Making 200+ Delrin Flange Nuts - Messy!

[widgitmaster]

In the beginning, I was cutting an 8 foot bar of 1.5 dia Delrin on the bandsaw in to 1.062 pieces! That was so much extra work, and a loss of much materal! So I bought a 90 deg head and a stub arbor for my Milling machine, along with a 1/6" x 6" dia saw.

Now my shop looks like a blizzard in Florida! The saw cut the parts really nice, the finish was excellent because I stoned a slight radius on all the saw teeth! The length held within .005 (due to chips on the stop), and a nice parallel cut!

Now I have eliminated a second opperation of facing the parts in the lathe, so next opperation is to set up the 3-jaw chuch on the mill to drill, Countersink, and 1/2-10 Acme tap all the Delrin blocks!

The next opperation is to screw them on a piece of Acme thread in the spindle of the lathe, and turn the flange and face slightly to true it to the thread.

Then my last opperation is to drill the 4 holes in the flange, then sell them on eBay!

If I only has a CNC MILL or LATHE in my garage!

Eric

[Geof]

Eric;

Be a bit paranoid about keeping the Delrin dust and chips cleaned up. Solid Delrin burns very well with an almost invisible flame, dust and chips can go up like gasoline. It is not a good lesson to learn from experience.

[widgitmaster]

No ShiI! Thats the 1st I've heard of that, and I've done a lot of delrin!

I don't think my new mill would look good with scorch marks on it!
Lucky for me, i'm a neet freak! I have vacuumed up the whole shop already!

Eric

[widgitmaster]

Today I drilled and power tapped the delrin parts with a 1/2-10 ACME plug tap, then I turned the flange on the lathe! Next opperation is the 4-holes!

Eric

[widgitmaster]

It's been a long time sense I've worked on these! My shop has grown, and now I have a bigger lathe, and a used tapping head I won on eBay!

I found a tool holder that fit the 5/8 shank on my tapping head, and mounted it in my lathe's tool post after dialing it in at spindle zero!

Then I took my 1/2-10 Acme tap and ground the shank down to 5/16 diameter with my surface grinder, to fit in my tapping head.

Then I held the delrin blanks in the 3-jaw chuck, and ran the tapping head into the hole.

Now that is 100 times easier than using the old 9x20 lathe with zero power!

[sanddrag]

Hrrm. Auto tapping machine in a lathe, that's a good idea, never really thought of that. I always just reversed the lathe motor. Of course I was using nice big LeBlonde lathes. I'm a bit concerned about reversing the motor (without stopping it) on my little Chinese lathe.

[widgitmaster]

Well, it's been a long time sense I've made a big batch (150) of Delrin Acme Flange nuts!

My shop has improved greatly, and I now have a few new methods for making them quicker and more accurately!

The first thing I did was to convert my new engine lathe to an 8-station turret lathe, and make an 8-position carriage stop!

Then I purchased a new 6" 3-jaw chuck with bolt on jaws! These are much nicer, as I immediately made two sets of jaws out of aluminum! The soft jaws can be precision machined to hold the Delrin blanks really true, so that a few operations can be done on the first side!

Then the blanks are held in a 3/4" 5C collet to finish the other side! Lastly I drill and tap the holes in my mill!

100 nuts takes about 2-days or 25 hours non stop!

[awemawson]

OK it's awhile back now and you've probably taken the fire precautions after Geofs post about delrin burning, but I can echo it from personal experiance. I was welding some sheet parts, needed a quick clamp to stop something moving, and used one of those 'squeeze up' jobs that work like the gun for a tube of sealant. It was a long way away from the welding area. Helmet on and welding away I heard a crash. Stopped to look and found that clamp had fallen off, rescued it and it had no pad foot. Looked at the sheet on the bench, and there was the pad burning with an almost invisible flame. A stray spark must have landed on it from perhaps 4 foot away.

[widgitmaster]

This weekend I spent a few hours running the lathe, and finished turning 150 blank flange nuts out of Delrin!

This task is much more efficient now that I have the 8-station turret, and the new 3-jaw chuck!

The 1st operation was to place the saw cut pieces in the bored out soft jaws, then set tool #1 to face the part. Then I made sure the facing tool stopped at the center of the part, and set zero on the dial. Next, I took a 13/32" (.4062Ø) stub drill and turned the shank to 3/8" (.375Ø) so that it would fit in my tool holders. The drill became tool #2, using the spindle zero setting on the dial. This tool did not require a stop to a specific depth, but one was assigned to that tool. The next tool is a 5/8"Ø 6-flute 90° countersink, set to a depth using stop #3. The next tool is a nice brazed carbide tool bit, with the long turning edge set parallel to the freshly faced part. Then I set the 4th stop to a depth of 5/8", and turned the blank to a diameter of 3/4" in one full depth pass. The last tool was a custom made thing from a broken 1/2"Ø shank end mill held at 45°, and it was set using stop #5 to put a slight chamfer on the part. That way I didn't have to put my hands with a file near those large spinning soft jaws!

The next operation was to use a 5C collet, holding the turned part on the 3/4"Ø to face the back side, chamfer the hole with the countersink, and turn the OD to 1 1/2"Ø

Now the parts are ready for the mill, where I will drill the 4-holes and power tap the 1/2-10 ACME threads.

VIDEO1 (82.34 MB) 1st operation
VIDEO2 (40.45 MB) 2nd operation


Widgit