I need a slow drill

[junkyardjeff]

I need to drill the crank in my 235 for a bolt to help hold the balancer on,I ordered a fixture to do it and it has stamped on it 400 rpm or less and I know I have no drills that will go that slow so who sells one.

 

[kctyphoon]

Look at cordless with different speeds.. i think close enough is good enough..

Looking at just the m18 fuel, the low speed is 550.. I bet all others are pretty similar. I’m sure the crank wont care.

 

[Kev442]

Corded 1/2" drills are rated from zero RPM. If you don't have one, somebody you know probably does.

 

[PhysicsDude]

Use half trigger on low gear....

 

[The Cobbler]

rent a Milwaukee angle drill , they can be run real slow by reversing the 90° adapter

 

[kctyphoon]

Pretty sure I watched a YouTube vid of a guy doing this to his hellcat, and he just used a cheap HF right angle pneumatic drill. Maybe it was a member from the board?

 

[DFB]

Trouble with cordless drills is none have any form of trigger lock switch to maintain a set speed so your always going to vary it up and down some.

Drilling the end of crank for a bolt might take a bit of time

Two of my older corded Makita drills both have trigger locking switches, On the big 1/2" is only 550RPM max but the lock doesn't engage until the trigger is fully depressed

On the DP 3720 3/8" it has a dial on the switch to set the speed slow to fast and then can lock. (Now and again I come to realize why I still keep them and haven't sold them off over all the cordless drills I have )

Obviously that drill of mine is obsolete as new, though can still be found used looking around on the web. Sadly I didn't see any similar 3/8" VSR drills with that type of switch anymore just the full speed lock on button and of course the RPM will be too much for the application. But still can get geared down corded 1/2" drills with a 550 rpm and lock switch.

 

[dogdog]

I have the older version of this from HF... I think it's Chicago Electrc.... looks and feels filmsy but works... I bought it to drill out the lug bolt off the VW that got seized from the impact monkey...

https://www.harborfreight.com/12-in-heavy-duty-low-speed-spade-handle-drillmixer-56179.html

https://www.harborfreight.com/12-in-heavy-duty-spade-handle-drill-63112.html

The ridgid version
https://www.homedepot.com/p/RIDGID-9-Amp-Corded-1-2-in-Spade-Handle-Mud-Mixer-R7122/100523157

 

[ChrisLS8]

All my Milwaukee drills are variable speed trigger and 2-3 speed settings

 

[DenisG]

Milwaukee Hole Hawg tops out at 300 RPM on the low speed setting.

 

[seber]

Look for an older corded drill with screw adjustment in the trigger. That used to be very common on inexpensive drills.

 

[metlmunchr]

The crank bolt is normally a 7/16-20. The proper tap drill for that would be a size W letter drill @ .386" diameter, or slightly over 3/8".

235 Chevy cranks were all forged steel, but not particularly hard like a high performance alloy steel crank would be. If you use a size W cobalt split point drill, you can easily run it at 80 ft/min surface speed which would be right at 800 rpm. The split point will be much easier to push as compared to a standard drill and a bunch cheaper than buying a big drill just to get an unnecessarily low speed.

To get the best finish for the hole, you could pick up a small can of dark threading oil at HD or one of the other box stores. Withdraw the drill every so often and dip the tip in the oil and then go again. The threading oil will also be the correct lube for tapping the hole and will make a big difference as compared to motor oil or any other such substitute lube.

Edited to add: a 25/64 drill will also work fine and might be easier to find than the letter drill.

 

[junkyardjeff]

The crank bolt is normally a 7/16-20. The proper tap drill for that would be a size W letter drill @ .386" diameter, or slightly over 3/8".

235 Chevy cranks were all forged steel, but not particularly hard like a high performance alloy steel crank would be. If you use a size W cobalt split point drill, you can easily run it at 80 ft/min surface speed which would be right at 800 rpm. The split point will be much easier to push as compared to a standard drill and a bunch cheaper than buying a big drill just to get an unnecessarily low speed.

To get the best finish for the hole, you could pick up a small can of dark threading oil at HD or one of the other box stores. Withdraw the drill every so often and dip the tip in the oil and then go again. The threading oil will also be the correct lube for tapping the hole and will make a big difference as compared to motor oil or any other such substitute lube.

Edited to add: a 25/64 drill will also work fine and might be easier to find than the letter drill.

Even though I had the correct tap I did not have the W bit so I ordered both when I got the jig to drill the crank.

 

[kctyphoon]

Look for an older corded drill with screw adjustment in the trigger. That used to be very common on inexpensive drills.

Now that u mention it, I think one of the $20 HF drills I had did have that.
I think the bigger question is what's gonna fit in the space .

 

[junkyardjeff]

I am going to borrow one but will have to get one since I will have more cranks to drill in the future.

 

[bob15]

The Metabo corded drills BEV1300 will go to 180 max rpm (setting 1-1) and their older BE1100 (setting A-1) will do 150 max rpm. This is hold the trigger and that is max rpm with no need to try and hold a light trigger like on a variable drill.

I used the Metabo for drilling out the crank on my SBC 327 last winter and it was easy with the super slow speed.

 

[Kev442]

Not that I'm recommending it for drilling out a crank, but this is one of my 1/2" drills. I don't use a corded drill often, but it sure is nice to have a fully featured one at this price point. Same as HF, if you get 3 projects out of it, it's paid for.

https://www.menards.com/main/tools/...ill-4-5-amp/eid370/p-1444448111277-c-9072.htm

 

[Farmall450]

Use half trigger on low gear....

Ding ding ding

 

[webscrounger]

You could look on eBay for a used corded Milwaukee Magnum drill (like 0234-1 or 0244-1) on the cheap.

