P&W 1830 Radial in 1/6 scale.

[Bill Gruby]

I forgot, the crank parts have an interference fit and also 3/0 Taper Pins holding then together.

"Billy G"

[petertha]

(02-28-2013, 11:45 PM)Bill Gruby Wrote: You got it, that's exactly how it will work.

I may have a similar issue on a radial design I'm working on & would like your opinion. How are you retaining the crankpin ends to front & rear crankshaft segments so the shafts are perfectly aligned & the assembly is removable for tear down one day?

I dont think I could fit the crankshaft + master rod as a pre-assembly into my crank case, so it would have to go in order like below. I was visualizing something like a set screw with extended pin segment. This could screw into the web part & pin extend into the crankpin itself. Kind of like a jesus bolt principle. I could reach the screws through a cylinder opening in crankcase. I thought about tapered pins, but with locktite or whatever, I guess that would be permanent, no? Ive also seen where the webs are slotted accross the crankpin hole & the pin is knd of clamped in place. Seems like a lot of effort.

I think my assembly would only fit something like this:
- rear crankshaft half into crankcase through front of case opening, align into rear bearing
- master rod in through CC front, wrist end up into #1 cyl hole
- crankpin comes in, through master rod hole & set into rear crankshaft half
- front crankshaft half into CC through front, it then aligns to crankpin
- button up with CC front cover, front bearing alignment etc., crank journals now aligned to common axis.
- now...somehow 'fix' the crankpin to both front & rear crankshaft web elements

A picture would probably be much clearer. I dont want to subvert your nice post. Just let me know & I can take it off line.

[Bill Gruby]

Sounds like extremely tight quarters. Let me think on that one and see what I can come up with. Is yours a single row radial?

The proverbial square peg in the round hole (broached square) It's starting to look like a crankshaft.

"Billy G"

[sasquatch]

Interesting stuff Bill, thanks for posting this.

[Bill Gruby]

Last one today sas, I'm beat. Finish shape of bottom end. Top end tomorrow.

"Billy G"

[f350ca]

Looking real good Bill.

[Bill Gruby]

Front bank of crank is done. 30 hrs. so far in this crankshaft. Onto the second bank, have fun.

"Billy G"

[TomG]

Nice job Bill, it's amazing how fast the hours add up on these projects. How are you going to finish the bearing surfaces?

Tom

[Bill Gruby]

Time adds up for sure Tom. You don't see it till it's done. Bearing surfaces will be polished with honing oil and 600 Crocus Cloth.

"Billy G"

[Bill Gruby]

Another drive gear needed to be added. This time a modified Boston H3230. Bored and hub turned off, It's done.

"Billy G"