Milling with SRP Player on the Small CNC Mills (MDX-540)

Digital Media TutorialWritten by Eric Kurzenberger

This tutorial will walk you through the steps of creating and running a 3-axis milling toolpath using SRP Player on the small MDX-540 CNC mills. SRP Player is basic toolpathing software which is easy to use, but limited in functionality. If you require more complicated toolpaths, you might want to try using MadCAM through Rhino, which is explained in a separate tutorial.

To start, make sure you’ve done the following with your model in Rhino:

• aligned your model so the origin is at the top center of your block (it can be helpful to draw a box representing your block around your model)

• drawn a base for your model, so that the model; trying to model without a base may cause the mill to get confused as to where the bottom of your model is

• saved your model as a .stl (stereolithography) file

Model without base Model with base

Once you’ve got your model as an .stl file, you can open SRP Player from Start > Programs > Fabrication > SRP Player on one of the small mill workstations.

I. Initializing SRP Player

When you launch SRP Player for the first time, you will be asked to follow a few steps to initialize the software; this is where you set your units and your default tool. Make sure the mill is on, then click Next.

The software will search for the mill, then tell you what mills are connected. Highlight MDX-540 (Roland MDX-540) and click Next. If the MDX-540 does not show up in the list, make sure the mill is on and the USB cable is connected.

You’ll next get a prompt telling you that the MDX-540 cutting machine was selected. Click Next.

Enter the units you used in your Rhino model (mm is recommended). Click Next.

You’ll be prompted to register the tool you’re using for milling. You can use one of the pre-loaded tools or create your own.

To create your own tool, click New. Enter the Tool Type, Material, Diameter and Flute Length, making sure to put in the correct dimensions of your tool. If needed, you can measure your tool using calipers available from the shop. Then click Register to create your tool.

Make only the tool you’re using is checked in the list of tools to avoid creating your toolpath with the wrong tool. Then click Next.

You’ll now get a message that initialization is completed.

Click Finish to open the main SRP Player window.

II. Creating and Previewing your Toolpath

Once the main SRP Player window has opened, select Open from the SRP Player File menu, then browse to your .stl file to open it in SRP Player.

In the Model Size and Orientation window, verify that your model dimensions are correct; if they’re not, you may have selected the wrong units for your model. If necessary, you can use the X, Y, Z fields or the Scale checkbox to change the size of your model.

Also verify that the model is oriented so that the surface to cut is facing up using the XYZ axes in the model display. On the small mill, the XY plane is the plane of the cutting table, with X going across the mill and Y going into the mill, and Z is parallel with the tool. You can change the orientation of your model if needed using the radio buttons around the green head.

If you weren’t prompted to go through the Initialization process when you started SRP Player, you’ll need to choose your tool now by selecting Options > Add/Remove Tool and choosing or creating a tool as described previously in the Initializing SRP Player section of this tutorial.

Once you’ve verified your model’s dimensions and orientation are correct, choose the material you’ll be using by selecting Options > Add/Remove Material.

In the Add/Remove Material window, select the material you wish to use, then click Cutting Parameters.

In the Correct Cutting Parameters window, select the tool you are using, then verify the Cutting Parameters. Confirm that the Feed Rate, Spindle Speed, and Cutting-in Amount (also down as Stepdown) values are correct for your material, following the guidelines laid out in the shop’s Guide to Feeds and Speeds.

If you have questions about what feeds, speeds and/or stepdown to use, contact the shop faculty for guidance.

Once you’ve verified the cutting parameters, click Close to close the Cutting Parameters window, then click OK to close the Add/Remove Material window.

Now that you’re back in the main SRP Player screen, click Type of Milling at the bottom of the right pane.

Choose the following options for your type of milling job. Each selection has a graphic to illustrate what it means.

Better surface finish will give your model a smoother look, but can take 2-4 times longer to complete, depending on your model.

If your model is mostly angular surfaces rather than curved, it’s best to choose Faster cutting time.

Model with many flat planes will similarly mill faster, but with less smoothness than Model with many curved surfaces.

