The E-Board Project: Episode III

So while I was gone over the weekend my new thread cutters came in the mail. I also got a wireless Nunchuck from Logic 3. This one is going to replace the wired one I am using for prototyping.

So long story short. I finished the first drive shaft. I am probably going to finish one side of the drive train first. That way I can make changes to the other side in case something shouldn't work as planed. Pretty much all that was left to do was to cut a thread on the shaft and make the washer, which is supposed to form a force fit with the wheele and the shaft.

  

Since there isn't really a lot of  area for the washer to press against inside the wheele I thought to myself. Why not increase the transmitable torque by adding a cylindrical press fit? I was in the shop so I didn't have anything to do the calculations with. I decided that 1/10 mm excess should work ok. I knew that that the bearings usually have aroung 5/100 mm and they sit pretty tight. So double that sounds good to me.

                                                  

 It turned out that 1/10 is quiet a bit when it comes to actually putting the part into place. I figured if I heat the wheele and cool the washer it might actually make difference. So I put the washer in the freezer for a few minutes which cooled the part to around -7°C and heated the wheel in hot water which was around 55°C. Who would have thought it would work... well actually it didn't. I had to use a hammer to get it in but oh well it was worth a try.

 Onve the washe was in there I only needed to add the nut an it was DONE! I need to get some M10 self securing washers though because I am too worried it will loosen.
I thought I would add a quick screen shot out of my CAD software for comparison. I think it turned out pretty good