Member postings for Mini

Hi,

Having used this old discussion as reference, I'd like to add how I was able to move a lot of stuck multisize collet blades again, after having bought two sets (really old and old stock):

I applied pure acetone with a paint brush and put the collet in plastic zip bags to keep the solvent from evaporating. The blades start moving under finger pressure after about 30 minutes or an hour, with little use of acetone.

The idea is a combined form of:

- Nick's method (this thread) "...into a bowl of cellulose thinners of nail varnish remover".

- A 2012 document "WD-40 Alternative: Final Design Report" testing and suggesting oil mixed with acetone as penetrating oil. (But the figures in the report tell that pure acetone works even better.)
https://www.engineeringforchange.org/wp-content/uploads/2015/12/ENGR103-WD40Alternative-FinReport.pdf

- "Cuisine sous vide" techniques, where you keep meat juice close to the meat in plastic bags, while cooking slowly at low temperature.

- The technique of using small recipients with special solvents in big ultrasonic cleaners:
https://mb.nawcc.org/threads/best-way-to-use-larger-ultrasonic-cleaner-for-tiny-parts.53026/

Hope that helps someone!
Bernt

...and I forgot to add the image of how I measured the angle difference:

Crawford Multibore C-series W850 collets in a Burnerd LC15 lever chuck (normaly working with Multisize EC collets)?

I (still learning a lot 5 years autodidact home CNC guy) add my little findings, for reference of those who, like me, where not able to find this bit of information. ...and also to be corrected if I'm wrong:

When shopping for Multisize collets, I found from time to time collet sets containing a mix of Burnerd Multisize and something looking to me as Crawford Multibore collets. Before reading in detail this discussion, I ordered some Multibore collets for my new old L15 lever chuck (besides a set of real Multisize EC collets).

After reading this discussion, I searched the Internet for the angles of the collets: 15 degrees for the Multibores (30 degrees included angle) and nothing found for the Multisize collets.

I was not sure if they where really incompatible, and having bought the material I had to try. When the material arrived, I was more careful, when putting the first Multibore collet in the chuck:

- The far end touches of the Multibore collet touches first the cone of the chuck, but with the spring mechanism and pushing very slightly, this looks rather good.

I decided to test to clamp 25 mm bar stock:

- The far end touches first

- Screwing the front nut a bit further and pushing the pivoting ring not very hard by hand, even without the lever of the lever chuck, the collet is able to grip the stock firmly.

Still not beeing sure about any difference in angle between the two collet systems, put a Multibore collet in the Multisize chuck. Leaving the collet empty, I closed the nut enough to make the lowest collet segment adhere to the chuck'ss cone. I put a lever indicator on the carriage to measure the angle difference (using the tangent function).

- There is a difference of about 2 degrees (4 degrees included angle). The Multisize EC collets must have an angle of about 13 degrees (26 include angle).

My temporary conclusion:

- Using Crawford Multibore W850 C-series collets in a Burnerd Multisize chuck (at least the LCxx models) is possible, but probably a bad idea because something bends, possibly badly.

Are there any other collets looking like Multibore collets and matching perfectly the Multisize chucks?

It would be nice to get feedback with your insights.