CrushGrind kits

[William Herzig]

Hello,

For those of you that may have turned both types of the CrushGrind pepper mill kits (shafted and shaftless) I have a quick question - Do they take the same drill bits for mounting the grinder into the base. I have looked at many of the different instructions, from different websites, and there is quite a variance between sites. I am trying to get started making these kits and will probably make both at some point, but if they take different sized bits I will need to decide on which one I would prefer to make first.

Thanks,

Bill

[Mike Golka]

William both use the same size holes. Here are the dimensions ( in mm) from the manufacture.

[Peter Fabricius]

William,
The hole sizes are the same as Mike said but it is always a good idea to measure the mechanisms before you drill the holes. There is an inconsistency on the instructions from different retailers so you have to measure and then drill accordingly.
For the ones we get here we use 1 3/4" Forstner bit for first hole, then 1 1/2" hole and a through hole sized to what you want eg. 1 1/8".
Note it is a good idea to use a tenon between the Top and Body as indicated on the drawing I found on line. Tenon on the Top and the upper end hole in the Body works nicely at 1 1/2".
Also note the most secure installation is to cut the recesses and let the clips lock into the recesses with a little epoxy in the recess to keep them from spinning.
No special bits are needed, drill with you have and if necessary enlarge slightly as needed, sand paper or a small parting tool.....
Peter F.

[William Herzig]

Thanks for all of the help, I can't wait to give these a shot. Just one last question - I have just found out about some copies from Asia so do you know if the ones at Woodcraft are the legit ones?

Thanks again,

Bill

[John King]

William,
The hole sizes are the same as Mike said but it is always a good idea to measure the mechanisms before you drill the holes. There is an inconsistency on the instructions from different retailers so you have to measure and then drill accordingly.
For the ones we get here we use 1 3/4" Forstner bit for first hole, then 1 1/2" hole and a through hole sized to what you want eg. 1 1/8".
Note it is a good idea to use a tenon between the Top and Body as indicated on the drawing I found on line. Tenon on the Top and the upper end hole in the Body works nicely at 1 1/2".
Also note the most secure installation is to cut the recesses and let the clips lock into the recesses with a little epoxy in the recess to keep them from spinning.
No special bits are needed, drill with you have and if necessary enlarge slightly as needed, sand paper or a small parting tool.....
Peter F.

Don't chuck up the wood and begin turning a peppermill until you have read Turning Salt & Pepper Shakers and Mills by Chris West. It's the definitive document on turning peppermills. Many pages are dedicated to mill projects using the CrushGrind@ mechanism. Detailed instructions, drilling guides and jigs for use with the CrushGrind@ mechanism are provided.

Use of the CrushGrind@ mechanism as designed requires no adhesive. Turn grooves in the mill body and cap and use the tabs to secure the GrushGrind@ mechanism to the mill body and the stopper to the mill cap. If for some reason you feel compelled to use some adhesive to secure the CrushGrind@ components to your mill, do not use an epoxy. It's a brittle adhesive and will likely fail when used to bond a very stable component (CrushGrind@ mechanism and stopper) to an unstable component (wood). Use some sort of flexible adhesive (E6000 comes to mind).

While a mortise/tenon arrangement may be desirable for some mill designs, it is not mandatory. The CrushGrind@ stopper can be used as the tenon on the mill cap. The mortise in the mill base is drilled (26 mm diam) or turned to match the diameter of the stopper in the mill cap. When the mill cap is mounted on the grinding shaft, the stopper centers the mill cap on the mill body. Eliminates hassle of turning mortise and tenon. Mortise and tenon can limit mill design.

