Author Topic: new sohc crankshafts anybody?  (Read 2330 times)

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Offline turboguzzi

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new sohc crankshafts anybody?
« on: March 21, 2015, 01:24:04 AM »
be warned, 15 mins needed, but well worth it.....


just in case anybody was worried that new cranks cant be made :)

sure, not a sohc's but....

Offline bwaller

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Re: new sohc crankshafts anybody?
« Reply #1 on: March 21, 2015, 04:41:17 AM »
Amazing.

Offline 754

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Re: new sohc crankshafts anybody?
« Reply #2 on: March 21, 2015, 08:27:11 AM »
 Watch Bost Crank manufacturing...really big stuff..
« Last Edit: March 21, 2015, 04:47:35 PM by 754 »
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Offline Old Scrambler

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Re: new sohc crankshafts anybody?
« Reply #3 on: March 21, 2015, 11:06:53 AM »
Cool 8) 8) 8) 8) stuff ;)

Apparently the machinist is now a 'techy' ;D
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Offline strynboen

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Re: new sohc crankshafts anybody?
« Reply #4 on: March 21, 2015, 12:42:25 PM »
its the most boring job ..to be operator..and programmer..on this machines.the days feel like veeks


.the best job are at the prototype shop..hvere you vork direkt under the ingenør..and can have influense on the job.

and use old types lathes and tooling machines .its real nice to fabrikate parts..to perfekt a machine..or thange /update older machines..have vorked on a ediketerings machine..vho puts marks/edikets/labels, on medicine packings..use printers direkt at the packing lines..

at the prototype shop..you hgave to thek the clock..or you gets home more auers to late evry day..it vas a fantastic time..until the shop moved to polen..and all men vas fires...free market and that stuff..polish dont pay tax.( or less).and got half paying at danish vorkers
i kan not speak english/but trying!!
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Offline simon#42

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Re: new sohc crankshafts anybody?
« Reply #5 on: March 21, 2015, 04:47:28 PM »
i would hate to be the person that programmed that , how many different operations and tool changes were there !
was surprised at how much metal it could remove in one pass .

Offline 754

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Re: new sohc crankshafts anybody?
« Reply #6 on: March 21, 2015, 06:24:16 PM »
Any crank like ours can be made for 4-6K if there was a demand..
If you want to see big metal removal watch the Bost Crankshaft video..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline turboguzzi

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Re: new sohc crankshafts anybody?
« Reply #7 on: March 22, 2015, 01:43:11 AM »
simon, it's all in the cement carbide tips AND huge horsepower lathes and millheads.
back when i was in tech school learning turning, a 0.1" / 2.5mm pass on quality carbon steel would be regarded huge, now seems to be common place.

Offline 754

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Re: new sohc crankshafts anybody?
« Reply #8 on: March 22, 2015, 03:15:32 PM »
It's more rigidity than horsepower. But that helps..
 You may be off on you tradeschool good cut depth description..my little southbend. Could handle half of that in mild steel with a HSS cutter, and it had maybe 3/4 horsepower.


On another note..there is a bout a 32 inch lathe near me, they were cutting 5/8 depth of cut in Chrome-moly..I think 4340..... And they grenaded the gears out of the headstock..! ! ! !
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline kmb69

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Re: new sohc crankshafts anybody?
« Reply #9 on: March 22, 2015, 05:07:22 PM »
I was a machinist for Schlumberger in the early 70's and we routinely removed .75" depth of cut, 1.5" off the diameter, on 9" diameter heat treated 4340 bars.
Running 450 SFM at .032 IPR, it was a 75 horsepower cut on Lodge & Shipley ProfiTurn 40's. The chips could hurt you real bad, almost DEADLY!

Offline turboguzzi

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Re: new sohc crankshafts anybody?
« Reply #10 on: March 24, 2015, 02:44:37 PM »
could be my memory playing tricks (it's been 35 years ago...) or that we, the young dudes, were given the weak lathes to cut our teeth on....
rigidity, sure counts. the cool old italian lathe in my workplace was replaced with some chinese cxxp because it didnt comply to safety standards anymore, and what a joke, need to tighten up the bed adjusters screws anytime i need a smooth cut.

Offline simon#42

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Re: new sohc crankshafts anybody?
« Reply #11 on: March 24, 2015, 04:33:38 PM »
perhaps it was the way we were taught yossef ?  either that or my memory is as rubbish as yours !
the chinese lathes do seem to be built down to a price  [ a price you cant make a good lathe for ]

Offline 754

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Re: new sohc crankshafts anybody?
« Reply #12 on: March 24, 2015, 08:51:26 PM »
I will say 75 hp lathe better peel off metal..my 7.5 hp is not too shabby at it..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Trad

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Re: new sohc crankshafts anybody?
« Reply #13 on: March 24, 2015, 09:40:20 PM »
That was incredible.
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Offline turboguzzi

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Re: new sohc crankshafts anybody?
« Reply #14 on: March 26, 2015, 02:54:04 PM »
out of curiosity did a quick check  and the baby in the video is 80hp :)
they have bigger 170 hp things too :O

Offline kmb69

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Re: new sohc crankshafts anybody?
« Reply #15 on: March 26, 2015, 07:01:14 PM »
I will say 75 hp lathe better peel off metal..my 7.5 hp is not too shabby at it..
Our L&S's were 60HP lathes running at 125% spindle load. But it requires a combination of spindle HP, X-axis HP, and Z-axis HP to take those kind of cuts.

out of curiosity did a quick check  and the baby in the video is 80hp :)
they have bigger 170 hp things too :O
The company I just retired from has 3 of those WFL's in Fryeburg, Maine. They are BAD BOYS!

Offline iron_worker

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Re: new sohc crankshafts anybody?
« Reply #16 on: March 27, 2015, 03:37:27 PM »
Wow, I need to work at Bost!  8)

IW

Offline 754

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Re: new sohc crankshafts anybody?
« Reply #17 on: March 27, 2015, 07:15:54 PM »
Bost = badass big machines..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline SOHC4 Cafe Racer Fan

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Re: new sohc crankshafts anybody?
« Reply #18 on: March 29, 2015, 03:18:39 PM »
Awesome video.
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