is all done now bar the re-hardening process.
it was a bit of work to get this one done. i annealed the original triumph sprocket and the original wl sprocket. i spun up a spacer to suit the new box offset. then i set up a jig to hold the sprocket in the lathe and make sure it spun true before i took just a bit of meat off the sprocket so the spacer would sit home true over it while i welded it in the vice. then the original wl sprocket was spun in the lathe and i machined a home for the spacer to mate to it. i welded the two together then bored out the front sprocket to allow me to get a socket right in to tighten the nut home. it runs perfectly true and the only thing left to do is re-harden the sprocket and fit it up. which brings me to my next point.
being.
i've had a fuck of a time in the last couple of days trying to see my way through the smoke and mirrors that seem to face me at each turn.
i have a good friend who lives near me....i see him every couple of days or so. he knows a hell of a lot about metal and working it......i started talking to him about the process and how i needed to know more.....i've hardened bits before but only as i was taught very early in my days.....looking at colours and cooling in oil but dave threw a spanner in the works when he alerted me to special hardening oil apparently having a higher flash point than standard motor oil or such.....
sorry for the rave but phonecalls, 100km trips to the machine shop supplier, phonecalls from there to people who know, people who don't want to tell cause its secret, send him to tech to learn, bullshit will baffle his brain and he wont know shit when we finish with him, this stuff takes 50 years to learn...he cant know it, he's only 42 he's not ready to know and the rest of the fucken crap i've listened to make me very upset, and i hate to hell when i'm told i'm not allowed to learn.
now here's the thing. if the people who know the techniques, who hold the information, who have gone before don't share this information with the people who are willing to listen and learn then its all a dying art and we should give up now.....the same goes for those wishing to learn i suppose, we need to be able to approach those that can teach with the appropriate level of respect and willingness to listen and take the information and techniques we learn and then do the right thing with them...ie: practice, get better, perfect them and then pass on to anyone willing to do similar.
anyway the last few days i have been trying to just get some simple answers, just a couple of facts so i can move on and all i've had is frustration.
its a similar storyline to the recent post on calebs cro customs blog that i reposted a couple of weeks ago....its the same stuff really....just about the passing down of information to those younger so we can keep the circle unbroken.
on saturday im hoping i will have some answers....im taking my sprocket to see a man and his forge. ill let you know what happens.
11 comments:
I admire you so much mate for your dogged pursuit of knowledge.
I would have just found someone to do it for me and switched on the TV.
Hey Matt, a couple of years ago a certian person said to me " ya wasting yor time you can't build a Hot Rod!" From that day a fire was lit inside me and I knew that I had to prove this Fucking Not it all that I could do it. When I started it I too was a little frustrated with answers I was getting from the so called "experts", but as time dragged on with the build and my constant nagging and perservence I got the answers I was looking for. Most of the time it was grab a beer take a step back and look at it in different head space. Hope all is well down there mate.
Cheers Luke
Matt,
this is the very reason I retrained and began working as a teacher this year. We've got to soak up as much as we can from the old boys with the real skills and knowledge and pass it on before it dies with them.
Love the blog btw
-Pat
Matt, just do it. Heat the sprocket to 1650*F or close to it and quench it in oil, any oil. You can qluench it in water but that is too great a shock for the steel and it will break under stress. You can still quench it in water but you will have to put the part in a 350*F oven for about a hour or so to draw the steel back (we used to heat it with a torch until it turned straw color). When you quench it in oil it doesen't end up so brittle. Hang it from a 1/16" welding rod when you quench it and keep the part moving when it is in the oil until the oil and part reach the same temperature. This will keep the sprocket from having areas that are harder than others. Heat treat is only as complex as you make it. I don't think you are going to have to go to the moon and back on this bike so just do it. Check it with a file after you are done and if it files you didn't get it hot enough.
Regards
Greg Hornbostel
Hi Matt. I'm sorry to hear about those guys who don't want to help you learn about heat treating. It seems very silly that they are threatened by the idea of passing around knowledge. (i'm guessing that they have other issues too!)
Coincindentally, I just had the opposite experience regarding heat treatment. I've been emailing a friend down in Australia who makes big JAP vtwin racing motors, and he gave me some great advice about making crankpins, heat treatment, material choices, etc. And the local heat treater was a good guy too: he case hardened my pin for free when I told him it was for my old motorbike! ;) I'll share the story on my site pretty soon, and pass on the knowledge that I've gained.
