flip up toolholder

[BogstandardParticipant @bogstandard]

Chris,

 

I always give due recognition wherever I can. This design was a combined effort, and it was John’s input that got rid of my mental blockage and showed the way to proceed. Sometimes it takes help from other people to move a project along, so never refuse another brain when the going gets tough. If you don’t, it could take years to get to the final goal, if ever.

 

There are lots and lots of old ideas that are out there that have been tried in the past, only to fail because of maybe one little hurdle that could not be got over. It could be just the strength of old materials in the past were not up to today’s standards, or the machining facilities were not available to the original designer.

 

There is very little new at all today, just old designs brought up to date or ‘rediscovered’.

 

With regards to reposting, you will find it will be very intermittent for a long time to come.

 

 

John

[chris stephensParticipant @chrisstephens63393]

Hi Pailo,

They are good, aren’t they?

It really is a tool that everybody should have, but I bet there are lots of old fogeys who will say that they don’t need one because they know how to thread cut because they having been doing the same way for fifty years. Poor deluded fools!

chriStephens

[Chris TriceParticipant @christrice43267]

I’m midway through making one as we speak.

[John Stevenson 1Participant @johnstevenson1]

Posted by chris stephens on 21/06/2011 23:27:31:

 

I bet there are lots of old fogeys who will say that they don’t need one because they know how to thread cut because they having been doing the same way for fifty years. Poor deluded fools!

chriStephens

 

 

 

I is one

Amazing that it hasn’t been thought of before and I use virtually nothing else now and i screwcut most thread I do as then are critical they have to be parallel plus the way the small TOS lathe works, reverse is 1/3 faster than forward, it’s a no brainer to do

John S.

[Hugh GilhespieParticipant @hughgilhespie56163]

Hi All,

Just finished my version of the flip up holder. It is pretty much as per Bogs / John S / Uncle Tom Cobleys design. My only tweaks were to make it so that it ticked the boxes for:

 

Uses insert tooling

Uses an existing 12 mm shank tool

Fits the S2 size QCTP on my Colchester which uses 20 mm square tooling.

 

The only modification I made to the original design was to make the locking bar thingy and its locating slot tapered with a 25 degree taper each side. This ‘SHOULD’ mean that you get more positive location when the tool is pushed down onto the taper during cutting. I don’t know if this is critical but it’s nice that there is zero side to side play when the tool is pushed down.

 

I alos used some Oilite flanged bushes for the pivot bearing – mainly because I had some kicking around. Probably overkill but they do look nice!

 

I haven’t tried it in anger yet. In fact, I have never cut a thread on a lathe so it will be interesting to say the least!

 

Regards, Hugh

[Chris TriceParticipant @christrice43267]

Funny how close some thinking is. I have some Oilite flanged bushes which I also considered except that my version is a little too small to include them so I dropped the idea and custom turned a pivot/screw. In all other respects (except the tapered seating – good idea) mine looks remarkably like yours. I’ll post photos when it’s done.

 

[BogstandardParticipant @bogstandard]

Hugh,

 

If you look at my original article, where John S came up with the idea of the block at the front to take the side loads, John suggested what you have made, and I personally thought that having the taper might not be the right way to go.

 

If you are using the non offset method for cutting, ie straight in, then no problems, as there would be equal pressures on either side of the taper. But if cutting using the offset method, either left or right hand, then the cutting forces are coming from one side or the other, and so the taper would tend to ride up the tapered block, so raising the cutting point off centre.

 

That was the theory behind it, and why a straight sided block was used. I never attempted what you have done, so never had the chance to test out the theory.

 

 

Maybe I was wrong to go the way I did, but if I was you, I would keep an eye out as the tool beds itself in and the pivot gets a little wear on it. That theory just might turn into reality.

 

A very well made tool BTW.

 

 

John

Edited By Bogstandard on 23/06/2011 22:49:23

[Hugh GilhespieParticipant @hughgilhespie56163]

Hi John and Chris T,

 

Thanks for the comments. My thinking on using a tapered seat was that if I used a square seating bar then it would need some clearance in the slot to prevent binding. As the locking bar is about half way between the pivot point and the cutting tip, any side to side movement at the locking point would be doubled at the tip, so with a 1 thou bar clearance, the insert tip could move by about 2 thou.

