Pegs and their holes - being accurate

[woodPixel]

Looking for any wisdom available that will assist.

I make kids coat racks that have these shaker style pegs in them. Lots of them. They fit very tightly into a 19mm socket made with a fantastic Freud 3/4" Forstner bit (it is amazingly sharp). The tightness of the fit makes for a better product. The socket is 20mm deep, angled at 15° (not that this is too relevant). To fit them, they are deftly twisted in with a bit of TB by the shop.

Making them is a bit of a slow process and Im hoping to speed it up. I make about 16 and hour. This isn't about the pegs themselves, but how one gets a really accurate spindle to fit tightly into socket.

Currently I use a nail-board and a chunk of MDF drilled with the various sizes I use. The spindle is turned down with a skew to +1mm then quickly sanded with a bit of 120 to size. If it fits over the matching "half hole" on the MDF drill-board then its parted off. The spanner is used too - it has a 19mm opening at one end... I jam-fit that over the very end of the spindle to do a final test.

Im curious what other people do and if there any thoughts on how to improve the fit/process/speed.

398363 398364 398365

[orraloon]

I do pretty much like you and have a test hole handy to try the fit. I also use the spanner method at times. Thing I have found is a peg that fits today may not fit tomorrow.
Regards
John

[ian]

Buy the pegs from a specialist supplier.

Lee Valley sells them for about $1.20 CAD each. Shaker Pegs - Lee Valley Tools (http://www.leevalley.com/en/wood/page.aspx?p=32805&cat=1,250,43233)
In terms of your rate of production -- about 16 per hour -- your pegs are costing 4x as much. (Maybe 3x after delivery.)

and if you buy from Lee Valley's supplier, the cost is probably less than $1 each delivered to Canberra.




I did warn that you wouldn't like the answer, but you are asking about working smarter, rather than harder. :wink:

[woodPixel]

Alas, the design is unchangeable. These must be made... plus, I do get paid exceedingly well for them, so that isnt really the thought.

[ian]

You should still consider outsourcing.



Earlier this year there was a thread about tapered table legs (turned) which morphed into a discussion about production turning.
A poster from the US has a very snazzy lathe with a quick action tail stock which is used with a router and template. Two passes with the router, one climb cutting, and a piece is done. From memory his production rate for something like your pegs would be one every 60 seconds or so = 40-50 per hour.

It would be worth a search


Edit: This is the post I was thinking of

370163

routers and lathes go together well in many instances! your situation would be a great application.

https://www.youtube.com/watch?feature=player_detailpage&v=P12E08byJ6k
My lathe has been built with special set ups in mind but for straight tapers you lathe could be easily adapted temporarily with a few pieces of material.

You will need to attach a flat board to the ways of your lathe to serve as a work table. this will be removed when not being used so your lathe can be used conventionally.

You will need to construct a "c" shaped bracket that will hold the router in the vertical position and at the right height off the work surface to cut your rotating stock.

the bottom front of the bracket will become the depth stop

screw a board to the top of the work surface to serve as a template at the desired angle.

if you wish you can rough the stock to the approximate shape first

roughing cuts with the router are ALWAYS climb cuts. (prevents blowouts and digging in)

finish cut is conventional.

Have fun!

[Kuffy]

I used to work for a production turner and the newer hydraulic copy lathes couldn't turn a pin with a vertical wall. But he also had a centauro hydraulic copy lathe which had a couple of pin cutters. We used to do a secondary machining pass on this machine to cut the pins that the bigger more expensive machine couldn't.
Centauro TStar 1600 CNC Wood Turning Lathe at Scott+Sargeant Woodworking Machinery / UK (http://scosarg.com/centauro-tstar-1600-cnc-wood-turning-lathe)
Those two contraptions on the top rail of the machine are the left and right pin cutter.
Imagine a corner chisel https://www.carbatec.com.au/handtools-and-handplanes/specialty-handtools/narex-corner-chisel
Bevel up which gets lowered into the spinning workpiece via the lever you can see. You can set how big the pin will be by setting stops on the pin cutter to prevent it from lowering too far. It was pretty accurate but a bit of a pain to get the size dead on.

