Messages

Thank all of you for your help. In my opinion, the DBS-22 gives a lot of hassle. Maybe my expectations were to high. After seeing Tubalcain video, I regret I haven't bought a belt grinder for €180 instead of a DBS-22.

Petromax,

I am out of practice with my DBS-22. In your dropbox photos I did not notice you setting the distance from the universal support and the grinding wheel. Also, I did not notice you grinding the secondary bevel.

Whenever I sharpen a drill bit, I first watch Alan Holtham's video. If ou can pause the video between steps, it may simplify things for you. Once you get the jig working correctly, the results are worth the frustration.

You should not have a negative clearance angle.

Hang in there. This will work. Keep posting.

Ken

Hello Ken,

I used the setting template for the distance and the angle:
https://www.dropbox.com/s/5k8r28y10wt40se/20160108_152810.jpg?dl=0


Indeed, I did not grind the secondary facet, just to show that the clearance angle of the primary facet is not good and this is the reason why the tip of the drill is getting to hot.

https://www.dropbox.com/s/xrfvhvx77zb7ojx/blue%20tip.jpg?dl=0

I'm still having problems whith sharpening my drills. Here are some pictures from the steps I took:

1. Mounting the drill:
https://www.dropbox.com/s/zw8c6gllflffb8t/Screenshots_2016-01-08-16-30-45.png?dl=0
https://www.dropbox.com/s/lwx8wv584aiv9o6/Screenshots_2016-01-08-16-28-18.png?dl=0

2. Setting the point angle at 118° and the clearance angle at 11°
https://www.dropbox.com/s/rynqvs5pp05nd1o/Screenshots_2016-01-08-16-31-28.png?dl=0
https://www.dropbox.com/s/qyolpq35jb97ocu/Screenshots_2016-01-08-16-29-38.png?dl=0

I just focus on the primary facets. After grinding, the drill is still correct aligned. The I checked the point angle and as expected,  the angle is 118°.
https://www.dropbox.com/s/tfa1pnkpzkl2hv0/Screenshots_2016-01-08-16-32-43.png?dl=0

But when I check the clearance angle, I noticed there is something wrong. The angle is negative, so point (A) is rubbing the surface and the drill generates heat. Drilling a hole in wood is not a problem, but (mild)steel is not possible without overheating the drill.
https://www.dropbox.com/s/qep7ik0o1xd0pv2/Screenshots_2016-01-08-16-42-45.png?dl=0

I took also a picture from an other (new) drill. As you can see the is a neat clearance angle.
https://www.dropbox.com/s/zun9a05y4yv88fo/Screenshots_2016-01-08-16-34-29.png?dl=0

What am I doing wrong?

   Wish you well, Paul. Are you sharpening an already formed cutter or making one from a blank HSS stock piece? Years ago in vocational technical school was when I ground the one I mentioned. It was done using a standard bench type grinder.

I make them from blank square toolbit steel.

Thanks for your replies. It is not a problem that the surfaces are a little hollow, this also happens with a normal bench grinder. Carbide bits require a very high cutting speeds and are therefore not always useable.

I just bought the SVD-110 and I hope this jig helps me to find a method for sharpening my HSS toolbits, otherwise I have to develop my own jig. I thought there was an easy way...

I'll let you know if I found something usefull.

Hello guys,

I was wondering how to grind/sharpen HSS toolbits for my metal lathe. These bits are quite complicated to grind because there are many important angles. Has anyone find out a technique for this job?

https://youtu.be/Mn9jpqI8rao


Regards

Thank you for your replies. Yes I reduced the speed, but used no cutting oil. I also thought there was no need to pre-drill with a smaller diameter when I use a four facet drill.  Maybe there is something wrong with the geometry.


I'll try again...

I tried to grind several drills. The result seems to be okay, but after drilling just one hole in mildsteel, the point of the drill is getting blue. My conclusion is that the drill is overheated at the very top of the drill. The cutting performance is not very bad, but I expected more.

What am I doing wrong?

(HSS drills 8..10mm, 118° top angle, 11° cutting angle)

https://www.dropbox.com/s/q63r507ob287x51/20151227_141004.jpg?dl=0
https://www.dropbox.com/s/41g87wfkezm6ktr/20151227_141122.jpg?dl=0
https://www.dropbox.com/s/y0ld6ohofocj9dl/20151227_141424.jpg?dl=0

I took this picture after drilling one hole.

https://www.dropbox.com/s/w4i98xklp3jha2k/20151227_142217.jpg?dl=0