Knurling tool

[Neil WyattModerator @neilwyatt]

Just to confirm RDG don't advertise with us.

Neil

[SteviegtrParticipant @steviegtr]

I did a couple of video's of the problems i had with the cheap one i bought & how i got it better. But still want to make a nice one. The 2 i narrowed down to from comments etc is. The Graham Meek one or the Hemingways kit sensitive one.

Steve.

[ZanParticipant @zan]

Stevi. , o had one like that, but the arms were too weak with little metal either sine of the adjusting screw. They bent in use when the screw was tightened. Useless went in the bin. Got a really decent one engineer built, from a secondhand stall at donny

Edit. The poor autotype……

Edited By Zan on 05/08/2021 21:23:55

[Graham MeekParticipant @grahammeek88282]

Of all the knurling tools I have used in my profession, the Marlco has been the the Roll-Royce. However the problem with all scissors type knurls is that the Load applied is centrally displaced about the Fulcrum point and the Knurls point of contact.

Having the Knurls and the Fulcrum so far apart allows play to creep into the system. To control this side cheeks are added or in the case of the Marlco guide slots. This refinement is what keeps the knurls directly above one another, and does not allow them to displace due to the helical thrust forces imposed by the design of the wheel.

Displacement of the knurls is easily seen as one knurl usually takes precedent and the knurl is anything but a diamond pattern.

To move away from the long pair of arms, the 0-50mm Knurling Tool that I designed has a slight leverage advantage when it comes to applying the load required for the knurling operation. Because the arms are shorter the lateral displacement is less of a problem and the Keep Plate checks any side play. Further the arms are of a more robust design with no chance of flexibility or weakness.

In use the knurls are brought into contact over the centre of the revolving work piece, (which should always be skimmed, the corner chamfered, and I never use just bar stock), using the knurled knob. The Knurling tool is then moved off the workpiece and the knurls adjusted (about half a turn more with my knurls), self-act feed is engaged and the lathe does the rest.

An additional pass with further adjustment might be needed, but once a feel for the knurls has been acquired then I can usually produce a knurl in one pass. Material type does have a bearing on this adjustment, and the number of passes that are required.

Lastly as regards the eccentric lever on the Marlco tool. I was taught to use this at the end of the knurling pass to release the pressure on the knurls and allow the tool to be moved off the work. Using this lever alone allows multiple items to be produced once the main adjustment has been set.

Regards

Gray,

[SteviegtrParticipant @steviegtr]

Well Gray may i thank you for the in depth workings of your design. It has a slight resemblance to Arny's hand . From the terminator film.

Looks like i have a project.

Steve.

[bernard towersParticipant @bernardtowers37738]

Made the Hemingway/Marco version during lockdown, what a revelation I thought my knurling were passable before but now their pretty to look at and repeatable which is useful as generally there’s more than one on most jobs. Nice kit to make.

[SteviegtrParticipant @steviegtr]

From some of the comments i have had i guess i have to eat humble pie. Yes cheap & cheerful is not always the best way to go. I once built a porsche 911 turbo replica because i could not afford the real thing.

I have a bandsaw & pillar drill by Aldi as some will know if watched my youtube video's. They work as expected, not perfect but get by.

So back to the knurling tool. I am just uploading a review of the cheap one i bought. I will be doing a in depth review & build of the one i am about to embark on. God knows how long it will take me to make. I am leaning towards the Hemingways sensitive version. Simply because it comes with all the stock required for the build. I did price up to make the Graham meek design & the stock comes to pretty much the same, if not more due to the min lengths of stock you have to buy. Admitedly i would have some over for other projects.

Steve.

[SteviegtrParticipant @steviegtr]

Well guys & gals, for anyone who wants to buy a cheap & cheerful knurling tool. Here is the conclusion i came to. Some of you will say i was not using it correctly. But really it is not fit for purpose.

I know there are certain members on here that do not want to be my bestest pal, but this is not worth buying.

Steve.

Not so good knurling tool

[Neil LickfoldParticipant @neillickfold44316]

Cheapy tools can sometimes turn into an apprentice training exercise over a few weekends to fix properly. Sometimes you just end up with the hardened or the more difficult parts to make, and then completely remake or find some other way to make the tool to be functional as intended. Sometimes things need spacers, or clearances for pivoting , or pivoting washers, etc

[JasonBModerator @jasonb]

Did not bother to watch it all Stevie so you may have figured it out.