It would be quite the exercise to build a jig to do this, but I am aware that there are people out there that go to crazy lengths to build a jig for everything. I am the complete opposite, I hate jigs, hate making jigs, hate storing jigs, hate designing jigs, hate paying for jigs, but sometimes I do need to do things that I hate :(

[woodPixel]

I love jigs. They are great. They are used extensively here :) Setting them up is a pain, but the results are worth it.

Turning the pegs isn't hard. Once you've done 250 one can almost do them in their sleep :). I'm not looking to outsource (I am the outsource!) or buy a $30k machine. I don't mind the work, nor am I innacurate, it was just a sizing question.

Some time ago I was studying the shaker pegs and how they have the skirt on the bottom. They provide for a very neat fit when done that way, but unfortunately mine are inclined up 15 degrees.... Couldn't work out how to do that, so they are skirtless.

One thing I was thinking of, was with the ends, if I overturned them by +1mm, perhaps they could be fitted in by soaking the end in boiling water and crushing it down a bit. Jam it in the hole and when it expands and rehardened it will be a mega-tight fit.

They are shipped flat packed, so the store will need to do it, but it might be a solution.

Has anyone done this?

[artful bodger]

When I was an apprentice and going to technical school back in the day, they had these hand held dowel makers that you used on a lathe. You kind of bashed a bit of wood into the hole of the headstock spindle(no need for a tailstock) and just ran the dowel cutter along the spinning timber. A perfect dowel, in the blink of an eye.
Surely these dowel making jigs have featured on this forum before?.

[Old Croc]

A long time ago I watched the legendary Tiny Hayes making something similar. He used a shopmade sizing tool and I am fairly sure Sorbys make one.
Rgds,
Crocy.

[Skew ChiDAMN!!]

A long time ago I watched the legendary Tiny Hayes making something similar. He used a shopmade sizing tool and I am fairly sure Sorbys make one.

Seconded. And yes, Sorby does (http://www.cwsonline.com.au/shop/item/robert-sorby-970-sizing-tool).

[woodPixel]

I forgot to mention that I also use a Galbert Caliper The Galbert Caliper (http://www.petergalbertchairmaker.com/galbertcaliper.html) plus a board with clipped nails.


The nails are placed where the bead/cove points are on the final piece. One simply jams the nailed board to the spindle and it marks everything out almost instantly.


The Galbert is pretty amazing. It's the same in principle as the Sorby.


:)

[ian]

One thing I was thinking of, was with the ends, if I overturned them by +1mm, perhaps they could be fitted in by soaking the end in boiling water and crushing it down a bit. Jam it in the hole and when it expands and rehardened it will be a mega-tight fit.

They are shipped flat packed, so the store will need to do it, but it might be a solution.

Has anyone done this?the normal process to achieve a jam fit with a round tenon is to heat and dry the tenon using dry sand as the heat transfer medium.
I would expect a jam fit with a wet tenon to loosen over time as the tenon dried.

[hughie]

Looking for any wisdom available that will assist.

I make kids coat racks that have these shaker style pegs in them. Lots of them. They fit very tightly into a 19mm socket made with a fantastic Freud 3/4" Forstner bit (it is amazingly sharp). The tightness of the fit makes for a better product. The socket is 20mm deep, angled at 15° (not that this is too relevant). To fit them, they are deftly twisted in with a bit of TB by the shop.

Making them is a bit of a slow process and Im hoping to speed it up. I make about 16 and hour. This isn't about the pegs themselves, but how one gets a really accurate spindle to fit tightly into socket.

Currently I use a nail-board and a chunk of MDF drilled with the various sizes I use. The spindle is turned down with a skew to +1mm then quickly sanded with a bit of 120 to size. If it fits over the matching "half hole" on the MDF drill-board then its parted off. The spanner is used too - it has a 19mm opening at one end... I jam-fit that over the very end of the spindle to do a final test.

