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DBS-22 "play", 90 degree angle, other bits

Started by justme, March 07, 2018, 09:30:37 AM

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justme

RE: noticed same issue as DrSpin (existing thread from March 2017).  There seems to be a lot of "play" between the plate and moving 'top' of the jig.

Not sure if the "play" is 'at play' with an issue.  Attempting to sharpen a 1/2" x ~24 inch bit that is 90 degree - designed for wood.  The issue I've encountered is that following the videos and reading, no matter what I do - the primary facet gets removed when attempting to generate the secondary facets.  For clarity, here are my base steps:

Using SB-250 grindstone (also tried with the SG-250, but it was taking what seemed to be an excessively long period of time).
1) Use TT-50, true stone
2) Set bar distance via Tormek angle tool "hole"
3) Set jig angle to grindstone via angle tool (9 degrees)
4) Set bit depth via jig depth gauge
5) Adjust bit so that primary facet is parallel to bit holder center line (or slightly greater than center line - ie: worn bit guidance per manual)
6) Adjust primary facet stop depth so that bit touches grindstone, adding 1/8 - 1/4 turn to ensure that surface is "flush"
7) Grind both sides (results look good this far)
8) Make sure that Secondary facet stop is against Primary facet stop

-- Tried the following repeating the above steps, so that cycle is complete:
9) Adjust 1.5 turns.  Results: primary facet(s) appear to be removed (ground off)
9) Adjust 4.5 turns.  Results: primary facet(s) appear to be removed (ground off)

Haven't seen anything where someone has posted about running into this issue.  Hoping that someone with more experience with the DBS-22 may be able to point me in the right direction.  Another peculiar point is that the angle is evidently "extreme enough" that you cannot traverse the entire grindstone as the drill bit holder portion of the jig will intersect the grind stone at about 75% of the distance - moving from left to right.  It's this last point that gives me pause.  Given how everything else has created the ability to fully traverse a stone (left to right and back) - the fact that this angle cannot traverse the stone has left me wondering if there's "something else" that may be missing from the equation.

For reference, had no issue with other drill bits (1/2" and slightly smaller), but the angles where 118, 135, etc.  The only difference (in this case) is the 90 degree angle.  The bit in question is meant for drilling through wood only and it has a hole roughly mid-way through the fluted section of the shaft to use as a "pull" for lead line (wire installation/s).

In the end, if replacing a drill bit is part of the initial learning process - that's OK.  Just need to understand what/why this doesn't appear to be working as documented - to learn corrected process.

One other question, has anyone attempted to sharpen drill bits with "quick" connect/disconnect fittings?  Bits of this nature with sufficient length to span the bit holder, sharpen without issue.  Smaller diameters (shorter shaft) where the (integrated) connector ends up in the bit holder and the drill bit holder doesn't have solid contact with the bit "itself" - doesn't seem to work out too well.  Thoughts?  (Suspect that these simply cannot be sharpened, but thought it worth posing the question).

6 facet looks quite tantalizing, but until one has mastered 4 facet... (hopefully by then a "6 facet" jig will be available and a jig for spade bits)

Thanks!

Ken S

Justme,

Interesting post. As a telephone man, I used those long bellhanger bits for thirty five years. I used a mill file to sharpen mine. (No bragging about their sharpness)

I retired several months before purchasing my Tormek, and about a year before I bought my DBS-22. I have thought about sharpening some of my old bits. I will add them to my sharpening projects list. Incidentally, I resharpened my bits to 90°. Most of the holes I drilled were through soft framing lumber.

Ken

RichColvin

Justme,

It seems from your comments that the instructions on pg. 11 weren't followed for the secondary grind (though I may be reading this incorrectly).  Here's a link to the instructions :  https://www.tormek.com/media/105148/instruction_dbs22_en.pdf .

There are a few good videos about how to do this on YouTube.  Here are some links :

If you want me to try this with a ½" bit, I can do so this weekend for you (and video it), though I don't think my videos would be better than the above 3.

Kind regards,
Rich
---------------------------
Rich Colvin
www.SharpeningHandbook.info - a reference guide for sharpening

You are born weak & frail, and you die weak & frail.  What you do between those is up to you.

Ken S

Justme,

I have not had a chance to go into the shop, however, here are some ideas. First, I would reset the clearance angle to 11°.

Try resetting your bit angle from 90° to approximately 120°. Use this as a starting point. If you have more room, try getting closer to 90° gradually. Believe me, as an old telephone man, drill bit sharpening with a mill file was approximate. Your final sharpenings will be leagues ahead of typical.

Set your secondary adjustment to 1/2 turn. This will probably not be enough. Add in small increments until you reach the correct point.

