Camjack Knurler

[Hawkeye]

I'm looking forward to a few guys building their own. I'd like some feedback on how they work for you. I was impressed with the fact that I could force the knurls into the steel by turning the jack screw with my fingers.

 

[swatson144]

I got far enough along that I do not feel there are any insurmountable problems with the drawings. they are currently available here . As yet untested use at own risk etc. I will put it in the downloads section here on the forum when I have it in final form.

Hopefully my shoulder bolts will arrive today and I can finish it up and test it out and make updates to the drawings, finish the notes and post it. The 3/16" ball end cutter arrived. I probably should have just used bolts like Hawkeye (perhaps why he did?). Definitely should have procured the odds n ends before starting. It's just that I didn't consider them that odd to be NC, or NIS everywhere local.

It is sorta astounding what pieces one may need for a small project that can't be easily found locally in a city as industrial as this one. A lot of I can order it for you, or they come in a box of 25.

Steve

 

[swatson144]

It's finished. The first test didn't go so well but it is assuredly my fault as the tool behave perfectly. Actually it behaved as if it was 4X strength of what was needed to do the job.



The knurling is not right but it is deep and there was no problem to the tool. I haven't much practice or experience at knurling as it just wasn't called for a lot in the navy. Most likely something stupid I'm doing. Frankly I just stuck it on the lathe to let the green loctite set up and then got carried away.



Seen from the centerline you can tell the tool is still a little high and the tool holder is bottomed out on the compound on my 12x36. when I get around to it I'll likely change the mount to be more of a sideways T than a sideways L.

Even though I'm only using an AXA and the 1/2" mount is plenty strong using a 5/8" plate will give enough clearance for the height adjusting wheel on the holder. 9/16" also. I shimmed it out .030" for clearance

I went with a 5/16" x 24 TPI on the cam (jack screw) simply because it looked more to scale with the other pieces.

I tend to make tooling and not spend a lot of time on the aesthetics. I never know when they will work as desired, and I figure once they prove to work well, I'll go back and make them pretty. Perhaps some day I will. So far not so much.

I'll update the plans and notes http://www.totallyscrewedmachineshop.com/projects/camjackknurler/camjack.html

Steve

 

[ScrapMetal]

I got far enough along that I do not feel there are any insurmountable problems with the drawings. they are currently availablehere. As yet untested use at own risk etc. I will put it in the downloads section here on the forum when I have it in final form.

Hopefully my shoulder bolts will arrive today and I can finish it up and test it out and make updates to the drawings, finish the notes and post it. The 3/16" ball end cutter arrived. I probably should have just used bolts like Hawkeye (perhaps why he did?). Definitely should have procured the odds n ends before starting. It's just that I didn't consider them that odd to be NC, or NIS everywhere local.

It is sorta astounding what pieces one may need for a small project that can't be easily found locally in a city as industrial as this one. A lot of I can order it for you, or they come in a box of 25.

Steve

Thanks to both of you for making the plans available. I've got too many things on my plate right now but I will surely make one of these in the near future as I really like the design.

-Ron

 

[Hawkeye]

It doesn't matter what type of knurler you use. It still comes down to matching the work piece diameter to the pitch of the knurls. Get the diameter off and there's no way you will get a good finish. Get it off just the right amount and you will make a good fine pitch using a medium-pitch knurl set.

Steve, your camjack looks nice and solid. It should work very well for you.

 

[swatson144]

N = (pi ) (dia) (tpi)

N is the number of lines your knurl will make on the circumference of your part. TpI is the pitch of the knurl. In the unlikely event N is a whole number knurl away.

If N isn't whole say 14.4

diameter change = n (right of decimal .4) / (pi)(tpi)

Seems to be the common method.

There also seems to be thoughts that if it is slightly off a whole number the knurls will follow if set deeply and well lubed, probably about like mine did since I did no math, nor dust blowing or lube.

http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=1759&PMITEM=01295203&PMCTLG=00 and go to page 1752 for MSC's reference on knurling

Steve

 

[November X-ray]

Steve - I think you will get better results when you do use lube (or something) to flush the knurls clean with. I know with mine it makes noticable difference with flushing vs without!

 

[swatson144]

I finished my paying job so I got another run at it.



Turned out good enough for the 2nd try. Seems to need a little practice getting the tension right since you can put so much on it. seems to be nothing set in granite about this, just like playing music you just monkey around and practice, eventually the station will be in nice and clear.

Steve

 

[Hawkeye]

If you're wondering about the pitch of your knurls, take one out of the holder and slip a shaft through it. Roll it in a straight line along a piece of paper on a flat surface. there will be enough oil on it to leave a print of the ridges. Next, draw a straight line along the path you printed, parallel with the direction of travel. Mark one knurl line where it crosses this line and another 1", 2", 5", 10" (or whatever) further down - longer is better, until you meet up with a clear intersection where knurl, horizontal line and inch mark come together. Count the knurl lines, not including the first one. Divide by the number of inches to get lines-per-inch.

If you divide 1 by the lines-per-inch number and record it, you can make up a table to keep in the shop with a number of workable diameters on it. Here's the chart I keep in the shop for my particular knurls. It will only work if yours have the same pitch as mine.

 

[jayman]

Nice job! Nice idea! Looks pretty cool! Have you tried it with straight knurls?