(DIR) Return Create A Forum - Home --------------------------------------------------------- Chainsaw Repair (HTM) https://chainsawrepair.createaforum.com --------------------------------------------------------- ***************************************************** (DIR) Return to: Chainsaw Collection Pics - Signs - Whats on your be... ***************************************************** #Post#: 77562-------------------------------------------------- Re: Whats on your bench today By: chy_farm Date: May 31, 2017, 6:05 am --------------------------------------------------------- From yesterday my bench is full of old McCulloch 740 parts. Wanting to repair her crank shaft. She came to me some three or four years ago with this part broken, and this fragment fell off when I removed the clutch unit. So pondering over the cause and factors of this, what I have in my opinion is that the key in between the shaft and the clutch is hardened steel, but the shaft is not, can not believe but true. You can file this shaft so easily, amazing. And what's worse previous owner might have put some grease here when he placed the clutch, so clutch and the shaft was not able to keep decent friction to bear the brunt of this big power, and corrupted. #Post#: 77563-------------------------------------------------- Re: Whats on your bench today By: chy_farm Date: May 31, 2017, 6:08 am --------------------------------------------------------- Of cause I have already got a 'new' crank shaft lately on eBay US, and it's in my hand now. Probably your good eye sight already found it in the first pic above. I have been thinking to use this new shaft, but my second thought suddenly came to me, which is that it also might be fun to try some welding on this shaft. Chy #Post#: 77569-------------------------------------------------- Re: Whats on your bench today By: 3000 FPS Date: May 31, 2017, 9:52 pm --------------------------------------------------------- Looks like you have under control. Nice repair. #Post#: 77570-------------------------------------------------- Re: Whats on your bench today By: chy_farm Date: June 1, 2017, 8:16 am --------------------------------------------------------- [quote author=3000 FPS link=topic=1732.msg77569#msg77569 date=1496285557] Looks like you have under control. Nice repair.[/quote] Good evening 3000FPS, and thank you for leaving comment. Crank shafts we see these days, IMO, mostly have hardened surface, but this one seems it has never been undertaken hardening treatment. You can file its surface with a standard file very easily, that really amazed me. But on the other hand the key sitting in here is made of hard steel, so it's my presumption for the reason she got corrupted on this part was that the previous owner might have put some grease or oil on the surface of this key and groove, then he tightened the nut. So that this caused some friction-loss of this part and the motor power overwhelmed to cause this damage. My alternative is to replace this key from a hardened steel made to a rather softer bronze made, so that in the worst case the key get damage not the shaft. Pic first; Melted a bronze sheet to make a small ball, the gave it some taps while keeping decent flame on it. pic second; Bronze key sitting in the groove. Pic third; Gave cut to this key. Pic last; Clutch sits nicely on the place. #Post#: 77631-------------------------------------------------- Re: Whats on your bench today By: chy_farm Date: June 6, 2017, 3:59 am --------------------------------------------------------- I am thinking of other color scheme for 740, with polished magnesium cover, white body, and with some yellow parts like top lid, spikes and power pipe. All parts got treatment with paint stripper, washed and paper on the surfaces. Then got aluminum primer. #Post#: 77635-------------------------------------------------- Re: Whats on your bench today By: Chainsawrepair Date: June 6, 2017, 7:53 am --------------------------------------------------------- Like your ideas of coming up with your own color combos. 8) #Post#: 77637-------------------------------------------------- Re: Whats on your bench today By: 3000 FPS Date: June 6, 2017, 9:19 am --------------------------------------------------------- Looks nice. #Post#: 77638-------------------------------------------------- Re: Whats on your bench today By: chy_farm Date: June 6, 2017, 9:22 am --------------------------------------------------------- [quote author=Cut4fun . link=topic=1732.msg77635#msg77635 date=1496753627] Like your ideas of coming up with your own color combos. 8) [/quote] [quote author=3000 FPS link=topic=1732.msg77637#msg77637 date=1496758784] Looks nice. [/quote] Thank you very much for your nicest flowers gents, will do the best!! Chy #Post#: 77662-------------------------------------------------- Re: Whats on your bench today By: chy_farm Date: June 8, 2017, 5:41 am --------------------------------------------------------- Did some painting and assembling this afternoon. Now I can go further to the pipe things for her ! #Post#: 77663-------------------------------------------------- Re: Whats on your bench today By: Chainsawrepair Date: June 8, 2017, 7:56 am --------------------------------------------------------- Handle made from copper or just painted to look like it? ***************************************************** (DIR) Previous Page (DIR) Next Page