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Designing Parts in SketchUp in order to 3D Print

The model cuts up into parts. Your next task is to prevent it from falling apart once it prints. You can attach the model's components by integrating various mechanical and non-mechanical strategies into it.

SketchUp Tolerance

Using SketchUp to measure the part and your 3D printer to produce that part, you determine the tolerance. The printed 10mm cube will not have any measures that are exactly 10mm, even if it draws in SketchUp. Although they are small, barely a tenth of a millimeter, the differences can cause problems when connecting parts that already exist in reality.

In most cases, the manufacturer of 3D printers provides a tolerance number for the machine, like pm0.05mm. You should be aware of this maximum variation for that machine.

SketchUp Clearance

Parts need Clearance to slide past one another. The two won't fit together with a peg of 10mm in a hole of 10mm, as you can imagine. Although pegs and holes may fit perfectly in SketchUp, it won't be the same in the real world since friction will come into play. When the fit is too precise, the peg will not go through the hole as friction will create.

For the two parts to slide past each other, you need to add a small amount of Clearance. You can use a Clearance that matches the movement of the part. Spindle mountings, for instance, require more Clearance than snap fittings.

SketchUp Glue Use

You can stick anything to anything with glue. Unluckily, it is also the least reliable and weakest method. A glue joint in plastic can break under stress when temperature changes or if you look at it funny. Plastic glue joints are very weak and are likely to break under stress. Your part should be attached to a different system if it goes beyond just a visual model.

1. 3D printers rely on special glues to bond plastics like ABS, PLA, PVA, nylon, and PETT. You can order these glues online, but you must order them from a retailer.
2. PLA, a starch-based biodegradable plastic, has a crystalline structure that cannot be fixed by superglue. A lot of glue stays liquid and migrates across surfaces unexpectedly.
3. Epoxy should always be used whenever possible. It sticks to just about anything, but it is messy.
4. Three-dimensional printers cannot use glues that stick to flexible materials. Thermal welding is a process that can be used to attach parts made from those materials.

Press Fit

There must be very little space between two parts if they are press fit. The joints come together when the parts are forced together rather than through hardware or glue.

To create a press-fit, create an outer lip on one side of the connection and an inner lip on the other side with the Offset tool.

You can still assemble the parts if there is a clearance of 0.2mm or less between them. Here are a few things to keep in mind when it comes to press fits:

1. The press fit must have a tight connection for it to work. Press the parts together with a hammer, a clamp, or your body weight if you need a large amount of force.
2. In most cases, press-fit connections are one-way. Expect you won't be able to disassemble it ever again once you put it together.
3. Scaling up press fits is difficult. It's always a good idea to design at the size in which they'll be printed.
4. Press fits have narrow clearances, making it difficult to start. When you run a hobby knife along the edge of the hole, you will widen that area a bit and make it easier for you to put the parts together.

Bolts, Screws & Hardware in SketchUp

Connecting 3D-printed parts with metal hardware is the strongest connection possible. It is also great for things other than just prototypes, such as mechanisms or parts for robots. If you are going to incorporate hardware into your design, then include the hardware within your SketchUp model.<

SketchUp makes it easy to model your parts based on their measurements. Then save the components in the component library to use them again without having to make them again.

Here are some things to remember:

1. When drilling your holes, ensure that there are enough clearances for the hardware to be installed.
2. In cases where bolts or screws are used and you don't want to include a matching nut, you can slightly undersize the holes. By cutting into the excess plastic, the threads of the bolt will hold it firmly in place.
3. Including every fastener known to man, McMaster Carr and Amazon Supply are two online hardware suppliers. In the event that your local hardware store doesn't have what you're looking for, you can find it at these online stores.

Snap Fittings

A 3D printer can create snap fittings that are great to use for a variety of applications. Once you receive the parts from the printer, you can pop the model together.

You can also use snap fittings that are removable so that you can replace different components of your model as it evolves. Snap fittings are created by following two general steps in SketchUp, Use the Push & Pull and Line tools to create the tongue, The opposing part must be captured at the same point.

To learn more, watch the following video tutorial.

Video Source: SketchUp School

Designing Parts in SketchUp in order to 3D Print
Image Courtesy: all3dp.com