Hemingway Sensitive Knurling Tool Build - Part 1

Today we're starting a new project: the Hemingway Sensitive Knurler kit. I've had my eye on this knurling tool ever since I first got my lathe, and today we're going to build it. This is one of the classic British toolmaking kits, and building from someone else's design will be a new experience for me.

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

00:45 The design
07:05 The stock that comes in the kit
08:36 Drilling and reaming the guide plates
10:54 Slotting the side plates
12:52 Drilling and reaming the arms
16:21 Boring the trunion hole in the upper arm
22:33 Conclusion

[darylmorning]

Great respect to honoring their copyright. Honestly, I never would have thought about the "freeze frame" issue. Well done.

[philipzielinski]

Must be Knurlier season. First Adam Savage, then Quinn, now you. Interesting to see the different setups.

Also, thanks for being transparent about mistakes. It helps to know that not every cut goes as planned for you and the other top-shelf YouTube machinists. Helps us know when we goof we're not alone.

[jonofalltradesmasterofnone]

Great video as always,
I've just turned 58 and my introduction to machining anything was using imperial Fractions I was lucky enough to live next door to brilliant toolmaker, design engineer (Mr A. as we all knew him then) back in 1977. One thing he impressed on me was to work from first principles i.e. a imperial rule has the ability to measure down to 1/64 or 0.0156 the last 2 digits 25 are not important as that is a tolerance beyond the machines we were using (Myford super seven and a Dore Westbury Mill, self built by Mr A.)

Following this, I did my time (apprenticeship with a small company who insisted on using imperial but not with fractions but with decimals), however as I had learnt to use the fractions the decimals came easy and my mental maths was even better. When I left that job my next was with a company that insisted using metric but they needed to convert old imperial designs to metric so that was when the numbers 25.4 and 39.37 came back to me.

The Hemmingway kits have been around for probably 40 years but they always include everyone old or young in their drawings and instructions.

i'm about to start one of hemmingway's wobble broaches.

Keep the videos coming.
Jon.

[FireGuy]

I appreciate when you acknowledge a mistake, but I love that you acknowledge perfection isn’t needed either. Understanding where tolerance matters is a skill

[SWF]

Just want to say that I appreciate the effort and knowledge you put into your videos. Not sure why I watch them as I’m not a machinist but I enjoy learning about it. I’m a aircraft tig welder (build xray fuel lines for Lockheed f35) so maybe that’s why I enjoy the attention to detail and tight tolerances you follow. Thumbs up from me and hope you keep this type of content coming!

[MichaelLloyd]

First the sensitive knurler. Then the affectionate knurler. Followed by the ?? irritated knurler? What a great series!

[georgespeake]

I appreciate your teaching style because you make us who are novices comfortable and you include mistakes that make me feel competent. God bless!

[anonymousone]

Hi Clough. Something I realized a long time ago. When boring/reaming holes, I found that reamers were sometimes inconsistent maybe because the chip load is too great and forces the reamer off center a bit. Small holes are the worst. What I found that might help when reaming is to keep in mind almost all carbide end mills are slightly undersize. I drill the hole obviously undersize and then use the appropriate endmill to finish the hole to about .001" undersize. Then, If I want to ream it, then I just ream it to the exact size. Only reaming .001 creates very few chips, so the hole comes out pretty exact. Measure the endmill diameter before using this method. Also, be sure the mill collet has no noticeable runout.

[martinforrest]

‘Razor sharp helicopter’ made me laugh out loud.
Look forward to waking up on a Sunday morning (in UK) to watch your latest video. I know they are a huge amount of work but please keep them coming.

[Preso]

This is great. I'm due to start this same project very shortly. I have the drawings but I'm sourcing all the materials myself. I even got the Hemmingway knurls.

[jameskilpatrick]

I love that you call out the beauty and quality of the drawings, but still point out the problem of the old Imperial style of dimensioning as it relates to modern decimal DRO use. Thanks for being respectful of a legacy system while at the same time showing how to bring it into harmony with modern methods. I love your content. Thank you! :)

[kensherwin]

70 years ago, my dad would tell me that the difference between a poor machinist and a good one is how well he fixes his mistakes.

[alander]

Great project. I have been thinking of making the same tool. years ago I searched the internet for Hemingway and Malco info and pics. . By gathering some published measurements and scaling I 3Dmodeled the knurler. Had fun doing it, and enjoy looking at the exploded view of your model. I have yet to make it, but will enjoy watching you make it. I've been in the trade for 45 plus years making prototype one off parts for a engineering group, mostly precision hard tooling and tight tolerance NPI parts. I smiled when you beat yourself up for missing your goal of precision " Chasing Tenths ". Once you get your surface grinder you won't be happy with a milled finish. Thank you for all the efforts you put into your video's, very polished . Maybe when I retire ( still enjoy it and not ready to give it up) I will make one.

knurler.

[lv_woodturner]

When I do wood work, I use fractional imperial since I grew up with these measurements. Tolerances are normally not an issue.
When I do metal machining I use imperial decimal. This is so easy with machine tools like calipers, DRO etc. Tolerances can be required.
I am really surprised that the Hemingway kits use imperial, and especially surprised they are using fractional imperial.
Interesting build. I like the design.
Dave

[bulletproofpepper]

Great looking project, thanks for sharing. A straight knurled part can take up the extra space. We had a hand tool at work just for that. If the hole in the casing was sloppy. we straight line knurl it to tighten it up. Some people called the hand tool “vicegrips” thanks for sharing

[larryschweitzer]

I put a power feed on the knee of my mill a couple of years ago. Highly recommended! Saves a lot of time & effort. I did have to make the main shaft for it since the one that was claimed to be for my mill was slightly different. The hand crank is always on, with a spring to keep it away from the drive. I use the knee to mill to precise depth using the hand crank & DRO. I like to use a tap follower and the quick knee move enables that and changing from drill to reamer, or drill chuck to end mill.

[thefahj-]

One thing to remember about carbide endmills is that they generally run -.002" from nominal (at least fractional sizes). I would have roughed the slots with an undersized endmill then, gone in with an endmill to size. If needed, you can dial the tool off a little bit to open it up. With boring heads, when approaching finished size, leave the locking screws a little snug and don't touch them. That way you keep the adjustment screw a little loaded. Unlocking, adjusting then, locking again can sometimes cause unwanted movement. Love your videos, one of these days I'll muster up the courage to attempt your electronic lead screw 😉 I have an old Atlas\Craftsman 12" lathe with a quick-change gearbox. Inch pitches are no problem but, the few times I did metric pitches, I had to 3D print some custom gears.

[gbspikyfish]

I got really lucky on eBay a few months ago; spotted what looked like a Marlco knurler for a really good price, took a chance, and it turned out to be a Marlco - just the badge with the logo was missing. Given how good it is I can absolutely see the benefit in making this Hemingway kit.

[floodo]

Wow those engine kits that they sell look amazing

[olivier]

I totally agree on the difference being more about decimal versus fractional rather than inches versus metrics.