All for now. - John

[Fred Belknap]

I am in the process of making some Crush Grind mill and this thread has been a tremendous help. Thanks

[John King]

I am in the process of making some Crush Grind mill and this thread has been a tremendous help. Thanks

Fred - Following is one of my posts on subject on another web site. Perhaps it will provide some additional helpful tips/guidance. Could not download pdf files of mill body and cap. Too large for this forum. Send me a PM and I will respond with pdf files. - John

"Mark - Pass on the metric forstner bits and go with imperial carbide forstner bits. Don't waste your money on high speed steel forstner bits. They simply are not up to the challenge of repeated drilling in end grain. I use Freud carbide forstner bits. They are clean cutting and long lasting.

See the attached pdf files for mill body and mill cap boring measurements. Red lines are for a CrushGrind@ mechanism. The mill body is flat on the top. There is no tenon as shown in the CrushGrind Body.pdf file. The mill cap is flat on the bottom. The mill cap sits on top of the mill body and is centered on the mill body by the CrushGrind@ stopper in the mill cap. Only metric bit I use is a 26mm for the CrushGrind@ stopper recess in the top of the mill body. It's important that the CrushGrind@ stopper fit snugly in the mill body so that the cap stays centered on the mill body.

When properly installed, the CrushGrind@ mechanism requires no epoxy or similar adhesive. Here’s the deal.

Most, but not all, instructions for making CrushGrind@ mills provided by US suppliers specify 1) a 1 9/16” diameter hole in the mill body for the grinding mechanism, 2) removal of the spring clips from the grinding mechanism and 3) use of epoxy (or similar) to secure the grinding mechanism in the mill body. These same instructions specify 1) a 15/16” diameter hole in the mill cap for the stopper, 2) removal of the spring clips from the stopper and 3) use of epoxy (or similar) to secure the stopper in the mill cap. One can make a very nice pepper/salt/spice mill using these instructions. But there is a better way! It’s the no epoxy required way.

The manufacturer’s recommendation for the diameter of the hole in the mill body for the CrushGrind@ mechanism is 38mm (1.496”). I am good with calling that 1½” (1.500”). The manufacturer’s recommendation for the diameter of the hole in the mill cap for the stopper is 22mm (0.866”). I am good with calling that 7/8” (0.875”).

No epoxy (or similar) is required to secure the grinding mechanism in the mill body and the stopper in the mill cap if 1) the CrushGrind@ manufacture’s recommendations for mill body and mill cap hole diameters are used and 2) a groove is cut in the mill body and the mill cap to accept the spring clips on the grinding mechanism and stopper.

Sorby makes a groove cutting tool for CrushGrind@ mechanisms. It's available from Packard Woodworks. The part number is 108870. It’s a must have tool if one is going to install the CrushGrind@ mechanism in pepper/salt/spice mills using the spring clips and no epoxy. It's cleverly designed and marked so that cutting the groove in the mill body for the grinding mechanism and cutting the groove in the mill cap for the stopper can be near hassle free.

With the grinding mechanism and stopper press fit into the mill body and the mill cap, respectively, and the spring clips locked into the mill body and the mill cap grooves, epoxy is not required for a secure fit.

An excellent set of instructions for making a pepper/salt/spice mill using the CrushGrind@ mechanism can be found in Turning Salt & Pepper Shakers and Mills by Chris West, “Drilling and Fitting a CrushGrind@ Mechanism,” p 132.

In my opinion, the CrushGrind@ mechanism is far superior to the stainless steel grinding mechanisms. It can be used to grind pepper, salt and spices. The grind can be adjusted from course to very fine. It’s made of non-corrosive ceramic. There is a 25 year guarantee on the ceramic parts inside the CrushGrind@ mechanism.

Best video that I have seen is "Making a Peppermill, Focus on Design," by Ted Sokolowski. He does not use the CrushGriind@ mechanism, but his process for design and turning of the peppermill is excellent.

I have a couple of mills in process. Will post some photos here at later date.

