BGM-100 Standard Setup is NOT for Drill Bit Sharpening with DBS-22

[RickKrung]

Setup instructions (distances/dimensions) for the BGM-100 with bench grinders are NOT for use with the drill bit jig, DBS-22. 

I recently set up two BGM-100s on both sides of an 8" bench grinder following the instructions that come with the BGMs.  https://forum.tormek.com/index.php?topic=3737.0  My intended use at the time was for knife sharpening, which I have largely abandoned due to the heat generated. 




Setting up the BGMs using the standard guidelines provided in the manual results in the USB being entirely too low.  This is understandable, as the BGM manual makes no mention of using the setup for drill bit sharpening.  Instead, it is all about wood turning tools and the like. 


The USB needed to be set another 41mm higher than the standard BGM setup.  A Frontal Vertical Based (FVB) allows for setting the USB higher, as needed, but the USB is still too far away from the grinding wheel, at least with my current FVB.  Making the body of the FVB narrower would rectify this and allow use of the DBS-22 without further modification of the BGM height setup.  I was already thinking of how to streamline the FVB and make a couple more for this setup, now I have more justification. 


An additional aspect of the standard BGM setup is how close the inner USB support rod is to the grinding wheel.  For both the left (coarse) and right (fine) grinding wheels, the DBS platform and slider are too close to the grinding wheel, compared to the horizontal USB setup on the T8. 

On the T8, the platform is a little over 45mm away from the left edge of the grinding wheel.  I think this is too close as the DBS sliding platform tends to tilt as it extends out over thin air on the left side of the fixed platform.  I find that I have to pay special attention to preventing this tilting as it can mess up the facet grinds. 


On the left BGM, there is even less room, about 25mm, so I am certain there would be a problem with tilting. 


On the right BGM there is a lot of the platform to the left, but only about 25mm on the right.  That may not be a problem as the majority of the weight of the slider and drill bit holder jig is on the left. 


In short, I think the BGMs need to be further away, to the left and right, from the grinding wheels for adequate support of the sliding platform/drill bit holder.  I'll report back once I figure out how far seems good.  I'll also be moving the support blocks back enough to get the USB close enough to the wheels to use my current FVB and be able to do some rough grinding of drill bits. 

Rick

[RichColvin]

Rick,

That is great information.  I've only used the Tormek for drill bit sharpening, not the BGM-100.  Why where you using a bench grinder?

Kind regards,
Rich

[Ken S]

Interesting topic, Rick. We now seem to have enough members with the DBS-22 to put together a think tank. I have no doubt that the DBS-22 can be configured to work with a dry grinder. Like many of the forum projects, I do not think the possibility occured to Tormek, or may have been judged to have insufficient demand to make production cost effective. (I am not faulting Tormek for this. Like any other business, they must remain profitable to remain in business.)

Did you decide that the 46 and 80 grit 3X wheels were too slow when used with a Tormek? (I know, many drill bit users wait until their bits are comatose before thinking of sharpenng them.   

Ken

[RickKrung]

Rick,

That is great information.  I've only used the Tormek for drill bit sharpening, not the BGM-100.  Why where you using a bench grinder?

Kind regards,
Rich

The process of setting up the BGMs with a dry grinder (saying "setting up the BGMs with a bench grinder" sounds redundant ) began before I had the Norton 3X wheels and for sure long before I even knew about the Tormek diamond wheels.  I was not happy with the SB stone for taking off metal fast enough when drill bit sharpening and wanted to rough off the reliefs on a bench grinder.  I did that free-hand with some 1/2" - 3/4" bits and I liked it.  I got the Rikon 8" grinder and the BGMs before ordering the diamond wheels, actually not even expecting to be ordering them at all.  I was also working with the understanding that the white wheels and slower speed (1750rpm) of the Rikon that I got would work well for roughing HSS bits without damaging them nearly as easily due to heat. 

Subsequently, the Rikon and BGMs languished as I waited for the DC and DE diamond wheels, until a few weeks ago when I wanted to be able to rough some knife bevels and so got motivated to get them all set up.  I'm glad I did.  Even though my first and only attempt at drill bit sharpening using the diamond wheels suggested that grinding the reliefs is much faster and easier, I still want to have the bench grinder and BGMs available and I do expect to use them for it. 

As a matter of fact, I am planning on trying deviating from the nominal pattern/sequence for grinding the primary facets then the secondary.  I plan to try grinding the reliefs first on the BGMs and then taking the bits to the diamond wheels for grinding the primary facets and cleaning up the secondarys.  We'll see. 

Rick

Interesting topic, Rick. We now seem to have enough members with the DBS-22 to put together a think tank. I have no doubt that the DBS-22 can be configured to work with a dry grinder. ...snip...

Did you decide that the 46 and 80 grit 3X wheels were too slow when used with a Tormek? (I know, many drill bit users wait until their bits are comatose before thinking of sharpenng them.   

Ken

As stated above, it was in part, just wanting to finish something I started.  I also wanted to try using the slower speed, white wheeled Rikon to see what I thought of it.  If it works, it may reduce wheel changes.  Also, from that one bit-trial, I can see how not using the 3X wheels and just using the DC wheel might be enough. 

This is all pretty fluid stuff for me right now (and I'm not whining about the "ACC water"  ).  I don't know how it will all shake out. 

Rick

[Elden]

Jan,
   Have you set your drill bit jig:

https://forum.tormek.com/index.php?topic=3226.msg18859#msg18859

to grind on a bench grinder?

[RickKrung]

Rick,

That is great information.  I've only used the Tormek for drill bit sharpening, not the BGM-100.  Why where you using a bench grinder?

Kind regards,
Rich

Rich,

This is why I want a bench grinder for roughing drill bits.  These have up to 3mm that have to be ground off to reach viable flutes and some must have the center-pointing removed in order to be resharpened/reused.  I don't know if the friend that I'm doing these for will have them center-pointed. 


I have done some preliminary roughing with the white wheels on the Rikon and feel it isn't aggressive enough, so may resort to my old traditional high speed bench grinder to get them to where they can be shaped and prepared for the Rikon/Tormek. 

Rick

[Jan]

Jan,
   Have you set your drill bit jig:

https://forum.tormek.com/index.php?topic=3226.msg18859#msg18859

to grind on a bench grinder?

Elden, sorry for the delay in my answer.
I have used my drill bit jig only with Tormek.

Jan

[Ken S]

I found thid you tube modifying the BGM-100 to use the DBS-100:

https://youtu.be/tDiY_w_Rrv0

Ken

[ega]

I am just posting to thank Ken S for his YouTube link so won't start a new topic.