Very interesting. This looks like a great tool. Nice work.

Gday Cliff, I’ve just finished watching both Marks and your videos and following with great interest, this certainly is a great tool for any workshop to have and a brilliant build to improve accuracy skills, keen to see the next instalment mate, cheers

Where do I sign?!!!

I really enjoyed watching that cylindrical grinder at work. The finish on the mandrel is first class. Regards, Preso.

Thank you.

Criminally underrated channel, You are the best Cliff! Cheers!

Marks doing a bang up job on his. I would have liked to purchase one complete rather than building one myself, only because I’m not 100% confident I’ll be able to make everything correctly. But either way I just want one!

I want one of these so bad I can taste it !! Where do I send the check ?!

100mm chuck, bevel gears, bearings have arrived. How much do you want😮😮 dollars 😮😮 and where do I send it to..😊😊 Seriously.😊😊

is a knee mill a requirement ?

Very clever Cliff ! I have been racking my brain on how you transfer the rotation of the spindle to the linear advancement of the carriage. One look at the threading of the shaft and the advancement nut and it all started to make sense. I know now that one end of the lever is attached to the nut on the shaft. Next is to work out how the adjustable fulcrum point connects to the lever advancement of the carriage. I know now that I will solve the linkage before too long. My hat is off to you Cliff Ken Parsons Halifax Nova Scotia Canada

I watched Preso's video and then came over to watch yours, coming along nicely on both sides of the Ditch. 👍

👍👍👍👍👍👍

Just to offer my comment I personally would be inclined to buy e-plans and build my own. I'm 75% complete on a bandsaw mill that I'm building from plans seen on you tube. Otherwise I couldn't afford the bandsaw mill or the mill threading attachment which I think is awesome. God bless you on whatever way you go forward.

Just found your channel, I figure you have a yoke on the spindle and a threaded shaft which is rotated by the spindle. The yoke moves up the thread by a nut but pivots on the nut, The other end of the yoke arm is the thread pitch adjusting nut. which is the yoke arm pivot point. By moving the nut it changers the ratio between pivot point, the threaded shaft and the spindle, thus the yoke moves the spindle out at a different rate. This gives the different threads as the spindle rotates. good idea. You could also cut a four start thread with that probably, by lowing the cutter 1/4 of the pitch.

The beauty of it is that you make fasteners as strong as studs. No squashed structure under the head.

You sound like a bright Chap, could you explain the common statement of High Speed Steel? Or is it High Strength steel? What has speed to do with a material?

There are many home-shop machinists who enjoy the challenge of building fixtures and attachments to extend the capabilities of their existing lathes, milling machines, etc. Their budgets are limited but they have over-flowing scrap boxes and plenty of time. They will buy your plans if the cash outlay for purchased parts is modest. I had a look at Mark Presling's build video and think he's making a first-class commercial tool, but making it too expensive for home-shop machinists. Some suggestions - avoid castings or weldments (use bolt-together aluminum plates), avoid purchased ball bearings (use Oilite or brass bushings), avoid purchased shafting and buying the long drill for the central hole (use heavy-wall pipe), avoid purchased bevel gears (use the bevel gears from a charity-shop hand drill). Your device will be a necessity in every home shop if the cost is minimal. Consider two versions - 1st-class commercial, and home-shop good enough.