Hope above helps. Enjoy! – John"

[Tim Rinehart]

John and Mike are right on regarding the use of dimensions consistent with Crushgrind.us specs and not having to use any glues. There was some dialog about this a month or so ago, and I mentioned that I had sent a note to Woodcraft to modify their instructions to provide guidance on drilling the key bore sizes to allow a fit up that doesn't require any glues. I was pretty disappointed seeing the degree of variation for the same exact mill from one reseller to another. Haven't heard back, but that's ok...I don't think any of the resellers whose instructions I've seen have it right. Some get the right bore size, but tell you to remove the spines or tabs, others just have you drill oversized and use epoxy.

I'm giving a demo later this month at a local club, and recently put together a set of instructions that spell out the key fits, and a nearly foolproof way to get the axial positioning of the groove for the retention tabs just right. I did this more consistent with the Crushgrind.us site method, so no tenon fit between the cap and body, but can be modified easy enough for that based on mill design. Feel free to reference this for your mill.
As for the special tool, I used an old scraper and fashioned it similar to a box scraper, but with a 1/4" length side scraper to it, which looks pretty consistent with the Sorby tool and has worked fine for several I've made.

Crushgrind Shaft Style.pdf
crush grind tool.jpg

[Marty Tippin]

Is there any way to get the Crushgrind mechanism back out of the mill once the tabs are engaged? Or does your "test fit" sometimes become your "final fit" by accident?

I personally like the idea of epoxying the mechanism in place, as there is less perfectly precise milling to be done inside and I'd be a lot less nervous about a test fit.

[Tim Rinehart]

Is there any way to get the Crushgrind mechanism back out of the mill once the tabs are engaged? Or does your "test fit" sometimes become your "final fit" by accident?

I personally like the idea of epoxying the mechanism in place, as there is less perfectly precise milling to be done inside and I'd be a lot less nervous about a test fit.

Pretty much that's a no for the shaft type mechanism, either the stopper assembly or the lower grind assembly. Looking at the shaftless mechanism, depending on diameter drilled for the upper bore, may be possible to push something down to compress in the tabs and push it out...but not certain.

[Ryan Mooney]

Crushgrind Shaft Style.pdf
crush grind tool.jpg

Thanks for this Tim, very helpful - I like this design a lot better than the vendors description and your explanation/picture of the grooving tool is certainly clear enough to construct my own from.

[John King]

Is there any way to get the Crushgrind mechanism back out of the mill once the tabs are engaged? Or does your "test fit" sometimes become your "final fit" by accident?

I personally like the idea of epoxying the mechanism in place, as there is less perfectly precise milling to be done inside and I'd be a lot less nervous about a test fit.

Marty - Why do you need to make a test fit? If the CrushGrind@ mechanism tabs engage the grove cut in the mill body, why remove it? The fit should be tight enough that removal is impractical (impossible?) without damaging the grinding mechanism and/or the mill body. So, press the grinding mechanism into the mill body and move on.

DO NOT use epoxy to secure the CrushGrind@ mechanism. See my 9:12 am today post above. - John

[Tim Rinehart]

Thanks for this Tim, very helpful - I like this design a lot better than the vendors description and your explanation/picture of the grooving tool is certainly clear enough to construct my own from.

You're welcome. The one point I will emphasize in my demo is the location of the groove for the tabs. If it's set too far in, the tabs will not engage the groove and could theoretically allow it to come out at a later time. In reality, I suspect if you drill the 7/8" and 1-1/2" bores as outlined, the interference fit will resist a lot of pullout forces, That's why I make the comment in the instructions about better to not drill the locating bore too deep which could lead to lack of the tabs engaging out.

[Ryan Mooney]

That's why I make the comment in the instructions about better to not drill the locating bore too deep which could lead to lack of the tabs engaging out.

Yep that was very well stated and clear in the doc (at least if you read the whole thing, no guarantees there of course).

This will be my first set of pepper mills (lots of bowls and other weird items but finally decided I ought to do a few pens and pepper mills if only to say I've done it, we'll see how it goes) so all this discussion here has been immensely useful.

I did order one of all three types of kits that craft supplies sells (figured I'd do one of each and see how they worked) before the crush grind conversation came up, I'll just have to give the other ones to people I don't like as much