Internal Splines (and Hexes Too) 

A couple things keep coming up in the comments, so I figured I would address them here: In getting ready for this, I was able to find the pats diagram for the pump, it shows a one-piece, rigid coupler attached to the shaft. In fact, the shaft and coupler are listed as one part number. It’s not a lovejoy or other sort of flexible coupler. And yes, the fit on the spline as shown is probably a little tighter than it should be, but after several rounds of assembly and disassembly, the fit did loosen up a bit. I’m assuming there are some small burrs in there that got knocked down. If I had to do it over again, I probably would make take another .001 off. Additionally, the hex shaft is about .003” under the nominal dimension, and I made the broach to the nominal dimension, so there’s some wiggle on the connection on the hex end, so I’m not particularly worried about misalignment or vibration issues. Also, a flexible coupler probably wouldn’t have fit in the pump housing. The other two things that come up are 1) why not modify the shafts, and 2) why buy something to make it work. The answer is: because Jeremy Makes Things. I wanted to see if I could do this, and do it as close to the right way as possible. I knew the theory behind doing an internal spline, but theory and practice are two different things. I wanted to push my skills. As happy as I am with the end result, this project was just as much about going through the process.

I just love when somebody else volunteers your services

I love your "toolception". Making a tool, to make a tool, to make a part to fix a machine.

Nice to see a machinist who is more about the work and less about the image and vanity. Great to see real old school tools being loved and worked. Subscribed on first go.

You know you achieved complete machining self-reliance when “That’s probably not the last one of those I’m making” Is followed by making a goddamn broach. And to prove it, just make another one! Awesome job!

We had a spline shaft come in pieces, to the shop. I made a series of kerfs, carbonized it, and heat treated. Made a short broach to clean up the spline. Used a dividing head for the shaft. I think you should always knurl, as slow as it goes. Too often, the knurling wheels, weld on to the pins. Can't keep enough oil on them, knurling can produce a lot of heat.

This was great to watch, I’m a retired automotive engineer and have always been fascinated by one off projects like this. Bravo!

Jeremy, Thank you for sharing your (mostly) entire thought process plus the "oopses" that you ran into instead of doing like most channels that "hide" their mistakes and other things that don't go correctly. Seeing how another home shop Machinist goes about a job with similar (actually better! ;) equipment and raw materials is very helpful as well as giving an idea of that "aw sh**s" to expect is worth its weight in RU-vid gold!

Remember, "Persistence is the bitter part of valor."

I was really impressed not just by your skills, but your camera work, narration & the inclusion of issues in this difficult project. I believe this demonstrates your high intelligence & educational ability. Any student would be lucky to have you as an instructor. 👍

One tip, always use cutting oil when threading whether taping, using a thread die or single point threading and when broaching.

Meine Hochachtung für diese gute Arbeit.

Think the world forgot about good tool die maker. Everything that works mechanically has a good tool maker behind it. Thanks

I dread to think of the number of hours you put into this, but the results are very pleasing! I think a machinists jack might have been useful under the end of the workpiece on the shaper, it did seem to be deflecting a little.

I have a machine that requires a splined receiver/coupling for a splined metric shaft. I can't believe how hard it has been to find one. You've made it look like child's play.. Great job!

Thank you! As an old fellow who's been around and seen a few things . . . I learned a few things and was entertained in the process! Thanks again. You have a new subscriber.

Your skill at machining is amazing. You put all of the effort in your projects and they surely pay off! I still can't believe you just have 8k subscribers

Impressed with you making your own broaches, had never thought about that before. Definitely subscribing to see what else you build in the future. Great stuff!

I'm pretty impressed by the homemade square broach! Well done...!

Second time watching this. Thanks again for wonderful content and education.

That was awesome. I admire your patience and commitment to this project.

No c n c here, just pure talent

Congratulations Jeremy, your persistence and make-do attitude are always inspiring and the end result is a complete success!

2:12 "No one's ever gonna see that!" Over 214,000 people did! 😁 Nice work 👍

i like your sense of humor.. Seeing that i am not the only one, whose stuff flying around and never got found again , and also things just go wrong, get me a feeling, Not to be alone in a world, where people got hated by things.

Fascinating! I'm happy the algorithm suggested it.

You and Rustinox sure make a good case for the shaper. I definitely want one now. Thanks Ron

Very nice job. Hours of love went into that project.

Thank you for your authenticity in sharing this project! I so admire your abilities to adapt and overcome issues.

That was awesome to watch, you're a really skilled machinist.

I loved reading your whiteboard. Always subtle. Thanks for sharing

2:16 when you do a bunch of passes in fast forward, then show one pass in real time, my brain instantly goes “This is either the finishing pass, or the *disaster strikes* pass.” 😂 Also, love the to do list on the white board!

