MadModder

The Shop => Tools => Topic started by: Divided he ad on May 02, 2013, 05:34:31 PM

Title: Boring little things....
Post by: Divided he ad on May 02, 2013, 05:34:31 PM
Hi All, Made this up this morning on "another site"  and then work happened before I could post it over here :Doh:
So, here we go....


A while ago I needed to get a nice finish on a cylinder I was making... I hadn't got a boring tool small enough for my application.

So, I came up with this. I used it again the other day and thought it might be of interest to others?


A little show and tell....

First a sacrificial piece of aluminium drilled out at 5mm. (this will work on 3mm upwards.)
(http://i289.photobucket.com/albums/ll221/dividedhead/Workshop%20tools/Little%20bit%20boring/Image00002.jpg~original) (http://s289.photobucket.com/user/dividedhead/media/Workshop%20tools/Little%20bit%20boring/Image00002.jpg.html)


Then the tool... A carbide 1/8th burr held in a piece of steel hex by a pair of grub screws.
(http://i289.photobucket.com/albums/ll221/dividedhead/Workshop%20tools/Little%20bit%20boring/Image00021.jpg~original) (http://s289.photobucket.com/user/dividedhead/media/Workshop%20tools/Little%20bit%20boring/Image00021.jpg.html)

A slight kick over to prevent fouling as the shaft is slightly larger then the head of the burr.
(http://i289.photobucket.com/albums/ll221/dividedhead/Workshop%20tools/Little%20bit%20boring/Image00004.jpg~original) (http://s289.photobucket.com/user/dividedhead/media/Workshop%20tools/Little%20bit%20boring/Image00004.jpg.html)

Add a very fine cut and a quick squirt of WD40 and send it down the bore under a slow power feed...  the result is a mass on very fine swarf shavings.
(http://i289.photobucket.com/albums/ll221/dividedhead/Workshop%20tools/Little%20bit%20boring/Image00005.jpg~original) (http://s289.photobucket.com/user/dividedhead/media/Workshop%20tools/Little%20bit%20boring/Image00005.jpg.html)

And a nice smooth bore   :thumbup:

(http://i289.photobucket.com/albums/ll221/dividedhead/Workshop%20tools/Little%20bit%20boring/Image00012.jpg~original) (http://s289.photobucket.com/user/dividedhead/media/Workshop%20tools/Little%20bit%20boring/Image00012.jpg.html)

(http://i289.photobucket.com/albums/ll221/dividedhead/Workshop%20tools/Little%20bit%20boring/Image00014.jpg~original) (http://s289.photobucket.com/user/dividedhead/media/Workshop%20tools/Little%20bit%20boring/Image00014.jpg.html)



Well, that's it.

Other than to let you know that the spiral flutes on the burr are the design needed... The cross cut burrs don't give a good finish   :palm:






Ralph.
Title: Re: Boring little things....
Post by: Brass_Machine on May 02, 2013, 09:50:25 PM
Neat trick Ralph! There have been times I could have used this  :bang:

Eric
Title: Re: Boring little things....
Post by: Bangkok Mick on May 02, 2013, 09:52:32 PM
Thanks for your post, this will come in handy.

Cheers Mick
Title: Re: Boring little things....
Post by: Stilldrillin on May 03, 2013, 02:24:45 AM
It's just as good an idea, over here, Ralph!  :thumbup:

David D
Title: Re: Boring little things....
Post by: Meldonmech on May 03, 2013, 02:48:53 AM
Hi Ralph,

                A cool idea giving a fine finish, must get myself a set of burrs.

                                                            Cheers David
Title: Re: Boring little things....
Post by: Swarfing on May 03, 2013, 12:05:22 PM
I used a similar trick but sharpened up cheap glass drills, the ones with the spade brazed into the end. A burr is great idea for that small stuff.
Title: Re: Boring little things....
Post by: sparky961 on May 03, 2013, 12:25:10 PM
It sure beats grinding up a piece of HSS into a really tiny boring bar, like I've done in the past.
Title: Re: Boring little things....
Post by: andyf on May 03, 2013, 12:33:49 PM
I've used the good side of a 3mm 2-flute slot drill with a chip on the other side, but the burr is a better idea. More cutting edges to go at, and because it is pear-shaped, varying the top slide angle will bring new bits of edge into play.

But how do you set it on centre height, and is there a danger of two edges cutting at once, one above centre height and one below?

Andy
Title: Re: Boring little things....
Post by: Divided he ad on May 03, 2013, 04:25:11 PM
Glad you guys like it.

Never sure if it's a method that's been used a lot or not  :scratch:



Sharpened glass drills... Never thought of that one :thumbup: 

And as for sharpening HSS....  I totally suck at it!  :bang:

Setting the height.... I rotate it so it looks like a flute is horizontal and set it by eye.... Worked every time I've tried it so far :dremel:


That's all I can offer Andy. I'd guess that if two edges contact the deeper one would give the finishing cut? But this is a guess.... Never looked since it always worked.




Ralph.
Title: Re: Boring little things....
Post by: krv3000 on May 03, 2013, 05:46:00 PM
 :dremel: brill well dun
Title: Re: Boring little things....
Post by: PekkaNF on May 05, 2013, 01:45:07 PM
very nice one

I once made a small boring bar out of broken threading tap.
This booring bar is made of Dormer thread tap and rectagular mild steel stock. Ground until one "tooth" was left, with all it's cutting angles left.

PekkaNF