Persevere, you'll learn a bit and pass it on to us too.
regards,
Pete
Hang in their Matt,
The Brilliance you have achieved so far can be measured as a threat to those that don't want to help.
This sort of information is available, quite often entwined in big thick, oil stained books.
one in particular that now forms part of my soul is 'The Machinery's handbook', this has everything you will need to complete your good work sir.
Good luck bro.
G'day Matt
It’s something I can relate to, as I have been blessed in having one of my great mates fall in the "older and wiser" category. As a young guy (training as a mechanic) having him to show me how to do simple (for him) things like rebuilding a dizzy, tuning up an old Holden by ear, sorting out a tipper tray on his 50s Willys Ute – the list could go on forever. He was happy to show a younger, eager me ‘how its done’ having learnt it all through necessity himself over the years. Writing this makes me realise how much it made me appreciate and respect all this older machinery back then, and that I have an interest (slight obsession?) in now.
Now as I slog my way as an older student (i’m not that far gone – haven’t cracked 30 yet :) )through my mech engineering degree, I can’t help but feel that setting points and re-jetting a carb are a dying art – but like all art, it will still have it followers who appreciate it for what it is.
All the best mate, I thoroughly enjoy your blog. Keep it up.
gents....thanks for the comments...and to all the blokes that didnt comment but emailed me and offered help and info...im getting back to you one by one....it means a shitload to me that you are all watching and care to contact me and help...this i suppose is the reason why i write this blog. thankyou all.
guy, thanks mate...im trying fucking hard to learn it the "real" way...you know.....it just seems so much better when you learn it from a bloke in his shed then on some internet site....
lukey, all is good here...too much work and not enough play make me a dull boy but i hope it wasn't me that said that to you....anyway....you did what you set out to do in perfect trademan style.....and you still owe me a ride...
pat...my father used to say when i was a kid that he thought being a teacher was "the noblest of professions"...and now i do agree with him....in a world of distorted truths, passing on true correct knowledge is paramount....thank you.
greg......good tips there....so are you saying to heat it to 1650 then bring it back down to 350 before quenching it?......
pete, whose the JAP guy down here...love to seek him out....funny, i look to you to be my technical assistant so i cant wait for your post...ill be waiting for my early morning email as i always do when i get up ....thank you my friend.
thanks ben....ill check it out...i thought i may have had that book then went searching through all my boxes...it was the modern machinist i had not the machinerys handbook...ill try to find it.
pat w thanks mate...nice words...they mean a lot to a bloke out in the bush.....good luck young bloke.
so, something i have learnt in the last 24 hours is most sprockets are case hardened.....not totally hardened.....that being..the teeth are hard and the centre of the sprocket has some flexibility that will stop it from fracturing under load......if anyone has any more thoughts id love to hear....
thanks again blokes....
I,m sorry i cant offer any advise in'case-hardening your sprocket', but i just wanted to say that i'm suprised and saddened that you have met so much negitivity when trying to learn. Most of the time i find that when i have sort knowlage, people have been really keen to help me out. I guess the fact that you have had so many comments and emails offering advise, means that people still do want to share wisdom.
Good luck
Rob
If you just need case hardening, not through hardening, you have some choices. The simple route is to use Kasenit or something similar. Just follow the instructions on the can, heat it up, quench in water, dip it in the Kasenit (I think it is just a carbon powder), then heat and quench. Basically, you need carbon for the heat treatment to make the steel hard. Some steels don't have much C, but Kasenit will deposit onto the sprocket. I wrote up a quick article on my site about it last year when I hardened some pushrod ends.
(in the old days, blacksmiths would use bits of bones and horns to coat the metal!)
Another option is to carburize the part. But that requires a trip to the heat treat shop, and they'll heat it up and coat it with carbon. Then cook it properly to give whatever case hardness you want. My last part was Rockwell C 62, which is pretty darn hard. .060" minimum thickness. That left me plenty of material so that I could grind off .010" to make the part perfectly round again. You probably don't need that much for a sprocket.
By the way, I've run a lot of sprockets with teeth that weren't hardened. They last for a while, but you'll want to make sure that everything is straight and true. Crooked sprockets wear out fast and break chains too.
Hey Matt, Gunna be working down your way soon with the RTA so will let you know and drop in. Also it wasn't you who said but when we catch will have a yarn. http://rodsfinksandweirdos.blogspot.com.au/ Also I started my own blog.
Cheers
Lukefink
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