Shop-made dovetail cutter from drill rod

Fwiw ..while at it , you can make slotting mills , ROUnd noes mills , taps , angle reamers, counter bores , what ever .....i still have a set of removable pilot c/bores i made 40 yrs gao ...# 4,6,8,10, 1/4 in .5/16 .3/8& 1/2 inch .
..but cheap china stuff is ruining my fun ...last 14 mm tap i made cause i remembered them costing so much years ago , took abt 2 hours ....looked in catalog ...on sale for $12 ...back to working for #5 /hour again
best wishes
doc
oh yeah , in another life i made a 6x48 die for some screws for colt 45 grips ....screws were a tad tight but still went ok ....did not knwow that that a ten thou oversize tap shud have been used ..i just used teh 6x48 ace tap that i had
never had formal instruction , & therefore made a lot of scrap , but the second time around ,they worked...i still keep a worthless bannana shaped reamer from quenching "flat "....never again

i mention this only to tell you that while a tool maker apprenticeship wud certainly be better , you CAN successfully come in the back door ...
 
I think I like making the tools and jigs than the other projects.


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Many thanks to each of you who responded to my original post -- I appreciate it!

Regarding dovetail cutters using inserts: I previously made a 60 degree dovetail cutter (see Bob Warfield's at cnccookbook.com or some posted above in this thread) but thought I'd make a 45 degree cutter for what is only occasional use.

I'll use the 45 degree cutter in another project (making a parting tool holder for QCTP) which I'll post here. It uses a couple of 45 degree cuts; I haven't encountered a lot of those compared to 60 degree cuts, generally.

Thanks again for the feedback . . .

dovetail.JPG
 
Doc, now you got me going . . . would the version of dovetail cutter you described involve milling a complete 180 degrees of the meat off of the business end of the cutter? ala a D-style reamer? That's what I'm envisioning; correct me if I'm wrong.

I have a square 5c collet block as well as a hex one. Here I was thinking of making it all complex using a spin indexer, while you have the faster way. Use a good vise stop and a collet block would make short work of it.

I'm open to any more tips you have -- use this thread for whatever. For example, I didn't realize that quenching in a deliberate way (via drill press) yields less warpage! Makes sense, I just hadn't heard about it.

Is the general approach then to turn the drill rod to the right profile then mill flats, harden, temper, and stone? Seems as if one could make anything from reamers to dovetail cutters to Woodruff cutters! Not that the result would be art (in my case) but it might be fun and it might keep one going rather than stopped waiting for a purchased one to arrive.

Doc, if you have pictures or any more tips on this, have at it. Same to everyone else who's been nice enough to read and/or respond in this thread. I appreciate it.
 
DaRiddler said:
Many thanks to each of you who responded to my original post -- I appreciate it!

Regarding dovetail cutters using inserts: I previously made a 60 degree dovetail cutter (see Bob Warfield's at cnccookbook.com or some posted above in this thread) but thought I'd make a 45 degree cutter for what is only occasional use.

I'll use the 45 degree cutter in another project (making a parting tool holder for QCTP) which I'll post here. It uses a couple of 45 degree cuts; I haven't encountered a lot of those compared to 60 degree cuts, generally.

Thanks again for the feedback . . .
Click to expand...

I have been eying this 60° over on cnccookbook as of late. How has it worked for you? Did you use a TPGB or TNMP insert?
 
Dariddler
a D bit has only one cutting lip ........what i described has two ...the flat is milled from both sidesafter first turning the point of teh bar to desired contour the flat is located CENTRAL on the bar end ..& you essentially have what wud be a spear pointed flat wood bit w/ out the spear point but & shaped in a flat dovetail ........TWO cutting edges...
re quenching vertical in drill press...you have not heard of this because it is not in any text i have seen & most machinist do not make their own reamers or any of their tooling as they once did ...& the tool makers do not torch harden ...they need to be more precise industry is after the very MAX number of parts punched out before retooling..be prepared to blow out the flame if you quench in oil (0-1)......
i use the square collet block for fluting taps w/ an endmill, as well as special multiflute cutters when needed......but the two lipped cutter i described is really easy to sharpen ..just stone it
the olde tymers wud take a bar , heat th e end & flatten it out which expanded it thne shaped th e end like a flat wood biit w/ out the spear point ///put a center in teh end ,mountd in teh t/stock point ,th e flat held w/ a monkey wrenc & proceed to drill out what is chucked or on a face plate...there were alos special holders for th e flat that were mounted in teh tool post ....one advantage was the flat bits wud not grabinto the material at the end of eh cut like a twist drill , but any real depth has to have chips blown out ......
FWIW ...youcan make your own 2 lipped end mills this way ( slotting cutters )60deg ,,90degree pointed cutters .....
made a corner rounding mill this way once in aan emergency
best wishes
doc
i am getting ready to take some 3/8 flat stock 0-1 & make up a short flat bit head , insert it into a central slot of a one in bar & rivet it w/ 3 #16 nails ...make a 2 in & 1/2 in flat bit ....there are commercial ones but EXPENSIVE that use interchangeable size SPADE bits ..
best wishes
doc
 
Doc, thanks for the clarification. If you were to take some pictures of the project you mentioned, I think you'd find a lot of us would be interested.

JoeSixPack, I must admit I originally made the dovetail cutter with carbide insert thinking of the very common TNMG 322/321. But that insert doesn't have any relief, and relief is necessary in this situation. Here is a similar-sized insert on eBay that I'm going to pick up -- should fit the same way but with relief . . .

http://www.ebay.com/itm/TCGT-322-AN...164?pt=LH_DefaultDomain_0&hash=item29f0fb875c

From the several threads I've seen at Hobby Machinist and other blogs as well, the most common insert is TCMT -- being triangular, it provides three fresh points to use (not six, like TNMG, because TCMT isn't symmetrical front to back because of the relief). I see TCMT 32.52 is used popularly.

Bob at cnccookbook.com has a nice writeup about making a dovetail cutter that uses an insert. He says that he used TPGB because that's what he had on hand. But he goes on to say that he wants to check out TCMT inserts as well.

Incidentally, the graphic that best explains insert sizes etc. to me is the following:

CarbideInsertsChart.jpg
 
I too plan on making one of these. However when I started to look at what insert to build it for I looked at the commercial products. These all seem to use TDEX inserts. I don't see X on the chipbreaker section of DaRiddler's chart. After looking at some pictures of this type of insert I think X simply means it does not have a chipbreaker. They also don't seem to be used in anything but dovetail cutters. Has anyone else seen these types?

What would be the advantage of using a TDEX over a TCMT?

I can see that the TDEX has greater relief, as well as since it doesn't have a chipbreaker you should be able to use both sides of it, if I'm correct in my understanding.

I would assume using something less specialized than a TDEX means you can use it in another tool holder and you don't have to buy as many specialty inserts?

I'm still new to inserts and their are so many I tend to ask someone with more experience and just go with their preference.
 
I recently posted a video on Youtube,
It is long, about 30 minutes and concerns making XL timing pulleys.
In the video I not only cut the pulleys, but I show how to make the cutter from hardenable steel. The cutter has 3 teeth and is properly relieved. I used my CNC lathe to cut the tooth form, but for a more common shape such as a dovetail or slotting tool, CNC would not be needed. Using CNC one could make any type of gear cutter needed.
Cheers,
Ozzie
 
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