By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Allendale Jan 24th

Perfectly ground Twist Drills every time.

All Topics | Latest Posts

Search for:  in Thread Title in  
Neil Wyatt06/05/2014 15:50:23
avatar
Moderator
18232 forum posts
714 photos
77 articles

I'll have you know I would never wear moleskin. I'm very fond of moles.

Neil

John Stevenson06/05/2014 16:06:20
avatar
Moderator
5068 forum posts
3 photos

Moles - Bloody scourge those things are.

We used to catch them as kids and bury them alive.

Gordon W06/05/2014 16:46:19
2011 forum posts

Well at long last I am a fully authenticated Model Engineer . Moleskin trousers, hairy jumper, very deep pockets ( yorkshire man in Aberdeenshire) Drive a 2CV .

Michael Gilligan06/05/2014 17:20:15
avatar
16359 forum posts
712 photos

On the subject of van Royen ...

I was somewhat amused/bemused by this on "myhobbystore"

MichaelG.

WALLACE06/05/2014 23:24:19
304 forum posts
17 photos
Hi Gray.

Yep, I can see the detents would be lost - after I posted the suggestion, I dug out my unloved grinding jig to have a look....

Is there anyone out there who doesn't have one stuck unused on a shelf somewhere ?? !

But it is shocking quality -and has prompted me to have a look at a Reliance jig to see how that works with maybe possble improvements...(although my long term plan is to go down the 4 facet route using a jig that takes er32 collets on my Union t&c grinder - eventually ! )


W.

W.

Lynne07/05/2014 04:54:00
82 forum posts
27 photos

Hi, MEW 176 & 177, Drill Sharpening Jig, by John Shepherd, well worth a read.

2nd attempt. 1st showsin 'My posts', but not in thread .

Michael Gilligan07/05/2014 07:16:38
avatar
16359 forum posts
712 photos
Posted by Lynne on 07/05/2014 04:54:00:

2nd attempt. 1st showsin 'My posts', but not in thread .

.

Lynne,

Your 1st is there, at the bottom of page 3

MichaelG.

John Haine07/05/2014 13:26:46
3328 forum posts
176 photos

MichaelG, myhobbystore have clearly run out of bits, so we'll have to wait until they are re-stocked!

(But how come we can still see this web site?)

Michael Gilligan07/05/2014 16:14:09
avatar
16359 forum posts
712 photos

John,

Nice

MichaelG.

Bazyle07/05/2014 17:17:20
avatar
5463 forum posts
206 photos
Posted by Graham Meek on 06/05/2014 15:08:18:

Finally I am convinced that the excessive off-set built into the jig originally is to cater for drills with a different included angle, i.e. the other settings on the jig, (one size fits all). I have not bothered to look into this as my requirements for different included angles is zero, in my 40 so years of Toolmaking I cannot remember one instance where I have needed such a drill.

Gray,

Thanks for that. I was gong to ask what the other settings were used for. When I find mine I can just pin the wobbly joint permanently.

Thor07/05/2014 18:03:06
1275 forum posts
39 photos

Hi Gray,

thanks for the additional photos and explanations, much apprerciated.

Thor

Neil Wyatt08/05/2014 19:36:30
avatar
Moderator
18232 forum posts
714 photos
77 articles

Graham,

I had a 'play' with my plasplugs multi grinder yesterday. The drill holder is clever but imperfectly realised, although it's simple design does make a decent job of holding the bit at the same height for each flute.

Drills are ground at the top of the wheel, and the grinding is more or less normal to the cutting edge.

The setting jig has a triangular steel 'ramp' that sets the bit protrusion. A moveable 'V' at right angles to this sets the drill orientation by a four-point contact. You can use this as a check for symetrical grinding.

Drills are presented to the wheel with the bit turned slightly to the right, which more or less puts the cutting edge along a radius near the top of the wheel. An invisible, but presumably off-centre, pivot creates the backed-off edge as you turn the holder.

The weaknesses of the design are two fold - the tiny 70W motor struggles to keep the grinding wheel going at speed under any sort of pressure - so it's best for worn, not damaged, cutters. Secondly the plastic construction and some spindle end play mean you need to develop a consistent 'touch'. regularly turning the drill 9rather than doing one side at a time helps. The Tip angle seems to be accurate.

I suspect it would be worth duplicating the jig in metal.

Does anyone know how the sharpeners that have a drum with various holes for the drills to be poked into work?

Finally, anyone seeking the digital article (or other digital content) on MHS will be delighted to know that the effect of a system reset that rendered all digital editions 'out of stock' has now been rectified.

Neil

Neil Wyatt08/05/2014 21:45:59
avatar
Moderator
18232 forum posts
714 photos
77 articles

Hi Gray,

My jig appears to grind more or less accurate at 59 degrees, using an engineers protractor on the drill tip, a few days ago.

Neil

Neil Wyatt09/05/2014 10:47:15
avatar
Moderator
18232 forum posts
714 photos
77 articles

About 6 degrees, as best as I can tell by sighting across, but only a short portion of the pin is visible .

I deleted a duplicate post - the system seems to be throwing a few today.

Neil

Neil Wyatt09/05/2014 14:29:23
avatar
Moderator
18232 forum posts
714 photos
77 articles

Good guess - it's 52 degrees, to the nearest degree.

As with the mini lathe racks, it seems superficial similarity of design doesn't mean identical detail!

Neil

Russell Eberhardt09/05/2014 16:23:48
avatar
2600 forum posts
85 photos

There seems to be a lot of variation between different versions. I have just dug my 25 year old version out of the drawer and it has the post leaning towards the wheel by 6° and the V for the drill is at 55° to the vertical. So the drill angle will be 112°.

I wonder how much difference it makes having 112° instead of 119°. I suspect none. I will however stick to using my four facet jig.

Russell.

Michael Gilligan09/05/2014 18:45:44
avatar
16359 forum posts
712 photos

Gray,

It looks like you have succeeded in making a rather fine Silk Purse from the proverbial Sow's Ear.

MichaelG.

Neil Wyatt09/05/2014 19:36:52
avatar
Moderator
18232 forum posts
714 photos
77 articles

Hi Russell

The main difference appears to be the tedium and potential for error introduced by having to grind away a lot of extra metal to get the 'new' angle, especially where the new angle is less than 119 degrees and the extra comes off the heel of the drill point.

Neil

Clive Hartland09/05/2014 21:20:05
avatar
2604 forum posts
40 photos

Just a query and a thought on this subject,if you use the face of the wheel does the lip of the drill have to be exactly on the center line of the wheel? I am trying to envisage the set up if it was lower or higher. Any thoughts on this.

Clive

Versaboss09/05/2014 22:11:19
458 forum posts
51 photos

One more for the list of angles:

pin angle: 10-11° (protractor)

square bar (=vee) to vertical: 61.3° (digital gauge)

That would result in the angle vee -> pin of around 50° if my arithmetic is correct.

Clive, on my 170 mm grinder the drill touches between 1 and 2 o'clock! It would need a substantial block below the grinder to get near the center line (or the jig had to be mounted lower than the grinder).

Regards, HansR.

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Support Our Partners
EngineDIY
Eccentric July 5 2018
cowells
emcomachinetools
ChesterUK
Warco
Eccentric Engineering
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

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.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest