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For those with access to a 3-D printer, this little guide is worth its weight in gold: M5 Tapping Guide for MakerSlide.

regressedEE wrote:For those with access to a 3-D printer, this little guide is worth its weight in gold: M5 Tapping Guide for MakerSlide.

Give me the gold, and let me keep tapping with my drill.

cvoinescu wrote:Give me the gold, and let me keep tapping with my drill.

I hear they're giving it away in some village in Russia ... of course, there's a little work involved!

regressedEE wrote:For those with access to a 3-D printer, this little guide is worth its weight in gold: M5 Tapping Guide for MakerSlide.

Having never tapped anything before I'd have to agree. The tap guide and liberal amounts of oil are your best friends.

fishtoprecords wrote:There are three separate types of taps in the machining world. Or, rather, three with straight flutes, and lots more specialized ones.

• * tapered tap
  * plug tap
  * bottom tap

Most of your hardware store taps are tapered just like @ing showed. They have about 7 threads in the taper part before they get to full depth.

A plug tap has less of a taper, maybe 4 or so. They are easier to get crooked, but can tap closer to the bottom of a blind hole.

A bottom tap has very little taper, its designed to make the threads go to the bottom of a blind hole, after you have done most of the threads with a plug or tapered tap.

For the MakerSlide, you really want a tapered tap.

I'll add to that... for power tapping there are also gun taps, which have a cutting edge which is angled to push the chips down the hole, and spiral fluted taps which feed the chips back out of the hole like a drill. Gun taps are good for through holes or blind holes drilled deep enough to allow room for the swarf, and spiral fluted are preferable for tapping to the bottom of blind holes. There are also forming taps which create threads by deforming the metal rather than cutting. This can lead to very strong threads, as the metal is "cold worked" to make the thread. The tap is stronger as well because it doesn't have flutes ground into it.

Regular tapered straight flute taps are perfectly fine for doing your makerslide, but stay away from cheap taps which are made of high carbon steel, as the ones sold in hardware stores often are. Those are the ones that break easily. Go to an industrial supply place and get a decent quality tap that's made from high speed steel.

I second the HSS recommendation.

Also, for spiral-flute taps, there are several types -- the softer the material they are intended for, the wider the flutes. One variation is for the tap to have a short cutting section that tapers both ways, followed by a long shank (fluted for chip removal). These taps are tolerant to being held at a slight angle, and have less friction than a full-length tap. Of all the taps that I've tried, these are the easiest to use.

I tap using a clever little device that holds the tap square to the work and then use either the hand powered tap or chuck it in the drill, depending.

If using a (battery) drill, use a low speed and 1st gear, and cutting oil. Set the torque down low, & turn it up until it works, then up another notch.

Treat it like a hand tap if it is a hand tap, & spin in forward and back to clear the swarf out.

Being out of alignment with the hole is the main reason for snapped taps. Forcing the tap will break it, but the torque seeing will prevent breakage if you were careless, & you need to reverse a turn to clear it out before going forward again.

The speed and ease of tapping holes like this is a dream compared to doing it by hand, & you won't snap any taps. I do quite a few mild steel (laser cut) holes on some things, and have no issues.

But do buy a bottle of cutting fluid. It makes for an easier job.

Sent from my SM-N9005 using Tapatalk

Manual tapping went fine for me. What worked:

1. Also faced the common issue of the tap not fitting into the jaws. Didn't want to risk forcing the brittle tap into the the jaws, so instead, used the smooth end of the metal bar that slides into the tap holder as a tool to pry open the jaws manually. Made sure I applied pressure down as centered as possible so that the jaws would open up evenly. Then used a smaller diameter Phillips screw driver to pry them even further until the tap slid in almost hitting bottom with no problem.
2. Tightened that nut thingy around the jaws as much as possible until it could screw on no further. I used a vice to hold onto the bolt, and used the handle's own bar as a lever to tighten it (talk about re-use!).
3. Vice.
4. WD-40, nothing sophisticated.
5. First two to three turns I just had to trust would cut into the material and the tap would then automatically align itself via the extrusion holes.
6. After that, followed Ing Chao's recommendation of 3/4 turns CW, 1/2 CCW, 1/2 CW, 3/4 CW... etc [1].
7. Tapped 20 mm holes on both ends of the Z-rail (for both practice and foreseeing the Acme Lead Screw Upgrade [2]) going the full length of the tap. Also followed Ing Chao's recommendation of only going 3/4 of the tap if going all the way, then twisting it out, then re-lubricating. Further, used an air canister to blow out all metal shards from the hole, and an old toothbrush to clean the tap before re-entry, per Brian Dickman's sweet video [3].
8. For consistent ~12 mm taps across all other rails, I applied heat shrink tubbing on the tap to limit its depth. Didn't want to go too deep, waste time and material, or too shallow and have a hanging screw.
9. After I got the hang of it, watched TV after rail two, and went through 20 holes before I knew it.

Really really did not want to invest in more tools and time to get this step out of the way, so many thanks to those who provided answers using most of the tools we already had to work with!

[1] http://shop.shapeoko.com/products/shape ... -upgrade-1
[2] http://www.shapeoko.com/forum/viewtopic ... 603#p19766
[3] https://www.youtube.com/watch?v=ajg_kjLj5tY