The Shop > Tools
Thick stubby drills
PekkaNF:
OK, got a set of most likely sizes. Rotabroach brand. It's going to take week before I'll get them, bit time to figure out how to mount them.
Pekka
PekkaNF:
Haven't got the Rotabroach cutters yet, thinking of minimum cage length MT3 to Weldon adapter.
I'm considering making a simple MT3 to 3/4" adapter, minimum length. Nothing complicated there. However rotating coolant inducer would be interesting and probably even useful.
Has anybody here build coolant inducers, something like this:
http://www.rotabroach.co.uk/wp-content/uploads/2015/06/Morse-taper-arbor-up-view.jpg
Can't really see how I could build it super short, without going into very thin metal and here I will be using few hundred rpm and there is three times more power than magnetig drill has (Although I hope I don't need all that).
MT3 business end is about 24 mm dia and there needs to be enought meat for 19,05 mm (3/4") weldon. This Weldon seems to be of 23 mm lengt, two flats 90 degrees appart.
Lenght: Need some 6 mm for dog (27mm dia, 24mm flat, max od 38mm) and looks like very little extra lengt would be needed if I could squese the coolant inducer into 15 mm long space, diameter can be large.
Would Plastic (nylon) or something do, clamped between two metal washers?
Just toying with this coolant inducer, I haven't build any yet, but this is easiest application and I have tools that really could benefit from trough coolant capability (those are bit more pressure though).
Pekka
awemawson:
Over engineering it. Just use a squirty bottle of coolant :med:
PekkaNF:
Yup..could use bottle, but I'm not any more ambidextrous than bilingual....and automatic coolant feed is easier than drill feed.
Anyway I though that if it is not too bad and does not really add much length (and take much time), I could learn something here.
I might go for it (or not) or build it to work without the rotary parts even if it fails.
Pekka
PekkaNF:
Should get the Rotabroaches tomorow. Bearings, bits and seals should drop into mail box this week.
I haven't found many details/cutouts of the coolant inducer. My gut feeling tells that in this application simple POM/Nylon bushing shoudl work:
* I'm planning to use simple gravity feed little above of the mill head = pressure is low, volume is low
* low rpm
* a little lead does not hurt
* Takes up little axial play
* Some front feed drills seem to be fine with it!
But I started thinkkin...I have drills that have coolant channels and they could use whole lot higher collant pressure:
1) Normal shaft lip seals are fine to about 0,7 bar, there are high pressure versions, but they are not common stuff in bearing shops
http://fpparis.com/en/products/high-pressure-oil-seals
2) Whattabaut...PTFE/POM disc backed up with a DIN 988 ring?
http://www.cutwel.co.uk/filedepository/product-images/hole-making/indexable-drilling-systems/supercut-spade-drill-system/coolantringbp-1.jpg
3) I like this construction, but what material and purpose each seal part has?
The picture athe end of the page is interesting.
https://us.bigkaiser.com/products/coolant-inducers/hi-jet-holders.html
4) I googled hydraulic rotary seals and looks like whole lot of them are made with orings or with a backup ring and oring....then found a construction that seems to have a seal ring against rotating shaft and a oring as a elastomer to put pressure to this ring and to to seal he cavity.
Picture here clicks bigger:
https://en.wikipedia.org/wiki/Rotary_union
Pekka
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version