# Tubular CrushGrind Purpleheart Pepper Mill



## Kevin (Oct 29, 2014)

I call it the _tubular crushgrind_ because it sounds better than the _pipe crushgrind_. But the key to this mill is the pvc pipe. I used 1/2" for this mill but 3/4" could easily be used for a larger peppercorn chamber. I like this design for many reasons.

Makes a hard mechanical connection from the top to the grinder
Eliminates slippage with a 100% certainty
Makes tighter tolerances easy to get
Allows for nearly limitless lengths - just go longer with the PVC
Allows for a true 2-piece mill with the separation at the top versus the lower body
Allows for more liberty with form
Pepper never comes into contact with wood so aromatic species and even toxic species can be used for mills now 
Easy to build
I thought of more advantages this morning while I was running errands in town but can't remember them now. Anyway here's what my first one using this design looks like . . .










Here's the parts . . .









The tenon design on the top needs a change. I have a design in mind. This one does fit perfectly though and is tight enough not to pop off when the mill is tipped over yet easy enough to pull off to refill with peppercorns. However, I don't like how it looks. I think a 2-stage tenon with a pin in the lower stage and 2 small groves in the top of the tube would look better, and allow for a few more corns.



C&C welcome. I really like this design but I need to come up with a better name for it than the tubular crushgrind lol.

Reactions: Like 1 | Way Cool 5 | Creative 1


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## Sprung (Oct 29, 2014)

Kevin, I don't know a thing about turning/making a peppermill, but this looks easy enough that I think even I could do that - makes the crushgrind seem easier to make. Going to have to file this away for when the day comes that I try my hand at making peppermills...

What bit sizes did you use for this?


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## Schroedc (Oct 29, 2014)

That is a slick idea, I'd like to see a close up of the tenon on the bottom of the cap portion if you wouldn't mind, One suggestion would be to cut the top of the PVC to give you two "pins" that stick up, drill two blind holes in the underside of the cap portion to index into and then do a round tenon with grooves for a couple O-rings to keep it in......

Reactions: Creative 1


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## Kevin (Oct 29, 2014)

Schroedc said:


> That is a slick idea, I'd like to see a close up of the tenon on the bottom of the cap portion if you wouldn't mind, One suggestion would be to cut the top of the PVC to give you two "pins" that stick up, drill two blind holes in the underside of the cap portion to index into and then do a round tenon with grooves for a couple O-rings to keep it in......



That's a possibility. I have about a half dozen ideas. I was fairly certain I wouldn't like the flat tenon method but I started with it because my aim is to keep the design as simple and as efficient as possible. Colin I like your idea if we could simplify it some. I don't care for the o-ring method I used that on another mill for a top cap and it was a pita for me. I need to decide which way to approach it next time keep the ideas coming.


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## DKMD (Oct 29, 2014)

That's a nifty idea and a lot easier than what I envisioned! I'm anxious to see what you come up with for the upper connection... It's got to be tight enough to drive the mechanism but easy enough to remove for refills. I've also been frustrated with O rings, but PVC is a pretty slippery surface... I wonder if you could use a section of wine cork or some kind of tapered silicone piece epoxied into the cap piece?

Nice looking mill(and a nice little crotch of spalted FBE)!

Reactions: Like 1


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## barry richardson (Oct 29, 2014)

Very timely, I'm getting ready to make some mills. You mentioned that 3/4 PVC would work, how would you connect that to the mechanism?


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## SENC (Oct 29, 2014)

I'm glad I bet on you in the pool. Nice work!


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## Kevin (Oct 29, 2014)

barry richardson said:


> Very timely, I'm getting ready to make some mills. You mentioned that 3/4 PVC would work, how would you connect that to the mechanism?



I played around with that yesterday. I wanted to solve how to use a 3/4 corn chamber before going forward and because I knew Barry would ask lol. I discovered that a 1/2" male adapter ftes so perfectly you probably wouldn't have to drill it. As you know the threads are slightly tapered and the fit is so perfect you have to turn really hard as you screw it into the chamber. This shows the 1/2 pipe but all you'd need to do in order to use a 3/4" pipe is use a 3/4" x 1/2" male adapter and drill a larger hole section to accommodate it. As I was looking at things yesterday I determined that I could have used a 3/4" pipe and still easily turned the same shape and size mill as you see there in my first post.





If you do use a 3/4" pipe I would still pin the male adapter to the mechanism even though it's a lock-solid fit.

Reactions: Thank You! 1


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## Schroedc (Oct 29, 2014)

I took some measurements on the mechanisms I have and I think I'm going to pick up piece of 1" pvc tomorrow. It looks like it'd slide over the turning coupler and I could just punch 3 holes using my indexer and snap them together using the tabs on it....

Reactions: Like 1


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## Kevin (Oct 29, 2014)

Also I don't know if I mentioned this but in order to get the 1/2" pipe into the mechanism you have to turn the schedule 40 down a little bit as you can see in the image above. All I did was turn that pipe around as sort of a test for the male adapter idea just to see how it looks, but that's the tunred end with the hole in it that goes into the mechanism when you don't use a male adapter.

