Author Topic: I'm building an engine!  (Read 3952 times)

Offline russ57

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I'm building an engine!
« on: May 22, 2012, 08:58:12 AM »
well, at least i hope it will be an engine.

something like http://ridders.nu/Webpaginas/aanvraag_happer_inwschuif.htm i hope..

i started with the plans published in ME a couple of years ago, but Jan has updated the design, so i need to check what has changed.

anyway, here are the first bits, flywheel, crank and cylinder supports.  I now know what chatter is,  :smart: so dont look too close at the flywheel! There is a small bearing between the crank and conrod, salvaged from a hard disk drive.  I had to order bearings for the crank though, $8AUD each at local bearing shop, or $15USD for 10 from the states...supposedly a standard 'micro' skate bearing, but not here apparently.



and the crank supports.



which brings me to my first next problem...

I'm have difficulty in making one the same  :bang:, let alone 4... the supports are supposed to have 3mm of dia 10, with a transition to 6mm, total length 20mm. i started off with the base about 5mm long, and the narrow section 20, intending to face off each end to the correct length. I discovered it was almost impossible to reliably hold the short base (ER25 collet)  so i could face off the narrow end.

I think i will have to start again. New plan is - have about 30mm bar projecting from 3 jaw. face the end.  use a parting tool to turn a groove at the 20mm mark. I then have a reference point to measure from. Turn the base, the transition and the top to size. Drill the end (it is threaded both ends). part off, leaving slight evidence of the groove. Reverse (holding the narrow portion in the chuck), clean up the end and drill. Hopefully 4 pillars the same....

any better plan? I thought about trying to hold them all and mill to length as a set, but i doubt my ability to hold them.

anyway, more later.

-russ


Offline mzt

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Re: I'm building an engine!
« Reply #1 on: May 22, 2012, 09:33:23 AM »
dunno whether it would be a better plan, anyway:

chuck the bar, turn the smaller sections to lenght and finish (drill and thread the end), turn the base to size, part slightly overlenght.
When You've made them all, reverse each one in the chuck (collet?), lock the carriage and face each base to lenght.

or

make a disk, say 10/15 mm thick, diameter larger than the column base, drill a 6mm hole and cut along a radius.
Insert each column in it, and set the assembly into the chuck taking care the cut lies the space between two jaws.

Marcello


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Old 5" 1/4 HD Drives might provide some free bearings for the cranks, discarded printers too.

 
« Last Edit: May 22, 2012, 10:32:25 AM by mzetati »