Milling

Preparing Grab Cad and Google Warehouse Files for Milling on your MDX

Written by Roland DGA

Bot Parts

Flat parts created on a CNC router

Looking for new modeling files for your MDX? There are a couple of great libraries that can access for free. The first we recommend is Grab Cad. Grab Cad files are very high resolution, easy to download, and most are already .stl or Solidwork files.

Alternatively, you can access Google Warehouse for files, and then download them for viewing in the free Google Sketchup 3D modeling tool. These files can be exported to .stl for fabrication in your MDX. The downside with Google Warehouse is the program’s low resolution. With simple 2D parts like those shown in the robot on the right, this is not a big issue. But, for curved objects like a car body, you are better off using a big mill bit to smooth over the surfaces to get a smooth, high quality model.

SPKR bot

Assembled parts create “SPKR bot”

To get decent results from a Google Warehouse design like this Acura Integra (below), split the model into pieces for a 3-axis milling job in foam. Once the parts are milled they can be cut out and assembled together into a 3D model. The model quality for this job was acceptable and the manufacturing time was just three hours.

Follow this link to export Google Sketchup models to .stl using the free plugin.

 

Acura Integra DesignIntegra Foam Model

 

3D Tech Tip – MDF – a simple, inexpensive material to mill

Written by Roland DGA

MDF is a great low cost material that is easy to buy in lumber yard and home supply stores. It is made from compressed wood fibers and sold in sheets. We recommend using MDF for test cuts and simple parts because it is so inexpensive and machines quickly. It is important to seal MDF before you adhere it to your table with double-sided tape. A quick coat of polyurethane will do the trick. You only need to coat one side and let it dry completely before you mount it with double-sided tape. After your part is completed you can stain, paint or simply coat it with polyurethane to seal all of the surfaces. All of the samples below were created with simple 3-axis operations using a .125 end mill. The sign geometry was created with Roland 3D Engrave and the gears were free downloads from the Autodesk 123D content site. All tool paths were created in Roland SRP Player software. A 12” x 12” x ½” sheet of MDF was used to create all of the parts.

Click Mill Software – Milling without 3D Data

Written by Roland DGA

Click Mill software is included with every MDX-40A, and is a fantastic utility that makes it easy to do simple milling tasks and create simple parts without the need for CAD geometry. Typically Roland mills need CAD design data to generate tool paths in SRP Player or Modela Player and subsequently drive the machine. But what if you just want to surface a block, drill some holes, or create a pocket or channel? Click Mill drives the MDX-40A with simple commands based on the task at hand.

Here’s how:

Let’s say you want a simple, fast way to hold one or more parts in place for 2-sided milling. In Click Mill you can select the “Pocket” tab and then enter the values for X and Y dimensions along with the depth (Z). You can also select the option to cut the corners square or leave fillets…

 

Once the pocket is created, you can drop in your stock, mill one side, then flip the stock, place it back in the pocket, and mill the opposite side.Why not use Click Mill to pre-size your stock to fit directly in the pocket you just made? Just select the “Cutout” tab to create a piece of stock to fit inside the pocket. Now you have a piece of stock for your prototype and a pocket to hold it while you mill each side.

You can also use Click Mill to drill holes and create slots and surface stock.  Just like Modela and SRP Player, Click Mill automatically manages the cutting parameters so you don’t have to worry about feeds and speeds. Just tell it what tool to use and what material you are cutting and you are all set. You can also add new cutting parameters and save your custom settings for future use. Take some time to explore Click Mill software.

SRP Materials

Written by Roland DGA

One of the most common questions that we get at trade shows and from inbound phone/email leads is this: “What materials do your machines use and where can I buy them?” One of the key advantages of SRP is the ability to use a very wide range of materials. The fact that the materials are not proprietary and can be purchased on the open market keeps the cost of ownership for Roland SRP machines low. Here are some resources available:

Craigslist: This is a great resource for a wide range of materials, including plastics, woods and metals. Since SRP machines don’t use giant pieces of material, many times industrial scrap is a great way to buy smaller sized pieces that will fit into the machine. Since you are sourcing them locally from Craigslist, you can save on shipping costs and meet the seller face to face. Maybe they will have more scraps next month that you can take off their hands. www.craigslist.org Search for the specific material you need: Acetal, Nylon, Acrylic, Oak, etc.