The other two holes in the "tee" piece are so the arm positions can be adjusted to get you close to size and then the top screw is used for final adjustment that way the top arm does not end up pointing down much when knurling small diameters.

Set height by toolpost adjuster so bottom wheel just contacts when hanging down, then set top wheel to just contact with it pivoting in a suitable hole. Move away from work to tighten tool and then advance into rotating work. There is sufficient movement of the lower arm to allow it to move up for the depth of the knurl. 

Maybe it's not the tool that is "not fit to use"  

Although the 3/8" shank may fit a Myford it is described as an industrial tool and really suits a bigger machine where the shank can be set at a better height but you have fallen into the trap of buying bigger tools before and had to alter them.

Edited By JasonB on 07/08/2021 07:42:15

[derek hall 1Participant @derekhall1]

Some years ago I made the "basic" knurling tool from Hemingway Tools and I use it with straight knurls as I prefer that to diamond. This tool was easy to make and use, gives great results and is a very worthwhile addition to my workshop.

Regards

Derek

[Anthony KnightsParticipant @anthonyknights16741]

This is the knurling tool I made for my mini-lathe using a dedicated tool post.

[Peter BaverstockParticipant @peterbaverstock32334]

I have the same tool and agree the quality is poor.

I brought the lower wheel up to the underside of the work piece using the tool holder,then screwed down the top wheel.The results were as good as i have seen on any youtube video.

Regards,Peter.

[Clive FosterParticipant @clivefoster55965]

An under-appreciated benefit of the hand squeezed "nutcracker" breed of knurling tools is good stability when in cut.

I imagine its due to having two wheels on one side which obviously fights the tendency of a two wheel clamp style knurling tool to run over centre and past the workpiece. Even a Marlco can do that if careless about taking out backlash. How do I know?

I suspect there are other subtle force balancing aspects involved. Can't hurt that the pivot is on one size of the job but the squeeze handles are on the other so squeezing also helps stabilise things side to side.

Certainly my commercially made one is not exceptionally rigid. The arms are simple folded metal and the size setting bar quite slender. Works well tho' despite the size adjuster being a bit hit and miss. I never use it. Observation and squeeze feel does the deed.

I've often wondered if the same concept could be adapted to a lathe mounted version. Bottom arm on some sort of pivot'n slide mount so the lower knurls could take up the correct position on the job. Just lean on the top to cut. Flip top over to extract job.

Drawings for a duplicate of mine were published in Model Engineer dated 29 January 1999.

A similar, heftier device designed by Walter Burton was published in Popular Mechanics May 1965. Google books finds it at **LINK** which drops you into the middle of the article.

https://books.google.co.uk/books?id=buQDAAAAMBAJ&q=knurl#v=onepage&q=knurl&f=true

Or free downloads of complete editions Popular Mechanics can be found quite easily. Grabbing multiple years is not advisable if you expect to actually do anything in the next decade.

Clive

[SillyOldDufferModerator @sillyoldduffer]

Bit late in the day, but choice of knurling tool depends on what the knurl is for, and how many are needed.

In my utilitarian workshop, I mostly make things for practical reasons. I'm not into fine models, and rarely care about decorative qualities, because what I make rarely needs to look good. I paint to prevent corrosion, not to improve the aesthetics.

Knurling is done decoratively and/or to improve grip. Decorative knurls have to be consistent because the eye is so good at detecting flawed patterns. Cut knurlers are the go to tool for manufacturing these in quantity with minimum rejects. Bump knurlers are fairly consistent but a bigger stiffer lathe is needed than most hobbyists own. Scissor knurlers allow small machines to produce workmanlike knurls, but they're not particularly consistent. There's a bit of a knack to using them, and I wonder how many poor results are blamed on the tool rather than the operator. Maybe psychology kicks in: the beginner having failed to get acceptable results from an inexpensive tool leaps to the conclusion the tool is at fault. No excuses when the expensive replacement arrives: the learner has to learn how to use it, and does!

