Saturday, February 13, 2010

Measurements Continued

Last post I mentioned having some trouble getting a good measurement on the internal splines of the secondary sheave. I put it out to my readers for help and suggestions, and thanks to the powers of the interwebs, somebody suggested making a casting or imprint of the inside of the secondary (thanks Pascal).

I debated for a while what to use to do this: plaster, gorilla glue, expanding foam, potting flower foam. Then it hit me, wax! It's cheap, I have some in the kitchen, should be tough enough to get a good imprint and it's easy to do. This is the wax you'd normally use for baking and making somekind of weird candies or something. I've never made any food with it but apparently it's edible.

So I did, made a real mess with wax everywhere, I spilled some and spent more time cleaning and scraping wax than I did actually preparing. First, I cleaned the inside to get the grease, rust and junk out of the hole. Then I sealed one end with masking tape, sprayed WD-40 down the hole to act as a release agent for the wax and I was ready to pour molten wax down the hole.

A small side note on heating wax do not simply put wax block in your metal pot and put in on a heat source. This doesn't work, don't ask me how I found out. The proper way to do this is to place a smaller pot for the wax inside a larger pot filled with water, which you then bring to a boil...

The end result looks promising:

It took a while to cool, which is good because it allowed for plenty of cleanup time.
For those worried about dimensional accuracy, it was a very tight fit, so I think it will be good enough. Now I can use the proper spline measurement tools.

Monday, February 1, 2010

Jackshaft replacement and adapter

As mentioned before, we're in the process of trying to make something to connect the snowmobile bits to the car transmission bits. First task is to get measurements of everything, meaning the snowmobile secondary sheave (pulley for those not in the know), the flywheel/clutch assembly, and how much space we have to physically mount everything in the car.

Due to the weather (see Greg's post on carbs) I decided to start indoors and try to get measurements on the secondary sheave. Its a bitch to measure internal splines, because nobody at the shop has the proper gauges, so we're doing it from scratch. If we had the jackshaft from the sled of course it would have taken about 3 minutes... I'm gonna have to use a bit of trial and error to find the proper splines. I would also welcome any suggestions on a better way to do this.

Next post we'll try to get a couple crappy cad drawings (hah! that would make a good name for the Microsoft competitor to Google sketchup...) or something visual done, so our fair readers and the guys at the shop (who think this is a stupid idea) get the picture.

In other news, while laying this stuff out, there's a couple proposed changes to the layout of the super shaft replacement, things that will be better explained with pictures. You can kind of get an idea on how it all goes together in the picture below. There is also a pressing need to inspect our secondary, meaning let's take it apart, see how it works, make sure it actually does work and see if this facilitates measuring.

Lastly, I have been lectured (again?) on the need to properly align all of these shafts and make sure the supports are stiff enough to not cause unpleasant issues like splines failing. I almost feel like buying that !@#$% plasma cutter I've been wanting for a while to cut up the engine block and see if I can just use that as some sort of support structure...