Subframe Assembly

The rear subframe is starting to take shape. I drilled the 66 holes, counterbored some and reamed others to the proper sizes, then pressed dowel pins in an "every other" pattern. The side plates are both bolted and dowel pinned together. The idea is that the dowel pins are hardened to around 60 Rockwell and one hole side is reamed to .249" and the other hole is reamed over to .251" (dowel pins being .250" ideally) giving a secure fit between the pieces. The fit is so close that I have to tap the pieces together with a rubber mallet and also to get them apart. Once the pieces are together, 1/4-20 bolts are tightened down so the pieces dont come apart. The dowel pins provide much more rigidity and shear strength when compared to only bolts holding the subframe together. I have worked on the bellcrank mount and made spacers for the shocks and bolts those in place as well. The springs are on order, hopefully they will be in soon. There is a lot more work on this thing, updates to come.

Subframe Back Plate

Spending lots of time in the student shop working on the formula SAE car, today was my first official part that I designed, generated tool paths, then drilled/tapped and CNC milled on the Bridgeports in the shop. It was all of my creation. This piece is a crucial part of the rear subframe that is being designed for the new race car. All of the rear suspension, drive shafts, and differential all mount in the box-ish aluminum subframe that bolts to the back of the engine. By removing 6 bolts, the whole rear portion of the car comes off, away from the engine. I wish I had a picture of the design, its pretty trippy, and its still up in the air if its going to work. Fingers crossed! This part took a lot of setup and different operations. I wont go into details but there was a lot of drilling and tapping, then some CNC work. In the end, the part turned out flawlessly and should work very well. Enjoy the pictures. The first two show CAM tool path simulations.

Formula SAE Rear Uprights

After learning Esprit 2010 CAM software, we have been using this to create rear uprights for the Formula SAE team. It has been a huge learning experience, including multiple failures and problems along the way. A huge problem arose when trying to post process the code from Esprit to the Acu-rite controller for the Bridgeports in the shop. After re-writing and editing a generic 3-axis post processor for Esprit (again including many trial and error failures) we now have a working post processor for our setup. These uprights are milled out from a 4 x 8 x 1.8" block of aluminum. Much of the material is removed using 4 tools including roughing, ball and flat end mills. Posted below are pictures that document the process from solid model, to CAM tool paths, to final part (well almost final, final pictures will be updated soon).

Control Parts for Second Build

So I decided that I should invest in some new bearings, shaft collars and couplers for my second machine. Purchased some pretty basic stuff, Lovejoy couplers one side 1/2" the other 1/4", 1/2" shaft collars for the lead screws and some 1/2" ID bearings for the 3 axes. Bearings were from Ebay while the collars and couplers were from McMaster Carr; in all I think I spent around $35 for everything.

Control Box Update

The box is now completed with everything installed. Fans, power supply and control board are all crammed inside and everything is wired up and working. I ended up using DB25 connectors (radioshack) to make the connection between the control box and the wires that go to the CNC machine. If you look closely you can see the connector on the right hand side of the box.

Scroll Saw

I've gotten tired of always having to use a hand hacksaw to cut material and I thought about getting a little scroll saw to cut small stuff. This little machine was on sale and I thought it would make a good little christmas present for only $70. It can cut up to 2 inch thick material, variable speed, and the table tilts up to 45° for angled cuts.

I'm thinking about making a guide/miter gauge setup so that I can keep cuts square when I need to. I've been thinking about ways to do this easily at minimal cost and materials thats still accurate as well as how to mount it to the machine.

End Mills

Went exploring the Harbor Freight store in Sacramento and saw these spiral bits hanging on the wall. They were only $6 for a 3-pack so I thought I'd give them a try and see how they work. Probably wont get around to using them until my new machine is up and running but that's okay. I'm working on modeling the new build in Solidworks and I think I'll post some pictures on here when I finish working on it. The plan for the new machine is 1.5" square steel tubing with a cutting area of 2' x 3' again using the angle iron and skate bearings for linear motion. It will have a moving gantry to maximize cutting area as well as a redesigned z-axis.