# Bump straight knurling tool



## cascao (Jan 15, 2018)

After making a scissor knurling tool, I become intersted in making a straight knurling tool since it:

> is greath when you need transmit torque between a steel shaft and a plastic wheel.;
> it can bring me more choices when making stuff;
> I can "save" a interference mount part infortunatelly made too loose.



I took a 1/2" square and milled the wheel slot




Turned the 1/4" pin from a 1045 bar. Here you can see there a section slighty bigger for interference fit



Pin was heated red hot and quenched in water.



After welding the side tab and cross drilling the 1/4" hole, I pressed the pin



Test run. I've made a fine (0,8mm) and a coarse (1,25mm) wheel.




My knurl set



now waiting rain give a break for paint the tool


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## Ray C (Jan 15, 2018)

Wow Cascao...  I just saw your YouTube videos and happened to select the one making a brass spinning top.   I loved the music!  -And of course, the next best thing to operating a lathe is watching someone else do it.  Your video production was great!   





Ray


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## 4ssss (Jan 15, 2018)

Just an opinion, but knurling in a collet is not the best way of doing the operation.


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## cascao (Jan 15, 2018)

4ssss said:


> Just an opinion, but knurling in a collet is not the best way of doing the operation.


Why?


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## chips&more (Jan 15, 2018)

cascao said:


> Why?


And why again?


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## chips&more (Jan 15, 2018)

A single knurl puts pressure on everything in the operation. I would think the cross feed nut would be the first to be worried about. A collet correctly seated, a slim worry to wear, damage…Dave


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## f350ca (Jan 15, 2018)

Will straight knurls not work in  a scissor knurling tool ?
and another why?

Greg


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## chips&more (Jan 15, 2018)

f350ca said:


> Will straight knurls not work in  a scissor knurling tool ?
> and another why?
> 
> Greg


Straight knurls will work in a scissor type. Just make sure both knurls match.


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## 4ssss (Jan 15, 2018)

chips&more said:


> A single knurl puts pressure on everything in the operation. I would think the cross feed nut would be the first to be worried about. A collet correctly seated, a slim worry to wear, damage…Dave



Because of the pressures exerted when you knurl.  While a collet correctly seated may not get damaged  (I tend to think otherwise) it doesn't hold the part as well as in a chuck or between centers.   If you run the knurls across the part  left or right (not plunge knurling) you'll find that part slipping out of the collet.  As it is, a shoulder should be cut to keep the part from slipping into the spindle, and a center should be used to keep the part from slipping out.  A collet is actually a precision spindle, and any damage to it however slight throws it out of concentricity, and over tightening it  doesn't do it any good.


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## chips&more (Jan 15, 2018)

4ssss said:


> Because of the pressures exerted when you knurl.  While a collet correctly seated may not get damaged  (I tend to think otherwise) it doesn't hold the part as well as in a chuck or between centers.   If you run the knurls across the part  left or right (not plunge knurling) you'll find that part slipping out of the collet.  As it is, a shoulder should be cut to keep the part from slipping into the spindle, and a center should be used to keep the part from slipping out.  A collet is actually a precision spindle, and any damage to it however slight throws it out of concentricity, and over tightening it  doesn't do it any good.


If the material is slipping in your collet. Then you do not have a correctly seated collect. And then yes, you could have collect damage from the material being dragged across and or spun on the clamping surfaces of the collet. Make sure your material is round and to size. And you have a good quality collet(s). And everything is clean! Then material holding should not be a problem.


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## cascao (Jan 22, 2018)

now fixed my QCTP 110 knurl holder.


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