What size drill bit do you use with PSI stopper chuck

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sbwertz

sbwertz

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The kit apparently ships with a 23/64 but, but according to the reviews, that bit is too large. I have a 3/8 by 16tpi tap. Should I go with the 5/16 bit and hand tap the blanks, or is there another size bit that will allow me to screw the blanks directly on to the chuck without tapping? Should I use the inserts for cedar and other soft woods? (I have some beautiful cedar with a lavender tint that is very popular here.)


Thanks for your help.

Sharon
 
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sbwertz said:
The kit apparently ships with a 23/64 but, but according to the reviews, that bit is too large. I have a 3/8 by 16tpi tap. Should I go with the 5/16 bit and hand tap the blanks, or is there another size bit that will allow me to screw the blanks directly on to the chuck without tapping? Should I use the inserts for cedar and other soft woods? (I have some beautiful cedar with a lavender tint that is very popular here.)


Thanks for your help.

Sharon
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I see you are doing a follow up question. I do not have PSI stoppers but can tell you a few pointers. Every type of material and every wood species has different characteristics. So there is really no specific size to tell you. Trial and error are at times the best method. Soft woods will drill and tap different as to hard woods or even exotic woods. Plastics can vary also because not all plastics are the same. Starting with the basics is a good start as you listed. Dropping down asize or stepping up a size is basically your call.

As far as the inserts go they can be used for ease of disassembly purposes for cleaning. But what happens with them is that they can loosen easily which can help but can also cause failures. When I say loosen I mean the stopper from the blank, not the insert from the blank. Whenever I use inserts in any project, I add a bit of epoxy as I screw it in so it never backs out. For some reason I have to replace I drill it out.

Not sure if I helped at all or just crowded the air waves but that is my thoughts.
 
I am sure others may have more info for you so hopefully it will help.

Just one other note. If you do go with inserts, set them a little deeper so that the stopper does not lock onto the insert but onto the material. This will help it from creaping off. metal on metal can have a tendency to do that.:smile:
 
John is entirely correct in his answer.
My experience has been, in softer woods like cedar, I use the 5/16 in softer woods, the larger 23/64 bit will allow the blank to spin on the mandrel during cutting.
 
I haven't made any acrylic stoppers yet, so I can't say how well my method works for them. For wood though, after some experimentation, I have pretty much settled on using a 9/32 bit then tapping. I have found that that works quite well for a wide range of soft and hard woods.

A few times, I have forgotten to tap the hole after drilling. Soft woods like cedar threaded onto the chuck with no problem. Harder woods let me know real quick that I forgot to tap the hole first.

I generally prefer to take the extra minute or so to actually tap the holes rather than trying to screw the blank onto the chuck. I think the tap makes cleaner & better threads, but that's just my take on it.
 
Sharon; The minor diameter of the 3/8 x 16TPI is .2983" (This is the shank size without the threads).

A 5/16" drill bit would work with soft woods or a letter 'O' drill bit too.
 
When the hole is to be threaded using a 3/8x16tpi tap, the recommended pilot hole is 5/16". The latest PSI catalog says that the bottle stopper mandrel kit is furnished with a 5/16" bit. But in the past they did supply that larger bit with the mandrel.

Most bottle stoppers have a 3/6x16tpi stud. However, there are a few exceptions, so if you are planning to buy a bunch of kits, it would be prudent to make sure that you have the matching mandrel and tap.

By the way, if you have a spindle tap (that allows you to tap a hole in wood to match your lathe spindle, its very easy to make your own stopper mandrels using standard 3/8x16" bolts from the hardware or big box store. I have several shop-made mandrels in addition to the PSI mandrel - I turn the stopper on the metal PSI mandrel, and then transfer to a shop-made mandrel for finishing. That way I can have several stoppers being finished at the same time without having to worry about damaging one while freeing up a mandrel to finish another.

You can also buy 3/8x16tpi taps at the hardware store. Get a tapered tap - its easier to get the thread started with them. If you are working in metal, you may also need a 'bottoming' tap since a tapered tap won't thread all the way to the bottom of a hole. That's not as critical in wood since the stud will force it's way beyond the ends of the threads left by the tap. Alternatively, just drill the hole 1/4" deeper and run a tapered tap in as far as it will go.
 
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I use the PSI chuck and have found the 5/16 bit works best for the woods I use. When I used a larger bit the threads would strip during turning. You can also minimize the risk of striping the threads by knocking off the corners and doing some initial shaping before mounting the blank on the chuck.
 
Sharon,

The 5/16 is the correct tap for full threads in metal

Ruth Niles of bottle stopper fame recommends 11/32 or 9 mm. Those work well because wood tears,and crumbles at the top of the threads, and it takes a lot more work to get the torn threads with the tighter 5/16 hole.

