the 21tb and the 21 i tb Fanuc

Hello all Merry Christmas,
I have a question what is the difference between the 21tb and the 21 i tb Fanuc lathe control is it simply that the I model has the manual I guide? And is it possible to upgrade the 21 to a 21 i and what might be the approx. cost for the upgrade.

There is a couple years difference in release dates for those controls.

The 21TB could have machine builder developed conversational programming for a lathe. There was an option called MMC-IV which was Fanuc's Man Machine Control type 4. It was an add-on board that was basically a PC piggybacked to the control. Conversational programming for a mill was available as a Fanuc option.

The i series controls have the PC integral to the main board. Conversational programming for mills or lathes was available as a Fanuc option or could be implemented by the machine builder.

The hardware between the standard and i models is different. Upgrading a standard to an i would require replacing he entire control.

The following text is how Fanuc describes the 21B series....

This compact CNC provides carefully selected functions best suited for
controlling small machine tools. It is intended for use in low–end
machine tools, but equipped with advanced microprocessor and servo
control technologies. It supports high–speed, high–accuracy,
high–efficiency operations for machining. Moreover, this CNC can be
incorporated with the personal computer functions compatible with the
IBM PC (*) in order to differentiate it from other CNCs and to enhance
the machine tool functions. The personal computer functions, in
conjunction with the conversational automatic programming function for
machining center, will contribute to the production of easy–to–use
machine tools.

This text is how Fanuc describes the 21i series.....

The FANUC Series 16i, 160i, 18i, 180i, 21i, and 210i are super–compact
ultra–thin CNC models with built–in liquid crystal displays. Each CNC
unit is a mere 60 mm deep and features, immediately behind the liquid
crystal display, a small CNC printed circuit board developed by utilizing
state–of–the–art LSI and surface–mount technologies.
Super–compact ultra–thin open CNC models are also available. The
CNC printed circuit board incorporates PC functions that are fully
compatible with the IBM PC(*).

Looking at the Fanuc timeline, 21TB is from 94-97 and 21iTB is 2005-2010. 21 series have the Super CAPi conversational programming.
I think Manual Guide I started with the 31i models.

Fancuku said:

Looking at the Fanuc timeline, 21TB is from 94-97 and 21iTB is 2005-2010.

Click to expand...

I think the 21-TB was in production for quite a bit longer than that, my Emco Turn 325 has the 21-TB control and was built in 2000, I've seen lathes with it that were built as late as 2004 with it too.

I hadn't actually realised there was a third version of the 21 lathe control until this thread though, I have the 21-TB and 21i-T but hadn't heard of the 21i-TB before but a quick search shows it was put on some Harrison Alpha flat bed lathes.

The main difference that I've noticed between my controls is the 21i-T is much more compact, the display unit is the whole control plus a power supply and servo amp in the electrical cabinet, on the 21-TB the control unit is mounted next to the power supply and servo amp in the electrical cabinet and is far larger.

The impression I get is that the 21-TB was the cheaper option and used where more space was available, the 21i-T was used where the compact size was important, the 21i-TB seems to have some sort of conversational programming option. I'd imagine upgrading from say a 21-TB to 21i-TB wouldn't be worth the cost of doing but if you wanted to do it I'd contact someone like DNC Electronics and ask them for prices on the parts that you'd need to do it.