How do i make this eccentric part for elmers beam engine ?

Hi All , looking thro the drawings before i order the materials for Elmers #24 beam engine , can anyone tell me how this eccentric part is made ?

Any help appreciated

Chris[

IMG]http://i5.photobucket.com/albums/y185/whitebeetle/beameccentric001.jpg[/IMG]

sorry , here;s the pic

http://i5.photobucket.com/albums/y185/whitebeetle/beameccentric001.jpg

We had an interesting thread recently on making cams

Milling or grinding seem to be the least stressful routes, will try to find

http://www.model-engineer.co.uk/forums/postings.asp?th=51412

http://www.model-engineer.co.uk/forums/postings.asp?th=64873

search for "crank" in  main forum

http://www.model-engineer.co.uk/forums/searchresults.asp?Search=crank&SearchType=1&t=0

Edited By Ady1 on 08/04/2012 11:26:07

Chris,

This is not a cam but rather a circular section with a hole reamed off-centre by a precise amount, therefore it can be fabricated from mild steel bar. I have just made 4 sets for my engine by holding the turned bar in a 3 jaw chuck centred and mounted on the milling table which is then traversed the (half throw) distance and locked. This allowed all 4 excentrics to be drilled and reamed at the same setting before being drilled a tapped for a locking grub-screw.

Tony

You don't really need to mill or grind the part. Just use a 4 jaw chuck

Just use a length of bar long enough and lareg enough to fit the overall part in. Carefully mark the three centres on the faced off end and lightly dot punch. Next set up in the 4 jaw chuck and indicate the centre for the first eccentric, this can then be turned with a standard tool. Reset the work for the second eccentrics centre and use a parting type tool to machine that, finally set for the shaft centre and use the parting type tool again, then drill & ream before parting off.

Its really all just off centre turning, been doing a bit myself over the weekend, this part had 4 different centres, all done using 4jaw chuck and a pic of it stationary

J

This is not a cam but rather a circular section with a hole reamed off-centre

Aye. Right enough.

Got cams on the brain at the moment