Need some speed tips for getting a project done faster.

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Builder01
Posts: 405
Joined: Mon May 18, 2015 5:26 am
Location: Erie, PA

Re: Need some speed tips for getting a project done faster.

Post by Builder01 » Sat Feb 03, 2018 2:40 pm

The photo several posts above, shows what can be done with no power feed. The finish on the parts have in no way been polished. This was all done by feeding by hand. Sure you can have power feed, but, it is not necessary. Power feeds do not necessarily give a better finish than turning the wheels by hand.

What power feed is really handy for, is when you have extremely long cuts on a mill or lathe. I remember setting things up at many of the machine shops I worked at, and the cut would take an extremely long time to finish. No one wants to cut a stainless steel propeller shaft or steam turbine shaft with no power feed. But, miniature locomotive parts, it is not necessary.

David

Harold_V
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Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Need some speed tips for getting a project done faster.

Post by Harold_V » Sat Feb 03, 2018 4:50 pm

Builder01 wrote:
Sat Feb 03, 2018 2:40 pm
Power feeds do not necessarily give a better finish than turning the wheels by hand.
In general, power feed does provide a better finish, as it is consistent. The finish, what ever quality it may be, will be far more consistent. Hand feeding works, but tends to be irregular. It is unusual for anyone to be able to feed consistently, although that may not matter in some instances, or to some folks, who do not care about resulting finishes.

H
Wise people talk because they have something to say. Fools talk because they have to say something.

tornitore45
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Joined: Tue Apr 18, 2006 12:24 am
Location: USA Texas, Austin

Re: Need some speed tips for getting a project done faster.

Post by tornitore45 » Sun Feb 04, 2018 6:14 am

knurled wheels with square holes
While a "finger spin" small diameter tap driver for small taps is the way to go, filing a square hole is not going to be satisfactory.
Two set screw position radially half way up the axial hole will provide two flats to drive the tap and allow you to lock the tap if you chose to.

I have made a 1/2" driver for the very small taps and a 1.5" Disk to lock onto the smaller one for anything between #6 and #12 that require more torque that my arthritic finger can provide.
I usually power tap in Aluminum #10 or larger but depend on blind versus through and material thickness.

I quit breaking taps when I learned 2 things:
1) 100% is not necessary, 90% to 75% is perfectly fine for our kind of work and reduce breakage 100 folds.
2) Try to use mechanical alignment, whenever practical. If you start crooked (off axis) you are asking the tap the impossible. Unlike a drill bit the thread prevent to tap to self center and the deeper it goes the more off axis it gets.
Mauro Gaetano
in Austin TX

Pontiacguy1
Posts: 818
Joined: Thu Apr 26, 2012 10:15 am
Location: Tennessee, USA

Re: Need some speed tips for getting a project done faster.

Post by Pontiacguy1 » Mon Feb 05, 2018 2:10 pm

Most of your tap drill charts try to calculate the thread depth between 65% and 75%. echoing the above post: Any deeper of thread depth than 75%, and it takes a lot more power to tap with almost no additional strength in the threads. If you don't have one, get yourself a good chart with the tap drill sizes and also the clearance drill sizes for the common size threaded holes, and go with that. The chart I have on my wall also tells the tap drill sizes for all of the NTP sizes, and also the MTP sizes of taps. I've not seen another one with the MTP sizes called out on it, all the way down to 1/16". It also has all the taps down to 0000- 160. That's a little too small for me! The chart will also be handy for when you have a hole you need to make just a little bit larger than what it is. You can look down the chart to find your next biggest drill size, whether it be metric, number, letter, or fractional.

I also agree about starting a hole using the machine to hold your tap straight and centered on the hole. Even if you only put 2 or 3 threads in there, just the fact that you've started it straight will help you to break a whole lot fewer taps.

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