730 forum posts
I've been having a bit of a play this afternoon as the weather wasn't up to much.
Doubletop-Pete commented, in the above thread, that he felt that his Sealey was taking off too much metal; so was mine out of the box, albeit a second hand box.
Sliding the wheel towards the motor, will reduce the depth of cut on the primary grind, as it's a tapered wheel.
As you can see from my efforts, I've not quite got it right yet, but even 1/2" bits ground like this, will start off without a pilot hole or centre pop, though I accept the latter's bad practice.
The whole project took rather longer than planned
I sharpened several 1/2" bits using;
A Sealey SMS2008,
A brand new genuine Picador jig; Note that the Picador jig has the vertical pivot, and in theory at least, should work OK out of the box. Drill bit orientation is set by a movable detent on the flute to be ground.
A Reliance No.2 (which needs the bit cutting edge setting by eye). On this one it's recommended to use a projection of three times the drill diameter, so in this case 1 1/2"
I don't claim to be any expert at drill sharpening, but am generally considered reasonably dexterous. I'm sure many on here get perfect results freehand; I know can't
Left to Right, Picador, Sealey Split Point, Sealey Plain Grind, Reliance, New Unknown Make, New Unknown Make Four Facet, and lastly a New Presto 7/16" ( I didn't have a new 1/2" one).
The middle one, ground on the Reliance, was an older Morse tapered one which doesn't look to have had the flutes ground very well from new, hence the odd side view of the relief.
Edited By peak4 on 26/12/2018 17:19:39
|Clive Foster||26/12/2018 17:46:33|
|1663 forum posts|
I also did the "take out the pivot play" thing on a Picador. Discovered that the darn thing worked better with things "as delivered" slack. With the play taken out there isn't quite enough clearance angle at the a back of the flute with larger drills. From memory the effect starts to bite around 3/8" - 7/16". 1/2" drill ended up really sharp on the edge but barely, if at all, cut once fully engaged due to the back of the flute rubbing. Poor thing got a 5 years + stay in the box after that before I decided to give it another go following the instructions rather than improving things. Sometimes the maker does know better and sometimes crude works where precise doesn't.
Essential to make arrangements to accurately and easily adjust the distance between drill jig base and grinding wheel without things twisting and sliding every which way. Mine sits on a scrap of 1/4 plate bolted to the bench with 10 gauge side-plates to keep the jig straight. Wort thing then is getting the projection and angle of twist right. That darn location finger is rather un-useful. Mine gets done more or less by eye with the finger as a reference rather than a stop. I found a narrow, 1/2" or so, cup wheel more reliable than just using the side of a normal wheel.
When it comes to drill setting and location the cheap plastic, but rather decently performing, one in the original Plasplugs multiple sharpener set is the best I've seen. Positive stop for the projection with a sliding Vee gauge to set the angle of twist. "Grip the drill gently in the Vee holder and lightly push it forwards against the stop then turn until gauge is at it's lower point. Then tighten up the drill holder so that it is firmly held." Drill holder fits in the grinder proper both ways up so none of this business of trying to set the second edge exactly 180° to the first. Just grind one side, flip the whole darn thing and do t'other one. Genius. Why aren't they all made that way. Pity flexi plastic construction and trying to make the thing for thruppence three-farthing when fourpence ha-penny would have been a better budget makes getting best results a minor art.
In the process of making the missing bits for my "wallet came out smoking" Clarkson drill sharpener attachment right now. 3 years marinating in t'cupboard is about par. Be interesting to see how well the professional option works.
396 forum posts
Great thread. I'm going to have a play with my Sealey 2008 clone today. The realisation that the ginding wheel position was adjustable and would affect the depth of cut is the basis of my investigation . I have an idea of an approach to doing the basic setup without making it hit and miss. I'll see it there is a way of ensuring the split point still works. It may be a case of the best compromise position of the wheel to accomodate both.
|Henry Brown||12/04/2019 19:38:05|
|14 forum posts|
Very interesting, following with interest as I'm in the market for something to do a better job than I do at present...
|Dave Halford||12/04/2019 20:58:28|
|373 forum posts|
The depth of cut on the Sealey and the like is set by how far the drill sticks out of the holder, all you need to do is stick something on the metal pad, like layers of sticky tape for eample no need to mess with the wheel position.
BTW you can buy new wheels for them.
Please login to post a reply.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.