Broaching a cable wheel for a weber carb for a classic mini. Broach made with Emco 5PC

Follow up video showing broaching 2011, go on, have a look it is only 54 seconds long. • Proving 6061 is the pr...
Broaching the hole for a Weber carburettor shaft 7.0 diameter with two flats. This part is a cable wheel to fit to a weber carb on classic minis. I usually turn these myself but due lathes not wanting to work properly I had the made outside. When I make them I use 2011 machining alloy which usually broaches very cleanly. However with the 6061 that was used the broach was leaving a huge burr. I found it impossible to remove by hand. My attempts just left scratches on myself or the part and the burr remained. Only solution I could find was to mount them in the lathe and face it off with a boring bar using the Hercus PC200

[@plang42]

Any video from you mate, is great 👍

[@smallcnclathes]

Thank You and for making the time to leave a comment

[@GaryForgingOn]

that was interesting. I didn't think about using a fly press for broaching. Blacksmiths love fly presses .. Maybe one day I will find one at a good price. But as usual my problem is finding space in the shop. LOL Thanks for the video.

[@smallcnclathes]

Hi Gary and yes a fly press does need a bit of space. Thanks for your comment

[@mosfet500]

Thanks, I remember those Compact 5's, they were pretty darn good little lathes. I have it's big brothers a V10P metric and a Super II inch.
I usually use 2024, I'll try the 2011.

[@smallcnclathes]

Thanks for your comment. I have not heard of 2024, but here in Oz 2011 is our machine grade. Biggest problem with the Emco was the steppers losing steps

[@mosfet500]

@@smallcnclathes I like these small lathes, I'm using the Sherline with ball screws, I modded their milling machine to work as a lathe. Pretty good if you don't push them. You can make or buy some impressive headstocks with up to 5c spindles and very tight TIR's.

[@chrisjh777]

I find 6061 terrible to turn. 2011 is a pleasure to turn.

[@smallcnclathes]

Hi Chris, me too. BUT a friend with a large shop handles it ok. Large machines with lots of grunt and flood coolant. I make sure I mark any 6061 in my shop, but lets face it it reveals itself as soon as you try to turn it. In the past if a customer really had to have 6061 (weldability) and it was a big job I sent them to my friend. The money I would have made would not be adequate compensation for the aggravation. LOL

[@spikeypineapple552]

The reason you're having such a massive burr is because this broach isn't cut properly. As far as I can see, there's no gullet at all, which gives the same effect as having no front clearance on the cutting edge.
You've have had a better time grinding a flat on an existing round broach.

[@smallcnclathes]

Thanks for the comment

[@smallcnclathes]

After your comment I went out and tried some 2011, the result is here ruclips.net/video/B8yHEf1KlMs/видео.html
I have no doubt the broach design could be better, but also no doubt that that burring did not occur when I used 2011. Thanks for you comment, you made me get off my backside and check how it worked with 2011, I appreciate it.

[@paradiselost9946]

@@smallcnclathes i came in the other way, so now im here... i have to agree, looks like theres insufficient gullet mostly. are they lands or bottom clearance on the edges?
then theres zero "top rake" as yeah... thats a pretty hard thing to grind in, a concave surface given the space available... 6061 is "sticky" as, only thing nastier is copper, imho...

[@smallcnclathes]

I know so little of broaching that some of the terms you are using are foreign to me. I made it to someone elses design. The broach always worked ok in 2011, it was not a problem until 6061 came into the picture. My fault as I did not specify 2011 on the drawing when I had them made. I would normally make them myself and use 2011. Thanks for taking the time to comment, I appreciate it. Nigel

[@smallcnclathes]

When I started making cnc parts, I quickly realised that with only 1/2hp at my disposal and spray mist as coolant 6061 was never going to work for me. Works for others with larger machines etc but I decided to stick with 2011. Never had a supply problem and to be honest there have been times when I have sent a job that needed 6061 elsewhere, just not worth the aggravation when there is easier work to be done.
Thank You for your input with your comments