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Boring heads for beginners
- Thread starter jwmelvin
- Start date
- Joined
- Dec 20, 2012
- Messages
- 9,422
Ebay is probably still your best bet if you want a Criterion head. Brand new, a DBL-202A (takes 3/8" bars) was $250.00, while a new 202B (1/2" bars) was about $350.00. Stupid because the only difference was the size of the bar holes but that is commercialism at its finest. Lots of Ebay sellers seem to think they can sell a beat up used head for nearly the same price as a new head just because It has the name on it. Still, deals are there if you are patient and know what to look for.
If you buy a used head, look for one that is in near mint condition. The main body is black oxide coated. If that coating is worn off from repeated cleaning then the head has seen a lot of use. Likewise, if there are crash marks on the silver tool holder, walk away. The integral tapered gib must be intact. There are three smaller gib screws on the side (there is a ball bearing under each one and the two outer ones were originally sealed with red wax. The wax may be gone of the gibs were adjusted) and 3 bar locking screws on the silver sliding part of the head. Pass if any of the gib screws are missing unless the deal is ridiculously good because you need all three, with the bearings, in order to have a working head.
The A-model uses the lighter and cheaper 3/8" bars. This is not a minor thing because the smaller bars are a lot cheaper than the 1/2" shank bars and work just as well. Plus, the centripetal forces are lower with the lighter bars. The B-model is far more common, though.
Import clones abound, with prices all over the place. Not too long ago there was a ridiculous deal on an Interstate 202 clone on ebay. I have one and it is almost identical to a Criterion but I haven't even taken it out of the packaging so I cannot confirm its construction. Maybe ask the forum about any clones the guys may have tried. I will say that Criterion has a well deserved reputation. My heads are decades old and perform like new so I tend to prefer them.
There are many other Criterion head configurations - facing/boring, tenths calibrated, etc. There are many other high quality heads, too - Kaiser, Wohlhaupter, Narex, etc. Depends on what you want to spend and what your needs are. For the vast majority of hobby guys, a DBL head will suffice.
If you buy a used head, look for one that is in near mint condition. The main body is black oxide coated. If that coating is worn off from repeated cleaning then the head has seen a lot of use. Likewise, if there are crash marks on the silver tool holder, walk away. The integral tapered gib must be intact. There are three smaller gib screws on the side (there is a ball bearing under each one and the two outer ones were originally sealed with red wax. The wax may be gone of the gibs were adjusted) and 3 bar locking screws on the silver sliding part of the head. Pass if any of the gib screws are missing unless the deal is ridiculously good because you need all three, with the bearings, in order to have a working head.
The A-model uses the lighter and cheaper 3/8" bars. This is not a minor thing because the smaller bars are a lot cheaper than the 1/2" shank bars and work just as well. Plus, the centripetal forces are lower with the lighter bars. The B-model is far more common, though.
Import clones abound, with prices all over the place. Not too long ago there was a ridiculous deal on an Interstate 202 clone on ebay. I have one and it is almost identical to a Criterion but I haven't even taken it out of the packaging so I cannot confirm its construction. Maybe ask the forum about any clones the guys may have tried. I will say that Criterion has a well deserved reputation. My heads are decades old and perform like new so I tend to prefer them.
There are many other Criterion head configurations - facing/boring, tenths calibrated, etc. There are many other high quality heads, too - Kaiser, Wohlhaupter, Narex, etc. Depends on what you want to spend and what your needs are. For the vast majority of hobby guys, a DBL head will suffice.
- Joined
- Dec 20, 2012
- Messages
- 9,422
JW, I forgot to mention that it is not a good practice to put step blocks directly over a T-slot like it is in your pic. The clamping pressure transferred to the step block is over the thinnest part of the T-slot casting. Best to put a steel pad under the block.
Good point, I should have thought about that. Thank you.
I spent some time hoping that I could find an import that was a middle step between the common low-end option for around $75 and a new Criterion for ~$250. Doesn't seem to be much out there that pops out at me. I know that middle ground is ideally a used Criterion, but I may end up going with a new one to save the wait, attention, and luck required to get a good used one.
- Joined
- Aug 7, 2018
- Messages
- 668
Hi Guys,
Unless you want a precision hole, then hole saws are well worth using. You can buy them in 1/8" or 3 mm increments from 3/5" up to 12" in diameter. It has already been mentioned about tool cutting speeds for single point boring heads and the bigger diameter the slower you need to go, well hole saws can be run several times faster, simply because of the number of teeth. Also most manufacturers will have a set of recommended speeds for their saws.
Unless you want a precision hole, then hole saws are well worth using. You can buy them in 1/8" or 3 mm increments from 3/5" up to 12" in diameter. It has already been mentioned about tool cutting speeds for single point boring heads and the bigger diameter the slower you need to go, well hole saws can be run several times faster, simply because of the number of teeth. Also most manufacturers will have a set of recommended speeds for their saws.
New guy here jumping in, I am not a machinist so I don't have any experience with the really nice tooling. I have been using an HHIP pro series 2 inch head with my grizzly 0463 I just got done popping a 2.625 hole in some 3/4 aluminum yesterday. Head and R8 taper shaft were about $135 total from ebay. Contrary to what HHIP says about the head make sure you check those gib screws.
