Coffee In My Sugar: A Scissor Knurler / Lathe Question

[mikey]

Yeah, "bank" is just slang for very expensive, which that thing is.

Here is what the OP is thinking: I'll be using the lathe for prototypes / small runs of 6061 BMX pegs 31mm-37mm give or take.

He won't need a big lathe to knurl with but for a production situation he is better off with something that can pass the working stock through the spindle bore.

 

[Aukai]

I don't have my knurler yet to say how it will perform on my PM 12/28 which has a 1.5" through bore, or if that machine is even a consideration for use. UPS Ground

 

[davidpbest]

I bought a scissors knuler from Shars, and after about 2 hours use, I concluded it wasn't precise enough for my needs. The knurling wheels were sloppy as was the scissors joint and I could not get a decent knurl out of it in 316 stainless. I thought for a while about doing a serious rebuild/modification to it like this, but then decided it was just too much trouble to make the wheels easily removable for different knurl patterns.

So I broke down and bought the Eagle Rock K1-44 based primarily on this review. I could not be happier with it.

I run a PM1340, and the Eagle Rock is a good paring for this lathe - this is the one I bought. I have added several different knurling wheels sourced from MSC.

Here's an example of the Eagle Rock on my PM1340 in action with 316 stainless.

And the results:



It is important to get the OD dialed in properly for the given knurl pitch. Attached is the spreadsheet I use to figure the proper OD once the pitch is known. Maybe this will be useful to someone.

 

[Titanium Knurler]

I bought a scissors knuler from Shars, and after about 2 hours use, I concluded it wasn't precise enough for my needs. The knurling wheels were sloppy as was the scissors joint and I could not get a decent knurl out of it in 316 stainless. I thought for a while about doing a serious rebuild/modification to it like this, but then decided it was just too much trouble to make the wheels easily removable for different knurl patterns.

So I broke down and bought the Eagle Rock K1-44 based primarily on this review. I could not be happier with it.

I run a PM1340, and the Eagle Rock is a good paring for this lathe - this is the one I bought. I have added several different knurling wheels sourced from MSC.

Here's an example of the Eagle Rock on my PM1340 in action with 316 stainless.

And the results:

View attachment 312793

It is important to get the OD dialed in properly for the given knurl pitch. Attached is the spreadsheet I use to figure the proper OD once the pitch is known. Maybe this will be useful to someone.

Very nice, and thanks for the spreadsheet.

Dorian sent me a live worksheet like this:

Once it is downloaded and activated you just punch in the appropriate numbers and it calculates the missing data. I tried to attach the worksheet but got the following message:

...so I am unable to pass it on but it has turned out to be a handy tool for me. If anyone can figure this out I am happy to try to re-send the worksheet.

Mike

 

[mmcmdl]

I don't have my knurler yet to say how it will perform on my PM 12/28 which has a 1.5" through bore, or if that machine is even a consideration for use. UPS Ground

Shucks Mike . I sold my Eagle Rocks years back on the bay . If I only woulda known . The Eagle Rocks were good tools . I made a scissor knurler years ago out of Almar which was my scissor type keeper . I have a tangential knurling tool which works absolutely great but has a 1" max capacity . As far as the regular old push type knurls , I have more than a few .

 

[darkzero]

That Dorian calculator is pretty cool with all the detailed info it provides. I have a basic knurling calculator on my phone (all I need).

 

[davidpbest]

If anyone can figure this out I am happy to try to re-send the worksheet.

Mike

Open the spreadsheet and see if you can save it as an XLS file instead of XLSX. That might work, or it might kill the features of the spreadsheet, but if you can get it saved as .XLS, you can post it here (or at least I was able to). On my system, the XLS format is a drop-down as shown below:

 

[Titanium Knurler]

That Dorian calculator is pretty cool with all the detailed info it provides. I have a basic knurling calculator on my phone (all I need).

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Thanks Will, that is very nice, straightforward calculator.

I imagine the Dorian calculator may be geared toward the pros. For example, someone that is straight knurling on the end of a rod to engage a knob, handle or wheel; someone that actually needs to predict the growth of the knurling pattern. I think most hobby guys are primarily knurling for decorative or grip purposes where we don’t really need to know such things and just want to avoid double tracking and get a nice looking knurl.

 

[Titanium Knurler]

Open the spreadsheet and see if you can save it as an XLS file instead of XLSX. That might work, or it might kill the features of the spreadsheet, but if you can get it saved as .XLS, you can post it here (or at least I was able to). On my system, the XLS format is a drop-down as shown below:

View attachment 312805

Thanks! I will give it a try.

 

[Cadillac STS]

LooseNut, just for the sake of completeness I thought I would throw in some info on the three wheel type knurler that DarkZero mentioned. The advantage of this type of knurler is that you can apply a tremendous amount of force to the three knurl wheels without putting any lateral force on the spindle/spindle bearings or displacing your work. Because of this you can knurl very deeply in one pass and you can knurl thin(.085”) stock if ever needed. I am not sure if the scissor or clamp-style knurlers will work on real thin stuff.

I think this style would work well for your intended job since it would put a deep knurl pattern on your 6061 with a single pass and with minimal stress on your dream lathe. However, these knurlers are expensive and there is no used market for them; I looked for months and couldn’t find a single one on eBay or CL. I eventually broke down and purchased a new one from Dorian. Another disadvantage for you is that the tool post shank is large on these tools. To get a three wheel knurler to handle up to 1” stock the shaft is .75” and to do 1.5” stock the shaft is 1”. I had to modify my tool holder on my PM 1236-T to get the 1” shaft to fit and to align with my lathe center.

Anyway, here are a couple shots from the Dorian cotologue and some shots of a project I just finished where I put a deep diamond knurl pattern on a 1.25” piece of O1 tool steel in one pass. BTW, the PM 1236-T had no difficulty with this job. Knurnling does not seem to require a lot of HP so I don’t think that will be much of an issue for you and your new lathe.

Good luck with your project and keep us posted,
Mike
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Wow this is begging for a DIY project using a 3 jaw chuck mounted in the tail stock with the 3 jaws modified to hold knurl wheels. Slot the end of the jaw and drill for a hardened pin for the 3 knurl wheels.... Maybe small 3 jaw mounted on a stick to mount in the QCTP even easier...