The Bucket Foundry

**F5 Dave** · 25th May 2014, 20:42

My MB is done that way

**husaberg** · 25th May 2014, 21:49

Originally Posted by HenryDorsetCase

dont laugh at me if this is a stupid question but could you offset grind the crankpin to get the result you want?

Originally Posted by Kickaha

Not stupid at all, we did exactly that by starting with a bigger pin than we needed for my GN and which is a far superior bike to the one Husaberk is building because it actually runs and finishes races

20mm pin 24mm hole would only work with 2 piece bearing

**husaberg** · 25th May 2014, 21:51

Originally Posted by F5 Dave

My MB is done that way

You have a 20mm hole 22mm bearing

**F5 Dave** · 26th May 2014, 19:38

Oh yeah right, I think no one understood the way around.

**husaberg** · 26th May 2014, 19:56

Originally Posted by F5 Dave

Oh yeah right, I think no one understood the way around.

I think I will ask marsheng he's the guy that did it for shitkicka' grumpy I understand did the rest warwick supplied the witty reparte and the foul odours........

**Kickaha** · 26th May 2014, 20:01

Originally Posted by husaberg

I think I will ask marsheng he's the guy that did it for shitkicka' grumpy I understand did the rest warwick supplied the witty reparte and the foul odours........

Grumph came up with how to do it though and luckily enough the DR200 pin works out spot on for the offset grind to get the stroke right, a longer rod and fit the 125 webs

**Grumph** · 26th May 2014, 20:06

Originally Posted by husaberg

20mm pin 24mm hole would only work with 2 piece bearing

Okay, you've already heard one of my suggestions - here's a more complicated one...

Make a pin from scratch - not hard i've made around 6 so far....this has a 24mm end and an offset 20mm shank. the 24mm end is only as long as the drive side web is thick, the 20mm dia offset ground remainder is the rest of the required pin length.
The timing side crankweb is bored maybe 26mm and a bush pressed/welded in and bored to the stroke you want.
The pin offset is obviously the same figure as the stroke reduction in the timing side web.

On the other site your comments obviously indicate a reluctance to finish up with an undercut on the mainshafts - this way you'd only have an undercut on one side - and it's the least loaded - and full engagement of the pin on the other side.

Yes, maximum offset on the pin will only give a stroke reduction of say 3.9mm - 2mm offset = 4mm stroke remember....How much do you need to reduce it anyway ?

Complicated, oh yes, do able ? yes again - but the bore and bush option is IMO still the best.....

**husaberg** · 26th May 2014, 20:16

Originally Posted by Grumph

Okay, you've already heard one of my suggestions - here's a more complicated one...

Make a pin from scratch - not hard i've made around 6 so far....this has a 24mm end and an offset 20mm shank. the 24mm end is only as long as the drive side web is thick, the 20mm dia offset ground remainder is the rest of the required pin length.
The timing side crankweb is bored maybe 26mm and a bush pressed/welded in and bored to the stroke you want.
The pin offset is obviously the same figure as the stroke reduction in the timing side web.

On the other site your comments obviously indicate a reluctance to finish up with an undercut on the mainshafts - this way you'd only have an undercut on one side - and it's the least loaded - and full engagement of the pin on the other side.

Yes, maximum offset on the pin will only give a stroke reduction of say 3.9mm - 2mm offset = 4mm stroke remember....How much do you need to reduce it anyway ?

Complicated, oh yes, do able ? yes again - but the bore and bush option is IMO still the best.....

I think the bush solution is best I can get excentric pins, but doubt they will be long enough for the nsr ,why is the weld and fill such a bad idea? Is it the distortion, or cause it would result in a bad finish internally

**Flettner** · 26th May 2014, 20:37

I have welded and remachined crank pin holes before, just have to be careful of what the crank is made of. It might harden up after you have welded it ( probably need to let the weld cool slowly ), this will then require internal grinding, another level of cost complication. Seem's my old Kawasaki cranks wern't made of anything too special they welded and machined ok. I just used standard old low hydrogen arc rods.

**Grumph** · 27th May 2014, 06:37

Originally Posted by Flettner

I have welded and remachined crank pin holes before, just have to be careful of what the crank is made of. It might harden up after you have welded it ( probably need to let the weld cool slowly ), this will then require internal grinding, another level of cost complication. Seem's my old Kawasaki cranks wern't made of anything too special they welded and machined ok. I just used standard old low hydrogen arc rods.

All true...Yes, distortion is to be avoided. The kawa cranks would have been a forging, that mob are very good - but conventional - engineers. The crank husa is looking at may be a casting....Honda....Send Flettner a closeup of the inside of the webs Husa for his opinion cast/forged.
i've been saying grinding too LOL - Flettner, these guys are happy to simply bore a web for a pin....then run it to 13 plus. I'd happily pay the extra for precision grinding even if it hadn't hardened.

**husaberg** · 30th May 2014, 21:01

seen this...
http://thekneeslider.com/pattern-mak...musket-v-twin/

http://thekneeslider.com/casting-the...v-twin-engine/

**husaberg** · 30th May 2014, 21:16

might have posted this one before.....
But it has what I am looking for.....
http://www.autospeed.com/cms/article.html?&A=112614

**WilDun** · 31st May 2014, 19:07

Originally Posted by husaberg

might have posted this one before.....
But it has what I am looking for.....
http://www.autospeed.com/cms/article.html?&A=112614

HUSA,
That's quite a good site for a beginner (like me) pretty clear descriptions and of course, related to bikes!
I have got my furnace mostly all cast (in refractory concrete) and it will also be wrapped up with ceramic wool - I got that for nothing and it saved me $80 or so on refractory concrete ! - it's all a little harder to do than it seemed at first! - but maybe soon ....... who knows