Model Engine Maker
Help! => Hints, Tips & Tricks => Topic started by: Captain Jerry on March 24, 2019, 12:00:36 AM
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The only way to get tall nuts is to make your own. I have made a few in the past but my current project is going to need about 36 tall #2 -56 nuts. I have used 303 stainless hex and parted them off after tapping but I seen to loose more than I make and there is still a bur to remove and chamfer to add. On top of that, since you can only tap about 5/8" deep with a #2-56 tap, you only get 3 useable nuts, allowing for parting tool loss for each setup. A slow and laborious process at best.
Today, I decided to get serious and get some production going. The first step was to keeo from loosing them so used a short stud a a #2-56 large pattern nut. After cranking the nut down against the shoulder, I ground off the threaded shank to leave 3 full threads. This will be used as a mandrel for polishing and chamfering the nut after cutting off.
The hex stock is drilled and tapped in the lathe as you would expect. The three exposed threads are then screwed into the stock, tight up against the large pattern nut. The mandrel is only an inch long. I then use a special gauge ( small needle nose pliers) to set the exposed length of stock to the desired height of the nut plus the thickness of two steel washers. The washers are slipped over the end of the mandrel and the large nut to act as a guide and to protect the jaws of the lathe chuck. Using a small hacksaw against the second washer, I cut the nut off. I drops into a small tray under the chuck, and because it is attached to the mandrel, it doesn't bounce around and get lost. I pick up a file and file the end of the stock in the chuck to remove any burr and the pickup the mandrel with nut still attached from the tray. A five second twiddle against the belt sander to remove any burr and add a little chamfer.
Take a breath and repeat.
I can get four nuts before needing to drill and tap again. My tap drill wanders off center very slightly but I can get three sets before the hole has wandered off center enough that I need to clean up the end of the stock with a parting and respot with a center drill.
After I got the process worked out, I was able to 40 nuts in less than an hour before running out of stock.
From now on, I will hacksaw my nuts off.
Jerry
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Are there supposed to be pictures?
Um, with that thread title, forget I asked... :o
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Are there supposed to be pictures?
Um, with that thread title, forget I asked... :o
Of course there are pictures. Wanna see um?
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think so!
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Technical difficulties. Try later.
Jerry
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bit of a worry with that heading :lolb:
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With that heading I was expecting to see blood :facepalm2:
When I did the 10BA square (3.2mm A/F) nuts I use a carefully shaped thin parting off tool to part them off but found it was best not to drill/tap beyond one nut & parting off length or the drill wandered off ::)
Jo
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And if you grind your parting tool correctly it will put the chamfer on the stock still in the chuck as well as parting off the completed nut so no need to file or do a second op to chamfer.
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I suppose I could do a better job of grinding the parting tool. I may try that again. But there is still the problem of flying nuts as the last bit is parted. I also felt the need to run the tap through the parted off nut to be sure of good thread form without burrs. But I think I will stick with the hacksaw for now. I get a very high rate of output compared to previous parting efforts.
Technical problems resolved. Here are pics.
#1 Spot with center drill.
(https://farm8.staticflickr.com/7915/46541090825_e06a61515d_c.jpg) (https://flic.kr/p/2dUFfQr)nuts l0001 (https://flic.kr/p/2dUFfQr) by captain.jerry Ginn (https://www.flickr.com/photos/140341766@N06/), on Flickr
#2 Drill for tapping, 3/5" deep.