Consistency isn't important if the knurls only purpose is improving grip. More important that the knurl be blunt to reduce abrasion. As even well-made knurls on heavily used tools damage the operator, knurls are discouraged in industry. Anyone who doesn't believe me is invited to ride a push-bike fitted with knurled metal handles along a bumpy country lane!

Dave

Edited By SillyOldDuffer on 07/08/2021 10:00:55

[VicParticipant @vic]

Cut knurling seems to produce a better result.

https://youtu.be/vj8pp3YJijg

Edited By Vic on 07/08/2021 11:18:08

[Gary WoodingParticipant @garywooding25363]

These were done with my clamp-type tool. Examples in aluminium, brass, MS, SS. and silver steel.

Edited By Gary Wooding on 07/08/2021 14:44:29

[SteviegtrParticipant @steviegtr]

Posted by JasonB on 07/08/2021 07:11:48:

Did not bother to watch it all Stevie so you may have figured it out.

The other two holes in the "tee" piece are so the arm positions can be adjusted to get you close to size and then the top screw is used for final adjustment that way the top arm does not end up pointing down much when knurling small diameters.

Set height by toolpost adjuster so bottom wheel just contacts when hanging down, then set top wheel to just contact with it pivoting in a suitable hole. Move away from work to tighten tool and then advance into rotating work. There is sufficient movement of the lower arm to allow it to move up for the depth of the knurl.

Maybe it's not the tool that is "not fit to use"

Although the 3/8" shank may fit a Myford it is described as an industrial tool and really suits a bigger machine where the shank can be set at a better height but you have fallen into the trap of buying bigger tools before and had to alter them.

Edited By JasonB on 07/08/2021 07:42:15

Hi Jason, today my Son came round to see me. He saw the knurling tool that i posted on to youtube. His 1st comment was Dad, the one i saw on youtube was massive. I said no that is the one i posted.

You said it was too big for my poltry Myford.(transposed). It is dinky. It is made for a small lathe like mine & i guess yours. The jaws are centre to centre 2" long. The Heminways sensitive one i am just starting is much larger than this one. I do not know why you support some not so well made imported, far eastern tools & continually belittle me for trying to point out the shortfalls of such pieces of equipment.

I will be doing a complete build video of the Hemingway to the best of my poor ability, I just hope some will like what i am going to do. Sure you can slag my work,.

But you must remember i am an Electrician by trade . With knowledge of many things & a master of none.

The description of being a industrial tool is a typical Chinese proverb. 

Buy my item best , special, long life, hardness, bull—t.

Steve.

Edited By Steviegtr on 11/08/2021 03:11:00

[JasonBModerator @jasonb]

Stevie, most of what I said in that post was how to set and use that tool correctly, at least if you set it up and use as intended you will be in a better position to say if it is rubbish or not. As you did not have it set correctly who knows where the fault was?. I think RDG even supply a shorter spring with it for when the arms are positioned closer together. Nowhere is I say it was good and would work, just to at least give it a fighting chance by using it correctly.

Fitted with smaller spring and arms moved closer together.

Your biggest problem will be having the range of tool post height adjustment to set it properly as unlike the similar priced one they sell as for the myford it does not have fully swinging arms. RDG even say it will fit some myfords depending on toolpost and as you have had toolpost "issues" in the past you may not be able to get the range of movement of the shank. I have that one in my link and it works fine for me even with short arms and the adj nut near the working end..

Your other problem with it seemed to be adjusting the nut close to the chuck, I and at least one other poster have said to do it away from the chuck and then advance the tool, This is simple safety advice but if you are happy putting your hands near the moving chuck then that's fine with me.

Crisp enough for me both 20mm steel EN1A

 

Edited By JasonB on 11/08/2021 09:46:43

[JasonBModerator @jasonb]

To give you the benafit of the doubt I just watched it all.

At 30secs in you say "Unless I'm mistaken"

At 5.30secs in you say "Forgive me if I have something wrong"

So just pointing out that you were mistaken and had something wrong.

You then have 14mins of video "correcting" an problem that doe snot exist if the tool is used correctly. Even after that you could not get it to close down to the 7mm min dia that you mention it should do

What I will defend is tools being used incorrectly and the tool then getting the blame. Could still be a pile of junk but at least it can have a decent review. Bit like watching a car review and moaning about poor performance only for the driver to have left the hand brake on.

