Help with information on this tool

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atunguyd
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Joined: Tue Oct 20, 2009 9:39 pm
Location: Durban South Africa

Help with information on this tool

Post by atunguyd »

Hi wonder if anyone can help me? Today at a pawn broker I saw a cut knurl tool. It had not price so I asked the shop keep who said he was not sure as it was on his "old system" he eventually just said I could take it for the equivalent of about $20. I think I got a great score here but not really sure. Also I am totally unsure n how it actually gets used.

Can some help identify this tool? It has "Zeus 210" engraved on it so it looks like it is from Germany.

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atunguyd
Posts: 199
Joined: Tue Oct 20, 2009 9:39 pm
Location: Durban South Africa

Re: Help with information on this tool

Post by atunguyd »

Just following up incase anyone else ends up with a similar tool.

Turns out this is a cut knurler manufactured by a German company Hommel Keller. A very expensive tool (about $1300) if bought new.

Someone on the net sent me the original instructions and I found the local agents here in South Africa who sold me a set of new wheels for it as the old ones were in poor condition. The tool works perfectly once the directions are followed and getting a perfect knurl is both easy on my skills and my lathe. Looks like this one tool will knurl diameters from 10mm right up to 250mm so it is much more versatile than a clamp knurler. It also has teh benifit apparently that the knurling being cut as opposed to formed will not increase the diameter of the workpiece.
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Harold_V
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Re: Help with information on this tool

Post by Harold_V »

Well done!
I'd enjoy seeing a picture of a cut knurl. I've never seen the tool, let alone use one.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
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GlennW
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Re: Help with information on this tool

Post by GlennW »

Any chance that you could post an image of it in use to show how it is oriented in relation to the stock?
Glenn

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atunguyd
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Joined: Tue Oct 20, 2009 9:39 pm
Location: Durban South Africa

Re: Help with information on this tool

Post by atunguyd »

Here you go Harold.

This was on a scrap piece of aluminum that I put into the 3 jaw and used as is. Didn't even turn it concentric first so it had about 0.1mm runout to start.

The city itself was no different to any normal court in the lath with a hss tool. No pressure required at all and it cut on one pass.

On the weekend I will experiment with doing it properly (ie turn down the bar first and spend a little more time getting the tool adjusted.

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atunguyd
Posts: 199
Joined: Tue Oct 20, 2009 9:39 pm
Location: Durban South Africa

Re: Help with information on this tool

Post by atunguyd »

Glenn sure I will this weekend.

Basically it mounts in the lathe tool post with that flat silver part aimed towards the head stock. The wheels are mluntrd on an angle the post they are on can be turned and locked into place. The silver plate has markings to indicate what diameter you are knurling they go from 10mm to 250mm.
Once this is set you approach the the workpiece and have one wheel above and the other below the centerline. The adjustment screws on either side rock the head so that you can get both wheels to make contact with your part. Once that is done the x axis is plunged in by the tooth depth plus 0.1mm. In my case that is 0.5mm.
The lathe z axis is engaged and the cut starts and stops when you determine the knurl length is achieved.

Apparently this is diameter agnostic and if the knurl is not deep enough you can come in for a second pass and it will find its pattern again.

I made retaining covers (aka washers) for it tonight as you can see below.
I will get some hex counter sunk screws this week too.

Next is to make new adjustment screws, the previous owner bent these ones.
Such a precious tool requires a lot of love [emoji23]

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atunguyd
Posts: 199
Joined: Tue Oct 20, 2009 9:39 pm
Location: Durban South Africa

Re: Help with information on this tool

Post by atunguyd »

Just realised that now that I have a part number I could search for more info and the manufacturer has a video on how it is used.

https://youtu.be/ZcOYYrtwAks

Mine I think is an older model of this one as my knurling posts need to be manually adjusted each by hand (not a screw to move both together in unison). But really just about the same.

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GlennW
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Re: Help with information on this tool

Post by GlennW »

Since it is cutting the knurl, Is the pattern determined by the carriage feed?
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!
atunguyd
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Re: Help with information on this tool

Post by atunguyd »

I dont think so Glenn, but within reason. I guess if your Z travel is so high that the tool moves on before the part has completed one revolution then perhaps that would distort the pattern. The bottom wheels cuts the one half of the pattern and then the top wheel cuts the next half and since they are so close you only need about 30 degrees of rotation to get the pattern to form.

