Mill conversion. Home made "Marvin" attachment

[glens5]

Home made "Marvin" attachment horizontal to vertical mill conversion.
1" spindle with MT2 taper.

[mwmkravchenko]

Pretty slick. How well does it work?

[glens5]

Takes a few minutes to set up and align but other than that it seems to work just fine.
I haven't checked for run out yet but if there is any I'm sure it'll be from the Banggood collets and holder.

[DIYSwede]

I haven't checked for run out yet but if there is any I'm sure it'll be from the Banggood collets and holder.

Really nice build! Thanks for sharing!

Personally, I've been down on my luck on BG MT2 & MT3 ER32 collet holders (4 of them, all in all).
2 years between placed orders hoping the harsh buyer feedback would've shaped up their quality issues. Guess not...
Link: https://www.youtube.com/results?sear...Collet+sets%22

The Collet holders: +/- 5 hundreds of a mm in runout (sic!) and non-coaxial to boot in all 4 cases...
Worse than the worn-down 3-jaw in the 50 years old lathe at work...
My only REAL LEMONS in a 70-ish item order history - too bad that would happen to "precision pieces"...

No biggie for me to regrind the ER32 tapers down to below +/- 2 thousands of a mm, tho -
about half of the ER32 collets in the (M & Imp) sets were in as bad a shape as the holders, too:
both non-coaxial and non-concentric when tried in the new-ground holder.
Finish was excellent, throughout - no rough edges, finely ground and clean
(others have reported bad cuts, rough edges and shavings within).

Even being cheap-to-the bone and given my 20-20 hindsight, I shouldn't have ordered them in the first place.
Guess I now have to shim their compressible saw cuts up, fit them in holder and regrind 'til "good enuff"?
-Yeah, right! Sub-6 mm collets just a piece of cake to regrind! "Happy machining!"
As per their original state - the bad ones are perfectly useless for my intended purpose.
-Why even pay for runout and non-coaxiality, when you could get that for free in a dirty, old 3-jaw?

Just my 2 cents & YMMV
Johan

PS: Perhaps the small collets could be honed? Another upcoming project/ waste of time?

[Toolmaker51]

<snipped>
Guess I now have to shim their compressible saw cuts up, fit them in holder and regrind 'til "good enuff"?
-Yeah, right! Sub-6 mm collets just a piece of cake to regrind! "Happy machining!"
As per their original state - the bad ones are perfectly useless for my intended purpose.
-Why even pay for runout and non-coaxiality, when you could get that for free in a dirty, old 3-jaw?

Just my 2 cents & YMMV
Johan

PS: Perhaps the small collets could be honed? Another upcoming project/ waste of time?

Consider bedding them in low-temp alloy. Most are bismuth based, the low temp won't alter heat-treating or anneal what-so-ever. Plug ID with a stub of properly sized aluminum rod, so drilling and boring will be easy. Chuck the holder and dial in. These are educated guesses, certainly easier and more precise than 6 or 8 tiny shims...

[glens5]

I checked the run-out on the Banggood collets. Some are as much as +/- .010 and the mt2 taper holder +/- .002 so a poor buy at any price.
The spindle run-out is negligible but I had turned the inside mt2 taper at the same time as the rest of the spindle on the lathe so I'd be surprised if there was any.

[DIYSwede]

Consider bedding them in low-temp alloy. Most are bismuth based, the low temp won't alter heat-treating or anneal what-so-ever. Plug ID with a stub of properly sized aluminum rod, so drilling and boring will be easy. Chuck the holder and dial in. These are educated guesses, certainly easier and more precise than 6 or 8 tiny shims...

@ TM51: -Thanks for that (hitherto unconsidered by me) tip!
-Haven't even got any Wood's metal to start with, but I guess I'll have to score some now.
@glens5 : Bummer that BG hasn't shaped up their QC for these items during the years, and also:
their complaints department "didn't seem to fire on all cylinders", or was merely using a stalling strategy.
And then suddenly my "forthright and factual" review on their page got lost somehow...
Finally - after a tedious and tragi-comical e-mail chain I finally got my refund (less pp and local tax, tho).
Looking forward to perhaps eventually waste another fine 10 hours of grinding these "freebie" collet sets.

-See, it doesn't take much to make a cheap, masochistic hobby machinist happy!

[Drew1966]

Elegant. Simple. Good job of doing ones best to battle Murphy.

[NortonDommi]

Very nice. I'm thinking that it is super smooth in use?

[Toolmaker51]

Countless little horizontal mills went to scrap because potential buyers couldn't visualize this.
Driving from the machine spindle infinitely better than placing that weight atop the fabricated spindle housing. And, still have ready use of the horizontal spindle. You say the bore is #2 Morse Taper; appears those are drawbar [not drift] holders?