hello. I’m looking for an easier system to change tools than unscrewing collets every time, and re-zeroing tools. Is it possible to have a select set of spindle tapers with collets already set to size with bits inside? Kind of like you’d see in an ATC except you put the tool in manually lol. Any info would be helpful, and links to where this stuff could be done or purchased also appreciated!
The easiest trick is just to plan your ops around tool shank size. For instance assume you are going to rough cut, profile, bore some holes, and chamfer to make something. Assuming you use a 3/8" endmill for roughing and a 3/16" one for boring the holes you can save some time by using a 3/8" V-mill for the chamfer and sorting the operations as: profile, chamfer, drill. Then you only do one collet change for instead of two.
A cheap and more flexible system here is to use 1/2" shank ER20 tool holders that are pre-setup with tools. Leave an ER20-1/2" collet in the spindle. Change tools by opening the spindle collet enough to pull the tool holder out and put another one in. It takes about half of the time because you aren’t popping out the collet and swapping it.
I bought 4 of these when I first got my MR-1 and it was an improvement, but not as good as an ATC. I bought product B0BGQKGNM6 on Amazon.
I don’t need them anymore and would sell them (lightly used) for half price ($50) plus shipping.
I also found it useful to increase the size of the probe’s spindle to 1/2" so that it could go in directly. I made a simple sleeve on the lathe and secured it with some green loctite.
There are downsides. Stacking up two collets roughly doubles your potential runout error. There is also extended tool stickout which reduces stiffness somewhat. For my use I found the tradeoffs worth it, but if you are going for maximum MRR then this isn’t the right approach.
Anything changing the spindle is a big project. I think it’s worth it (I’m almost done with a spindle swap), but it adds a lot of cost to the machine ($2-5k – with $2k being the cheapest possible aliexpress spindle).
Though this isn’t perfect this is what I do.
I have a whole slew of collet sizes and nuts and unscrew the tool then install the new one. Yes you still need to measure it each tool swap, but the machine does that for me. It saves time as I have the tools ready for the entire job and I don’t have to swap the collet out of the nut for different diameter tools. Relatively cheap too. I think I got the collets and nuts from maritool.
Note that the MR-1 uses totally unique collet nuts and you have to buy them directly from Langmuir. The Maritool ones have the wrong threading and can damage the spindle nose (if you thread them on directly without a collet you’ll see that they are very loose, because they are 25mm major diameter instead of 24mm).
1 Like