I battle to get my head around how it works as there is a lot happening with the part and the two cutting tools rotating and then all three angled relative to the others, from what I have read it is better to think of it as hobbing as opposed to cutting. Not that that helps my brain as hobbing is also a bit of an enigma to me too.

What I can tell you is that it does on the surface look like a way better way to create knurls, assuming you are not purposefully trying to enlarge the diameter of the workpiece (like in the case of a pin that is loose). Less demand on the machine than using a traditional push knurl tool and way more capacity than a clamp knurler (although I cannot find a use case for knurling a 10 inch diameter bar - at least I can say that I am equipped to do so).

I saw this tool mentioned on the gadget builder website years ago here https://gadgetbuilder.com/Cut_Knurler.html and I always wanted to try build one but time and trying to source the wheels held me back. When I saw it at that pawn broker and was told the price I realised that the machining gods want me to have one.
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Harold_V
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Re: Help with information on this tool

Post by Harold_V »

Like you, I'm not convinced that's truly a "cut" knurl. While I'm not familiar with the tool in question, it appears to me that it doesn't cut, but displaces, the chief difference being it's done strictly at the corner of the wheels, greatly reducing knurling pressure. I couldn't see any chips in the video.

If I'm wrong, I stand to be corrected, and I suspect you'll find chips resulting from the cut (most likely very fine, truly swarf), and the diameter of the knurled piece will have not changed. Is that how you found it to be?

I suspect that the adjustment between wheels is to compensate for any potential error in pitch, to eliminate the possibility of splitting the knurl. The typical plunge type knurling tool adjusts for that by side movement.

Thanks for the pics and further description. Looking forward to further input.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
atunguyd
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Joined: Tue Oct 20, 2009 9:39 pm
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Re: Help with information on this tool

Post by atunguyd »

Harold_V wrote: Thu Jun 09, 2022 1:48 am Like you, I'm not convinced that's truly a "cut" knurl. While I'm not familiar with the tool in question, it appears to me that it doesn't cut, but displaces, the chief difference being it's done strictly at the corner of the wheels, greatly reducing knurling pressure. I couldn't see any chips in the video.
There are chips but quite small (that video is also pretty low quality). It is an interrupted cut so I would also expect the chips to be very small. This vide shows the action a bit clearer (the end of the video shows the use of the tool - the entire video is the making of it)
https://youtu.be/vj8pp3YJijg?t=747
Harold_V wrote: Thu Jun 09, 2022 1:48 am If I'm wrong, I stand to be corrected, and I suspect you'll find chips resulting from the cut (most likely very fine, truly swarf), and the diameter of the
knurled piece will have not changed. Is that how you found it to be?
Yes the diameter was actually in my case reduced however my first test as I said was with a scrap bar that I did not turn down first - I will do more testign on the weekend and report back.
Harold_V wrote: Thu Jun 09, 2022 1:48 am I suspect that the adjustment between wheels is to compensate for any potential error in pitch, to eliminate the possibility of splitting the knurl. The typical plunge type knurling tool adjusts for that by side movement.
Agreed - since there are two cutting wheels the alignment needs to be perfect to ensure that they both cut to the same depth and thus avoid a lopsided knurl (if that is the correct terminology?).
Also the spacing between the wheels needs to be setup so that it matches the diameter of the workpiece and in turn the angle of the cut (perhaps this is related to the relief and cutting angles. Part of the setup involves touching the wheels onto the workpiece and noticing the cut that is made in the workpiece - the intention is that with such a light cut the resulting pattern should be 1/3 the width of the wheels. If it is not then the spacing between the wheels is adjusted to achieve this.
It may be cleared in the instructions which I will now attempt to attach to this post. Apologies for the size of the below image but the text is small and if I try to reduce it then it cannot be read.
https://ibb.co/NStYgd7
Harold_V wrote: Thu Jun 09, 2022 1:48 am Thanks for the pics and further description. Looking forward to further input.

H
You're quiet welcome Harold - and can I please say that I am quiet excited to be able to provide information to you. I have indirectly received a vast amount of knowledge from you in this forum and being in a position where the student can teach the master so to speak, I find really titillating.

Some more information on this type of knurling and instructions to build your own - https://thebloughs.net/cut-knurling-too ... -assembly/
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GlennW
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Re: Help with information on this tool

Post by GlennW »

I found this, so now it makes a bit more sense being able to see the orientation of the wheels to the part. It appears that there is more contact than just the corners of the wheels to create the pattern.
knurl.jpg
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!
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