may need a larger target, especially with a large and heavy gantry.

I see, I didn't know that! Luckily I will be using Mach3! If I still need a bigger target for some reason then I can lathe a new target.

[Kitwn]

I see, I didn't know that! Luckily I will be using Mach3! If I still need a bigger target for some reason then I can lathe a new target.

The devil is always in the detail.

[JAZZCNC]

Thanks for the suggestion. I will check the feasibility of moving the sensor to the ballnut bracket! I was also thinking that for fine adjustment with this simple setup, one could use a dial indicator when adjusting the target.

You won't need to adjust it to that degree. I don't use Linux CNC but believe it just works like any other gantry squaring routine in that it sees the switch and you tell it in software how far from the switch you want it to move so it squares the gantry. The switch is just a trigger, the closer you get to square the better because your not loading the bearings, etc, but you don't need it to be to the micron.!

The size of the target shouldn't make a difference if the switch distance is set correctly. What a larger target does allow is more room for clearance, basically, it allows more room over shoot, which you don't want anyway because of the twisting gantry.
Also if you are using Servo's then it's all immaterial because you'd use Home-to-Index, so again you just using the switch like a trigger, then the servo will Index to the Encoder.

Looks good.I think I could make a stiffer bracket out of aluminium without any problems. That X-axis ballnut bracket looks interesting. If I am not mistaken I would think you are using a rotating ballnut. Any chance I could get a closer look at that?

Yes I used to make them out of aluminium but I prefer to 3D print them now because if anything hits them the bracket snaps off and saves the switch. The bracket is strong enough so it doesn't flex causing false triggers etc but yet weak enough to snap if thumped with somthing heavy.

Regards the Rotating Ballnuts then yes your right. All Axis except Z-axis are using rotating nuts but I cannot take any claim for the design, Jonathan designed them and kindly allowed me to use.( I actually bought some of the parts from him and made the others) If you search the forum you'll find a thread about them.

[joe.ninety]

@NordicCnc

Can I ask you a couple of questions regarding your CAD drawings that you're posting here...

1. Were they done using Fusion360?

2. Have you modeled all the elements yourself, like the carriages and rails etc, or have you just found existing DXF files and imported them?

3. If imports then could you share the source?

I'm asking because I'm using F360 and am having real problems with the dimensions of my imported DXFs. I've been using DXFs from the HiWin website, but whenever I import them into a design the dimensions are all out. The imported DXF are never the same dimensions as they are on the 2D drawings, so aren't really useful.

All I'm doing at the present is just using solid shapes to represent the items I want. So a HGH20CA carriage for example is a block 77.5 x 44 x 25.4 with a channel running through it to represent where the rail goes.

Looking at your design drawings, you seem to have everything fine?

Cheers

[JAZZCNC]

I don't use F360 but would imagine it works just like Solid works where it will allow you to import Step or Stl models which if Hi-win don't supply a direct F360 format like they do for SW you could use. DXF is mostly a 2D format and you want a 3D model.

Also for Component models I use Traceparts
https://www.traceparts.com/en

[NordicCnc]

@NordicCnc

Can I ask you a couple of questions regarding your CAD drawings that you're posting here...

1. Were they done using Fusion360?

2. Have you modeled all the elements yourself, like the carriages and rails etc, or have you just found existing DXF files and imported them?

3. If imports then could you share the source?

I'm asking because I'm using F360 and am having real problems with the dimensions of my imported DXFs. I've been using DXFs from the HiWin website, but whenever I import them into a design the dimensions are all out. The imported DXF are never the same dimensions as they are on the 2D drawings, so aren't really useful.

All I'm doing at the present is just using solid shapes to represent the items I want. So a HGH20CA carriage for example is a block 77.5 x 44 x 25.4 with a channel running through it to represent where the rail goes.

Looking at your design drawings, you seem to have everything fine?

Cheers

I use Siemens NX which I am lucky enough to have a work related license for. If I wouldn't have that I would probably be using Fusion 360.

The linear rails and blocks are downloaded as STEP files from the hiwin configurator: https://motioncontrolsystems.hiwin.c...near-guideways

The ballscrews I have modeled myself without any threads. This is because I want to model the ballscrew F-lengths myself, and I have no need for the thread visualization anyway

I also use traceparts and grabcad for other models like servo motors. I like the STEP format best, no issues so far!

Skickat från min SM-A530F via Tapatalk

[joe.ninety]

@NordicCnc

Thanks for that tip re the Step files. I went back in and re-downloaded all the files as 'Step' and my problems went away.

The only problem with the rails is that you need to specify a length before the website will create the 3D file for you. Think I'll knock up my own version and just keep that as a 2D drawing that can be extruded to the length required. Although it will obviously lack the actual positioning of the mounting holes.

Cheers

[joe.ninety]

Also for Component models I use Traceparts
https://www.traceparts.com/en

Thanks for that tip. Looks like an interesting site.

Cheers

[JAZZCNC]

@NordicCnc

Thanks for that tip re the Step files. I went back in and re-downloaded all the files as 'Step' and my problems went away.

The only problem with the rails is that you need to specify a length before the website will create the 3D file for you.

Just get a few different lengths and lay them on top of each other, aligning with each bolt hole to keep the spacing. It's always better to work accurately and mate the bearings to the surfaces of the actualy rail they would run on, this way you don't get accumulative errors building up as the model grows.