Make sure you write down your final settings.

While it might look like there is quite a variety of these bits, 1/4, 3/8", and 1/2" probably cover 90% of the bits in use. Once you work out your basic setting and get some practice, you should be able to sharpen these bits quickly. Quickly enough to make the work profitable, especially if you can get connected with your local telephone, cable or satelite provider.

I have often stated that I consider the DBS-22 Tormek's most advanced jig. It is worth your time to work with it enough to really understand it. Pay particular attention and practice to getting the secondary grind adjustment correct. Going slowly with this will speed up your operation.

I consider Alan Holtham's video our best resource. I rewatch it every time before using my DBS-22.

Be patient; you will soon master sharpening your bits.

Ken

ps The old term "bellhanger bits" refers to doorbells.

Elden

#4
Quote from: justme on March 07, 2018, 09:30:37 AM

6 facet looks quite tantalizing, but until one has mastered 4 facet... (hopefully by then a "6 facet" jig will be available and a jig for spade bits)


Six facet, some spade, and brad point drill bits can be done with the DBS-22 with two simple modifications. Two new pivot (fulcrum) holes must be drilled in the DBS-22 base.

https://forum.tormek.com/index.php?topic=1622.0
shows the modification for spade and brad point bits.

https://forum.tormek.com/index.php?topic=3265.0
brings up the question of the possibility of a 6 facet grind with the DBS-22. In that post, Janne shows a couple of pictures showing a 6 facet grind he accomplished with the DBS-22.  He later stated how he obtained the placement of the pivot (fulcrum) hole.

   My DBS-22 has both modifications done to it. Sadly I have not tried either one yet except as trial set-ups. Both of those look great!
Elden

justme

So Rich's post "Jeff Fischer's video" - was the key.  While using the DBS-22 on a worn bit, you do the primary facet - then stop and "reset" the drill bit to be parallel with the lines on the bit holder (or pin).  This is key.  Unfortunately, this wasn't listed as a step that one should take (possibly inferred?).  While the geometry and changes through process should be evident - this minor nuance was evading me, due to not thinking/realizing what was changing while being opposite the action.  Once realizing and thinking through what was happening - everything became quite clear.  It was more about how much was removed (or not) and how it changed the geometry of the bit in the holder.  (Also happens to illuminate what to consider if working on a broken bit, etc)

The adjusted process should be re-documented as:

- True Stone (optional)
- Set bar distance w/angle tool
- Set jig angle w/angle tool
- Set bit depth using depth gauge
- Align bit in holder based on 'current' geometry
- grind
- Re-align bit to match indicators (or pin), if it doesn't line up
    - Do not expect primary grind results to be "parallel" to the lines, particularly true if more material needs to be removed to get to a good starting surface
- Set secondary facet angle
- Set secondary facet depth
  - Starting with "existing" (touching stone) depth and slowly working up.
  - Small bits may only require 1/8 turn (or less) to get secondary facet.  Very easy to overrun (as Jeff Fischer points out in his video)
- grind
- hone (optional)

Evidently, the correction of the primary facet was enough to cause the bit's geometry to become offset - as Jeff Fischer noted.  This isn't listed in the Tormek docs or Tormek video.  Granted, one may argue that said operator should have caught this during process - however having it documented would have been most helpful for those new to the process.  This minor nuance makes the difference between "it's just a bit" and what appears to be a perfect 4 facet bit.  Tried process on a couple bits - variety of sizes and the adjusted process yields the correct results.

+1 to Rich for locating a source that 'caught' the issue.

Follow-on question: given what happens with a 90 degree angle - what's the implications of extending the bit (ie: more length on the action side) so that the bit holder cannot come into contact with the grind stone?  With larger bits where it's easy to see the alignment the amount of bit between the holder and the grindstone shouldn't change anything - should it?  Can't seem to visualize how, say "doubling" the amount of shaft, would negatively impact the process.  The process seems solely dependent on the angles and rotation of the bit's head - not the location of the bit holder on the sliding plate - correct?  Doubling shaft length would alleviate the good chance of scraping the bit holder on the grindstone.

Thanks!

Ken S

Excellent sleuthing!  You are also fortunate to have two of our best reference persons, Elden and Rich on the case.

About the projection length...... I would suggest giving it a try. I don't see any harm, and, it might solve the problem. Go for it, but tread lightly and post your result.

It's unfortunate that the drill bit jig is not in more common use; it really is a versatile jig.

Ken

justme

Ken,

Agree that the DBS-22 is an excellent jig.  The education curve and perhaps price may be a barrier to more widespread adoption.  Although the price (IMHO) is fair for the components of the jig - especially if you consider it as an investment over some time period (10+ years?)