(https://farm8.staticflickr.com/7866/46733191794_f521fc3406_c.jpg) (https://flic.kr/p/2ecDPL7)nuts l0002 (https://flic.kr/p/2ecDPL7) by captain.jerry Ginn (https://www.flickr.com/photos/140341766@N06/), on Flickr
#3 Tap #2-56 to full depth of tap
(https://farm8.staticflickr.com/7829/46541090035_9a0b137cc4_c.jpg) (https://flic.kr/p/2dUFfAP)nuts l0003 (https://flic.kr/p/2dUFfAP) by captain.jerry Ginn (https://www.flickr.com/photos/140341766@N06/), on Flickr
#4 Insert mandrel
(https://farm8.staticflickr.com/7872/47403392632_987af232d7_c.jpg) (https://flic.kr/p/2fdSM7Y)nuts l0006 (https://flic.kr/p/2fdSM7Y) by captain.jerry Ginn (https://www.flickr.com/photos/140341766@N06/), on Flickr
(https://farm8.staticflickr.com/7899/47403392532_1ed29040e0_c.jpg) (https://flic.kr/p/2fdSM6f)nuts l0008 (https://flic.kr/p/2fdSM6f) by captain.jerry Ginn (https://www.flickr.com/photos/140341766@N06/), on Flickr
#5 Set depth to height of nut plus thickness of two washers using special gauge
(https://farm8.staticflickr.com/7915/46541090545_b963912aa8_c.jpg) (https://flic.kr/p/2dUFfKB)nuts l0009 (https://flic.kr/p/2dUFfKB) by captain.jerry Ginn (https://www.flickr.com/photos/140341766@N06/), on Flickr
#6 Add two washers to protect chuck jaws
(https://farm8.staticflickr.com/7803/47403392372_c52c2c6617_c.jpg) (https://flic.kr/p/2fdSM3u)nuts l0010 (https://flic.kr/p/2fdSM3u) by captain.jerry Ginn (https://www.flickr.com/photos/140341766@N06/), on Flickr
#7 Hack it of with blade against outer washer
(https://farm8.staticflickr.com/7881/46541090465_8946b99994_c.jpg) (https://flic.kr/p/2dUFfJe)nuts l0011 (https://flic.kr/p/2dUFfJe) by captain.jerry Ginn (https://www.flickr.com/photos/140341766@N06/), on Flickr
#8 Mandrel with rough nut.
(https://farm8.staticflickr.com/7901/47403392202_c5659dfd57_c.jpg) (https://flic.kr/p/2fdSLZy)nuts l0012 (https://flic.kr/p/2fdSLZy) by captain.jerry Ginn (https://www.flickr.com/photos/140341766@N06/), on Flickr
#9 File end of stock for next nut
(https://farm8.staticflickr.com/7888/46541089905_bb1f4d60dd_c.jpg) (https://flic.kr/p/2dUFfyz)nuts l0013 (https://flic.kr/p/2dUFfyz) by captain.jerry Ginn (https://www.flickr.com/photos/140341766@N06/), on Flickr
#10 Twiddle the cut off nut against belt sander or disk sander or file if you prefer
(https://farm8.staticflickr.com/7847/47403392062_6896cde5a0_c.jpg) (https://flic.kr/p/2fdSLX9)nuts l0015 (https://flic.kr/p/2fdSLX9) by captain.jerry Ginn (https://www.flickr.com/photos/140341766@N06/), on Flickr
# 11 Finished nut
(https://farm8.staticflickr.com/7921/46541090185_524d93e28e_c.jpg) (https://flic.kr/p/2dUFfDp)nuts l0016 (https://flic.kr/p/2dUFfDp) by captain.jerry Ginn (https://www.flickr.com/photos/140341766@N06/), on Flickr
#12 repeat from #4
This is a bunch of finished nuts and a couple of nuts applied. They are not perfect but that is not out of character with the rest of the model.
(https://farm8.staticflickr.com/7907/47403391742_f75ce74098_c.jpg) (https://flic.kr/p/2fdSLRC)nuts l0019 (https://flic.kr/p/2fdSLRC) by captain.jerry Ginn (https://www.flickr.com/photos/140341766@N06/), on Flickr
(https://farm8.staticflickr.com/7899/40490293113_f829a7d0e5_c.jpg) (https://flic.kr/p/24FZktX)nuts l0020 (https://flic.kr/p/24FZktX) by captain.jerry Ginn (https://www.flickr.com/photos/140341766@N06/), on Flickr
I know. I need to work on washers now.
Jerry
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Jerry--that has to be the absolutely best thread title I have ever read. I've been chuckling about that all day.--Brian
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That's almost as good as drunken shop elves.
Art