BT35 to BT30 Conversion parts?

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CNC Apprentice
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Joined: Thu 12 Sep , 2013 20:02 pm
Hardware/Software: Cyclone TU150E (Running KMotionCNC with Servos)
Novamill running V5
Triac VMC

BT35 to BT30 Conversion parts?

Post by moray » Sat 18 Aug , 2018 20:26 pm

Given the ever increasing rarity of BT35 tooling, I'm wondering what would be needed to convert from a BT35 spindle, to a BT30 spindle.

Comparing the Triac parts list (I can only find a parts list for the ATC spindle), to the diagram/parts for the VMC spindle (viewtopic.php?f=51&t=5484), I see most of the parts are the same.

The only differences appear to be the following parts
Spindle BT35-TR3/103, BT30 - TR3/103A
Drawbar BT35-TR3/703, BT30 - TR20/110
Drawbar collet BT35-TR3/105, BT30 - TR20/109
Number of disc washers/springs BT35 uses 52, BT30 uses 44.
Ball bearings (BT30 uses 5 off 0.25")

Now going by the VMC list, I see the key parts are listed except the spindle, and are available (or were in February..).
Are spindles still available?

I would probably buy everything internal to the spindle, so I'd be looking at the following list-
Drawbar - TR20/110 (now VMC/0107)
Limit Nut - TR3/113 (now VMC/0113)
Preload Nut - TR3/110 (now VMC/0111)
Springs - BI00196E (44 off)
Drawbar Collet - TR20/109 (now VMC/0106)
0.25" balls (5 off)
BT30 Spindle - TR3/103A
Plus it looks like there should be a grub screw in the drawbar collet, but I'm sure that's a minor thing to source.

Is this all correct?

Obiviously that doesn't include modifying the tool disc/holders, which brings me onto the question, are the springs (TR3/728A) and rollers (MCV2/711) still available?

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