 

[Miss the Pontiacs]

Look for an older corded drill with screw adjustment in the trigger. That used to be very common on inexpensive drills.

I got a B&D like.that for Xmas 40+ years ago, still have it.
Check pawnshops and garage sales

 

[junkyardjeff]

I am going to get me one with a 1/2 chuck.

 

[johninct]

Get an air drill.

 

[theoldwizard1]

It sounds like what you want is a TRIPLE gear reduction drill ! These typically have a maximum speed of about 600 rpm (not good for small bits), but they also have "wrist snapping" torque.

I have yet to see a battery operated triple gear reduction, but both DeWalt DW245 and Milwaukee 1001-1 make corded version.

 

[king nero]

Why are you limited to 400 rpm?
Is 400 rpm the max speed of the fixture?
Is that because of the bearings or something?

I see no reason to limit yourself at 400 rpm. Neither drill bit nor crank will care, so I don't see the problem?

 

[junkyardjeff]

Want a slow drill to reduce the heat on the drill bit,all I got are faster drills and have a hard time from burning up drill bits even with lubrication.

 

[bob15]

It sounds like what you want is a TRIPLE gear reduction drill ! These typically have a maximum speed of about 600 rpm (not good for small bits), but they also have "wrist snapping" torque.

I have yet to see a battery operated triple gear reduction, but both DeWalt DW245 and Milwaukee 1001-1 make corded version.

Metabo's cordless goes to 0-500 rpm. And like I said earlier, the Metabo corded goes down to 180 rpm....with a 2 speed gearbox. Why the need for a triple reduction? See the attachment for their speeds

 

[DFB]

Geez a Milwaukee M12 RA 3/8" chuck cordless drill is only 800 rpm max

Might need a few batteries though

 

[dogdog]

For some reason.... those slow drills have higher torque than the battery operated ones... some situations you'll needed high torque slow speed to drill out stuff... not just RPM alone...

 

[dylanmitchell]

Milwaukee M18 2701 the compact brushless non-fuel has a mechanical clutch with 0-450/0-1,800 RPM and 500 in-lbs. of torque.

 

[Seagoon]

Why are you limited to 400 rpm?
Is 400 rpm the max speed of the fixture?
Is that because of the bearings or something?

I see no reason to limit yourself at 400 rpm. Neither drill bit nor crank will care, so I don't see the problem?

Did you read the first post?

 

[Bogie1632]

Just a thought but do you have a good air supply handy? Plenty of air drills you can get that speed with. Some only free spin at 500 rpm, full trigger pull, at recommended pressure/flow. Easy enough to drop it down just a bit to lower the drill speed.

Good luck.

V/R
Bogie

 

[junkyardjeff]

Went to HF and did find one 1/2 drill that had the screw to adjust the speed on the trigger,going to look at others this week and going to borrow one from a guy at work to get it done this time and since I will have more to do in the future I will get one. I really do not like borrowing tools but the state got a bunch of my money for tags this week I will do it this one time to get the job done.

 

[junkyardjeff]

Went to the basement to put the clothes in the dryer and a drill on the shelves got my attention that I do not remember where it came from but its a 1/2 and according to the tag goes to 575 and not variable speed,its a good old heavy duty Craftsman most likely from the 60s but still a little too fast. Did not remember ever having it so it must be something my dad got but he has been gone 22 years and I think I need to take a few hours to see just what I have in this house.

 

[DFB]

Went to HF and did find one 1/2 drill that had the screw to adjust the speed on the trigger.

Its a Miracle

 

[theoldwizard1]

For some reason.... those slow drills have higher torque than the battery operated ones... some situations you'll needed high torque slow speed to drill out stuff...

TRIPLE GEAR REDUCTION or two speed gear box.

 

[theoldwizard1]

... its a 1/2 and according to the tag goes to 575 and not variable speed,its a good old heavy duty Craftsman most likely from the 60s but still a little too fast.

Likely triple gear reduction !

I have slightly newer version (late 70s) Craftsman Industrial that is 0-600 RPM.

 

[dogdog]

Went to HF and did find one 1/2 drill that had the screw to adjust the speed on the trigger,going to look at others this week and going to borrow one from a guy at work to get it done this time and since I will have more to do in the future I will get one. I really do not like borrowing tools but the state got a bunch of my money for tags this week I will do it this one time to get the job done.

The screw is just a mechanical stop the trigger and electronic is variable speed as in dependents on how much of the trigger you pull... the screw is actually helpful if you wanted to set a max speed .... without having to worry about heavy finger...

 

[2oolhound]

Tech Tip No. 233346854001

Here's a trick I often use in these situations:

Take a drill with a "D" handle on the back and remove the "D" handle.

Now place a bolt with the proper thread in the back of the drill in place of the "D" handle. Next cut the head off this bolt and tighten the chuck of a second drill onto the bolt. Now set the 1st drill to spin at one of the specific speed settings and then set the 2nd drill to spin at 400 rpms slower BUT in REVERSE! You can now drill your hole at the specified speed! This tip tends to work best with cordless drills or long extension cords as the cables tend to get tangled up pretty fast, specially at the faster speeds.

 

[dylanmitchell]

Do Milwaukee's one-key and other brands similar tech let you set a speed? Would a 1//2 fuel one-key let you set it to 400 rpm? I have a few fuel tools but they're not the one-key versions. Screw adjustable trigger would be to simple and easy to use for me I need something complicated that requires a smartphone and degree in computer science... joking... simpler is usually better...

But wait there's more what about a Raspberry Pi connected to the drill to set the torque...only half-joking...