Thread: D Bit Grinder

Hi, does anyone own or have any experience with H & F's Toolmaster universal D Bit Grinder?
are they worth the money? their on sale this week for about $1300,
leroy.

I new a guy who had one exactly like that . He could grind end mills slot drills and twist drills . I need one myself but it's a lot of cash right now.
What choice do we really have ? How many tool and cutter grinders are out there new for $1300 ? The only thing that puts me off is the one I saw had 5c collets . Why 5c why not ER collets that most metric people have ? If it comes with a range of 5C collets ok but if it don't it's an extra expense .
I think I would buy it if I had the money .

( If it comes with a range of 5C collets ok )
It comes with 10 5c collets both metric and imperial,
leroy.

The 5C collets are easily found and would be preferred to the ER collet in many ways due to the former being rear pull (as opposed to front push) which provides more clearance, and having greater pass through ability.

These grinders are essentially a copy of a Deckel d-bit grinder, however the Deckel use their own collets which are relatively expensive and much harder to find. The 5C was used as a more modern upgrade.

Whether you "need" one will depend on whether you want to grind d-bits. I don't have one but would like to get one at some stage if my career. If you're buying one to sharpen end mills and drills I think you're buying the wrong tool for the job. If however you're wanting to grind d-bits, then that is the tool. If you don't know why you would want to grind d-bits, you probably don't need one

Depending on the type of work you're doing, they can be an incredible tool, but if you're using one a lot you've almost certainly crossed the machinist to toolmaker line, and that's not the path everyone wants to go.

I'd love one too, but too many $ for my liking, I'll just settle for my rotary tool mounted on my lathe, poor man's tool grinder!

Originally Posted by leroy

( If it comes with a range of 5C collets ok )
It comes with 10 5c collets both metric and imperial,
leroy.

Then that's ok , the add I saw did not show any extra collets . I saw a friend sharpen a slot drill in the same looking machine and the advertising says it can sharpen , endmills , slot drills and twist drills .
Seems the right tool to me not that I'm an expert on tool and cutter grinders . Do a double check of it's specifications to make sure .

Originally Posted by leroy

Hi, does anyone own or have any experience with H & F's Toolmaster universal D Bit Grinder?
are they worth the money? their on sale this week for about $1300,
leroy.

A great little machine for licking over slot drills and end mills (end and periphery) up to 5/8"/16MM shank dia, with supplied collets and attachment for standard length cutters.

The drill sharpening attachment is nigh on useless but that's just my thought on it.

Radius cutters both mill and lathe tools can be ground easily but does require a slight mod for setting ease. (see pic)

Best bit of kit for the home workshop the loose change can buy! Was $1240 I think early this year.

Let's not forget that many of us had all the machines we needed when in the workforce but after retirement things do change. Doesn't take too many larger diameter end mills/slot drills to eat up the purchase price so better to sharpen than throw away.

DBitGrinder.jpg

Add to the above a fixture for form cutters and it becomes just that bit more useful.

FormAttach.jpg

That is a rough copy of a Deckel type SO D bit grinder.
Deckel Grinders cost 5-6 times as much for the same capacity so quality IMHO is suspect for something that cheap.
It should be noted that these grinders are designed to grind D bit style cutters which are straight fluted.
They can sharpen the ends of endmills but you cannot use them to sharpen the flutes as they are helical and the cutter passes the grinding wheel in an arc which prevents you from twisting the cutter to follow the flute helix.
They can be useful for making special straight fluted cutters etc though.

The supplied attachment for end mill peripheral grinding. Just needs suitable tooth rests to suit cutters being ground to complete the setup.

EndFixt.jpg

I have an older grinder with u2 collet. I recently modified straight shank er20 holder to fit but not yet to put on test as I don't have the collets yet. It does stick out a bit.
20171111_112116.jpg20171113_230041.jpg20171113_230127.jpg

Originally Posted by shedeng

That is a rough copy of a Deckel type SO D bit grinder.
Deckel Grinders cost 5-6 times as much for the same capacity so quality IMHO is suspect for something that cheap.
It should be noted that these grinders are designed to grind D bit style cutters which are straight fluted.
They can sharpen the ends of endmills but you cannot use them to sharpen the flutes as they are helical and the cutter passes the grinding wheel in an arc which prevents you from twisting the cutter to follow the flute helix.
They can be useful for making special straight fluted cutters etc though.

They are pretty much an exact copy as a Deckel grinder, and a Deckel will generally cost about half to a third what the Chinese one will. However the Deckels don't come up all that often these days, there was a time they seemed to pop up frequently (with the closure of manufacturing tool making divisions I guess). BUT the Deckel is used and like any tool grinder it could be worn badly. It could also be perfect. You roll the dice The funky Deckel collets never change however. Not a problem if you own a Deckel mill.

I've heard they're rubbish at drill grinding as sold, but would probably make a good kit to improve. A quorn T&C grinder isn't dissimilar in many ways, and many of the functions it does could also be done on a d-bit grinder with some inventiveness. The H&F grinder will grind end and side flutes of end mills.

OldRustyToolie,
Didn't see that attachment, changes everything I said.

Hi Guys,

Following my experience with building the John Moran, 4-6 facet drill grinder, I've been considering whether it would be useful to try and build a universal grinder along the lines of the Deckel... Or would I be better off looking at the Quorn or something similar.

Grinding the end teeth of slot drills and end mills on this type of machine is easy enough, grinding the radial relief on the helical peripheral cutting edges is another story considering that the spindle appears to be mounted on plain bearings in the end mill grinding attachment. End mill sharpeners such as Darex and Harig use air bearing spindles for a smooth almost frictionless sliding action.

Yes I have a Darex end mill sharpener with an air bearing. The machine works perfectly and is a pleasure to use. I also have another tool and cutter grinder and although I haven't used it for end mills I have used it to sharpen quite a number of slab mills and it also works very well. However the slab mills I sharpen between dead centres, which are reasonably low friction. If the cutter was held in such a way that it couldn't ride freely on the finger I think the results would be poor. The finger on the Darex is a fine point so it can be used up close to the wheel, the finger isn't all that substantial but because of the air bearing it doesn't really need to be. On the T&C grinder I made the finger quite a lot more substantial and something similar would I think be required for something like the D-Bit sharpener if it was to successfully sharpen the flutes of end mills.

End mills aren't especially challenging to sharpen, but need to be very accurate if they're to work properly. The flutes are simply sharpened by traversing part the corner of a wheel (to make it a point contact) while a finger ensures the cutter turns and maintains its same relative position as it's traversed. The operator uses slight finger pressure to hold the cutter against the finger. The ends can actually be somewhat more challenging if it's a small cutter, as you need to grind far enough to fully sharpen the end, but not too far as it will hit the opposite side. I think a lot of people mistakenly think the end of end mils is 90 degrees to the flutes, but in fact the angle is less than 90 degrees so that the outside of the cutter does the actual cutting, without the inside rubbing. Looking at the shadow profile, the end of the cutter would look something like a "W" (with of course vertical sides).