Making the small drawbar for the spindle on my home-made indexer.
In the moment, it appears that I fed the carriage twice to zero instead of once on this pass. Clearly lost track of it while checking the fit.
As I said, vex.
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Machine I hate my change gears!
- Thread starter PaulL
- Start date
Machine
In the moment, it appears that I fed the carriage twice to zero instead of once on this pass. Clearly lost track of it while checking the fit.
As I said, vex.
You can't appreciate your own work till you make some mistakes. It sucks but they happen.
140mower
Don
I try to think of it as cutting stock down to size for future, smaller projects...... I do it quite often.
Somewhere I have a long 1/4" brad tip drill bit bent in half. For some reason I thought it was a good idea to mount it in the Bosch Colt on the CNC router and spin it up over 20K RPM. Not being well balanced it immediately decided to bend at right angles just before it went in the collet.
Had it snapped off in my direction I might not be here.
Ah the mistakes...
Had it snapped off in my direction I might not be here.
Ah the mistakes...
Quite frankly, I try to forget all my mistakes (unless I learned something) as soon as possible. My wife gleefully keeps track of all of them for me. Hence the need to forget asap - preferably before she knows I made them. Unfortunately, most SWMBOs have eyes in the back of their heads and another remote controlled pair in the shop that are wired to turn on at the sound of "F&#K!"
And much better now. Here's the indexer's spindle assembled, with the MT3-ER32 captive by the drawbar.
And here are the parts to date, including the body, whose next step is boring for the spindle:
Thinking it's time to give it its own thread.
I will say I'm impressed how easy it is to work with the collets compared the chuck for small parts!
And here are the parts to date, including the body, whose next step is boring for the spindle:
Thinking it's time to give it its own thread.
I will say I'm impressed how easy it is to work with the collets compared the chuck for small parts!
140mower
Don
This was supposedly rated for 30,000 rpm, and the die grinder 25,000..... It never touched the work, it vibrated slightly on start up and as soon as it got up to speed the bending began. It was mounted in an electric die grinder with a slide switch at the back of the motor, so not easy to switch off. If I live to be a hundred, that day will always be engrained in my mind as one of few things that took me by surprise in the shop. My wrists still get sore thinking about trying to keep that beast under control.
I found that MT3-ER32 plus a 1/16" set of collets for $119. Annoyingly I see the same set now for $85. That was $250 cheaper than any lathe-spindle mounting solution I could find. And an R8-ER32 for the mill was another $25.
I had been looking for a 5C chuck, but after the chuck and the adapter plate and a set of collets I was getting into closer to 4 figures. And the MT3 will fit this shop-made dividing head.
I'm still very much on the "figuring this out" end of the learning curve, and I will say that "tools for tools" are a great low-commitment way of figuring all this out!
How do your chucks mount to your spindle?
That's exactly why my 5C collet chuck lives on my lathe more than all the other chucks combined.
A three bolt pattern on the backplate with a registered boss.
DPittman
Ultra Member
Yup cost comparison was the same reason I decided on the mt3 collet holder/drawbar that I have. A 5C chuck would have been nice but I would have never been able to justify the cost of the chuck and all the collets that I have for my setup.
Every situation is different. I got a set of 5C collets and a spin Indexer with my mill/drill. So all I had to buy was the 5C collet chuck. I got that quite reasonably priced on Amazon about 8 years ago. I guess it all depends what you have, when you got it, and what you need. I think most of us start with something we got and then build on that. As a result we often times end up very differently than if we started fresh with a goal and a plan to get there in our minds.
140mower
Don
Yup, my er40 collets and mt3 chuck came with my little round column mill, so for me it made sense to make one for the lathe. As a bonus it involved my first time internal threading and I also cut my first metric threads on my lathe..... Finally got to use the transposing gears I have been hoarding for so long.
I'm fairly certain I'm going to wind up with a set of 5Cs and a good chuck. Having seen how nice it is to work with the ER32 for smaller stock I'd sure like to be able to work long stock as well. That the 5C wind up flush in collet blocks is nice, and I can see that against the stick-out of the ER32.
But it will wait until the passing of certain "macroeconomic headwinds" as they say.
The bore on my Harmonic Drive wasn't large enough for the lathe set of 5C collets so that's why I went with the ER32 collet chuck and the blocks. I think my big rotary table isn't even close to that large an ID.
Minor improvement to my drawbar - I turned a step on the retaining ring, and now the bar stays centered on the bore instead of flopping around:Here's a tool for my tools ;-)
Drawbars are simple enough, but there's lots to learn!
I also machined a new base for my indexing jig. I now have to get over my anxiety and just bore the main spindle hole through there ;-)
I actually believe this is a worthy improvement on a mill drawbar too. Early on in my membership in our forum, I read comments from some members about drawbars rattling around in the spindle and making a bit of noise at certain speeds. Low and behold it happened to me. Since then I have made a centering button for all my drawbars (4 altogether) and no longer get any drawbar rattle at all in any of my machines.
It wasn't easy to do this on my Bridgeport or my Bridgeport Clone because the drawbar threads for the collet are rolled instead of cut. As a result, the shaft is actually smaller than the thread. Any centering button that goes over the threads, ends up loose on the shaft. I solved this by drilling the button to fit the shaft not the threads, and then tapped the button so it could be screwed on over the threads but remained tight on the bar.