Im curious what other people do and if there any thoughts on how to improve the fit/process/speed.

398363 398364 398365

reduce the dia of the Forstner bit and the fit will always be tight.

[Kuffy]

I was just catching up with some of my youtube subscriptions, and I came across this. He is making a baseball bat with spikes. Effectively the same thing. The way he got his tenons/pins cut was pretty good. Another reason you must buy a CNC :D

https://youtu.be/4cazESXWTic?t=7m

I set it so the clip starts at the 7 minute mark. The entire video is pretty crap.

[woodPixel]

Hughie, mate! Smaller holes. Should have thought of that ;)

Hehe.

I banged another 16 pegs out this arvo, all 0.5mm smaller than the 3/4" forstner. I was thinking to slice the tail and insert a foxed wedge in. A bit of glue at the shop and a good shove should do the job.

Kuffy, will watch the video. One could always do with a few more en-spiked baseball bats. Curious why you might be watching such a thing... planning something? ;)

Edit: watched the video... I don't have a cnc (yet!) but I do have some CMT tenon dowel-y maker-y things for the drill press. One happens to be 3/4". I was thinking, rather than turning the block in the chuck, that I could pre-tennon the block, fit the "tenon dowel end" into a pen turning chuck and turn from there.... Hmmmm. Shame it's 11.30pm, otherwise I might have just gone and fired up the DC and lathe :) ... In the morning then!

[Kuffy]

It is one of Frank Howarths videos. He makes some cool vids, but this one sucked. Bloody boring voice over all the way through. It is just one of the 100's of woodworking related subscriptions that I have. IIRC a bunch of youtubers were making dumb zombie defense weapons to coincide with the release of a new series of some zombie show. I gave it some thought to making my own weapon, but when my mind wandered to a crossbow and test firing in the shed and ricocheting off a steel beam and into my head, I put the idea into the too hard basket.

There is this video too. He uses a long dowel maker/plug cutter to make legs for the sheep.
https://youtu.be/ZzZVFjU8CSw?t=2m55s This I think is actually a very good way to go about it, dunno if you can get a long plug cutter @ 3/4". Set up a jig to hold the blank vertical in the press and drill a bunch of them every minute and then you can be more rough, or less precise when turning the shape which will also speed things up.

[doug3030]

IIRC a bunch of youtubers were making dumb zombie defense weapons to coincide with the release of a new series of some zombie show. I gave it some thought to making my own weapon, but when my mind wandered to a crossbow and test firing in the shed and ricocheting off a steel beam and into my head, I put the idea into the too hard basket.

Using weapons against zombies is pointless. They are already dead.

There is only one sensible course of action in the event of a zombie apocalypse.

Go to Costco.

- They have heaps of food and other essential supplies.
- They have solar panels on the roof providing enough power to keep essential services going for a long time.
- The building is solid concrete which the zombies cannot penetrate.
- And best of all - the zombies will not be able get in through the front door without a membership card.

Cheers

Doug

[woodPixel]

Walking Dead. I saw the barbed wire bat. Season 7 opener!

This is the plug cutter I just dug out of the drawer. https://www.amazon.com/CMT-529-191-31-Cutter-Diameter-32-Inch/dp/B000P4JJCQ ... I seem to have a few sizes, all unopened :rolleyes:

These are the pegs before they are cut off to the right length using a jig and Japanese Dozuki. I don't even need the template to make them any more, they are literally done in my sleep.

398598 398599

Some good ideas in those videos.

[woodPixel]

Zombie apocalypse averted.

Finished up another batch. Tossed a few of the others. I reverted back to a tried and true method of calipers. Set them to +1mm and used a parting tool to get the depth right.

Have to admit - the old school ways really do work. I belted 24 out in no time flat.

It was a very relaxing thing to do a longer turning session. The rhythm, actions and movements relax the mind - almost a form of meditation.

Thanks to everyone for their inputs.... (except for Costco, where I think the zombies currently reside!)