Modifying small screws

Here's how I go about modifying the ends of small screws...

https://s3-us-west-1.amazonaws.com/f...he/35508-1.jpg

A brass 'collet' is made for each size of screw by tapping a short slug of brass with the required thread and then milling a small flat on the slug. The screw is then threaded through the collet and secured in place with a lock nut. The collet is then inserted into a steel tube and locked in place with a set screw.

The whole assembly is then stuck in a 5C collet on the lathe and the required work performed. (The picture shows a dog point put onto a 2-56 screw.)

The brass "collets" are easy to make and, over time, you'll acquire a collection of them to fit the screw sizes you use most frequently. They're a handy use for the uselessly short bits left over from stock rods.

Thanks mklotz! I've added your Screw Modification Tool to our Lathe Accessories category, as well as to your builder page: mklotz's Homemade Tools. Your receipt:

<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="http://www.homemadetools.net/screw-modification-tool"><img src="http://www.homemadetools.net/uploads/128070/screw-modification-tool.jpeg" /></a></div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="http://www.homemadetools.net/screw-modification-tool">Screw Modification Tool</a> <span> by <a href="/builder/mklotz_3">mklotz</a></span> </div> <div class="tags">tags: <a href="http://www.homemadetools.net/tag/lathe">lathe</a>, <a href="http://www.homemadetools.net/tag/modification">modification</a>, <a href="http://www.homemadetools.net/tag/collet">collet</a></div> </div> </div> </div>

Another great idea, thanks.

very interesting, I have seen automotive engine head studs that require the dog point but what are you using such a small one for?

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Originally Posted by jere

very interesting, I have seen automotive engine head studs that require the dog point but what are you using such a small one for?

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In this particular case it was for a working model of a WWII deck gun...

http://www.homemadetools.net/forum/m...6438#post66433

https://s3-us-west-1.amazonaws.com/f...e/111217-1.jpg

What a fantastic piece! Absolutely awe-inspiring model making. :hattip:

Ken

Ken said it better than I could! the "working " part really caught my attention too!

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Originally Posted by jere

Ken said it better than I could! the "working " part really caught my attention too!

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Yes, the handwheels train and elevate the barrel, and the recoil absorber mechanisms all work as in the real thing. The barrel is made from a turned down .22 rifle barrel so it's fully rifled. The quick-lock, quarter-turn breech block is operated via the handle. The only thing that's unrealistic is the blocky structure on the breech block which contains the trigger mechanism and the firing lanyard.

It can fire .22LR. However, we have five grandchildren so the firing pin is removable and hides in the dummy shell you can see in some of the pictures. [Real ammo is kept in a gun safe.]

Here are a couple more pictures...

https://s3-us-west-1.amazonaws.com/f...he/66433-1.jpg



https://s3-us-west-1.amazonaws.com/f...he/66433-3.jpg

What an incredible piece of work. :clapping:

Which specific model of deck gun was the inspiration? What scale did you use?

Ken

Wow, your precise workmanship on this model is fantastic and having a working model takes it to yet another level. I found on your website the section for "Information Nuggets" very interesting. Looking forward to seeing more of your custom tools (and your model examples).

Paul

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Originally Posted by kbalch

What an incredible piece of work. :clapping:

Which specific model of deck gun was the inspiration? What scale did you use?

Ken

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It's not a model of any particular gun. The gun resembles a British quick-firing six pounder. Although historical details from the magazine article were sketchy, I would imagine that this is the sort of gun that would have been used on the British Q-ships against submarines or unarmored merchant ships.

The scale, such as it is, is largely guided by the use of the .22 rifle barrel.

Quote:

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Originally Posted by Paul Jones

Wow, your precise workmanship on this model is fantastic and having a working model takes it to yet another level. I found on your website the section for "Information Nuggets" very interesting. Looking forward to seeing more of your custom tools (and your model examples).

Paul

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Just to whet your appetite - here's a breath-powered, double-acting, piston-valve steam engine...

https://s3-us-west-1.amazonaws.com/f...he/36632-1.jpg

The connecting pins are made of 1/16" drill rod turned down to 0.030" and then split with a 0.010" slitting saw on the end. Once in place the split ends are spread apart slightly to keep the pin in place.

Exquisite Model engineering Marv! :clapping::hattip: Incredible craftsmanship and finishes all the way down to the shell! That breach door and firing mechanism is too much for words, let a lone the brass sites...Wow, Holly Cow...and then some! I'll have to check out your website as Paul mentioned!

Your screw holder is very cool too and could use the benefit of it...make a fair amount of dog points and taper points my self.

Thank You for sharing your talents and ideas with us!!! Wow--:hattip: ~PJ

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Originally Posted by PJs

Exquisite Model engineering Marv! :clapping::hattip: Incredible craftsmanship and finishes all the way down to the shell! That breach door and firing mechanism is too much for words, let a lone the brass sites...Wow, Holly Cow...and then some! I'll have to check out your website as Paul mentioned!

Your screw holder is very cool too and could use the benefit of it...make a fair amount of dog points and taper points my self.

Thank You for sharing your talents and ideas with us!!! Wow--:hattip: ~PJ

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It doesn't stand out in the photographs but the dummy shell has a brass tip on the projectile to imitate the typical brass fuses with which these shells were equipped. I Loctited some 1/16" brass rod into the steel before turning the ogive shell profile.

