Turning an Eccentric Cam on the Lathe: Hemingway Sensitive Knurling Tool Build - Part 5

Today we're continuing work on the Hemingway Sensitive Knurler kit. I've had my eye on this knurling tool ever since I first got my lathe, and now I'm finally building it. This is one of the classic British toolmaking kits, and building from someone else's design will be a new experience for me. Today, we're making the eccentric cam, slotting the arms, and making all of the fiddly little parts needed to complete the tool.

Tools used in this video:
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Licensed under Creative Commons: By Attribution 3.0 License

00:00 Intro
00:25 Turning the eccentric cam -- side 1
04:08 Drilling and threading the cam
05:54 Turning the second side of the cam
07:26 Turning the lower pivot pin
08:50 Turning the brass bushings
09:33 Making the lever arm
10:31 Making the Tommy Bar
11:18 Grinding a slotting tool
12:55 Slotting the knurl pins
14:39 Locating and drilling the knurl lock screw holes
16:45 Milling the knurl slots in the arms
19:38 Conclusion

[Preso]

Thanks James. It's very fortuitous that I'm about 2 weeks behind you on this project. The irony of needing a knurling tool to finish the knurling tool was not lost on me.

[Realtime]

Inheritance machining is doing the same tool and it's interesting to see how you both approache it

[GenericAnimeBoy]

The collet block in the 4-jaw was a good call on as far as conserving setups. Very nice!

[andersmansdotter]

Extremely well done commentary of the processes. Haven't been to your channel for a long time. You have really increased your number of tools and seem to make great use of them.👍👍👍👍👍

[TimWelds]

Looking great! This has been a fun build series to follow along on.

[roylucas]

Great video. It’s so good to pickup new techniques. With a little luck these new techniques will turn into new skills. Thank you.

[DK-vxzc]

great job! great narration and videography. Love the CAD modeling, gives great perspective

[Cenedd]

Hi James. That carbide parting tool looks like an MGMN-200. You can pick up MGGN200 inserts for aluminium from the usual import places. They're already sharp and seem to do a much nicer job on aluminium and steel on my 'smaller' lathe (a Sieg SC4 - I think they call it an 8.5x20).

[twobob]

Lovely job as ever, I'm still loving the new backdrop. Fannncy.

[rak]

Excellent work as always, and very enjoyable to watch. You have pointed out many times the importance of removing a cutting/threading tool before removing a part. I've had many cuts from small end mills by forgetting that. Maybe have another look at your video where you remove the 2nd arm after threading? 😀

[davidthompson]

From the time you started spinning the lathe it looks like the part is wobbling. Was that intentional as discussed in earlier comments or am I wrong in my understanding or the part is not wobbling?

[mocarp]

The cutter spun up with the draw bar tightening with your hand there and then what looked like you instinctively reached in as if your were going slow down the bottom of the arbor. After seeing that I realized how close you came to getting a serious boo boo and I got a sick feeling. At first I thought you hit the on lever too soon. I am always amazed how quick an injury can occur. Glad you came out unscathed (physically). Did you have to take a break and change your shorts?

[AmateurRedneckWorkshop]

Well done as usual. Thanks for the video keep on keeping on.

[joat_mon]

Nice work!
Great video. Can't wait to see the tool in action.

[DavidLorenTosh]

“we aren’t animals, after all” just earned a comment! 🎉

[Cjarka_]

I have noticed that any 2 flute endmill doesn't really make a smooth cut unless it's slotting because the tooth always leaves the cut before the other tooth cuts in

[matthewspitz]

Oh those animal separating chamfers…😂 7:05

[adamalterman]

I noticed your tip-of-the-hat to Blondi Hacks with your comment about chamfers. No complaints, though, now a days, not referencing your source might bring you criticism. Not all of us are "animals." :)

[HM-Projects]

The parts look great, you make it look easy as usual. I guess you're getting popular, so many targeted spam comments 🤣

[kevinarndt]

11:28 What is the make and model of your end mill grinder?