 

As I said, I have never actually cut a screw thread in a lathe so I don’t exactly have a wealth of practical experience to fall back on and I don’t know whether a potential 2 thou wobble matters or not. I must confess that I hadn’t considered using the offset method for cutting, all my thinking was based on going in straight which, as John says, means equal sideways loads and minimises the chance of the tool riding up on the taper. All I can do is try a few experiments both ways and see if there is a problem.

 

I chose the angle of 25 degrees to be big enough so that there is no possibility of the tapers binding together.

 

For info, the lock bar itself and the 20 mm tool shank are key steel – sort of EN9 – and I intend to heat treat these bits to harden them. I am also going to turn off the final couple of threads on the M6 cap screws used to hold the tool shank.

 

Regards, Hugh

[chris stephensParticipant @chrisstephens63393]

Hi Hugh,

I admire your faith in a flip up, especially when you have not even tried thread cutting, yet. The only trouble is you will not know how much better they are because you don’t know what to compare it to.

 

About sideways pressure binding, there should be none as the tool must be free to drop down to its cutting position before the next pass is taken. Once the cut is under way binding is not a problem. If the tool is not fully down under its own wait and needs the cutting action to force it down the first threads will not be correctly formed, this will lead to confusion when trying a nut.

When the tool is on the return traverse the tip only will lift about 2-3mm, which will not be enough to need all off your taper, although I can see why you would think it would be necessary.

 

You will find that when you cut a thread, by either straight in or offset top slide method, that the tool almost exclusively cuts on the left hand side. It is more like taking a normal sliding cut, to reduce diameter, than it is cutting a single “V” groove, where the tool does cut on both sides at once. To prove the point I have it in mind to make a different type of “flip up” where the tool rotates about the horizontal plane. It would have a stop to take cutting load but would be fee to rotate to the left when reversing the saddle. A light spring might be needed to bring the tool back to its stop when it is clear off the workpiece, but that would be a small price to pay to prove the point.

 

I hope you have fun learning to thread cut, you have the best tool ever for the job. If there is a minor criticism it is that you have to have a run-out groove or under cut, (something not needed with to old fashioned style of thread cutting) to save chipping the TC insert . As you get more experienced, and confident that you can reverse the lathe at the right point, the run-out can get quite small and be almost un-noticeable.

chriStephens

[Tony JeffreeParticipant @tonyjeffree56510]

Posted by chris stephens on 24/06/2011 12:23:58:

 

You will find that when you cut a thread, by either straight in or offset top slide method, that the tool almost exclusively cuts on the left hand side. It is more like taking a normal sliding cut, to reduce diameter, than it is cutting a single “V” groove, where the tool does cut on both sides at once. To prove the point I have it in mind to make a different type of “flip up” where the tool rotates about the horizontal plane. It would have a stop to take cutting load but would be fee to rotate to the left when reversing the saddle. A light spring might be needed to bring the tool back to its stop when it is clear off the workpiece, but that would be a small price to pay to prove the point.

 

Chris –

 

I think the flaw in this particular variant is that if there is any backlash in the leadscrew, when you reverse the spindle the tool would want to rotate to the right (i.e., against the stop) and would therefore not flip out of the way. So this would effectively be the same as the situation you would be in if the tool wasn’t pivoted at all.

 

Regards,

Tony

[KWILParticipant @kwil]

Chris

 

You would also need a second tool to cut left hand threads?

[Peter G. ShawParticipant @peterg-shaw75338]

Tony has raised something I have been wondering about.

 

My setup does indeed have backlash, do not know how much, but sufficient to have caused damage when I have reversed without backing out the tool. In this instance, can a flip up tool actually work?

 

Regards,

 

Peter G. Shaw

[Tony JeffreeParticipant @tonyjeffree56510]

Posted by Peter G. Shaw on 24/06/2011 15:43:45:

Tony has raised something I have been wondering about.

 

My setup does indeed have backlash, do not know how much, but sufficient to have caused damage when I have reversed without backing out the tool. In this instance, can a flip up tool actually work?

 

Regards,

 

Peter G. Shaw

Peter –

 

If there was absolutely no backlash in the leadscrew drive, you wouldn’t need the flip-up tool; you could reverse the drive without retracting and all would be hunky dory. The whole point behind the flip-up tool is that it allows you to reverse the drive in a machine that does have backlash. However, if you change the way it pivots from flipping up (as in the original design) to swinging left (as in Chris’s suggestion), it doesn’t give you the desired result at all.

 

Regards,

Tony

[chris stephensParticipant @chrisstephens63393]

Hi Kwil,

Indeed it would, but quite frankly that is a low priority. All of my various thread cutting tools have positive side rake for cutting RH threads, if I were to cut a LH thread I would need to make a new tool.