Reactions: Like 1 | Creative 1


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## manbuckwal (Oct 29, 2014)

How bout using a pin or two for strength in the top end of the PVC and lil longer round tenon notched out ?


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## Kevin (Oct 29, 2014)

manbuckwal said:


> How bout using a pin or two for strength in the top end of the PVC and lil longer round tenon notched out ?



I think that's what I described somewhere above. This drawing sucks really bad but I think it's decipherable . . .



 

This is one of about half a dozen ideas roaming around in my head. The little brass pin is in the tenon which just pulls out of the PVC shown as blue. Trying to keep it looking clean but also easy to make for production runs for those that make them by the dozens at a time. I might even do that at some point.


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## manbuckwal (Oct 29, 2014)

Kevin said:


> I think that's what I described somewhere above. This drawing sucks really bad but I think it's decipherable . . .
> 
> View attachment 62931
> 
> This is one of about half a dozen ideas roaming around in my head. The little brass pin is in the tenon which just pulls out of the PVC shown as blue. Trying to keep it looking clean but also easy to make for production runs for those that make them by the dozens at a time. I might even do that at some point.



I prob missed that thru all the reading lol . Might be able to use two pins in a + pattern if needed ? Very cool simple idea u have come up with !

Reactions: Thank You! 1


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## kweinert (Oct 30, 2014)

I sort of tried this once before but your way is more elegant. For the top I tried putting 2 L shaped grooves in the top of the PVC and then a pin in a tenon on the top so you could slide the lid on. I wasn't entirely happy with it because it's very difficult (at least for me) to cut the L shapes sufficiently accurate to provide a good fit between the top and the body. I also tried gluing the PVC to the mechanism but that hasn't worked out well. It either broke loose or ran (too much epoxy) and it wouldn't turn at all.

I suppose you could even extend the tube above the top of the body and have it fit into a recess in the lid. Glue a threaded piece in the top and to the top of the tube?

Just thinking out loud.


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## Kevin (Oct 30, 2014)

kweinert said:


> Glue a threaded piece in the top and to the top of the tube?



I thought about that. Briefly. Tightening would come automatically. Loosening for a refill would be a pain because there's no way to lock the mechanism. You'd have to unscrew the nut, remove the crusher, then hold the metal rod with needle nose. Too complex for most grandmas. Plus fitting the threaded male+female fittings - all too involved I'm aiming for extreme simpliicty. 

I'm gonna try my 2-step tenon on the next one.


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## manbuckwal (Oct 30, 2014)

And yet another idea.............. Would be to glue/pin a shorter piece of PVC into the cap that is notched to slide over the sch 40 PVC "shaft" that has been modified on the end to have basically two decent "prongs" ?


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## Kevin (Oct 30, 2014)

Thought of that too Tom. But there needs to be a good amount of friction to hold the cap on when the mill is tipped over.


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## manbuckwal (Oct 30, 2014)

Would a neodymium pin magnet inserted into the pvc ends be strong enough to hold the cap on in most instances of tip over ? Not dropping it on the floor obviously . I'm sure u have already thought of most possibilities lol .


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## Kevin (Oct 30, 2014)

manbuckwal said:


> Would a neodymium pin magnet inserted into the pvc ends be strong enough to hold the cap on in most instances of tip over ? Not dropping it on the floor obviously . I'm sure u have already thought of most possibilities lol .



No I haven't thought of everything no way. The magnet is an interesting concept, but I'm aiming for absolute simplicity. I like the idea but want to keep parts and processes to a minimum.

Reactions: Like 1


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## David Hill (Oct 30, 2014)

Nice thinking y'all!
I have some crush/grinds that I've been wanting to use, but the mills I have in mind required a lot of design and precision turning so they would work/fit together. Been puttin' them off--now no excuse.
I had been turning long tubes with the blanks, with recesses to fit the clips--whew!


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## David Hill (Nov 9, 2014)

Ok! I tried my hand at making a mill with the crush/grind like this. I like using the PVC pipe and used the coupler and brass rod at the mechanism end. The top had me buffaloed for a bit  and then having to change inside dimensions due to the pipe got me too--I used 3/4 pvc. Found that leaving a little longer tenon on the top along with cutting a groove for an "O" ring a little farther down helped. Since my tolerances were close, I used the peppermill tool to make a space for the "O" ring on the body. Passes the "knockover" test and turns easily.
BTW the best place to get larger "O" rings is an auto parts place--waaaaay cheaper than hardware stores.
I'll post pics later.


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## Kevin (Nov 9, 2014)

David I can't wait to see the pics. 

Re: o-rings pick up one of these 407 o-rings for less than $15 



 



 

Every shop needs one. For your peppermills once you know what size you want Fastenal is a good source for buying several or many of one size.

Reactions: Informative 1


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