I'll have to give it a try on another 90 degree bit and see if that works out.  Using standard method, the left hand side corner is what will catch the stone.  Worst case, I chew up a drill bit and have to replace it - which is amicable to determine if it works.

I did play with the quick connect/disconnect style drill bits.  Due to their hex styled connection - it makes it a bit awkward.  I did have good luck getting 4-facet point - especially after learning the "re-center" step.

RE: 6-facet / spade / brad : Given the exacting nature, would prefer to purchase a unit "already setup" (so I'm not the one to screw up the hole...).  Also means that I've have a slide plate/top for standard drills and a slide plate/top for 6-facet/spade/brad.  Do you happen to know if just the slide plate and associated top plate can be purchased without purchasing the entire setup?  (eg: "replacement" parts)

Thanks!

Ken S

Justme,

Here is a link to a dealer in the US who handles parts. I have had good deslings with them. In fact, they do enough Tormek business that I was able to purchase my second T7 from them. My first unit was stolen, however, I did not need all the components. (The thieves took the Tormek, however, they missed the jigs and accessories, including the water trough.) Advanced Machinery gave me excellent service.

I never know where our members live, and do not assume everyone lives in the US. The site will give you an idea of cost and parts numbers you can use with your dealer. Being thrifty, I keep a running parts list and try to get all I need with one shipping charge, although DBS parts will quickly get you above a free shipping minimum.

https://advanced-machinery.myshopify.com/pages/replacement-parts-for-dbs-22-drill-bit-sharpening-attachment

On a practical level, I would do some tests with your bit to see how close you can come to 90° and still clear the jig/grinding wheel. I retired nine years ago, however, in my distant past memory, I recall new bits coming from the factory with the standard 118° bevel angle. I resharpened them closer to 90º. Hand holding the bits in the field with a mill file, my ninety was definitely "ninetyish". I don't think ten degrees or so would make much difference.

I still think you may have a mis set angle somewhere in the mix. I have contacted Tormek support for some help on this.

Keep us posted.

Ken

justme

Ken,

Will take a look at the URL - Thanks!

Yes, not sure what may be 'amiss'.  I like to break out the manual that came with it, each time I sharpen bits.  Enables me to double check steps and ensure that they are being followed - until I get to a point where the process becomes natural.

While most bits may be 118 degrees, this one was originally a 90 degree - a bit of an odd "critter", but designed to be specific to purpose (vs. standard drill bit).  Admittedly, given what the Tormek can do - could easily convert to a different angle, but would like to keep the 90 degree angle.  The only other possibility - granted haven't checked because I think it "highly unlikely" - is that the jig mounting bar is not absolutely square.  From a comparison to a 2nd one, (just rough view) - looks straight.  Perhaps I should try with the other bar to see if that makes a difference.  Yes, when I decided to get into the "Tormek thing" - picked up every jig, all 3 grind stones, the rotating base and even the Tormek workbench/cabinet.  Probably a little excessive, but makes for a nice little workstation and keeps things clean and tidy.

Since all the standard drill bits that I've done (118 degree) have come out virtually perfect, following the manual - not sure that it's an angle.  Unless the suggest angles (based on diameter) on the angle tool aren't correct for a 90 degree bit?  Thoughts?

Attached is an image of the first drill bit that I had attempted to sharpen on the Tormek - that was via simply following the manual.

Thanks!

justme

Quick comment to prior post - had thought about attempting to use the SJ-250 on the facets, but was concerned that I wouldn't be able to exactly match the angles.  Had wondered if the extra finishing with the 4K grit would enable longer life and better cutting by the bit.

Ken S

Justme,

Neither of the two Tormek DBS videos (one being the sponsored video with Alan Holtham) show even using the stone grader. While it is possible to finish with the SJ, in the industrial world the extra time is not practical. Drill bits live in a rough and tumble world. Bell hanger bits are no exception. While you might take very good care of your bits, most users just soldier through to get the job done. Leaning on dull bits and overheating are the common practice. I was one of very few who even filed my bits.

Alan Holtham does mention grading the wheel fine for small diameter bits. This is logical; small bits, like narrow chisels concentrate the force. Using light grinding pressure, especially with the final passes, will produce finer edges. I would make sure the shaped leather wheel removed the burr and call it a day.

Ken

RichColvin

Justme,

The picture looks great.  Did you hone the edges on the leather wheel ?  I've never done that, but wonder if there is value in going down that path.  Any insights ?

Rich
---------------------------
Rich Colvin
www.SharpeningHandbook.info - a reference guide for sharpening

You are born weak & frail, and you die weak & frail.  What you do between those is up to you.