Machining 70 degree angle

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Hanz
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Re: I thought this odd too...

Post by Hanz » Fri Jan 24, 2003 11:34 pm

Harold- Yes, it' s pretty neat stuff. If I find a link I will post it. It is what we use to build up (cast) crankshafts that are undersize. I had a cylinder head that someone cut the valve seat insert too deep, straight into the water jacket, and they filled it right up. From what I know, the part is preheated very hot, almost to the point of molten, before the weld is sprayed on. The great features of this repair is that it stays 'soft,' and will bond 100% without further cracking as in the case with using nickel rod.

I will post more info tomorrow- Hanz
[url=http://www.hanzenginehouse.com]www.hanzenginehouse.com[/url]

Harold_V
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Re: I thought this odd too...

Post by Harold_V » Sat Jan 25, 2003 3:20 am

Thanks for the description, Hanz. Now it makes lots of sense, especially on cranks, which are generally ductile iron, not gray iron. Ductile is far easier to weld. The part that I didn't understand was the preheat. With that, there's no reason for the parts to end up hard.

There are times when I wonder where I've been! I should have been aware of this operation, but somehow it had escaped me. Just goes to show you can't know everything! [img]/ubb/images/graemlins/grin.gif"%20alt="[/img]

Harold
Wise people talk because they have something to say. Fools talk because they have to say something.

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philinmt
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Location: missoula, montana

Re: I thought this odd too...

Post by philinmt » Sun Jan 26, 2003 11:57 pm

Harold, If you want I will get the names and numbers that supply the rod or powder for castiron, but it will put a real dent in your wallet(it runs over 100.00 a pound but there is a lot of repairs where it is worth it) ....Back to the 70 vee ,he needs to cut, It might be better to find the rise over the run of the angle and map it out for a ball endmill and bump cut it every .005 or so and then file it smooth. I dont think a stadyrest needs to be 100% right and it will be a good trick to get the vee and the flat right on..Phil in Mt

Harold_V
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Re: I thought this odd too...

Post by Harold_V » Mon Jan 27, 2003 2:09 am

Hi Phil;
That's a mighty fine offer, but my interest is more of curiosity than anything. I was quite surprised to read about spraying steel on cast, which really got my attention. The work I did in the aero-space industry revolved around a lot of aluminum and stainless, so I'm not up to speed with iron aside from knowing it's not easy to weld, which may help you understand my surprise.

If I was involved with heavy repairs, I might be quite interested in the magic filler you spoke of. I can't see me buying $100/lb stuff out of curiosity, though, especially on my social security income! [img]/ubb/images/graemlins/grin.gif"%20alt="[/img] At this point, I wouldn't have any use for it, but that might be different in the future when I start building a model locomotive.

Regards machining the 70° angle on the steady rest, I had suggested it be done in one setup to avoid the possibility of mismatch. Indexing it would be great if there was a good, solid face from which one could set up a second time, but steady rests don't generally provide such a feature, assuming it would have to be clamped to an angle plate. I failed to consider that the rest, when taken apart, may present a flat face that can be firmly clamped to the table of the mill, however, so if that were the case, I'd agree that indexing it and dialing it in would likely be a good way to go, necessitating only one setting of the head. It sure would be a lot easier to suggest methods if one had the parts in hand first!

The ramping you suggested would be a great way to make the cuts, but pretty cumbersome on a manual machine. I recall milling a helix that way once. The two hours it took would have been more like a minute or two with a CNC, but I didn't have one then, and I don't have one now. Just as well, considering what I know about CNC wouldn't fill a small thimble. I'm the old school kind of machinist, don't even use a DRO. [img]/ubb/images/graemlins/smile.gif"%20alt="[/img] Somehow I'm proud of that, for I consider it a sign of having truly learned the machining trade at a fundamental level. [img]/ubb/images/graemlins/wink.gif"%20alt="[/img]

I recall your futile search a few months back for an employee that knows the old ways. It's hard to believe that we're getting hard to find! Still, when I think about it, for the most part, the guys coming up today have all been on CNC stuff. It's a whole different world anymore.

You keeping busy in Montana? My nephew just sent a long article about how Montana and Wyoming are doing a lot better than a lot of other states. I'll send a copy if you're interested.

Harold
Wise people talk because they have something to say. Fools talk because they have to say something.

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philinmt
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Re: I thought this odd too...

Post by philinmt » Mon Jan 27, 2003 8:24 pm

Yes, but we are in a nitch market..We have the largest machinery in the state and have been around for over 50 years(my dad started the shop after ww2) Also there is very little we cant do. I like the cnc, but if i have a chose I will do it on the manul machines. My favoret is the vert slotter or the bullard vtl...the least liked is the lathe work making shafts. The truble with Montana is that we have no industry left, the mines are closed, and the sawmills are all but gone...some day we will have a real good auction, but I have my home shop just about set up and some of the big jobs dont have the spark thay used to have...must be gitting old...Phil in mt

Harold_V
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Re: I thought this odd too...

Post by Harold_V » Tue Jan 28, 2003 7:42 am

Yours is a pretty common story, Phil. Around our parts, loggers are having a tough time, though there will always be something to cut down. What and how they harvest has undergone a tremendous change in the last few years, however.

You're fortunate to have the work you do from all indications. Lots of shops going under these days. My old buddy in Utah had to let go his best man, had him for over 30 years. He's down to no employees and has to keep working to pay off the bank loan he got to try to keep his last employee, the one mentioned above. The thing that's so hard to deal with is that from the time he started his shop, mid 60's, he's never had a bad go of it. There were about 20 of us that started small shops, and almost to the man we had great success. Lots of work, and of good quality. Things are tough now, and may be getting tougher. Hard to say. There's lots of doom and gloom out there.

I was almost 55 when I retired. If you can see your way clear, go for it. My only regret was not retiring sooner, but an empty wallet helps make those decisions for you! [img]/ubb/images/graemlins/grin.gif"%20alt="[/img]

I've thoroughly enjoyed my retirement so far, but I've also had a lot to keep me busy. I don't think a guy would be well off to just sit. With a home shop, I don't know if that would happen, though. Keep a good thought! [img]/ubb/images/graemlins/smile.gif"%20alt="[/img]

Be cool!

Harold
Wise people talk because they have something to say. Fools talk because they have to say something.

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