Select Block workpiece and Cut top only. While flip milling, which allows you to cut both the top and bottom of your block, can be done on the small mills, it’s outside the scope of this tutorial.

Click Create Tool Path to continue.

Choose your workpiece material, then enter the dimensions of the workpiece (block) you’ll be using. The numbers in parentheses are the minimum dimensions that the block needs to have to mill your entire model.

When choosing your block size, it’s best to have a block at least slightly larger than the minimum dimensions.

If you have a block but don’t have the dimensions, you can click Measure Size and follow the prompts of the Workpiece Measurement wizard to measure the block using the mill. But it’s much easier and quicker to simply measure your block with a ruler.

Once you’ve put in the dimensions of your workpiece, you’ll see a green outline over your model representing your block.

Now click Create Tool Path to generate the toolpath. This will automatically create both a roughing and a finishing pass for your model. You’ll see a Processing window while the toolpath is generated.

Once the toolpath is ready, the icon underneath the Create Tool Path button will turn and red and say Created. You can then click on the Edit button if you want to view the roughing and finishing passes by clicking on them, then click Close to go back.

Click Preview Results at the bottom of the right pane to continue.

You’ll now be given an estimated time for your milling job. Click Preview Cutting to get a view of what your job will look like after it has been milled

After you’ve verified that everything looks correct, click Perform Cutting and the bottom of the right pane.

Verify that your tool (and only your tool) is listed in the Tool List.

If the incorrect tool is listed, you’ll need to select Add/Remove Tool from the Options menu as described previously in this tutorial and make sure only your tool is checked, then recreate your toolpath.

Once you’ve verified that only your tool is listed, click Start Cutting.

III. Running your Toolpath

After you click Start Cutting, you’ll be prompted to install your tool in the spindle, if you haven’t already. Make sure the cutting length (the length of the actual cutting part of the tool) is equal or greater to the number specified.

In my example, the cutting length is 98mm.

Once the tool is installed, click Next.

You’ll be prompted to select the location on the block you used as the origin. Click on the top radio button, as you used the top center of your block for the origin.

Then click Next.

You’ll get a Start Cutting screen. Click Next to begin cutting.

Once you click Next, the spindle will begin turning and the mill will begin cutting! Make sure your tool and block are securely loaded and there are no obstructions around the mill!

Once the mill has started running, verify that everything is cutting normally.

If you need to stop the mill immediately for safety reasons, use the red Emergency Stop button on the mill! Do not stop the mill using the software.

Once you’ve verified that your job is running correctly, you can launch the VPanel software to directly control the mill and adjust your speeds and feeds as needed while milling. Launch VPanel from Start > Programs > Fabrication.

When VPanel first launches, you’ll be prompted to connect to the MDX-540 mill. Click OK.

You’ll then see the VPanel interface. The interface will display the tool’s position in either the Machine Coordinate System (which uses the machine origin as 0,0,0) or the User Coordinate System (which uses the origin you set previously, depending on which is selected from the dropdown.

It will also display the current spindle speed (in RPM), the feed rate (in inches or mm per minute), and the load on the spindle, represented by a percentage.

You can adjust the Cutting, Moving and Spindle Rotating Speeds if needed by clicking the blue down and red up arrows next to the speed you want to change.

If you want to pause your job momentarily, you can click the Pause button to stop the mill’s movement.

WARNING: pausing the job will not stop the spindle! If you need to stop the mill immediately for safety reasons, use the red Emergency Stop button on the mill!

Once your job is paused, you can click Stop Spindle to stop the spindle, if needed. If you want to examine your mill job, clicking Move to VIEW will move the tool away from your block and bring your block forward for viewing.

To resume your mill job, click Resume.

To stop your job completely, click Stop Cutting. In the confirmation window that opens, click Quit Cutting to completely cancel the job.

Because the job did not complete successfully, SRP Player will give a warning that a cutting machine error was detected. Click OK to acknowledge the error.

Once your job is finished, a confirmation window will open. Click Finish to close the window.

When you’re finished, unload your block and tool and clean up the mill.