2015 POTD Thread Archive

[extropic]

[snip] I have the 5C collets. My other equipment uses 5C collets. I am trying to stay with one system. [snip]

Oh. OK

 

[Mark_f]

Another option, while a fair bit of work, would allow you to use the whole inside diameter of the spindle for longer stock. I made this a while back and really enjoy using it.

http://www.hobby-machinist.com/threads/5c-collet-chuck.24762/

I was really impressed with your particular build . It looks great. It also looks very large and heavy. I think I will have to make a few sacrifices to stay where I kind of want. I want to make this unit smaller and not huge in size. This will require that I won't be able to pass long stock through it, but that is not a big issue because 95% of what I do is smalls and short. I am wondering if your design can be reduced some in mass without loss of integrity.

 

[Round in circles]

Mark, I made something for my SB 9a similar but threaded the end and used a nut similar to an ER40 adapter to push on the 5c collet rather than to use a drawbar. Works great for me and still lets you pass stock through the spindle as you would with a regular chuck.

I too was going to suggest that , adding an internal lip /collar to the " nut " to press the collet body into the holder .
To loosen the holder I've made a weighted ( molten lead down th tube ) slightly cone shaped flat nose aluminum headed ram rod that gets quickly slid in the hollow spindle .

 

[mksj]

Been wanting to switch out my steady rest and follow rest fingers to roller bearings. The stock ones are brass tipped and measured ~0.740" in diameter, so turned down some oil hardened 3/4" rod, center bored/threaded and then slotted the other end for a some MRC M4ZZ ball bearings which are 0.195" wide, ID 0.249" OD 5/8". The bearing retainer rod/screw is such that the bearing rotation will not loosen the the 1/4"28 thread tip under forward rotation. I also added bronze bearing rings over the bearing so as to not damage supported material. The ring is replaceable. Fun project, always learning new ways to make and machine parts. I sometimes have problems milling the flat screwdriver slots in metal because of the small end mill and high speed. This time I milled the slots using the tip of a Keo No 2 center cuter, which worked surprisingly well.

 

[cascao]

Steady rest bearings does not work well when swarf jam behind the wheel

 

[markknx]

So here is the answer to the tool question above
ATTACH]116134[/ATTACH]

The tool I call it a dog, is welded to one piece of steel (in this case a pour stop) and the second piece can be forced up tight by driving in a wedge. This is used where clamps are not able to fit or there is no place to clamp.

I have seen these used when 2 halves of large tanks are being joined. same as above only to bring used to line up the 2 sides of the weld joint.

Hope at least one person is able to use this idea or lean from it.
Mark

 

[Dan_S]

Tonight's project, Was to clean up some saws that I purchased on eBay. After a bath in Purple Power, & a soak in Evaporust, they look almost brand new.

 

[extropic]

I understand what you are saying but you missed the point. I don't want to invest in another set of collets and chucks and adapters. I have the 5C collets. My other equipment uses 5C collets. I am trying to stay with one system. That being said I believe this will work and I thank you all for your ideas. I think with everyone's comments , I now believe I have the information to make an accurate and useful addition to my tooling.

Guilty as charged. I very often, maybe usually, miss the point until it's published. I think I understand the priorities now. Thanks.

 

[Mark_f]

Guilty as charged. I very often, maybe usually, miss the point until it's published. I think I understand the priorities now. Thanks.

It is good though to have all the points of view, and I thank you for expressing yours as it also makes good sense in many cases. Personally I like getting all the views and opinions. It makes it easier to make an informed decision .

 

[chevydyl]

Made a press brake die for a customer, it's made of A2, 12 long 5 high, three quarter thick, 85deg included. Programmed a triangle of 42.5deg and cut it in steel, the lapped the surfaces, indicated the mills nod to that angle gage, used the mitsubishi 3inch face mill, 400rpm 4.75 Ipm .030-.040 doc, after both faces were done I tossed in a 3/32 radius cutter and blended the flat. Then stoned all the fresh cut edges for a perfect blend.