Square Pegs Into Round Holes

[Ulma Doctor]

Hey Mike,

Great idea!
Are your printed bushings split? ...or do you just rely on the ability of the collet to squeeze 'em tight enough?

-brino

Thanks Brino,
the 3/8" collet bushing fits the tool blank snugly. there was no need to split that one.
the 1/4" collet bushing fit a bit looser, so i split it with a hacksaw to make it work on this go around.
on subsequent printings, i'll adjust the 1/4" collet bushing inside dimensions before the print.
i still have a 5/16" bushing to design and test.

 

[Ulma Doctor]

Another chip in the myth that these grinders are limited in their uses

If you are eventually looking for metal square collets, E355/U2 ones are avialable. Or make you own using Harold Hall's methods.

It amazes me how many things I use my Ender 3Pro for that otherwise would have taken a day or two with subtractive machining, or not possible at all with my present tools. It is worth a bit of time getting the settings correct so that items are printed to intended size. I recently switched to slicing with Simplify3D as it is easier to get the settings sorted out.

thank you very much for the information @ub27Rocks
the Ender 5 i got a couple months ago has proven indispensable for prototyping projects like these!
i have not tried Simplify3D but, i'll take a look
thanks again!

 

[Ulma Doctor]

I did some grinding on a 1/4" Hss blank
a 10° tool was on the menu!




while i was at it i decided to take a very inexpensive brazed insert carbide bit and turned it into a razor sharp instrument of material removal!






here is a shot of the cutters i have put a wicked edge on...

they all have approximately 1/32" radii at the business end


if you hang around long enough, you'll see the chips they make

 

[mikey]

if you hang around long enough, you'll see the chips they make

I was just thinking that you gotta' tell us how they work!

 

[Ulma Doctor]

Metal munching, eh? Pretty cool there, Doc!

You can have the 3D printer. I want the tool grinder!

Thank you very much!!! @mikey ,
If i gain skills on this grinder, i'll be trying to shamelessly reproduce (poorly) your brilliant and brutally tested HSS grinds

 

[mikey]

Nah, you'll do it even better, Mike. When you find the magic geometry, please share it, okay?

 

[Ulma Doctor]

Was thinking I'd like to have those 3d files, as I have 4 3d printers.
Problem is I have no deckle

you could use them in 5C or Er systems too, i suppose
if you would like them, i'll share them
(you can send me an email ulmadoc@gmail.com)

 

[savarin]

I would love to see a video of you grinding them if possible.

 

[Lo-Fi]

Lovely work! I'll be doing similar on my forthcoming "broken milling vice conversion to tool grinder" project for use with ER32 collets. Probably put a little top hat brim on one end to stop the collar going right through the collet.

It seems weird having printed plastic stuff in a machine shop, but 3D printed parts absolutely have a place IMHO. You could spend hours making those collars in metal and not get better results than you do with the printed ones. Just takes a while to get your head around it and into the mindset. I've printed all sorts of arbors, adaptors, spacers and whatnot. My most ambitious (and very successful) project has been printing plates for my dividing head.

I've settled on Cura as a slicer, but I'll check out Simplify!

 

[rgray]

you could use them in 5C or Er systems too, i suppose
if you would like them, i'll share them
(you can send me an email ulmadoc@gmail.com)

Thanks so much for the offer. But my fixture on my cutter grinder will not fit my 5c collet block.
I do have an er20 fixture for drill sharpening that could do small square bits. largest collet is 1/2" I think.
Way back when I machined an aluminum block with a 1/2" slot that fits in the fixture of the grinder.
I put 1/2" hss bits directly in it to sharpen and for smaller bits I took 1/2" cold rolled and square broached 1/8,3/16,1/4,5/16,& 3/8" holders that hss bits of those sizes fit into and then the 1/2" cold rolled fits into the aluminum holder so i can sharpen all those sizes.
That of course was a way more expensive way to do it with the cost of the square broaches and all.
Nowdays I suppose the 1/2" holders for the smaller bits could be printed. Square in a square....might have to try that.