Drilling the auger motor shaft to accommodate a new auger with cotter pin?

[Don2222]

Hello

The new auger I got has a hole and cotter ping. Has anyone successfully drilled a hole through the case hardened tool steel auger motor shaft? It is very hard!

I hear this 1/8" inch diameter 118 degrees carbide tipped die drill like this is needed? $11.23
(broken link removed to http://dewitt-tool.com/dadie18diedrills.aspx)

 

[SmokeyTheBear]

That is what jigs, clamps, and a drill press are good for.

 

[MountainSean]

That is what jigs, clamps, and a drill press are good for.

Yep. Nice drill press with an industrial diamond drill bit. Goes through hardened steel so nice.

 

[Don2222]

Yep. Nice drill press with an industrial diamond drill bit. Goes through hardened steel so nice.

Hi Mountain Sean
Why do most diamond bits like this 1/8" state only for tile and glass? $7.75 is more in my budget.
http://www.discountdiamondbits.com/18quot-diamond-drill-b18.html

Would this for $50 for a .122 inch work better. 0.122 is little smaller that the 0.125 1/8" I need and out of my budget.
http://www.ukam.com/diamond_solid_thin_drills.htm

Do either of the above do case hardened tool steel also?

 

[pell it]

Order a motor from USSC for the 5660. It will have the hole in it already!

The case hardening is only a few thousandths thick. If you properly fixture the shaft on a drill press, as previously stated, just use a couple HSS drill bits. One to get thru the case hardening (re-sharpen or dispose of after) and one to finish the job. I am surprised the shaft is case hardened and I doubt it is tool steel. If it is through-hardened tool steel, Carbide is your best bet.

 

[pell it]

Another tip is to kiss the shaft with a grinder where you want to start the hole. This will remove the case hardened skin and expose the softer steel below.

BTW What diameter is that motor shaft?

 

[jtakeman]

I'm with pell it, Carbide all speed, little pressure(or it crumbles) with some lube. Cobalt will also work and is usually easier to find.

 

[MountainSean]

Hi Mountain Sean
Why do most diamond bits like this 1/8" state only for tile and glass? $7.75 is more in my budget.
http://www.discountdiamondbits.com/18quot-diamond-drill-b18.html

Would this for $50 for a .122 inch work better. 0.122 is little smaller that the 0.125 1/8" I need and out of my budget.
http://www.ukam.com/diamond_solid_thin_drills.htm

Do either of the above do case hardened tool steel also?

I was just reminiscing back to my childhood days working with my grandparents in their machine shop. Nice bank of 3 drill presses with various bits for drilling through hardened steel, plate steel, or cast iron or ceramic. Pretty much whatever they needed to drill through to make whatever tool they happened to be making. I didn't mean for it to be taken as a suggestion and apologize for any confusion there.

 

[Don2222]

I was just reminiscing back to my childhood days working with my grandparents in their machine shop. Nice bank of 3 drill presses with various bits for drilling through hardened steel, plate steel, or cast iron or ceramic. Pretty much whatever they needed to drill through to make whatever tool they happened to be making. I didn't mean for it to be taken as a suggestion and apologize for any confusion there.

Interesting. So I just ordered a 1/4" and 1/8" Carbide Tip drill bits. Always learning something new!
The 1/4" is for drilling out the set screws so I can reuse the auger. The 1/8" is for the cotter pin,

According to dewitt the Carbide Tip Die drill bit is better for hardened steel.
"Run at 75 to 100 surface feet per minute with steady hand feed. It is a good pratice to clear the drill from the hole to allow coolant to wash away the chips. Designed for drilling hardened steels in the range of 45-65 Rc. Note: Sizes under 11/64" are sold carbide spade construction"

The full 100% carbide drill bit is better for Iron and what not.
"Solid Carbide drills are designed for drilling abrasive materials when drilling accuracy must be maintained and/or when used in high temperature drilling applications. Solid Carbide drills are used on materials such as cast iron, non-ferrous alloys, high silicon aluminum, copper, plastics, bronze, hard rubber, plexiglass, and other similar materials"

http://dewitt-tool.com/

 

[jrsdws]

100sfm for your 1/8" carbide tip drill is about 3000rpm.

Fixturning is most important. When drilling out a pre-existing hole, your bit will have a tendency to want to bind as it's not cutting from center as designed.

Make sure you have everything aligned perfectly and locked down tight. The case hardened skin will likely chatter and chirp and might really damage that tip, but then will go through the rest easy if it lives. Increase feed pressure to engage it harder if it starts to chatter.

 

[jrsdws]

I should add that as a machinist for 25yrs....I don't believe the 75 to 100sfm is necessary nor ideal if you cannot provide adequate steady feed....which is near impossible by hand.

Good alignment to the hole and great work holding with a firm steady feed pressure will be key to success.

 

[imacman]

I'm with pell it, Carbide all speed, little pressure(or it crumbles) with some lube. Cobalt will also work and is usually easier to find.

x2

 

[Don2222]

That is what jigs, clamps, and a drill press are good for.

Ok Smokey, How does this Sears Craftsman Model 25921 Drill Press with Black and Decker single speed drill and a 1/4 Carbide Tipped Die Drill look?

Will it do the job?
(broken link removed to http://www.ebay.com/itm/Vintage-Sears-Roebuck-Co-Craftsman-Drill-Press-Model-335-25926-/261134880051?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D11%26meid%3D3979878635200354346%26pid%3D100011%26prg%3D1005%26rk%3D2%26sd%3D290812547058%26)

 

[MCPO]

Ok Smokey, How does this Sears Craftsman Model 25921 Drill Press with Black and Decker single speed drill and a 1/4 Carbide Tipped Die Drill look?

Will it do the job?
(broken link removed to http://www.ebay.com/itm/Vintage-Sears-Roebuck-Co-Craftsman-Drill-Press-Model-335-25926-/261134880051?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D11%26meid%3D3979878635200354346%26pid%3D100011%26prg%3D1005%26rk%3D2%26sd%3D290812547058%26)]

Hopefully you weren`t serious Don.
I`ve seen those jigs before and to be honest I think they are more of a nerdish homeowners toy.
Here`s one that`s still not a top quality brand name but would be a big step up in quality and one that should be up to the task.http://www.harborfreight.com/garage-shop/stationary-drill-press/5-speed-drill-press-38119.html

 

[bonesy]

I bought an after market auger motor for my BigE, don't need it yet but I noticed it does not have a hole in the motor shaft for the cotter pin that my existing setup has. Do you think this motor shaft will be hardened?

 

[ironpony]

tap the hole in the auger and add a set screw .50 cents

 

[Don2222]

I bought an after market auger motor for my BigE, don't need it yet but I noticed it does not have a hole in the motor shaft for the cotter pin that my existing setup has. Do you think this motor shaft will be hardened?

It is very hard! Hole should be min 9/64" or max 5/32" just order the carbide tip die drill bit and you will be all set!

I also used a C-Clamp to hold the motor on the stand. It worked super!

 

[bonesy]

Im getting a bench top drill press for Christmas so that'll be my first project with it.

 

[Don2222]

Hey jmbones

That's cool, here is the pic of the hole. I put oil on the shaft a couple times during drilling to keep it cool. Worked great!