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: diamond screw design
: diamond screw design -- efendy	Post Reply	Top of thread	Engineering Forum

Posted by: kotasasi ® 06/07/2009, 15:56:52 Author Profile eMail author Edit

Can any one help me in designing a daimond screw for using in levelwind for winch application.

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: diamond screw design
: diamond screw design -- efendy	Post Reply	Top of thread	Engineering Forum

Posted by: jboggs ® 05/14/2008, 09:48:46 Author Profile eMail author Edit

I know what a "yankee screwdriver" is. Is that what you mean? Come to think of it, the threads on the shank are in kind of a diamond shape. Maybe that's where that name came from. You don't see them much anymore, because of all the battery powered drivers now. The basic idea is that you have a spiral threaded shank that slides into and out of a handle. An internal spring pushes it outward. The spiral grooves on the shank engage teeth on the bore of the handle so that as it slides in and out of the handle, it is forced to rotate. A bit holder is attached to the end of the shank. To operate it you simply insert the bit into the screw head and press on the handle. The bit rotates the screw. I grew up using these things with my dad. They were indispensable tools for the handy man. Yankee Screwdrivers What is a Yankee Screwdriver? A Yankee screwdriver is something that a lot of people have seen on their father's or grandfather's (forgive the sexism, but unfortunately, few women were working screwdrivers at that time) workbench -- it's a "push screwdriver", where a pushing motion is converted into a turning motion by a spiral cutting in the shaft. They can also be used as a traditional ratchet screwdriver and even as a conventional "fixed" screwdriver. The original maker of the "Yankee Brand" push screwdriver was (seemingly) North Brothers Manufacturing. At some point, North Brothers, or at least the Yankee brand name was bought out by Stanley Tools. (can you tell my history here is more via observation than research?) Stanley has discontinued producing the traditional Yankee screwdrivers (push screwdrivers), and in fact, they were last produced in the United Kingdom. So yes, for a while at the beginning of the 21st century, the Yankee Screwdriver was available only from the Brits. However, there are some similar devices that have been available from other sources on and off for many, many years. For purposes of simplicity, when I say "Yankee Screwdriver", I mean any of these various brands, unless stated explicitly. To add to the confusion, Stanley now uses the "Yankee" name on some of their NON-push screwdriver products. I'll just ignore those. Some pictures here would be nice. Eventually. They predate modern "power drivers" by decades -- I have several Yankee screwdrivers that are almost 100 years old, and are still 100% functional. There seem to be three primary sizes of Yankee drivers, I'll call them "small" (around a foot long, extended), "medium" (around a foot and a half, extended), and "large" (over two feet long, extended). The small ones are the size of a conventional screwdriver, and do not always have a lock on the spiral action. The medium size ones are my favorite -- long enough to do the job, not so long as to be considered a weapon. The large ones are...large. They do a job wonderfully, but they can have clearance issues. For most uses, the medium sized ones are my favorite, but I have a large one I like. I just don't carry it with me. Curiously, some of the "non-Yankee" push screwdrivers seem to follow these same basic sizes. There is also what could be called an "Extra Small", which feels like a "home" oriented tool to me, which has a much shorter "push" than the "bigger small". Many of the "Extra small" Yankees I've seen have a handle that unscrews permitting the storage of bits (both screwdriver and drill) with the screwdriver; a very nice feature on what is otherwise a tool I've not found overly useful, as the shorter "push" just doesn't seem to do much for me. Bits Yankee Screwdriver bits are..unique. They do not (directly) use the (now) standard 1/4" hex bits. Unfortunately, each of the screw driver sizes uses a different size bit, meaning you can't pool your driver bits well at all. Most of the used Yankee drivers I have seen at garage sales have only one bit or no bits in them. Replacement bit sets are not typically seen hanging on the shelf at your local hardware store. There are several makers of Yankee to standard hex bit adapters made now, some links below. I've got some adapters, though I must say I do prefer avoiding adapters and using "real" bits, as they are smaller and thinner than an adapter and a bit. One issue you may experience with the Yankee to Hex bit adapters is the fact that hex bits are designed to deliver torque to the bit, but provide easy removal of the bit by simply pulling on it. The problem with this is a Yankee screwdriver can apply a force to the bit in other directions -- most notabily, when releasing the spiral mechanism, they will often throw a hex bit out of a magnetic adapter, and launch it across the room (ok, usually only a few feet, but usually enough to toss your most unique and important bit into an unrecoverable place). The standard Yankee mount both provides twisting force to the bit, but also securely holds the bit in place. Some of the Yankee to hex bit adapters do provide various ways of holding the bit in place beyond a magnet -- sometimes, a screw-down collar, in other cases, a spring retainer. The Spring Thing All of the Yankee screw drivers I have seen in my life before I got interested in them myself were "spring-loaded" -- you push the handle in, compress the spring, the bit turns. Let go, the shaft extends on its own from the