# Practice Posting >  Video that came before the last one

## mastersdlm

This was part 2 of the tool holder build. Technically 2.1  :Smile:

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## jimfols

I fast forwarded through the whole thing. Please let me know if I missed anything.

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## Okapi

Sorry, but I can't understood the precise use of the tool excepted for the bar in the third video, my english is not good enough and the sound is very loud, you use it to cut in one operation multiple depth, but can you modify those values without grinding the cutting tools ?

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## mastersdlm

Yes. I can adjust the depth by loosening the setscrew. This isn’t a precise project. It has no tolerances or really even set specifications. I just need to be able to knock them out as quickly as possible.

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## mastersdlm

Will do

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## Okapi

Ok, thanks, as a non english natural tongue guy, it was not totally clear for me what was the precise project. ;-)

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## Toolmaker51

> Sorry, but I can't understood the precise use of the tool excepted for the bar in the third video, my english is not good enough and the sound is very loud, you use it to cut in one operation multiple depth, but can you modify those values without grinding the cutting tools ?



Holders of this type are called 'gang tools'. By positioning cutters for simultaneous action, this saves spindle time, part handling, and tool post locations. Two main cases are duplicate parts at once, or several features on one; either particular method can increase production. 

Utilized on a single item at a time, some cutters are often form tools.
I'm sure it would take some planning, and an accurate setup, but certainly has been used to step out multiple parts by moving the carriage by same increment as tool spacing. 
There are QCTP holders made for holding multiple bits, though not wide as this shop made version.

If someone needed a larger quantity of parts, this is probably #3 higher method over normal single part, single bit work on engine lathes.
#2 likely installs a QCTP and variety of holders. This saves material handling by tool changing to complete at least one end of an item.
#4 might add turrets to carriage or tailstock.
That's about far as it goes a single spindle manual lathe.

Next could be screw machines like Traub or Brown & Sharps; continually fed barstock, turning and parting off where slides encircle the spindle and cams advance tools in succession. Form tools are utilized largely here.

Next are multiple spindles -Davenport, ACME Gridley, New Britain etc; that have separate toolsets at each spindle. Like screw machines, only suited to large quantity, these spindles are spread over a larger area to run bigger diameters.

All of these exist in the manual realm, each evolved into CNC.
Somewhere in that evolution, the Swiss type was born, which sort of combines all of these operations along with indexed milling and cross drilling. Both the 'carriage' and bar move to create feed. . .

Those brand names are machines as well as patterns - describing arrangement of functions - built by others too.

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mastersdlm (Apr 6, 2019),

Okapi (Apr 1, 2019)

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## Okapi

Thanks for those explanation Toolmaker, this is a tool we never use or learn to create in toolmaker formation when it exist again, I just see one in use in France by an old worker who makes miniature cannon barrels in bronze years ago, my small experience in making multiples is with turret head or with the Schaublin rotating tool holder out of the normal use of my favorite Tripan system(never made more that 10 similar pieces excepted screws at my workshop… :Headshake: ).

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Toolmaker51 (Apr 2, 2019)

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