Now, if the brass tip unscrewed to show the functional fusing mechanism, that would be impressive! :rofl:

I'm kidding, of course. I think that deck gun is one of the greatest examples of the model maker's art I've ever seen.

:bow:

Ken

Quote:

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Originally Posted by mklotz

Yes, the handwheels train and elevate the barrel, and the recoil absorber mechanisms all work as in the real thing. The barrel is made from a turned down .22 rifle barrel so it's fully rifled. The quick-lock, quarter-turn breech block is operated via the handle. The only thing that's unrealistic is the blocky structure on the breech block which contains the trigger mechanism and the firing lanyard.

It can fire .22LR. However, we have five grandchildren so the firing pin is removable and hides in the dummy shell you can see in some of the pictures. [Real ammo is kept in a gun safe.]

Here are a couple more pictures...

http://i81.photobucket.com/albums/j2...20GUN/gun5.jpg

http://i81.photobucket.com/albums/j2...0GUN/gun10.jpg

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I love it! Fantastic work! :)

Hi,
Like all my friends above, this is really impressive and I am totally fan of your work ! :clapping:
Christophe

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Originally Posted by kbalch

Now, if the brass tip unscrewed to show the functional fusing mechanism, that would be impressive!

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I'll get right to work on that.

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I'm kidding, of course. I think that deck gun is one of the greatest examples of the model maker's art I've ever seen.

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High praise, indeed. Many thanks.

Had a ton to do yesterday but this model was on my mind all day! The more I look at it the more I get all the intricacies you performed to build it and would guess something on the order of 100 components. Like the elevation and turret drives all the way down to the round head rivets. The most intriguing is the firing mechanism with (I'm guessing) a spring loaded pull. I tried to zoom in on the breach also to see if there was some kind of ejector but could see well enough. Your working Ships Gun is a true work of art, craftsmanship and engineering!! :hattip:

I'm a big fan of the Internet Craftsman Museum down in Carlsbad and hope to go there some day. Your model rivals some of the best I have seen on their site and do hope that you share with them some day as well!!

Checked out your site and busted me up the first thing on your software was a Catanary calculator. Couldn't open it in Win7 but will load it on my XP laptop to give it a spin. It made me look up a spread sheet I made back around 2000 to calc all the Cat affects for various tubing materials and lengths (up to 20') for the drill machines I designed and built. The calcs were just so I could strategically place some pneumatics, delrin V blocks, springs and quadrature counts that would allow the 20' linear drive to squirt a 20' stick through the headstock...A fun rush back through time. Great website chocked full of useful info and tools!!

Thank you kindly for sharing your wizardry, ideas and talents with us! :bow: :hattip: ~PJ

Yes, it's spring loaded with a detent attached to the spring-restrained trigger ring from which hangs the firing lanyard. There is no ejector mechanism. The gun is not really meant to fire despite the fact that it can. It's eye candy and a real attention getter as a desk ornament.

By all means do not miss the Craftsmanship Museum if you're down this way. Joe Martin, the late owner of Sherline, was passionate about model engineering and originally set the display up in their factory. Since his death it's moved into a much larger building and expanded its collection considerably. Joe's efforts to create the museum are much appreciated.

Very close by is the Antique Gas and Steam Engine Museum...

AGSEM

which has large scale operating steam machinery as well as a working blacksmith shop and a whole bunch of other stuff folks like us enjoy.

Have lunch at the Tip Top deli...

http://www.tiptopmeats.com/

You won't regret it. Trust me on this.

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It's eye candy and a real attention getter as a desk ornament.

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That's an understatement but, either working or eyecandy...its stunning and thought provoking too!

Thanks for the clarity on the trigger/firing mechanism. Thanks also for the links and I won't miss either of those on that trip! The menu looks Outstanding! How could I not trust Einstein with his tongue out¿ :beer: ~PJ

That, sir, is a work of art.

I stopped model engineering some years ago but never achieved anything as impressive as that, just studying the photo's makes you realize the many and varied setups and types of machining involved. Beautiful work.

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Originally Posted by olderdan

I stopped model engineering some years ago but never achieved anything as impressive as that, just studying the photo's makes you realize the many and varied setups and types of machining involved. Beautiful work.

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Thanks, Dan.

Some of the more interesting bits are completely hidden. The conical gun base is one-half of a DIY ball bearing. Half cylindrical tracks in the conical section and the flat plate section on which it rests form the races that enclose ~40 1/8" steel balls that form the bearing. Like the gearing, these are lubricated with high-viscosity grease (the kind used in microscope and telescope focusing gear) to give that slow, smooth feel one associates with big machinery.

Inside the conical base is a bevel gear, fixed teeth-up to the base plate. A companion bevel gear engages it and has a shaft that projects horizontally through the conical base to an exterior spur gear. This spur gear is driven by the worm on the end of the shaft that connects to the hand wheel for the trainer.

One of the toughest jobs was arranging for the interrupted thread breech block to close smoothly. Lots of cut and try work there. I was often tempted to build a simpler sliding breech as seen on many guns but the interrupted thread just looks so cool I had to persist.

Wow!!

Ralph