WHAT DRILL BIT TO DRILL TAIL SHAFT FOR H@T

WHAT DRILL BIT TO DRILL TAIL SHAFT FOR H@T TRYING TO INSTALL MY RE SYE TRYED COLBOT AND IT JUST WONT START NEED IDEAS ASAP THANKS

1) Back away from the CAPS LOCK key, it makes your posts harder to read.

2) I'm assuming you've done the "hack" part already. If you haven't, you won't get a bite with a drill bit, unless you're very careful and you've got a very good drill bit (the shaft is case-hardened.

3) Once you get the "hack" part done (if you haven't already,) you'll need to centre-punch the shaft, use a centre drill to get started (or use a small drill bit first and work up progressively,) and make damned sure you get it on centre! Measure four times, cut once.

4) What size tap? I can't find my ruler with the formula on it, and I can't recall it offhand, but there's a simple formula (probably findable online - check a machining site) to determine tap drill size. "Become wise in the Way of Google-Fu, Grasshopper."

Did you cut the shaft back to the specified length? That shaft is very hard on the surface (And back through the shaft for a good distance).

If you did you should be ok, Just start the hole with a smaller bit (I used 1/8" to start) & work your way up. do not apply too much pressure, Use plenty of cutting oil & keep the RPM's down on the drill or you will burn up the bits fast. I don't like using the Kobalt bits because they seem to snap easily.

PS: RE recommends you drill a 3/16" hole first then drill a 21/64" hole
Then use the 3/8" -24 tap to tap the hole

I have already done the hack part but the darn thing still will not get started small 1/8 bit and all and as all ways lots of lube thanks for the quick replys

A standard HSS bit is fine. Low speed, high pressure, lots of cutting oil.

What FrankZ said. If you've already cut the end of the shaft off, you've got the case out of the way ("case" as in the "case hardening".)

Low speed, middlin' pressure, and flood with cutting oil. May help if you support the vehicle (by the axles) on stands to spin the output shaft in the other direction (idling in first or first/low should do, and it will help make sure you're on centre.) Kinda like the easy way to do the "hack" part in the first place.

well been outsidefor a fewand it finaly going man is it slow thanks for the info

5-90 said:

4) What size tap? I can't find my ruler with the formula on it, and I can't recall it offhand, but there's a simple formula...

Click to expand...

Yep.

Major diameter - thread pitch = minor diameter

start small and go slightly bigger each time.
i think i only used 3 different drill bits for the hackntap
i started tiny and worked up.
of course i say
since you would not want to have to replace the shaft
measure 9 times cut once.
and use brand new bits, it will only help,
of course use a really good tap. go slow as hell, back it out, use oil, and go slow!!!!!!
i have full snap on tap and die set that i use for these fun times.
a good expensive tap is worth it.