Model Engine Maker
Help! => Hints, Tips & Tricks => Topic started by: Dan Rowe on May 19, 2019, 10:23:48 PM
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Here is my latest method to make square nuts on my Levin lathe. I am using 3mm square keys 50mm long for the stock. The first step is to square up the end. Sticking out of the collet just enough to remove the rounded end. I use the front tool first because it is much smoother on the corners than the back acting cutoff blade. There is a stop rod set for the front tool so it will only go deep enough to make the stock round.
(http://www.7-8ths.info/gallery/6/213-190519130004.jpeg)
(http://www.7-8ths.info/gallery/6/213-190519130123.jpeg)
Then the back acting cutoff blade cleans up the cut. The front blade is just a tiny bit thicker on the end face so it left a small landing on the bottom of the nut.
(http://www.7-8ths.info/gallery/6/213-190519130240.jpeg)
Now a spot drill followed by the tap drill. I can drill far enough for 9 or 10 nuts.
(http://www.7-8ths.info/gallery/6/213-190519130340.jpeg)
(http://www.7-8ths.info/gallery/6/213-190519130433.jpeg)
I have a lever collet closer so operating the collet is much quicker than a standard drawbar. I made a stock stop rod with a 8-80 thread which is a really fine thread and I wanted to use the tap and die I scored on ebay. What is not shown is the pusher rod to advance the stock.
(http://www.7-8ths.info/gallery/6/213-190519130521.jpeg)
The front tool adds the chamfer on the top of the nut and the washer detail on the bottom of the next nut.
(http://www.7-8ths.info/gallery/6/213-190519130624.jpeg)
I have a lever tailstock so I simply put the 1-72 tap in the drill chuck in the tailstock. This would not work with a screw type tailstock, but a sensitive drill attachment could be used. I spotted a lever one on ebay with a MT2 or a MT3 taper.
I use one hand to start feeding the tap and the other hand turns the spindle. There is a single hole in the top of my drawbar at my thumb so I count 5 turns in. The form tap starts to act as a lead screw after the first turn so the tailstock feed lever moves all by itself in and out.
(http://www.7-8ths.info/gallery/6/213-190519130724.jpeg)
(http://www.7-8ths.info/gallery/6/213-190519130843.jpeg)
The final op is to cutoff the finished nut. The cutting bit was ground at a slight angle so the nut drops off first with very little bur.
(http://www.7-8ths.info/gallery/6/213-190519130942.jpeg)
The finished nuts are shown.
(http://www.7-8ths.info/gallery/6/213-190519131042.jpeg)
I made 10 nuts in 15 minutes so I am really happy with the process and speed.
Cheers Dan
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Nice technique and a good result too. Must be a pleasure to do on that fine little lathe too.
Bill
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Bill, I have several lathes including a Cowells but the Levin is without any question my favorite. The nuts I am making are nearly exact size for a 1" heavy sq. nut in 7/8" scale.
I am working on the tooling to make the square bolts. I have a Levin turret but 1/2" shank tooling is a bit scarce. I am nearly there and I will post the method when I get it working.
Dan
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Nice, far quicker than my production of about 100 8 & 10BA square nuts at 10 an hour. Mind you, after an initial disaster when parting off with a parting off tool, I used a Dremmel with an elastic disc for parting off. This was mounted on the top slide.
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Hi Dan,
Very neat! Filing that away for a latter day.
On the 1/2” tool front, yes I know you are in the US, but 12mm isn’t far off......if you can get it .......eBay maybe?
Cheers Kerrin