As my tool seems to work with short arms, sideways movement and the nut in the same place as yours then those issues can be ruled out of the design which just leaves build quality or user.

[bernard towersParticipant @bernardtowers37738]

Hemingway sensitive tool just after building, lower is 1a upper is 316

[SillyOldDufferModerator @sillyoldduffer]

Posted by Steviegtr on 11/08/2021 03:07:27:

Posted by JasonB on 07/08/2021 07:11:48:

…

Maybe it's not the tool that is "not fit to use"

…

…

I do not know why you support some not so well made imported, far eastern tools & continually belittle me for trying to point out the shortfalls of such pieces of equipment.

I will be doing a complete build video of the Hemingway to the best of my poor ability, I just hope some will like what i am going to do. Sure you can slag my work,.

But you must remember i am an Electrician by trade . With knowledge of many things & a master of none.

…

With respect Steve, perhaps the problem is you! No shame in that, because everyone has to start somewhere, but in engineering it's never good to rush to judgement before understanding the problem.

Poor results in the workshop are due to Tools, Material, or the Operator, usually in some new situation. Of these the biggest problem is the operator, because he is responsible for planning the job, choosing materials and tools, setting machines up, and optimising feed-rate, depth of cut, cutting speed and much else. It's not easy, requiring a steady hand and applied judgement. Learners cannot assume tools 'just work', they have to be used appropriately, which comes by reading, training, and practice. Learning has to be approached with a degree of caution. Perhaps the worst training material available to the home machinist are the Internet videos made by amateurs who don't properly understand machining yet. Lots of good machining advice on the internet, but also far too much third-rate junk: videos just as flawed as the cheapest, nastiest, Chinese tool. Over-confidence is no substitute for skill.

I'm on the forum to learn and to share what I've learned. Happy to be told whenever I get the wrong end of the stick because everyone on the Forum benefits from the correction. It's not about my ego and fantastic* work! For me the forum is about improving what Model Engineers know and do. Better for posts to be politely honest, rather than agree with SillyOldDuffer's latest faux pas in hope of sparing my delicate feelings!

Doesn't help when bad workmen blame their tools. Leads to beginners fretting about 'quality' and flapping around the second-hand market when they would be better off learning for themselves by cutting metal.

Anyone who thinks I'm wrong about anything I say on the forum is free to say so, Please do, if the explanation is good, I should change my foolish ways! If it's any consolation, I've lost count of the number of times Jason has put me right. And he's not the only one, blush. Done me the world of good.

Dave

*Fantastic can mean 'extremely good', or 'absurd, crazy'. Readers choose which applies to my efforts, not me.

[not done it yetParticipant @notdoneityet]

Don’t you just luuurv you tube. Anyone can put up videos, give reviews, etc.

Lots do it as ‘influencers’ for some really dodgy products.

Let’s face it these people are just trying to earn loads of money for bulling-up a product.

It takes experience and skill/expertise to make good honest videos. It also takes careful analysis, to sort out the good from the bull excrement.

I might look at Steve's videos, but whether I agree with what (and how) he has done it, I mostly keep to myself (not always, mind).

The first thing I look for, when viewing you tube reviews, is whether the person is trying to promote a product – trying to be a slesperson; the second is the ability of the tuber – an example might be someone milling, using a Jacobs type chuck to do side-milling, which immediately relegates them to rank amateurs.

[not done it yetParticipant @notdoneityet]

As an aside.

I also note that my post where I said (very honestly) that RDG were getting a good ‘going over’ has been removed.

That was an accurate posting on my part. The truth. Truth is obviously something that some cannot live with. Just quietly removing the post indicates something to me. I wonder, now, whether the other post which was not too favourable to that company has been qietlly removed or “adjusted”.

Do we have a lover or mate of RDG among the moderators?

[David George 1Participant @davidgeorge1]

Here is a video of my clamp type knurling tool. It has an additional bit that the rolled are offset to the left and so you can get nearer to the chuck jaws.

As I said previously if anyone wants a copy of the drawings just drop me a message.

David

[Author]

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