Tapping 8020 Extrusions

clutzer said:
rst said:
I tap with my M12 milwaukee all the time.  What you need is considered a gun tap.  Use slow speed and constant pressure and use WD40 or dedicated aluminum thread cutting fluid (available from machinist suppliers... Fastenal, MSC, etc).  8020 material is amazing stuff.  Their 15 series works perfectly with Festools clamps.
I downloaded their SketchUp profiles for their extrusions and the ones with slot width of 0.32" or 8.14mm seem like they would be extremely tight with Festool clamps.  Can you confirm some of these dimensions with your own experience?

Note: my Festool clamp dimensions are purposely proud by a tiny fraction of a millimeter.

Either 15 or 40 series work with the Festool clamps, no problem. They are actually kind of loose.

RMW
 
Taps bind quickly when chips have nowhere to go.

I get wanting to do it faster however you're not just risking a $10 piece of AL.  Since time is limited A broken tap (~$10) also risks stopping what I'm doing and driving to the hardware store (time) to buy 2 more taps (I did just break one so buying only one more would be stupid ~$20).  I've just learned the hard way more than once - slower is faster.  I've probably personally saved thousands in consumables, materials, and hours in time following this simple rule.  I follow it even though I have maybe a dozen of the taps too.      Maybe that's why I still have a dozen (shrug).
Well, all I can go by is practical experience.  I bought a 3 pack of cheap taps from Amazon, proceeded to tap over 50 holes and I still have 3 cheap taps from Amazon, with the first still cutting fine.  No wasted aluminum, no wasted time.  As I said before, everyone has their own approach to these things.  I value my time and will usually take the opportunity to produce good results in less time even at the risk of some failure.  I am not an engineer, but I have read some opinions that the impact driver actually outs less stress on the tap than the torque of either a manual tap or a drill.  Seems like you have an approach that works for you- I was just posting my own experience for those that might be wired more like me.
 
When tapping you want to jog the tap in and out repeatedly.  This is how tapping machines work, it drives until a preset torque and then backs out and restarts.
 
I machine and tap aluminum on a daily basis; lots of 2-56 holes. The best solution is a roll or form tap. It produces a stronger thread, is chip free and the tap is much stronger than a similar sized cut tap. Works well for materials no harder than mild steel, but best for non-ferrous materials.

The only issue is that the hole diameter to be tapped is larger than for an equivalent hole diameter for a cut tap.

I have linked a chart:  http://www.championscrew.com/form_tap_drill.htm

You may have to drill/ream the extruded hole pattern of the 80/20 cross section for form taps to work.

I have power tapped larger taps sizes successfully with a cordless drill and without a guide, but I'd probably avoid anything under a 4mm or #8, and even then, tapping true to the hole centerline is iffy, and could still cause breakage.

Tom
 
rst said:
When tapping you want to jog the tap in and out repeatedly.  This is how tapping machines work, it drives until a preset torque and then backs out and restarts.

Old technology. Tapping is not done this way any more in the modern world. Hand tapping with "Hand Taps", yes, but many posters have emphasized the use of spiral flute points. In, Out, Done.

This thread illustrates the point there are many ways to get this job done. It is a bit like getting advice on breaking in an engine after a rebuild. Ask ten guys, get ten answers. Most poster could have started their post with that comment and then written: "Add this technique to the list that work."
 
tomsharres said:
I machine and tap aluminum on a daily basis; lots of 2-56 holes. The best solution is a roll or form tap. It produces a stronger thread, is chip free and the tap is much stronger than a similar sized cut tap. Works well for materials no harder than mild steel, but best for non-ferrous materials.

The only issue is that the hole diameter to be tapped is larger than for an equivalent hole diameter for a cut tap.

I have linked a chart:  http://www.championscrew.com/form_tap_drill.htm

You may have to drill/ream the extruded hole pattern of the 80/20 cross section for form taps to work.

I have power tapped larger taps sizes successfully with a cordless drill and without a guide, but I'd probably avoid anything under a 4mm or #8, and even then, tapping true to the hole centerline is iffy, and could still cause breakage.

Tom

Forming taps are cool but in 8020 that would require opening up the holes and in some profiles there would likely not be enough material to withstand the outward pressure and the walls may crack. I like forming taps when they can be used because there are no chips to deal with.  [thumbs up]
 
Since this thread has started up again, I thought I would share my experiences and offer a few comments.

First, the extrusions don't seem to put much strain on the taps.  I have now made 5 different tables for different purposes and have yet to dull my first tap.  A while back I noticed what happens to the material being removed to form the threads.

[attachimg=1]

I also should point out that I use the 40 series light extrusions as opposed to the ultra-light that RMW uses.  The difference is that mine only have the circular hole without the "wings" that his have.  This should make mine more of a challenge to tap.  But as you can see it simply pushes the waste up the hole in a spiral.

I personally don't see much application for the drill and tap taps ( it doesn't look like it would cut threads deep enough) but find the speedtaps interesting.  Also just because they can work in an impact driver doesn't mean that they have to be used in one.  I find the hex head the most interesting thing about them.  Also all their mention of plate thickness seems to be just that, steel plate.  I would like to hear any experiences with this application.  But before I try it, I need to wear out this tap first.

Dick Perry
 

Attachments

  • DSC01226.JPG
    DSC01226.JPG
    79.9 KB · Views: 1,223
Back
Top