spring. After I bought my first, I did a little googling for them, and found a reference to someone finding a very old Yankee screwdriver without a return spring, with some speculation as to whether it never had one or it was broken. Since then, many of the Yankee screwdrivers I have purchased have NOT had the return spring, and I think I can say with good confidence, considering the otherwise perfect operation of some of theses tools, the spring is not broke, it just isn't there. Some of them have got a large screw on the handle, which APPEARS to be a "spring access screw" -- I say this because there is no way to store bits in this area, and I have one that has both the spring and the large screw head. Remove the spring, it behaves just like the ones I have that do not have springs. I've since heard from a number of people on this topic, and the general consensus is that while the spring provides conveinient one-hand operation, it is very easy to have the screwdriver slip and do dammage to the piece you are working on. Without the spring, the tool almost requires two hands, once of them right near the work, allowing it to be a very precise tool. Why care about Yankee Screwdrivers? Well, they are cool. It turns out they are a very useful tool for computer building and repair -- they can put a typical screw in or out of a typical computer in two or three strokes, with greater speed and greater control than one will find in all but the best power drivers. They are lighter than most power drivers, and have no magnetic fields to mess with monitors or disks, which is also a nice feature. Plus, there is just something retro-cool about working on a brand new computer with an 80 year old tool. Non-Yankee Yankee-style tools I recently acquired a "Millers Falls Co" (Greenfield, Mass) Yankee-style driver. It is the same size as the "Large" Yankee drivers, uses the same bits as the large Yankees. Quality tool, primary difference between it and my large Yankee driver the Millers Falls Co driver has the spring (looks like it was removed from my large Yankee), and the "shifter" is a twist-collar near the locking collar. Patent date is 1926. Harbor Freight at one point sold a Yankee style driver with hex bits for amazingly cheap. Unfortunately, it was junk, I purchased a couple and they fell apart very quickly...and I think they knew it and quit selling it. New Yankee Screwdrivers Shortly after I became interested in these things, I brought the three I had to a client I knew to be interested in fine tools. A week or two later, Harold called me up to say, "Nick, guess what is on the front cover of the newest Garrett Wade catalog?" Sure enough, Garrett Wade is importing them from England. He had promptly picked up the phone and ordered one for himself. The order-taker told Harold that this had been one of the most popular cover tools he had ever seen. I purchased a couple for friends of mine who was getting married as a wedding gift (I had to order two -- they don't share tools well!). While I didn't unpackage them at the time, I have since had a chance to look them over. It is an impressive tool, at least for today. Is it quite as "nice" as my 90+ year old Yankees? Not sure. However, it does have a real, honest to goodness wood handle, and it works well. It feels a little lighter than mine do, but that's not all bad. The shaft lock collar is actually labeled with "On" and "Off", which confused me for a while: "On" means "Lock on", I was stuck thinking it meant "Tool is ready to use". Garrett Wade now says that "Stanley has stopped production of all Yankee Screwdrivers". Sounds like the end of an era. Yankee Resources Note: I do NOT endorse or recommend any of the vendors here. I have probably not bought any products from them. As with everything on the Internet, including this poorly researched page, buyer beware. Make your own Yankee screwdriver bits. I've done this, it works. The 1/4" hex bits fit nicely in the mid-sized Yankee screwdrivers, a bit of work with a grinding wheel or (in my case) a Dremel cutoff wheel did wonders. Highland Hardware sells Schroder Spiral Ratchet bits and screwdrivers, which are compatible with Yankee products. They also sell a Schroder screwdriver with a hex chuck, which is rather "interesting" as well. They claim Schroder is a descendant of the Millers Falls products. Garrett Wade also sells hex adapters on the same page linked above for Yankee Screwdrivers. Garrett Wade's price is relatively high. I have a couple of them (large and medium), and they are very nice. Unlike most of the adapters on the market, GW's has both a magnetic hold on the bit AND a hand-tightened friction lock. This is a good thing, as the adapter WILL NOT let go of the bit. This is sometimes a problem with the magnetic holds with a heavy bit -- the act of "opening" the tool will sometimes shoot the bit across the room. The shaft of the adapter rotates like the collar of the Yankee Screwdriver itself, giving you another place to hold it, which is nice since it does add a bit of length to the bit. David Pope wrote me and told me Lee Valley Tools has a Yankee-to-hex bit adapter which looks rather nice, and the price is very interesting. I have since received feedback from another reader that the 7mm adapter fits the mid-size Yankee drivers perfectly, the 8mm adapter is a little "off" -- could be fixed with some grinding, but doesn't quite lock into the large Yankee drivers like it should. Yankee Screwdriver stories Yankee Screwdrivers in Art and Literature Tell me your Yankee Screwdriver stories, and let me know if I can add them to this page, and how to attribute them to you. (In general, you probably don't want me to post your e-mail address unless you are already something of an often spammed Internet celebrity.) You can even find them at amazon.com