I like to soak the threads after removal from the mandrel or tap, soak them with some thin CA, and after it has set up for sure, run the tap through the threads one more time.

Never lost a bottle stopper yet.

By the way, the Ruth Niles web page includes a great tutorial on making bottle stoppers as well as a huge gallery of ideas.
 
Sharon,
I don't have an answer to your question either... I stopped using the PSI mandrel for bottle stoppers a long time ago and now work exclusively with a pin chuck. But I know also that the cedar being as soft as it is, even on a pin chuck can be difficult to work with... it can come loose and wobble on the pin.
 
Thank you all so much for your help. I really wanted to hear from people who actually used the chuck and had experience with various woods. You have given me the information I needed. I have a 3/8 by 16 tpi tap, and a full set of fractional, letter, numbered and metric bits, so I am pretty well set up. I have enough scrap woods that I can drill a hole in a scrap of....say, cedar.... and see how it holds on the mandrel. I like the idea of "hardening" the threads with CA then re-tapping. I plan to drill and tap and round the blanks here at home and take them to the Center ready to turn.

Can someone give me a link to Ruth Niles' web page?
 
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sbwertz said:
Thank you all so much for your help. I really wanted to hear from people who actually used the chuck and had experience with various woods. You have given me the information I needed. I have a 3/8 by 16 tpi tap, and a full set of fractional, letter, numbered and metric bits, so I am pretty well set up. I have enough scrap woods that I can drill a hole in a scrap of....say, cedar.... and see how it holds on the mandrel. I like the idea of "hardening" the threads with CA then re-tapping. I plan to drill and tap and round the blanks here at home and take them to the Center ready to turn.

Can someone give me a link to Ruth Niles' web page?
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Sharon

Here you go. To it is the only stoppers I use. Ruth is a member here as well. A real nice person. Her stoppers have been copied but she will be the only place I buy them.


www.nilesbottlestoppers.com
 
I always loved looking at the artist gallery for stoppers on her web site. The talent and ideas are endless. My next stopper I buy from her will be the ones that stand on their own. I think that is a cool idea.


Bottle stopper gallery
 
I use the PSI system, I do NOT USE the 5/16 bit that is furnished, I drop down a size to a 19/64 or 9/32 drill bit. After I drill I drizzle CA on the inside of the hole. LET THE CA DRY COMPLETELY and then tap with a 3/8 tap. I again drizzle CA on the tapped threads, let that dry and run the tap again in the hole. ALAWYS MAKE SURE THE CA IS DRY before tapping.

This will strengthen the threads so the threads should not tear out on you. Sharp chisels and light cuts when you start with a square block.
 
I round everything before I let my blind turners start turning. Even the partially sighted ones can't distinguish where those flying corners are and they can hurt their hands. So I've been rounding all the stopper blanks before letting them turn them. We have been turning the little silicone stoppers that have a dowel to mount them, but instead I turn a tenon on the blank and chuck it up in pin jaws on a regular Nova chuck for them to turn. I will probably do the same for the steel ones...round them, drill them, and tap them here at home and take them down there ready to turn. I will definitely use the CA to harden the threads. Thank you so much.

And yes, I will make SURE the CA is dry...don't want to glue the tap into the hole!
 
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sbwertz said:
I round everything before I let my blind turners start turning. Even the partially sighted ones can't distinguish where those flying corners are and they can hurt their hands. So I've been rounding all the stopper blanks before letting them turn them. We have been turning the little silicone stoppers that have a dowel to mount them, but instead I turn a tenon on the blank and chuck it up in pin jaws on a regular Nova chuck for them to turn. I will probably do the same for the steel ones...round them, drill them, and tap them here at home and take them down there ready to turn. I will definitely use the CA to harden the threads. Thank you so much.

And yes, I will make SURE the CA is dry...don't want to glue the tap into the hole!
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You need not ask me how I know, but gentle heat to about 180 degrees F softens the CA and allows removal of the tap without damage.
 
Hi Sharon, I use the 5/16 drill bit with the 3/8 tap on my PR blanks, and it works great. On wood, I go a different rout, and put an E-Z Lok threaded insert in and don't have to worry about the threads coming out of the wood. They are pretty cheap on Amazon (I wouldn't spend $2 a piece on the PSI ones)
 
KCW said:
Hi Sharon, I use the 5/16 drill bit with the 3/8 tap on my PR blanks, and it works great. On wood, I go a different rout, and put an E-Z Lok threaded insert in and don't have to worry about the threads coming out of the wood. They are pretty cheap on Amazon (I wouldn't spend $2 a piece on the PSI ones)
Click to expand...

You can buy them in Home Depot also.
 
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