If you want a universal threading tool, you run the risk of not having the best tool for a specific job.

 

Hi Peter,

Indeed it would, do I sound like I am repeating myself? Anyway go for it, you wont regret the time spent.

 

Hi Tony,

The sideways rotating tool was a spur of the moment thought, not so much as an improvement on the Flip Up Tool(FUT) but more as a demonstration of cutting forces when threading. What you suggest might indeed be a problem but nothing that can’t be resolved if the will is there.

I suppose the degree of backlash in the leadscrew drive and the size of the run-out groove would play a part in any problems or cure thereof.

When(?) I get time to give the matter some thought I shall make one to see what happens. Remember that the first E in SMEE stands for Experimental, and without experiments we can only stand still.

chriStephens

[BogstandardParticipant @bogstandard]

Hugh,

 

I find that the clearance either side of my block is only a couple of tenths, if not less. Just enough to allow the swing up part to actually swing up and down without binding. You really do need to keep the side forces off the rear pivot point, and it is the front block that is the most critical part in achieving that.

 

 

Peter,

 

Have no fear of backlash. When I was trying this tool out, I actually introduced a fair amount by having the change gears loose, and all that happens on the runback is the tip of the tool raises a little higher. But if your machine does have a lot of inbuilt backlash, then I would suggest when the tool comes off the job and gets ready for another cut, simply give it a little bit more of a runup (maybe 1/4″) before it starts to cut. That will allow your gearing to sort itself out before getting down to work.

 

With regards to cutting left AND right hand threads with the same tool. I use the same tool for both, cheapo brazed threading tools from J&L, blue for non ferrous, red for ferrous. They are ground symmetrical, so cut both ways perfectly, but if cutting deepish threads, I have to grind a flat on the left hand side so that it doesn’t start cutting into the opposite side of the runout slot. I don’t normally have trouble with left hand threads, but if it is a small one, and I am cutting towards the end that has tailstock support, then I would narrow down the tool cutting face on the LHS as well.

 

I have found that in all honesty, people will try to make things just too complicated for the job in hand, maybe done to make themselves look more important.

Keep things simple, and if it works, stick with it.

Don’t make things complicated just for the sake of it or because that is the way it has been done since the world began.

There are usually easier ways for jobs to be done, especially if you are only doing one or two parts, and near enough is usually plenty good enough.

 

I actually have the rough idea for doing exactly the same thing as the swing up, but for internal threads, and you wouldn’t believe how easy it was to come up with the solution, and what an easy design it is to make (if it works of course).

 

When I have some more time to myself, I will get it made and developed, and shown to the world for free. That is if someone doesn’t beat me to it first.

 

 

Bogs

Edited By Bogstandard on 25/06/2011 11:38:41

[chris stephensParticipant @chrisstephens63393]

Hi Bogs,

I agree that an internal tool would be quite easy, in principle, I can foresee slight problems on medium size threads such as the 6-10mm range. I suspect that the threads would have to be somewhat larger than the pivot for the cutting tool.

If I make one I shall not show it here till you have shown yours first, as the idea is yours, you deserve any credit.

I hope your current problems resolve themselves satisfactorily soon, so you can get back to “work” , we need more people like yourself who are both skilful and original thinkers who are not hide bound by convention.

chriStephens

[BogstandardParticipant @bogstandard]

Don’t wait on me Chris, your ideas might be better than mine, plus it could be ages before I can get to it.

 

There are always more ways to skin a cat, usually one easy way, then lots of difficult ones. The secret is finding the easy one, so that everyone can have a go at it.

 

All the people who come up with good ideas and make them available to the public should be commended,

 

Unfortunately, a lot of them are so complicated that it puts them beyond the reach of the average metal murderer, and so maybe only a couple of dozen machines or whatever is shown actually get made.

 

By average, that means we don’t have a 5 axis CNC work station, or a spark eroding machine at the bottom of the garden, and never will.

 

John

[chris stephensParticipant @chrisstephens63393]

This message is primarily for Bogstandard, but the rest of you might be pleased to hear that I have successfully made an internal version of the flip up threading tool. No pictures just yet and probably not till after the next “work on the table” at SMEE in September.

At present it only works down to about 12mm, but I think that is good enough for most purposes.

At present it appears a little bit rough as it is only a “proof of concept” prototype, but half an hour with a fine file will soon change that, then it will be up to the standard of appearance expected, from me, by SMEE.

chriStephens

 

[BogstandardParticipant @bogstandard]

Well done Chris.