Freeman Supply: Freeman supply offers plastics, casting materials, urethane boards and cutting services to supply you with specific materials cut to specific block sizes. You can visit them on the web at www.freemansupply.com

Ebay: For industrial scrap, a good source is Ebay. Just search for the material you need. Many times a material will be listed by its generic resin name IE: Acetal or by a specific brand name: Delrin.

Material Overview:

Sintra PVC foam board is used mainly in the sign industry. It is available in a wide range of colors and thicknesses and is used to quickly cut flat parts that can be assembled into 3D objects. The material is light, relatively strong and inexpensive, which makes it great for educational applications, form studies, flat pack designs, etc. Google “Sintra PVC” to see examples and a wide range of suppliers.

Acetal (one brand name is Delrin) is one of our favorite plastics for prototyping. It machines extremely well, holds tight tolerances, remains dimensionally stable and is self lubricating. It is great for tough plastic parts like the MDX-40A fan blade. Acetal is used for a wide range of prototyping and manufacturing applications, including rollers, bearing blocks, fixtures/jigs, enclosures, etc. Acetal can be purchased from plastic supply houses, but less expensive options are on Craigslist or Ebay.

Renshape is a brand name of urethane board made by Huntsman. It is also referred to as tooling board, butter board, renboard, chemical wood, Sanmodur, etc. Renshape is available in a wide range of densities, from soft foam that you can dent with your finger to aluminum-filled epoxies for short-run injection molds. Renshape is great for form studies, appearance models, tool path verification and urethane molds or master patterns for rubber molds. Renshape is available from plastic supply houses like Freeman Supply. You can order a sample kit from Freeman to get a good feel for the different material weights available. At Roland DGA, we like to stay away from the ultra light weight versions since they create a lot of dust that goes everywhere. The peach colored version is good for quick form studies while the medium weight versions are good for most applications and are typically a pinkish brown color. Renshape selection chart.

Other Materials to Consider:

Extruded styrene sheet: If you live in a colder climate you can purchase extruded styrene insulation sheets at Home Depot or Lowes. They come in 2’ x 8’ x 2” thick sheets and cost about $15. This is a great material for low-cost models that are light and buoyant. It’s great for school projects, architectural terrain models, form studies, etc. Product overview.

Hard Woods: You can visit Home Depot and find open boxes of oak or other flooring strips. For about $10, material can be purchased that is great for signs, wood models and more.

Polystyrene foam: Polystyrene foam can be milled on a Roland MDX mill as well, to achieve the soft surface textures and flexibility for custom medical, sports or footwear applications

Prototype with Wax for Easy, Precise Results

A great material for prototyping parts is wax. It cuts easily, holds details and is very easy on tooling. You can also melt a project down and recast it into a block to use again! But you can’t use just any wax. You must use wax that is formulated for CNC machining. Fortunately, there is a source for machinable wax on the web that offers a range of sizes and will cut to size as needed: www.machinablewax.com

Use V-Panel to Control the Data Feed Output Speed of the MDX-540 series

Written by Roland DGA

If an MDX-540 series machine is running rough or making strange noises when moving in a circular pattern, but running fine in X & Y, then a quick setting change in the V-Panel could solve the problem.

First, update the firmware and V-Panel software to the most current version. Updates for all products are on the Roland support wizard.

Then go to the V-Panel > Options. On the main tab the feed output should have .2 as the fastest setting and .05 as the slowest. Select the slower setting and re-run your test program. This should solve the problem.

Why it works: Some software programs used with the Roland machines, such as Dr. Engrave, do not control the data feed output.  So by slowing it down in the V-Panel, the machine will run much smoother under load.

Special thanks to Deborah Cox of Peak Solutions for this technical tip. She used this info from the Roland DGA technical support team to help get a customer up and running and was kind enough to suggest we share it. Thank you Deb!

Tech Tip: Add or Increase Margins in SRP Player

Written by Roland DGA

When previewing a model in SRP Player you might notice that the entire area around the supports is not cut out (fig 1). This is an easy problem to solve in SRP Player:

  • Go to STEP 3 “Create Tool Path”
  • Click “Edit”
  • Under each process, click the “+” sign in front of “Modeling Form”
  • Check the “Add a margin” box
  • Click “automatic” (or enter a specific value)
  • Click “apply”

Repeat this for each process, and then recreate the tool path. When you preview the model you will see how this simple change modifies your output results. The “Make sloped” option is used for molds or patterns that need draft for easy part release.

Roland DGA, Corp.