sparky 25

I need to resized a hole on a piece of hardened steel,

its a 1/8 scale axle im trying to fit a set of axle extenders onto,

only trouble is that the hole in the axle is too small to take the 3mm drive pin that the extenders use,

anyone resized a hole on an axle before?

Dirty_Vinylpusher

If it's only half a mill you should be right.

Have you got a drillpress?
Otherwise you'll probably snap a couple of drillbits.

sparky 25

Yea i have a drill press,

will an ordinary steel bit be able to bore the hardened steel?

Dirty_Vinylpusher

Try it and see.
If not, go out buy a hardened one.

da mad maori

yeah try with the drill bit you have and alot of cutting fluid at a low speed and just take your time....

do you know how to sharpen drill bits with a bench grinder ?

Lars from Norway

As the hole is allready predrilled i guess this will be easy.And if it should snap in the hole you can knock the drill bit out from the other side!

sparky 25

Yea i`ve sharpened a few drill bits in my time using a bench grinder,

while sharpening a bit i usually hold the drill bit so that the leading edge of it is facing upwards

with the bench grinder wheel rotating into the leading edge, i try best to keep the angle of the new edge as close to original,

are there any better methods of sharpening the bit with a bench grinder?

i guess there is no real answer to my question other than to give it a go and see,

gona have a go at it this weekend, i`l just keep the drill speed down and use plenty of oil, thanks guys[sm=thumbup.gif]

QSPSB2

Answer!
NO.. you will need to purchase a carbide or HSS bit to perform this task

Marvels air tool oil works quite well as a cutting/cooling agent as well... Not to mention it's very cheap!

Dirty_Vinylpusher

When he said steel bit I assumed he meant HSS bit.

Johnnysplits

might have to usea cobalt bit to go through hardened steel

Fabe

Yeah...I invested in a nice bit a while ago to drill through some hardened gears in a differential, but that didn't work out so well. Then I decided to go the adventurous road: heated up the shaft to soften the steel, drilled the gear with a normal HSS bit, then heated and rehardened the steel. The gear is still alive...

da mad maori

heres a hardened HPI Baja axle i cut with a normal hss steel parting off tool on a lathe then drilled and tapped a hole.... (most average drill bits are hss..."high speed steel")


just whet slow and took my time (well it took around 40 secs as apposed to 5secs)

if you hear it squeal halfway through then sharpen it and go again

you should be fine

Soloratov

My Feedback: (1)

Just a suggestion, as I just did this a few days ago, invest in a cobalt, or better yet, carbide bit. Get some cutting oil, and go slow.......but push hard.

Dirty_Vinylpusher

....she said......

Soloratov

My Feedback: (1)

lol...dirty Dirty!

rangerfredbob

My Feedback: (13)

when I adapted the Genesis wheels onto my monster buggy I had to drill through the shafts on that, I went with a diamond bit in my dremel, took a while and lube, but it worked well, nice clean hole while regular bit barely touched it. diamond bits come in an assortment of like 5 at Harbor Freight for like $3

Dirty_Vinylpusher

Yeah there's these things you can buy that give you the correct angle.
They attach to the grinder somehow.
A mate lent me one once, but it was a bit old and crap and after having ground two of my drill bits down to the stump I gave it back to him and bought a new set of drill bits instead....

rrragmanliam

My Feedback: (1)

Forget that antiquated aperatus and get yourself a Drill Doctor. This is one of my favotite and most used shop tools. You will never buy another drill bit, and I guarentee every time you come across an old bit, your going to pick it up and put it in your pocket because you know you can make it good as new.

http://www.drilldoctor.com/

Darren

jimjeep

These are the best bits I've ever used on hardened steel or anything for that matter... they are the best!
[link]http://www.rodmanandcoinc.com/rodmanandcoinc.com/itemd2c7-2.html?UCIDs=1307321%7C1307865&PRID=1493540[/link]
They are money well spent.

motionmachine

Have you consider modifying the axle extenders (rotate 90 degrees and drill new hole) to accomodate the smaller 2.5mm pin?
Drilling the axle weakens the shaft, where as drilling a new hole in the extender weakens neither piece....

dimag093

Drill press,cobalt drill bit,cutting fluid and patience is the way to go [8D]

sparky 25

This was my initial thought,

and as i have tried to drill out the axle today with new 3mm hss bits without success,

i think i will order up some new 2.5mm axle pins and have a go at drilling the wheel extensions instead of the axle

mooman007uk

I use diamond bits on a dremel to enlarge holes, done many in the past with no bother and decent bits will get the job done in a couple of minutes, cobalt or carbide drill bits also work but a carbide end mill cutter in a drill press is the best tool to use as long as your drill will rev high enough.

sparky 25

Just ordered up a couple of 3mm cobalt drill bits, will try drilling the axle when i get them.