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: : diamond screw design
: : diamond screw design -- jboggs	Post Reply	Top of thread	Engineering Forum

Posted by: efendy ® 05/15/2008, 00:40:16 Author Profile eMail author Edit

thanks for the reply.. but that's not what i meant. this one is used normally on a level wind assembly where the umbilical will be winded accordingly on a drum. the umbilical guide will move to the right until the end of the screw and then it will move again to the left because of the diamond arrangement of the screw. in addition, it looks like a lead screw but has left hand and right hand (for you to visualise) thread on the same body.but i think the concept is the same to what you mentioned Modified by efendy at Thu, May 15, 2008, 04:47:22

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: : : diamond screw design
: : : diamond screw design -- efendy	Post Reply	Top of thread	Engineering Forum

Posted by: Kelly Bramble ® 05/15/2008, 07:52:56 Author Profile eMail author Edit

efundy, Post a picture or diagram for us. "diamond screw" may be have be a company or specialized product name goven in the past.

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Posted by: Marky ® 05/15/2008, 08:42:36 Author Profile eMail author Edit

Yes...it's the same as a lead screw. It's simply a ball screw with large lead. The diamond pattern is just a cross groove so the handle or nut can make a quick return....hense the up and down motion on a Yankee Screwdriver.

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: : : : : diamond screw design -- Marky	Post Reply	Top of thread	Engineering Forum

Posted by: efendy ® 05/15/2008, 22:12:53 Author Profile eMail author Edit

thanks all for the reply, this is actually the problem: I'm hoping you can help me out with some technical advice on some of the basic principals of level wind diamond screw design. We are designing the level wind assembly for our new Top Hat TMS (tether measurement system), I would appreciate your advice on the design of diamond screw in particular the relationship between the drum width, the number of raps on the drum and the number of turns and centre distance of the diamond screw itself. Current design data is as follows. Tether diameter, nom 35+- 1mm. have assumed 36 dia as the basis for the design The drum core will have lebus type half shells profile for 36mm cable and 22.5 raps, these will probably be supplied by Nylacast and made of PU but may consider Lebus also. inside distance between drum wings 810mm = 22.5 raps Diamond screw travel, = 22.5 - 1 x 36 = 774mm (is this a correct assumption?) Diamond screw pitch will be 2 x tether diameter. = 2 x 36 = 72mm, number of turns on diamond screw =10.75 = 774mm travel, would 11 turns be OK. To allow for small variations in tether diameter say + - 5mm the gearing ration between the drum and the diamond screw can be adjusted by changing the sprockets sizes. Do you know of any design data, text books or designers manuals for the diamond screws, who would be the best supplier to seek advice from and to manufacture the screw. I was considering Lebus, also there was a company in Hull I have used in the past but cant remember there name. Appreciate any advice you can offer. i attached the basic drawing of this diamond screw

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: : : : : : diamond screw design -- efendy	Post Reply	Top of thread	Engineering Forum

Posted by: Reigns ® 04/04/2010, 22:39:42 Author Profile eMail author Edit

Hi Efendy You got your answer? Would you like to share with me?

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: : : : : : : diamond screw design -- Reigns	Post Reply	Top of thread	Engineering Forum

Posted by: MARKING ® 04/10/2010, 02:01:55 Author Profile eMail author Edit

Hi If you want to know more photos and more information of winch diamond screw shaft and nut, you may search "Dalian Dehua" on/in "google map" or 'google webpage".

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: : : : : : : diamond screw design -- Reigns	Post Reply	Top of thread	Engineering Forum

Posted by: MARKING ® 04/09/2010, 22:43:09 Author Profile eMail author Edit

Hi Isend a photo of winch spooling nut to you for your reference.

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: : : : : : : diamond screw design -- Reigns	Post Reply	Top of thread	Engineering Forum

Posted by: MARKING ® 04/09/2010, 22:31:13 Author Profile eMail author Edit

Hi I can send only one photo to you for each email. I send a photos to you again for your reference.

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: : : : : : : diamond screw design -- Reigns	Post Reply	Top of thread	Engineering Forum

Posted by: MARKING ® 04/09/2010, 22:18:44 Author Profile eMail author Edit

Hi I try to send some photos of winch diamond screw shaft to you for your reference. I do not know whether to send success.

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: : : : : : : : diamond screw design -- MARKING	Post Reply	Top of thread	Engineering Forum

Posted by: Reigns ® 04/11/2010, 22:17:23 Author Profile eMail author Edit

Hi Thank you. I did not receive your email. My email is reignwars@hotmail.com Can you resend again?

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