MEAM.Design - MEAM 201 - A08: Final Bedplate


A08: Bedplate

The design you submit for this bedplate represents what will be cut for you final engine geometry.

To build your engine, you're going to need a plate that holds the mounting block (part 01) and crankshaft bearing tube (CBT,part 05) a set distance apart from one another. This plate will also serve as the backbone for whatever you decide to do to support your engine on a tabletop. Here's the pertinent geometry for attachment of the mounting block and the bearing tube:

A few notes:

1. The stock material will be 1/4" 6061-T6 Aluminum.
2. The bed plates will be cut using water jet at NextFab in Philadelphia, PA, followed by post-operations in our shop.
3. To interface with the mounting block, you'll want to use two 6-32 x 0.50"-long flathead screws with an 82-degree head (an upper diameter of 5/16" should work well). You will want to size these holes using an appropriate clearance (see the tap chart for guidance). You may use post operations in the machine shop to reach the desired final diameter.
4. The crankshaft bearing tube will need press fit into the bedplate, so you should be quite particular about the diameter of that hole. You should under-size this diameter by .030" to allow for reaming (***note:this is different from the specifications of A06).
5. The small hole near the CBT bore is quite useful for setting the timing of your engine, though it is not explicitly required.
6. You are allowed up to 4 additional interior areas. This limitation is enforced because each closed interior feature requires the water jet to restart cutting in a new location, which is costly.
7. Make your model as clean as possible. Disjoint contours will fail. Also, the machine cannot create true sharp interior corners (sharp corners will have a fillet of up to 1/16").
8. All line lengths, fillet radii, and radii should be at minimum 1/16".
9. You do not need to account for kerf.
10. Save your file as <Last Name>_<First Name>.SLDPRT and convert the file to a dxf file with the same base name. Upload both files to the Canvas assignment callout. For instance, John Schmidt would name his file Schmidt_John.SLDPRT and Schmidt_John.DXF.
11. Include a note on the comments section of the A08 Canvas assignment callout if your geometry knowingly varies due to a mistake in the position of the mounting holes on your mounting block.