Is anyone else interested in rotary broaching? The holders are a bit expensive. However, I think one could be fabricated for not much cost at all.
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Absolutely.
I was advised that they are expensive and rarely needed. I agree on the former, but would argue that if we have it, the latter would be untrue.
I have been considering trying to build one, though with a few improvements on the few how-tos out there. Like this oneā¦
http://www.docsmachine.com/projects/rotarybroach/rb01.html
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I would be interested in seeing one actually work, but canāt think of many places I would ever have used one. But if it were available, I would undoubtedly discover such places.
Given the cost of commercial rotary broaches I would say it wasnāt a cost effective purchase; however, I agree one could be made for a low cash outlay. But I suspect it would require a fair bit of āfreeā labor to produce. I also wonder how well such a tool would hold up to the abuse tools receive at the space.
I believe a holder would be somewhat difficult to screw up (although where thereās a will thereās a way). Also I doubt it would be terribly difficult to make. Although it would require that sine bar thatās been sitting in the acquisition queue.
We actually have acquired the sine bar.
And in my opinion, anything that requires a sine bar for setup moves it well into the ādifficult to makeā side of the spectrum.
And the above illustrated boring bar is why I think such a tool will get screwed up at the space. You have to do a number of really bad things to do that much damage to a boring bar, particularly one that was way to small to have been used in the lathe. Meaning they did that with the Criterion in the Bridgeportā¦
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Nothing prevents āusā from āfree laboringā it into existence, and only bringing it into the space for use by trustworthy souls, as long as āweā also provide the materialsā¦
I hate to be that way, but we donāt let ājust anyoneā loose on the HAAS, or the CNC Router, or the liftā¦
It is my intention to make myself one of these for personal use some day. If āweā wanted to, I would like to participate, even if that means I have to ask to use it, should I want to, at some point in the future, just because then Iāll know more about how to make my own when the opportunity presents. Kinda like our steam engine. Got no use for it, other than to learn. I see no reason we couldnāt learn on a rotary broach build as well, although, as stated, if the 'Space buys it, it belongs to them and will, likely be abusedā¦
course, this way is pretty idiot proof, and likely the only thing theyād do is hurt themselves if they abuse itā¦
I didnāt intend my comments about the quantity of āfreeā labor to discourage. Just saying that when avoiding the spending of cash by doing it yourself, it is real easy to underestimate just how much time you really need to spend. I know I significantly underedtimated how much time the size gears we need for the lathe would take to get us setup to cut. The smaller brass gearing I have cut in the past didnāt seem to take me that long to get setup for, but my memory may have gotten fuzzy.
That said, I would encourage anyone who wants to tackle a project like this. Love to see one of these work in person.
This would likely be difficult to do without DROs, but once itās done, itās just a JT33 taper at the top which an R8 adapter can be purchased for. The bearing is an ABEC 3 Timken 7303WN and could be somewhat expensive.
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I long for old fashioned blue printsā¦
I just happened to be looking at just this very thing, and came across this from NYC CNC.
So cool.
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Is someone looking for a wobble broach? I have one but with hex cutters. If you need one, let me know and maybe I can help.
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Hello Steve,
Well, as usual, I was going down the rabbit hole of āmake my own tool for the jobā and found a video of a guy creating a hex socket with a rotary broach. Iāll add it to the bucket list, but I think I can solve it a different way. 