Drill grinding attachment

[ukjimoo]

Hi all

Just been looking at the machine mart catalogue (from last thread) and noticed they do a drill grinding jig that fixes to the bench, next to the bench grinder and uses the side of the right hand wheel. Its £9.39 and does drills from 1/8 up to 3/4.
Looks ok to me. Has anyone bought one? are they any good?
Part no. DGA1

Jim

[Tim Bayliss]

Jim,
Yes I bought one but could never get it to operate as it is supposed to.
My opinion is don't waste your money, pay a bit more & get a Martek unit, one of the larger capacity versions, or similar self contained unit. There are a few different makes about.
Tim

[Chris Kelland]

I've got to agree. I have both and the attachment is going in the next club sale!

Chris.

[modeng2000]

I have tried to find a Martec sharpener but it seems that they have stopped making them.
Does anyone know if the Plasplugs DSH400 any good?

John

[Donald G]

I would wholey agree with the comments regarding the bench mounted drill sharpener, I cannot get a decent result from it, even though I have spent quite a lot of time trying.
I was lucky recently to purchase at the sale of a deceased members workshop, a second hand Martek unit, and imediately, I have great results, and nice sharp, equal ange drills. I think this model is now not available and I don't know if there is a similar unit available.

Donald

[Phil Sutton]

I have a drill grinder,given to me as a birthday present,I've no idea of the make off the top of my head,It is of plastic construction,driven by an electric drill,and goes up to about 3/8".It works very well if you persevere,very handy for all those sub 1/8" drills I keep breaking!

Phil

[andpartington]

hi i got the jig and it is ok when u get it set up right i only use it for the old drills i use for diy do not trust it with my dormers

andy

[alanstepney]

The Machine Mart sharpener looks the same as the Picador(?) one that used to be around long ago. Back when LSD meant far more than a recreational drug!
They do work, but only on drils from 1/8" to 1/2" (from memory).

I have seen the Plasplugs kit in operation, and it too works, but again is limited in the size it will handle, cannot be adjusted for drill angle, and would appear to be best for just "touching up" a drill rather than completely regrinding, for example, a broken drill.

The best way is to practice, practice and practice, how to do it freehand exactly as the "old timers" used to do. (A skill I have never mastered.)

I have a better way: a pal who worked in a toolroom way back, comes over every few weeks and sharpens all my drills for me. He actually enjoys doing it, and does so with a speed and accuracy that amazes me.

[Tim Bayliss]

I'm sad to see that the Martek units seem to have demised. Chronos used to sell them but I see now they no longer list them on their web page.
Have a look at sharpdrillbits.com. I'ts an American site that are offering an aid/guide for sharpening drillbits on a bench grinder freehand. I do sharpen drills over 1/2" freehand, as I was taught as an apprentice, but I find smaller drills are too fiddly for this type of sharpening. This accessory looks simple & it might well work for all sizes.
Regards,
Tim

[andpartington]

has any one used one of these looks nice and costs a a lot
www.international-tool.co.uk/products/product.asp?id=235

andy

[baggo]

Ouch!

As you say, it looks nice but you could buy a lot of new drills for what it costs!

John

[modeng2000]

I just hope I have made the right decision!
Bought a new Martec Professional drill sharpener at a reasonable price together with some spare parts. These should keep it going for as long as I need.
Normally I would avoid buying obsolete items but the reports about the tool were so complementary that I thought the risk was worth taking.

John

[ukjimoo]

We bought one of those drill doctors at work 5 years ago in an attempt to save money on new drill bits, because none of the engineers could sharpen drills and they all binned them once they were blunt.
It came with a video with a tutorial on how to use it. As i remember it was quite complicated to use and as a result it is still in the box nice and clean. Nobody ever used it!

[robertl]

Hi I'm a newbie here - greetings all!
Just browsing through your brilliant site - learning a lot too.
With regards to the sharpeners/jigs etc, I wouldn't bother. Learn to sharpen your own drills by hand. Don't forget though, that if you grind the cutting edge angles different sizes the hole will be bigger than the drill size. Get the angles correct too. You can buy gauges or make one. With bigger drills where there is usually a centre hole in the shank you can make a small jig from an old tailstock centre or the like stood vertically against a white background. During grinding to check your angle lengths, stand the drill on the centre and scribe a line on the white background with one angle and the the other. If they don't exactly line up look out. Re-grind until they do. The final test is that beautiful moment when you stuff the drill into the metal and two lovely swarf spirals result. If you only get swarf coming from one side of the drill you are likely to get an odd size hole.

[David Thompson]

I have a Picador sharpener and I find it works quite well, especially for the larger drills. I had noticed similar ones on offer recently. The Picador unit is not perfect, because of slight slop in the main pivot which allows it to take more than one depth of cut across the wheel, so I apply a bit of hand pressure to take up the play away from the wheel. I get better results more often than I do by hand and there are built in adjustments for different geometries.

For small drills, the "Wishbone" device is what you need. It is no longer made, but there have been a couple of DIY ones described in the magazines in the last few years. Unfortunately, it is still on my wishbone list.

[steammadman]

Have a look in august 2006 issue ol MODEL ENGINEERS WORKSHOP,
what looks like a handy little tool is described on page 30.
I have not tried this yet ,but i will be giving it a close coat of looking at,
and Mr Sparrow says it can sharpen your end mills and slot drills,if it does
then it is just what the doctor ordered.

[modeng2000]

I have just finished motorising my Martec Professional drill grinding attachment. It is driven by an induction motor rather than the electric drill as was originally intended, via a round belt and two pullies. If I was able, I would post a picture as it would then be self explanatory.

The bigest regret I have now is that I didn't get one of these sharpeners earlier although I paid a lot less than the original price as they are unfortunately discontinued. Another British invention down the pan!

The two drills I have resharpened seem to cut a hole at the intended size so I must be doing something right! I have had some instruction on hand sharpening but it seems that my joints must be different from other folk as I just can't get it right.

John

[houstonceng]

I've used the Picador/Machine Mart type attachment (actually neither of these makes) to good effect, but found that it needed to be carefully set with respect to the wheel. An article in the ME - I'll need to hunt it out - described a home built equivalent which adjusted the distance of the drill arris setting pin from the wheel in proportion to the drill size - and, IIRC, the rotation of the arris in proportion as well.

In a fit of "there must be a simpler method" I bought a Martek Pro. I didn't find this easy to use at all. The plastic collets don't grip very well and I found that the setting system didn't always put the drill in the correct place as the collet was tightened OR the drill slipped as - or after - the collet was transferred. Therefore, couldn't always guarantee what results were obtained.

One common feature of both units is that - unless you're only taking a light cut off the drill - not easy to get on the Martek - you are removing metal from the drill after fixing the position of the arris. That means the geometry will change. I got the best results on deep resharpening using the Picador type by resetting the drill and then taking very light finishing cuts on both edges.

Another down-side of the Martec was the need to use an electric drill. After resharpening a few drills the noise was getting to me. The Martec now resides almost permanently in the loft. The Picador type makes a few outings, but mainly I'm using a Quorn and the 4-facet/6-facet geometry.

Andy

[modeng2000]

I don't know if this will work but here goes.

A picture of my Martec setup - uk.pg.photos.yahoo.com/ph/john1noakes/detail?.dir=9a36re2&.dnm=dbb1re2.jpg&.src=ph

John