RedlineMan
Hot Rolled
- Joined
- Jan 29, 2012
- Location
- Vestal NY
Hello All;
WARNING - THIS IS OFF TOPIC. To those with a bug about that, keep reading, because this may actually provide some benefit for those doing something similar. I am using my old machines to make the pieces, so there's your hook, if you insist on one.
I am posting this here because machinists in general are great problem solvers. Those working on old machines are more-so. If you happen to be an OLD MACHINIST, then you are DEFINITELY a good problem solver, and just who I need to hear from.
I am looking for ideas on how to splice two shafts together to create an intermediate shaft for an automotive project. I have some concern about utilizing a method that will be as foolproof as the normal shafts are on these cars, which means I've never seen one fail even working with many hundreds more HP than they came with originally.
In the accompanying photo, you see the two shafts in question. The shaft section at the rear was harvested from a junk transmission fitting the CAR in question. The OD is as original, and it will be linked to the main driveshaft behind it via an OE coupling sleeve. The shaft in front was also harvested from a transmission, in this case that fits the ENGINE in question, or more precisely it's clutch disc, and will be turned down to the same OD. I have already made the pilot bearing pin you see pressed into its spline end. It had a nice machined ID, albeit for another purpose, and that application did not use a pilot bearing in the crankshaft. The pilot bearing pin was a hole other interesting and exciting adventure in and of itself, but I digress.
After a lot of wrangling about how to achieve this union, I've landed here, hoping to bring them together via a turned sleeve that they will press and weld into. The fit will be tight enough and the sleeve long enough that I am assuming a nice square and even registration of the two sections of shaft by default. The problem now is that I want to assure that I am as close as possible to approximating the spread of load throughout the entire assembly, as though it was one solid bar as per original.
My notions of a sleeve started at about 2.5" in length, about 1.5 thou less in ID than the shaft OD, at least .125" in wall thickness, and turned from a nice length of W1 tool steel I have. My first thought was to simply TIG weld each end, but as the concern over load transmission creeped in, I began thinking of ways to further integrate the pieces of shaft together over more of their length. Concern over concentrating too much load right at the welds brought me to the notion of only partially welding the ends, say at 12 and 6 o'clock, and then staggering a couple of plug welds in the body of the sleeve, at 3 and 9 o'clock, halfway toward where the ends of the shafts meet. Then I thought of making the sleeve much longer and doing more plug welds along its length. I've even wondered about some way to key the assembly together internally. I'm far removed from the ability to grind my own spline, or machine and broach the bits square.
Problem is, I've got ideas, but no real experience at this. The main goal is one and done; never having to build a second one. I'd much rather be accused of over engineering than ignorance, so any and all ideas are most welcome, and appreciated.
WARNING - THIS IS OFF TOPIC. To those with a bug about that, keep reading, because this may actually provide some benefit for those doing something similar. I am using my old machines to make the pieces, so there's your hook, if you insist on one.
I am posting this here because machinists in general are great problem solvers. Those working on old machines are more-so. If you happen to be an OLD MACHINIST, then you are DEFINITELY a good problem solver, and just who I need to hear from.
I am looking for ideas on how to splice two shafts together to create an intermediate shaft for an automotive project. I have some concern about utilizing a method that will be as foolproof as the normal shafts are on these cars, which means I've never seen one fail even working with many hundreds more HP than they came with originally.
In the accompanying photo, you see the two shafts in question. The shaft section at the rear was harvested from a junk transmission fitting the CAR in question. The OD is as original, and it will be linked to the main driveshaft behind it via an OE coupling sleeve. The shaft in front was also harvested from a transmission, in this case that fits the ENGINE in question, or more precisely it's clutch disc, and will be turned down to the same OD. I have already made the pilot bearing pin you see pressed into its spline end. It had a nice machined ID, albeit for another purpose, and that application did not use a pilot bearing in the crankshaft. The pilot bearing pin was a hole other interesting and exciting adventure in and of itself, but I digress.
After a lot of wrangling about how to achieve this union, I've landed here, hoping to bring them together via a turned sleeve that they will press and weld into. The fit will be tight enough and the sleeve long enough that I am assuming a nice square and even registration of the two sections of shaft by default. The problem now is that I want to assure that I am as close as possible to approximating the spread of load throughout the entire assembly, as though it was one solid bar as per original.
My notions of a sleeve started at about 2.5" in length, about 1.5 thou less in ID than the shaft OD, at least .125" in wall thickness, and turned from a nice length of W1 tool steel I have. My first thought was to simply TIG weld each end, but as the concern over load transmission creeped in, I began thinking of ways to further integrate the pieces of shaft together over more of their length. Concern over concentrating too much load right at the welds brought me to the notion of only partially welding the ends, say at 12 and 6 o'clock, and then staggering a couple of plug welds in the body of the sleeve, at 3 and 9 o'clock, halfway toward where the ends of the shafts meet. Then I thought of making the sleeve much longer and doing more plug welds along its length. I've even wondered about some way to key the assembly together internally. I'm far removed from the ability to grind my own spline, or machine and broach the bits square.
Problem is, I've got ideas, but no real experience at this. The main goal is one and done; never having to build a second one. I'd much rather be accused of over engineering than ignorance, so any and all ideas are most welcome, and appreciated.
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