Nifty CNC Machining

Various engine oil sump plugs, all machined from #4140 high tensile steel then chemically blackened for corrosion resistance. M14 x 1.5p are for Ford Ranger. M18 x 1.5p are for Hino trucks. M22 x 1.5p are for the customers own truck. Customers often provide sketches or samples to work from, reverse engineering is not a problem.

Life or death jobs...(namely to protect my own life or imenent death if I fail to do this NOW).
This job has been sitting on my bench for a week or so, it belongs to the most painful of all customers, my beloved wife. She nags like any other good wife does, until she gets what she wants, then moves on very quickly to the next project to keep me occupied, often before I've even started the previous ones.

Anyways, enough of that, this is actually the filter screen cover off my wife's beloved hairdryer. Yep! Super important, must be done now. She actually had the audacity to blame me for breaking the 3 tiny clip legs off the oem cover. Cheap plastic it was, now I machined a couple spares from acetal. So...she tried sourcing online which met with a fail and more whining, not from the hairdryer itself. Back they went. So...Friday arvo, and I've found a gap between jobs (put them all back to keep her happy). Well...I've done it, another happy customer.

Ps...its worth not being paid, she really does deserve me.

Repeat weekend work it is. 5/8" UNC stainless steel sockets. M20 x 2.0p stainless steel posts. M20 x 2.0p mild steel bosses.

Ok....1st up, forgive my poor photography and video skills. I know I'm terrible at it, we all have our ability limits. I'll try to put words and pics to what I have always done for nearly 40 years. It just works for me.

Soooo...some of you have asked how it's possible to complete a job with separate threads on each end in a single setup.on a single spindle machine with no sub spindle. Meaning both being right hand threads. A double engineers stud is the simplest shape as it's plain bar diameter with no shoulder or extruding shape to prohibit tool usage. In this case you could use the same tool geometry to perform both threads, only if they are the same pitch. 1st thread is standard right hand program, 2nd thread is plunged at 30degrees to the Z axis at the thread with then continued along Z axis to final length. I rarely do this. Spindle direction remains the same, clockwise M03. This method is not ideal as tool life is short. Advantage is job remains close to chuck as possible.

So...to tackle this I searched for a tool that would do what I wanted and found none available. That was a very long time ago, I have never seen one that will do this off the shelf, so I fabricated my own. I know some machinists will just use a grooving tool holder with 60 degree insert to gain the clearance. No good if back shoulder height is more than a few mm. They are just lazy. Think harder. How do you get a right hand toolholder to cut a right hand thread backwards away from the chuck? You invert the toolholder of course. Problem!....it's now 25mm off centre, so no where near correct. Some machines can adjust tool centre height. The Hicell is not possible. Sooo...using a standard Seco snap tap insert threading holder, I milled it down to bare minimum size to retain the integrity of the holder, then welded it to a block of steel upside down and back to front with a 25mm offset to the X axis centreline. Simples. It ended up just 15mm wide, meaning my job standout from chuck only needs to be that much more than normal. Yes, you will get vibes if you are not in stable cutting conditions or RPM is too high, go slower, take smaller cuts. It works.

Programming...can be done left or right hand, you choose. I choose right hand then swap the Z start and finish values on the thread section. Do NOT forget to change M03 to M04 to reverse spindle direction or insert will not cut and will break.

In short, tool holder is standard right hand insert, modified to become upside down, back to front, 25mm offset, Q set as a left hand tool. Thread is programmed as if it was left hand but due to reversing the spindle direction it becomes a right hand thread up to a shoulder. I'll add pics and video in comments (as fb won't allow combined) to help explain it. I have included to program sections for each thread in the pics.

Any questions? Feel free to ask.

Another batch of Stainless steel surveying equipment mounting base plates completed.

Saturday arvo job for my son. He's building an 80's project car that needed a couple of inverted flare adaptor fittings. Fine, you can get those. M16 x 1.5p & M17 x 1.5p to 9/16 × 18UNF JIC taper seal. Oh, plus 8 mm longer as the threads bottom out so do not seal. Nah....you can't buy those off the shelf. So....a couple of hours from go to woah, sketched them up off the sample, conversational generated the basic shape on the Hicell, then hand edited the life out of the code to blend several programs into one. I even added my own custom macro code for polar interpolation the hexagon. 1 simple program, run in a single operation, no sub spindle or 2nd op. Done. 4.5 minutes cycle time, not bad for 2 off. If I was doing a production run, I'd edit more code to shave that down under 4 minutes.

Another batch of 6061-T6 aluminium air deflectors completed and delivered.

Another small top up batch of K1045 mild steel pins completed and delivered. Dia. 57.000mm x 146.60mm with circlip grooves. Nothing special but still 4 separate setup operations each to complete them.

Finally completed and delivered this job. I do enjoy Machining K1045 mild steel. It cuts perfectly, no real swarf issues, holds size and great finish. These repeats are sets of hinge pins with milled location flat and lubrication ports. The matching spacers and washers complete the sets. Lots of tooling, separate setups and operations. Alot of swarf. Alot of machine run time hours. Every job completed individually. Pics show various stages of progress, in no particular order though.

Just a little K1045 mild steel job, lots of machine run time hours, then this customer just doubles the order. Oh well....nice to be busy