Making A Rotary Broach - Cutting Hex Sided Holes (DIY)

G'day everyone,

In this video I will be showing you the journey that I undertook to try and cut my own hex sockets. To do this I need to make use of a rotary broaching tool. There are commercial versions of this tool, but they are out of my price range for a hobby shop, so I decided to make my own. This will be a rotary broach tool for the lathe.

Making one should be a pretty straight forward job, but there are fine details that need to be done correctly in order to do this correctly. It took me a few weeks and several revisions to make this work. I hope you enjoy this video.

The two links below are well worth checking out. They provided me with a useful direction to go in when designing this tool.

Timestamps
0:00 - Intro
1:06 - Making The Tool Housing
2:34 - Machining The Housing
3:48 - Machining The Shaft
5:06 - Machining A Backstop
6:21 - Finishing The Housing
7:16 - Cutting The Dovetails
8:02 - First Assembly
8:45 - Making The Broach Cutters
10:17 - Adding The Ball Bearings
10:48 - First Test Cuts
12:00 - Making A HSS Cutter
12:54 - Using The Rotary Broach

#DIY #Machining #RotaryBroach

Mill - Sieg X2.7l
Lathe Sieg c3 7x14 Mini Metal Lathe

[BloodThunda]

HSS reamers will leave nice finish if you slow them down dramatically. I see a lot of people making this mistake. It has 6 flutes so it doesn't need high speed to keep it lined up with the hole as its fed down the pre drilled hole. Slow feeds & speeds with reamers. Also, use cutting fluid and not coolant, try this next time.

[TheLastTater]

I love that you share when things don’t go as expected. Some of the best channels show that. Great job, you constantly inspire me to do more with my mini lathe

[brucematthews]

One of the easiest to make but clever for it concepts I've seen. I wondered about the required offset angle until you mentioned just angling the tool post a degree or so off square. that turned on the light over my head! Like Deon below I also get fine results from my import reamers by using cutting oil, instead of coolant, and lower speeds. And don't feed it in overly fast. Feed it at roughly the same feed rate as a drill.

[timothypetroulakis]

A little tip on the reaming, slow your spindle, feed and you NEED to use some cutting oil, reaming dry is like tapping dry. Oil will improve your cut an unbelievable amount

[larrypalmer]

Very well done video and very impressive resourcefulness with impressive results. Your channel has become one of my favorites for innovative and original ideas.

[nexusofice]

Something about making your own tooling is always satisfying.

[TheRecreationalMachinist]

Great job, and thanks for the shout out! 👍 🇬🇧

[ArSeeStuff]

Love your work - and your 'can do' approach.
It's refreshing to see failures turned into success, and the reasons for each. 👍

[intellectualiconoclasm]

I not only enjoy your craftsmanship, I revel in your dry and self-aware wit.

[brucewilliams]

This was really well done. Thank you for putting this up.

[tcurdt]

This looks like magic. Would love to know a bit more details on why this actually works.

[damustermann]

I thought you're really going to file the stock. Even better, that's a neat little trick to get a cut started!

[danshepler]

When I wanted to make 1/4" hex I used the rear end of a Phillips head drill bit. Place it in a drill and use another mini grinder to concave the rear of the bit, it leaves the edges sharp and I was then able to drill a round hole in material and then tap the "broach" in making my holes to accommodate any drill bit.

[jacob_s]

11:15 THANK YOU!!! It always seemed to me that a rotary broach shouldn't be able to work, and that finally explains why it does.

[FCleff]

Thank you for sharing and sticking with this project and working out most of the design problems.

[carrambah]

I really don’t understand why you don’t have more followers! Your content is great

[shipsofscale]

Nice. I always enjoy watching your projects. I learn a lot.

[bobjimenez]

nice tool making video....Thanks!.
when you're buying your wobble broach setup for Rosan lock ring serrations, don't forget to buy the gauge too.

[xmodalloy]

Just a recommendation, but you should really run reamers a LOT slower than that.

[MachiningwithJoe]

Excellent video dude deciding to make your rotary broach into a tools holder is genius and very unique. A rotary broach is on my list of tools to make soon. Keep up the good work 👍