Jeremy, a while back I had a similar problem with a splined shaft from a Volvo Penta transfer shaft. In my case, splines were worn due to hard shifting and the metal not being hard enough. So, I simply converted the splined shaft to a hexagon and that made the process much easier, not to mention harder to wear down. Great job. A pleasure to watch as always. Gilles

Very nice video of making parts that match through trial and success. I especially liked watching the test runs before taking on the final piece.

Great job! So fun to watch. This is really splendid workmanship! 🙌

Very impressive spline work!

You crazy son of a B, you did it!

So cool to see this and the video of Andy’s Machines doing it similarly but vertically with that internal cutter he made. Great video! As always 😊

Excellent job on this. I hope you keep making videos.

That was excellent young man. 😊

Thanks for helping man. I live nearby. Crazy I stumbled onto your video. Very cool

Great result, well done. Thanks for sharing and explaining the process. I have watched a lot of Rustinox videos. He explains things well and add a lot of humor. I find those shapers fascinating. I'm hoping that one will come up at a good price one day...

I love hearing the thoughts and mindset of kindred spirits. My first video of yours, and I thoroughly enjoyed it. Nice calming voice, and the patience of a cat. 👍🇿🇦

A mighty fine effort, Jeremy. As you point out there is a world of difference between theory and practice. You mastered both!

Great stuff, I appreciate the subtle humor as well.

That's a freaking amount of time and effort you put into the project, thank you for the video. Subscribed.

I can watch your machines all day. Awesome videos guys.

Nice job! I recently did a simple keyway broach, and then used what I learned doing that to make a backface borer. Seeing the same idea used to make custom spline shafts is really cool.

Very nice project. You did an outstanding job. Thanks for sharing. Take care, EM.

You made a square broach and then used said broach without cutting oil, absolute rockstar!

Netflix: Are you still watchin? Someone Daughter: 22:03

Loved it. Yours is one of the most refreshing and honest machining channels out there. Love the seat-of-the-pants engineering, and the excellent result at the end. I would find making those parts way too intimidating, and put it off for years, so hats off to you for getting on with it. Keep on keeping on 👍

You've just put me off ever using an internal spline :)

That was a lot of effort and expertise. I'm blown away.

Really impressive work.

Your skills have elevated you above the realm of mortals. Well done Sir.

That was very interesting and a very good job. I'm impressed!

fantastic work, well done

Liked that the build had a meaningful purpose. Great video

You did a great job at making this look crazy simple. Incredible job! Great work! Thanks for sharing..

Always inspiring to see someone engage brain and not give in... My projects are no where near the complexity of this one, but after watching this, I now know not to give in!

Excellent work! Very interesting and much enjoyed! Thanks for sharing.

You've got some great skills and tools to put them to use - colour me very impressed! I really enjoyed that video

I think I found my favourite machining channel. Awesome how you share your process: like this might be a failure but here's how well find out or run it out. Excellent vid

Had a project coming up so I watched again, I will have to do it with my lathe to push the tool with the saddle.

Broaches. Brilliant.

Fantastic work, very entertaining to watch.

I work in an old school machine shop. Never made a broach, so I appreciate your efforts.

Amazing job Jeremy.

Amazing video! Well done

I envy you i no longer have a machine shop to work in great job

Impressive work and patience!!!

Loved it and it was kind of pleasing to see that I am not the only one to make mistakes.

Holy damn! This is really high quality content. Thanks for taking your time to show us.

Excellent real craftsmanship!!!! Awsome!!!

Thanks for sharing this with us.

Thank you for helping out a community ski hill!

Sometimes the Recommended knows exactly what I’m in the mood to watch. This was very engaging, thank you. Subbed.

Very interesting, like the broach making process, also small indexing head.

Thanks for continuing to post great content.

I love the fact that your knuckles are positively devastated with cuts and Knicks lol, that's evidence to me that you've been fighting with this for a while!

excellent work. thanks for sharing

Thanks for sharing. Great work !

This is an excellent trade to have under your belt..you will never go hungry..

Hi Jeremy, That was a really Tough Project, but you got it done. Hats off to you. After I get a new Lathe, a Shaper is going to be the Next Machine on my List. Great Job.👍

Well done Jeremy the end result is top notch.

10 out of 10 for persistence! Very impressive.👍

“Replace entire jeep” haha very nice!

Very good job !!! ...It is good to see someone that can do something with out a ""CNC"" and a stack of lap tops

Good job friend. Really good thorough work.

Really enjoyed the content, Jeremy. Good job!

Well as an amateur, I found this video absolutely fascinating. Thanks very much.

Your knowledge is very good.

Brilliant! Thanks for sharing 👍 🇬🇧

Really nice work and a lot of it ..

Well done!

This is inspiring! Thank you for sharing!

That was a head scrather but fun to watch....nicely done.

You the man, nice work! Keep em comin! Enjoyed watching!

That part came out awesome Jeremy👍 I know for certain I couldn’t build that coupler….especially dealing with splines. You did a really good job there….something to be proud of🙂