 

Working down to 12mm, to me, sounds just fine. Normally, below that sort of size, people will use taps anyway, unless of course you don’t have one to hand.

 

I await to see your design, and see how close it comes to what I have thought up. If it is better than mine, maybe I can pinch the idea and give it a good dose of looking at and maybe come up with something that will go down to say 6mm (using 1/4″ tooling), which is what I was basing mine on.

But I do have grinding facilities that allows me to make tiny cutting tools. If you need any making to maybe get yours to cut smaller, don’t be afraid to ask. But I suppose that facility would be available to you thru SMEE.

 

Isn’t it a great feeling when things turn out right and work as expected.

 

Again, very well done.

 

John

[wheeltapperParticipant @wheeltapper]

Cant wait to see that one Chris, I’m more than happy with my external one.

 

Roy

[chris stephensParticipant @chrisstephens63393]

Hi Bogs,

Thanks or your kind words and offer but I could grind up my own if needed. I did not grind the tool, as I had a few commercial ones to hand. The ones I used are similar to the ones at the top of the page; ;http://www.ifanger.com/fileadmin/Webmaster/Produkte/B_01/020104_Gewindestahl.pdf

 

I would be glad to hear your opinion of my effort, and of course there would be room for improvement, two heads are often better than one. Everybody’s experience is different, so everybody has a different way of doing things, even if the basic principle is the same.

In the next few days I will send a PM with details of the way it works, once I have checked to see if there are any problems that need sorting. Saves “egg-on-face” syndrome.

chriStephens

PS although SMEE has a very well equipped workshop, I have not yet found a need to use it yet, as I have most of what I need to hand in my own Engineerium.

 

[adyParticipant @ady]

It’s one of those things that makes you wonder why no one else has thought of this in the last 100 or so years ?

—————————————

 

That’s actually a great question.

 

My own answer is this:

 

Reversible motors? who made them?

Even a dog clutch was virtually non-existent, when did the ML7 have one?, Drummond M series lathes were made by Myford and were for Destroyers in WW2 and were expensive but when your country is at the edge of armageddon who cares about the expense.

 

So reversible motors were almost non-existent and even dog clutches were a luxury.

 

Sparey never said a thing about dog clutches in his amateurs lathe, not a button.

[adyParticipant @ady]

Even nowadays these products struggle.

 

Here’s one on fleabay which has been RELISTED

I couldn’t believe it when no-one bought it the first time round.

(A nice schaublin went for less than 50 quid a couple of days ago too.)

It’s got a multi direction dog clutch, an offset tailstock and was aimed at people who were capable of prototype work.

 

“perhaps the aim was to create a new, high-quality brand aimed at the experimental and top-end amateur sections of the market. In this sense the lathe did succeed …”

http://www.lathes.co.uk/edgar/

 

Apparently even nowadays folks just aint interested.

Edited By ady on 07/07/2011 01:43:53

[BogstandardParticipant @bogstandard]

Chris,

 

I am a great believer in taking advice, even if it comes from a raw beginner, almost everyone has a chance to chip into my designs if they feel the need to. Whether I act on that advice is another thing, but it does give the sharer a feeling of actually contributing and maybe helping in the final design. Plus they always get the due recognition if their idea is used, or why it wasn’t used is most probably shown in the post as well.

 

No one knows everything, although some people think they do, but until they prove to me they too can walk on water, they don’t. So why not take advantage of the people about you, they do have a lot to contribute.

 

Like yourself, which I have read in other posts by you, I don’t charge anything for advice, or in fact anything that I do, the only proviso being that if they too can help someone, they do it freely and without charge. To me that is what forums and discussion groups are all about.

 

It always leaves a bad taste in my mouth when someone does a post about making say a small and simple engine, showing no dimensional details at all, only to find at the very end, ‘you can buy the plans from………………’

I always have a feeling to do the same post, but showing all the dimensions and plans as I go along.

 

To me, sharing and helping for free is what it is all about.

 

BTW, just after the swing up toolpost became public and was proved to work, a German chappie started to advertise them for sale, but to a different design.

 

I have done a very rough sketch of his method of doing it, if anyone wants to give it a go. In fact my design for the internal one is very loosely based on it.

 

 

 

John

[Ken StraussParticipant @kenstrauss65445]

I’m curious about the German design that you mentioned. Any links to an advert or other details?

[Author]

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