Here we go again . . . MK4

[routercnc]

Thanks for the info. From what I have read (and I am no engineer) a R8 collet requires a holding force of about 2400 lbs to be safe. I am using part No. D2315162 washers from Belleville Springs 2 in P and 6 in S this give a free stack height of 28.5mm and a flat height of 24mm. 75% deflection height is 25.13 mm with a load of 12337N.

The guy on the zone recons 0.5mm will release the collet after the pre-load has gone.
The setup requires about 180Kg on the jack to give me 1260kg

I would be interested in the link for the calculator

Hi Clive,
I got the info together last night but no time to post out. Similar to your findings.

R8 needs 2500 lbf (11,000 N or 1,100 kgf) to hold it, maybe a bit more to be safe
Used calculator on this website:
http://www.meadinfo.org/2009/07/bell...ck-design.html

Used washers (())(( to get 15,000 N when flat.

Release distance was about 0.3mm (between holding load and flat load).

Looked at data on this site:
http://www.leespring.co.uk/browse_ca...=&pageNumber=8
part 500-125-1125

This was a quick look, I think it could be refined.