4 facet drill sharpening jig plans

Oops!

I have now seen page 6 of the PDF and all has become clear!

Please ignore my request for a picture.

Ian P

The A and B views are not isometric, they are views perpendicular to the faces.The dotted red squares show the horizontal/vertical limits of the faces and pass through the corners of the faces.

The dotted grey lines show what you could see if the block was transparent.

Garry Wooding wrote:-

"After breaking several #76 drills I used a high power loupe to examine the one remaining and was appalled to see how badly it had been sharpened. Since the broken drills had come from the same supplier......."

Another source of badly sharpened and therefore badly performing drills are those orange & blue plastic boxes of very small drills on sale at exhibitions. I took a new No.70 drill from such a box and put it under the microscope at x200. The image is poor because of the very small depth of field and getting good top illumination but one wonders just how such drills are "sharpened". It's also revealing to compare cutting edges of carbide inserts at that magnification. For example those of cheap Far Eastern origin to say, manufacturers such as Iscar. Once seen at x200 the obvious difference in performance (and price) is explained.

For some reason, my system will only download page 1. After that "There is a problem"

Any ideas, please?

Howard

It's no wonder they break so readily when you would need to use more pressure just to get it cutting.

Michael W

SORTED!

The PC would display the PDF, but not download it fully.

Managed to print it, and then I spotted a "Save As" button , Lo and Behold it down loaded.! Rename and ready for another print when the first gets covered in greasy handprints, as it surely will.

Must be something to do with old dogs and new tricks.

Howard

Don't assume all those 'microboxes' are from the same factory. I have one (Proops IIRC) and the drills in it work like a dream. Same with Chinese inserts, you can get any quality you like, but be prepared to pay.

Neil

I am having a lot of trouble with this PDF too. I can download it and look at it, but Print Preview will only give me half of page 1. It downloads as a folder, not a simple PDF file. Any suggestions?

When you click the link you should get a screen like the one in the screenshot. Click the Download button and choose the Open with option to view the the PDF in your normal PDF viewer (probably Acrobat Reader). You can then save and/or print it with that.

Thank you Garry. That worked. It is not a procedure I have ever used before. I will print it out and study at leisure. I do have Derek Brown's injector book which has his jig in it.