That's a terrific invention. I'd seen the earlier videos but this one is new to me. I didn't appreciate how small and compact the device is. I think it will be widely accepted by home-shop machinists, small maintenance shops, and maybe even commercial machine shops. But few home shops or small maintenance shops have a big Bridgeport mill. I think you should demo it on a smaller Chinese round-column mill with perhaps 8" reach. Many home shops don't have any sort of mill and their lathes lack threading capabilities. A smaller version that would bolt on a lathe cross slide should be popular. To protect your intellectual property, I'd suggest copywriting the drawings and selling them for $50 a set. If I could build one with less than $200 in bought-in parts, I'd buy a set of drawings. Best of luck commercializing this. There are lots of us out here looking forward to the reveal and a look inside the box. As for guesses as to how it works, I think you have the spindle supported by a variable-pitch nut - similar to a variable-pitch propeller or the variable stator blades on the compressor end of a gas turbine. Three narrow "blades" in the nut should provide sufficient spindle support. The spindle would have a malleable outer sleeve that the blades in the variable-pitch nut could cut into - Delrin or similar. As the spindle rotates it would back out of the nut at a rate determined by the pre-set blade pitch or helix angle. There are likely better (more durable) materials for the spindle sleeve than Delrin - perhaps some self-healing "carpet" with little microscopic radial fibres that would be deflected by the blades to form a temporary thread in the sleeve, but still support the weight of the spindle, chuck, and work. A return spring may be necessary for horizontal operation. The helix angle is determined by the thread pitch and diameter. For a 1-1/2" diameter sleeve, a 64 tpi thread would have a helix angle of 0.1900 degrees. A 9 tpi thread would have a helix angle of 1.3507 degrees. The blades wouldn't need swivels. They could be spring loaded to the shallow 64 tpi angle and deflected upwards by a circular cam ring with three ramps to angle the three blades up. With three blades, 100 degrees of cam rotation would shift/twist the blades from 64 tpi to 9 tpi. To minimize costs, avoid castings. The dovetail slide and spindle supports could use 1/2" aluminum plate and SHCSs. A foot of 1" sch 80 pipe would work for the spindle. The end could be threaded to accept the user's existing chucks. The variable-pitch nut could use X-Acto knife blades or broken hacksaw blades. Your bevel gears could be replaced with aluminum jockey pulleys and a round O-ring belt.

Hi, great design , looks that you are using a sine bar to generate the pitches?

Variable speed transmission that drive spindle in and out 12:46

Variable speed transmission that drive spindle in and out of

Very cool tool I bet some one in china is going see this and beat you to market as we watch this

