[atlas_craftsman] Re: Grizzly 3/8 in insert tools
- At 10:09 PM 3/27/00 -0600, you wrote:
>I just got my shiny new Grizzly catalog.Jim;
>Noticed right away a great price on 5 pc 3/8 in insert type tool holders, with
>wrench and inserts for just under $24! Anybody got a handle on the quality of
>these? Seems awfull good...or maybe just awful.
>Which is it?
I have a set. They work alright. They do have a problem in that
the tolerance on the fit between the insert and the shoulder that it is
supposed to lock against is loose. This lets the bit sift a little if you
try to cut in the opposite direction (say cutting on the return stroke of a
facing cut). I solved this by trapping a small piece of brass shim stock
(0.001 or 0.002") between the insert and the shoulder when clamping the insert.
The screw heads are a little soft an I have stripped the hex socket
out of two of them. I used a small drop of super glue to glue the allen
wrench in place to get then out (wait 24hrs to let the superglue reach full
strength). A real allen wrench rather then the cheap one supplied reduces
this problem. They do include 5 extra screws.
Over all I do like them. I made a ring washer the correct height to
place the holders on center, to replace the rocker washer. This allows me
to clamp them directly in the lantern post and gives a much stabler setup.
You can see this in some of my shots in the Minnie and maybe Atlas sections
of my Site (address below).
I also have Enco's set of TT-22X insert holders (also on sale for
$19 I think). These do not have the loose shoulder insert problem, but do
have the problem that this joint is too tight! The bits sit a little cocked
with the shoulder end not going all the way down onto the flat. This has
not seemed to hurt the cutting ability or insert durability, though.
One disadvantage is that only Enco seems to carry this type of
insert with any great selection available. The prices are about comparable
I would recommend USA made inserts. I have found them to hold up
better in service. I do use the cheaper import inserts in my boring bar
holders, but they are larger inserts and not used as much. They were so
much cheaper that the durability factor did not justify the extra cost.
In general I prefer the Enco holders. The two types TT-22x and TCMT
inserts are not interchangeable. They have different size and shape screw
I can recommend either type as a starter set. I will in the future
get an American made set of TT-22X type holders as when I can get the money
together, but i have a few other tool needs to fill first.
The inserts do hold up well to interrupted cuts. I back of on the
depth of cut, though. One thing to avoid is cutting so hard you stall the
lathe! The insert will spall of a section of the cutting edge. This piece
may weld to the workpiece and have to be chipped out before you can
continue. So be careful. Otherwise an insert will last quite a long time.
I have two insert type boring bars also. A large 1.25 min bore (I
think,over an 1" at least) Enco bar, and an internal threading (1" min bore)
bar from Wholesale tools. These use the larger 3/8" TPG/TPU inserts. The
Enco bar I got specifically for boring the cylinders on my loco (nice and
stiff setup). It woks quite well. The threading bar I use to make back
plates for the lathe. It works as a regular boring bar also, but you can
not cut to a shoulder with it. This needed a little grinding work to clamp
the insert correctly, but for $30 it was a bargain. I had to taper the head
of the screw so that the clamp could rotate enough to hold the insert.
In the future I plan to get the 1/2" dia. long boring bar to
complete my set.
North Augusta, SC USA
Builder Miinie #2
Captain R/C Combat Ship USS Arizona