Fixture Plate Suggestions

[RJS100]

I have some flat ATP-5 plate stock that is .75 thick that I would like to use to make a fixture plate. My plan is to screw some bocks to the underside that will register to one side of the T-slots on my X-Y table. I may also place the fixture plate on parallels in my vise (see attached).

Most of the hobby fixture plates I have seen have 1/4" x 20 threaded holes. Just a few questions:

1. Should the threaded holes go all the way through the plate to allow for easier clean up? This makes drilling them a bit more difficult.
2. Some of the plates I have seen alternate between threaded holes and bored holes. Do you think the bored holes are a big help? It seems that the bored holes would be more helpful for producing multiples of an item. This is not something I think I need.

Is there anything else I may add?

Best... Richard

[suntravel]

Typical I use these plates for CA mounting optional with holding screws custom for a part.

Holes for plate mounting recessed as deep as possible so I can flat mill the complete plate

viewtopic.php?f=66&t=10429

Uwe

[RJS100]

Thanks. I made a few tweaks. I have decided to use blind 1/4 x 20 threaded holes that are .625" deep.

Two questions:

1. I typically use pecking cycle when drilling the holes. With standard jobber length TIN coated YG1 P series drills. Can I drill these without the pecking cycle? I will need to drill about 180 holes.

2. I recently tapped holes to a depth of .525". I used MQL mist coolant. I have two 1/4 x 20 taps to choose from: One is a High-Speed Steel Chip-Clearing Tap, Uncoated, Closed-End, Plug Chamfer. The other is a Vanadium Alloy HSS Spiral Flute Tap, TiN Coated, Round Shank with Square End, Bottoming Chamfer. I have not used TIN coated one yet, but I like the bottoming chamfer. With about 180 holes to thread, do you think it would be possible to tap these holes with one step going to the full .625" depth? Do you think the TIN coated tap will work with just mist coolant?

Thanks as always... Richard

[suntravel]

I would peck with 2xD steps and use the uncoated tap with 1200 rpm

Uwe

[RJS100]

Thanks Uwe. Will do. I have only tapped a few holes at a time in the past. I got an error message that I do not fully understand when I use the tapping with chip breaking option in Fusion 360, so as a work around, I tap once to the 50% depth, then again to the full depth.

For what it is worth, I have posted the error message.

Thanks for all your help... Richard

[suntravel]

For a simple pattern of threads nothing is faster than Intercon to get the machine running...

Uwe

[suntravel]

Tapping with chip breaking is not supported in Centroid PP for fusion

But not to hard to change this.

Uwe

[RJS100]

No big deal. I will probably never have to tap this many holes again. Thanks for all your help.

I experiment with the uncoated vs. coated taps and the uncoated certainly works better. When I slowed down the TIN coated one to about 750rpm, it works ok.... just not great.

I really appreciate all your input.

Best... Richard

[RJS100]

Came out great! Thanks again.