Some further thoughts about using differential threads to produce the adjustable lift required in your ThreadExpress device. I'm looking forward to the final reveal because I'm sure your solution is better & simpler than my speculations. The problem is the tremendous range of threads necessary. 64 tpi requires that the spindle lift 0.0156" per revolution and 2" of thread requires 128 revolutions. 9 tpi requires that the spindle lift 0.1111 per revolution and 2" of thread permits only 18 revolutions. It simplifies things to use threads on the outside of the spindle to create the required lift. A pretty fine spindle thread is required to allow 130 revolutions for the 64 tpi threads, but that fine thread doesn't provide much lift when less than 20 revolutions are available for the 9 tpi. A compact solution is to limit the rotations to about 65 and have 2.5" of 40 tpi and a nut on the upper end of the spindle and 8" of 10 tpi and a nut on the lower end of the spindle. A 6" long cross lever is pinned at its 1.5" point to the upper nut. A slide on the lever is positioned anywhere along the lever to control the lift of the nut. The slide swivels on the end of a long vertical link pinned to a reference elevation. The other end of the 6" cross lever is pinned to one end of a 7" link with its other end pinned to the lower 10 tpi nut. When the spindle rotates CCW it backs out of the upper 40 tpi nut and lifts at 0.0250" per rotation. Spindle rotation also backs out of the lower 10 tpi nut and moves it down at 0.1000" per rotation. The link from the lower nut to the 6" cross lever pulls it down and rotates the cross lever 90 degrees CCW around its pivot on the upper nut. Because the cross link pivots on the slider, the position of the slider on the cross lever determines the total lift of the spindle. The total spindle lift is the combination of the spindle backing out of the upper nut and the lift of the cross lever that lifts the upper nut. The slider position on the cross lever determines the lift of the upper nut. When the slider is coincident with the pivot on the upper nut, the rotation of the cross lever has no contribution to the lift - it still rotates but doesn't move the upper nut. The total lift will only be the backing out of the upper nut at 0.0250" per rev and would mill a 40 tpi thread as the spindle rotates. When the slider is beyond the pivot on the upper nut on the short end of the cross lever, the rotation of the cross lever lowers the upper nut and SUBTRACTS from the spindle backing out lift producing total lifts of less than 0.0250" per rev to mill threads finer than 40 tpi down to 64 tpi. When the slider is on the other side of the pivot on the long/linkage end of the cross lever, the rotation of the cross lever in the slider raises the upper nut and ADDS to the spindle backing out lift, producing total lifts greater than 0.0250" per rev to mill threads coarser than 40 tpi up to 9 tpi. This cross-lever lift is important because with coarse threads fewer spindle rotations are required/available and the lift backing out of the upper 40 tpi nut is small. The 10 tpi thread on the lower part of the spindle is necessary to get the necessary lower nut movement to rotate the cross lever enough to obtain sufficient spindle lift for the coarser threads with the few available spindle rotations. But 64 spindle rotations are necessary for every inch of 64 tpi thread. This requires 6.4" of 10 tpi thread to accommodate the lower nut movement for this fine thread. The 7" of 10 tpi thread limit the rotations to about 65 and the amount of 64 tpi thread to 1". Longer fine threads can be made by repositioning the work in the chuck - why would one need more than 1" of 64 tpi thread? The amount of 40 tpi thread is limited to the 65 rotation limit of the 10 tpi thread or 1.6" travel of the spindle in the upper 40 tpi nut. The amount of 9 tpi thread is limited to the 6" of lift available with 7" of travel of the lower nut, but is more likely limited by the slide travel of the overall mechanism - 2 to 3". As mentioned previously, the slider swivels on the end of a long link pinned to the reference elevation. The slider's position on the 6'' cross lever is set by shifting a link from index marks that mark positions for the desired tpi or mm pitch. Range of lateral movement of the slider along the cross lever is about 5". The mechanism is mounted on a 1/2" thick base plate sliding vertically in a dovetail on the side of the milling table. As noted in the main description, the dovetail mounting can be shifted and locked to set the spindle at the required helix angle for the thread. The end of the link to the slide on the cross lever is pinned to the stationary part of the dovetail through a slot in the base plate. The whole mechanism is supported on the slider and cross lever and is lifted in the dovetails by forces on the slider. The spindle is supported at either end in bushings in 1/2" brackets bolted to the base plate. The cross lever, links to the 10 tpi nut and pitch-setting lock, and slider-supporting link all slide on the base plate. A vertical dado in an adjacent bracket bolted to the base plate receives tabs on the 40 tpi and 10 tpi nuts to prevent rotation but allow movement up and down the spindle. That bracket has to be far enough away from the spindle centreline to allow the slider support link to move from one side of the spindle to the other for the different thread pitch settings. As noted in the description, a crank and bevel gears are used to manually rotate (and elevate) the spindle during the thread milling operation. If bevel gears are not available, pulleys and a large O-ring belt could be used. As the crank on the side of the mechanism is turned, the spindle rotates the work CCW and backs out of the upper 40 tpi nut. The lower nut moves down the 10 tpi spindle threads. Its link rotates the cross lever 90 degrees CCW. The position of the slider on the cross lever determines how much lower-nut movement (lift) is added (or subtracted) from the upper nut to produce total lift. The total lift per rotation determines the thread pitch. The cross lever, slider and links all have to be beefy enough to support the weight of the base plate, spindle, bearings, chuck, and work piece. Congratulations if you got this far. Make any sense?

Hi, I've enjoyed your videos. I teach machine shop. I am interested in both the machine and the plans (would like to use our students to build one). Please contact me with the price for the machine, so I can make a proposal to my boss. Thank you,

I just found myself learning so much I owe you a beer or two!

