Model Engine Maker

Supporting => Tooling & Machines => Topic started by: Steamer5 on January 12, 2018, 07:02:15 AM

Title: Knurling tool, the cut variety
Post by: Steamer5 on January 12, 2018, 07:02:15 AM
Hi all,
 Yet another tool to keep me away from loco construction!

Bazmak on HSME recently asked for help on knurling.
  I had just expanded my collection of machinist clamps & so had been doing some knurling for the knobs on them, so was interested to see what he came up with. There was a quite a lot of discussion on the pros & cons of various designs / types. He ended up making a cut knurling tool with multiple heads. He tried a couple of ideas before settling on this design

As per Bazmak I sourced the knurls from flea bay, 4 different sizes, 0.5, 1.0, 1.5 & 2.0 mm, for $30 NZ delivered. Other sizes are available, the knurls are 28 mm x 8 mm.

So hereís my take on his design.

Photo 1
 I decided at the out set that I would make a quick change holder for this.
I had some blocks I had made some years back that I was going to made into a quick change Dickson tool holder, gave up that idea & brought a set. So the blocks have been looking for use.

Photos 2 & 3
I lined up all my tool holders & started measuring them up, averaged out the numbers & drew the holder up, well modified a drawing my son had done, a trial cut 6mm piece hadnít quite fitted at the time. I went & had a chat to the water cut guy before starting. This proved to be a good move. Itís time on the table that costs, doubling the thickness more than doubles the cost!  Right off home & onto the bandsaw & reduce the face thickness.

Photos 4 & 5
A couple of days latter I got a call to say the first block was done & would I like to pick it up & check that it would fit. It was a good fit. So okayíd the other 2. You can just see on photo 5 the left hand side were the jet cut out itís not quite perfect. A couple of strokes with a file fixed that & as its not a bearing face didnít matter. If I had them cut from plate this wouldnít of happened.

Photos 6 & 7
The knurl holders are made from 25 mm square, so I made them as a pair as the end that fits into the tool holder is 16 mm drilled & tapped 6mm for the retaining screw rod. Photo 6 shows my hi tech linisher,  polishing up the knurl holder blocks. Photo 7 the blocks & tool holder ( still needing some more finishing)

Photos 8 to 10
 Is how I setup the blocks in my ER 32 square block to machine the clearance groove across the outer end, & machine the angle across the end. This is done to give clearance so small diameters can be cut.

Photo 11 shows the completed tool holder & blocks. The 1.0 in the tool holder show the swarf produced, these things really cut!
Now I changed things after taking the photos. I realized that I didnít need the blocks to have individual screw cut rods, this makes storing them much easier. The one in the holder has the first knurled knob made, I loctited it to 1 rod, there is no load on the rod as it is only used to hold the block in the holder & once the knurls are aligned is just nipped up & so it is easy to remove to switch blocks.

Photos 12 & 13
And finally a couple of knurls done. The first was the knob to hold the blocks & the second the height adjuster knob for the tool block

Since finishing mine & posting it on HSME the discussion on cut knurling has continued. It would seem there are two types either leading edge or trailing edge, like this one.  If your pockets are deep you can buy these tools but they are expensive!

I had 2 other holders cut, as I had another plan! Now these werenít cheep to have cut,  I couldíve brought 3 standard Dickson holders locally for what I paid for each! However I reduced the overhang of the tool, with a little more though I could have reduced it some more.
Another block was bored out to take a 20 mm boring bar that Iíve had for sometime & had found a pain to set up by shimming etc so thatís going to make big hole boring a little easier in the future. All in all I think a worth while couple of project
Title: Re: Knurling tool, the cut variety
Post by: Steamer5 on January 12, 2018, 07:09:03 AM
And a few more.
Title: Re: Knurling tool, the cut variety
Post by: Steamer5 on January 12, 2018, 07:11:07 AM
And the last couple!