I value your input here and any response to this is welcome. - I am hoping someone will contact us wanting the design first and to take over supply. (Hopefully we would still be able to supply drawings to enthusiasts). But if nobody does, as others have pointed out, years have gone by, and I should not take the design to the grave with me! I do not have the time to undertake the huge project of manufacturing or even assembling this myself. The long-term manufacture, admin, warranty, and support is for a much bigger outfit than I. - I am also wary of selling drawings/plans. If the price is low enough to discourage copy sharing, the uptake numbers may become large, and I might feel somewhat obligated to provide support to a continually burgeoning demand. If the price is high enough to slow down demand, then this will encourage copy sharing. - Currently, the only alternative I can see is basically to gift it to the world as a ''hobby labor of love''. I could apply a verification restriction over the supply of full plans requiring partial build photos before the final specs are supplied just to slow down the uptake and discourage speculation. - I welcome viewers input here, there may be another approach I have yet to discover. I have found over the year's most engineering folk are genuine and honest and it gives my life meaning to find ways to contribute to them. Cheers, Cliff

While I haven't watched the entirety of Mark's first video, I saw enough to hear about the plan of producing engineering drawings for sale. My unsolicited advice: don't go this route. In a very short period of time, a Chinese company will acquire that information, then begin mass producing this, and you both will be hung out to dry in the sun. I have been in the field of parts manufacturing for 30 years and have never seen such a handy device. I think it's a great idea, although it will have a niche market. Best of luck to both you and Mark!

How do we, as budding KZbin artists gain a chance? I know you are going for visibility and won't be slighted if i don't get an opportunity. Thank you this is an impressive project. Thank you. All the best. Respectfully Term

I am torn between the elegance of an all mechanical design, and the simplicity of using encoders and steppers to do the same. Were I to make one, I'd likely do it the electronic way, as time has recently become very precious. But again ... I've got a good idea of the internals, and I quite like that aspect. In the same way that the Antikythera mechanism fascinates me.

I notice that your original machine was a 'stand alone' unit simply utilising an angle grinder as the 'miller'. I think that this route has possibilities because it overcomes the problems suffered by those who don't have a Bridgeport type machine (envy, envy) or lack access to one. I wonder if accuracy becomes a problem? As a person who way back as a teenager obtained a British 'O' level in Engineering Drawing I find that those three years of study such things as 'third angle projection' created in my head a sort of 'CAD of the imagination' (I was far better at free hand sketching afterwards) so that if you never reveal your mechanism I might just have been inspired to dream up my own version. As I have said the 'sine bar' concept allows you to 'describe' a helix which ranges from 'tends to zero (or a straight line) on one axis' to the same on the axis at right angles (or in the case of those rifling machines where sine bars are seen 'straight line rifling' which did appear in such things as experimental Baker Rifles in the late 18th to early 19th century. Looking forward to the next video.

It looks like you can handle a maximum of about 2" of thread anywhere from 64 to 9 tpi. I believe this could be achieved with differential threading on the spindle below the bearings - say 1" of 120 tpi on the upper portion and 4" of 30 tpi on the lower end. For this explanation I've imagined 60 tpi as the minimum and 10 tpi as the maximum for easy arithmetic. For 2" of 60 tpi you'll need 120 revolutions of the spindle. With 1" of 120 tpi and its nut is at table height, 120 CCW revs of spindle will raise the spindle 1". (Backing it out of its nut.) If the lower end of the spindle has 4" of 30 tpi and its nut is not fixed but prevented from rotating, 120 CCW revs of spindle will lower its nut 4" relative to the spindle but because the spindle went up 1", the lower nut will only lower 3" relative to the table. The lower nut is linked to one end of a fixed teeter-totter at say table elevation and pivoted on the spindle centreline, such that one end goes down 3" while the other end goes up 1". The rising end of the teeter-totter is linked to the upper nut, and will lift it 1" and effectively raise the spindle 2". 2" of upward movement in 120 revolutions will produce a 60 tpi thread. If the pivot point of the teeter-totter is a slot, shifting the teeter-totter along the slot will change the ratio between the down motion of one end and the up motion of the other end. For 2" of 10 tpi, 20 CCW spindle revs would be necessary and will raise the spindle 1/6" in the upper 120 tpi nut. 20 CCW revs will lower the lower 30 tpi nut 2/3" relative to the spindle but because the spindle went up 1/6", the lower nut will only lower 1/2" relative to the table. But we need 2" of total upward spindle movement to get 10 tpi in 20 revs. So by shifting the teeter-totter in its slot to give a input:output ratio of 1/2 to 11/6, 1/2" of lower nut downward movement would translate to 11/6" of upward nut movement which added to the 1/6" it already moved would give 12/6" or 2" of upward spindle movement. And 2" of 10 tpi with 20 CCW revs of the spindle. So the teeter-totter slot would be positioned to give a 0.5:1.8333 ratio - one end goes down 1/2" to lift the other end 1.8333". And lift the upper nut 1.8333" for a total spindle lift of 2". Even better ratios could be had with more travel of the lower nut. But more lower thread would be required and take more room in the mechanism. There may be issues with angularity of the links as the teeter-totter rocks from the lower to upper spindle position. But they can be minimized by maximizing the lengths of the links and minimizing the length of the teeter-totter.

Presser sent me

My guess is that the mechanism is a type of rolling ring gear. Such gears have been known for a long time in various applications. For example, Uhing or in the Haller UFS 155

Looks like a sine bar rifling cutter mechanism?

Ultimate story arc. Always wondered about the channel name. Thanks again for sharing your hard work and insights, love my ITTP probe!

Discovered you on Mark Presling’s YT channel. Definitely interested in this project. Subscribed.

A great unit. I am very interested in knowing more on it.

Hi, sent you an email with a (very) rough sketch of how I think it works inside. Love to hear what you think.

I've been looking for thread milling code to do npt threads on a CNC and assume that's how I got these videos recommended to me. I thought the concept was really neat, but didn't know how it worked until you pulled the cover off. It's an adjustable sine bar isn't it?

Thread milling for a manual machine.....what a good idea

Bottler idea. China, is your problem. They will steal the idea and do it quicker and cheaper before your arse can pucker. But mate, I do wish you all three very best.. ....and Yes, I would love one.😮😊

Hi Cliff I have followed Mark for a while and came here from his first ThreadExpress build video. I am in NZ as well (Auckland). I find this a very interesting machine and can see the potential uses. Let me know if you need any assistance as I'm happy to provide any help if you need it. Regards Jon.

Referred here by Mark Pressing’s channel. . . As a mechanical engineer I normally would hold back comments on mechanisms of which I can’t directly identify all the components but I am in agreement with some of the commenters that this application of a variable ratio drive is interesting. In my mind there are potentially two audiences - a number of them are hobbyists, the others being professionals. If the device is as promising as you think it is a hobbyist is more the candidate to purchase plans and build his own while the business owner would probably buy a finished unit with documentation, a warranty and support, etc. to be used in a commercial setting to expedite thread cutting. Additionally if the device is as promising as you believe, you have already engaged an IP/ patent professional while you work with other engineers to determine appropriate materials, manufacturing processes and costs for a commercially viable product. Looking forward to your lifting the tent flap.

Looking forward to watching Mark build your thread express! Can't wait to purchase plans.

I have wild dreams after eating Chinese......nothing clever like yours though

Onya Cliff 👏👏👏👏👏 I KNEW that sooner or later you’d find a way through the ‘product development / marketing’ mire… And you’ve hooked up with the PERFECT collaborator 👍 Can’t wait to see this progress further. I always had the notion that you could get a Company to actually get this into production… but I realise just how problematic that would be 😵‍💫 But a ‘project’ that can still be spread to the engineering masses, via drawings/subscriptions/ whatever… as long as your IP is protected…. well that’s a winning outcome anyway. Congratulations to you and Mark 👏👏 Regards Robert 🇦🇺