Having had the CTC Printer ac couple of weeks now, and enjoyed every minute I first did a modification to the HotEnd Fans to make adjusting the nozzle heights a Breeze. Ok, well this follows on and adds to the Ease of use. The Spring Loaded Feeder system isn't new, but apart from some nice looking Printed variants, there wasn't really a Metal version that suited me. So after a trawl through Ebay, I found a kit of Metal parts that looked promising for under £10 a kit. Well the first problem was the way CTC mount the HotEnds in that they are joined together with a 15mm square beam, and the kit comes as a stand alone Replacement kit.
So that was the first part of the kit to go in the 'Might Be Usefull One Day' parts box.
The second part to join it was the Traction Gear wheel, as I wanted to retail the original so as not to have Calibration problems. The Crank arm fitted (nearly) it needed shimming out to line the very nice grooved bearing with the throat of the Nozzle, so to was the Spring, Spring cap (an M5 short allen screw) and a tension adjusting Allen screw. So we've kept about half of the Kit... :)
Scope:-
1) To manufacture a viable Spring Loaded feeder for the CTC.
2) The Crank arm used must be Metal (not keen on the Plastic varients (personal choice).
3) The geometry of the Nozzles or the Gearing (Traction Gear) must stay the same.
4) Ease of Use.

So here it is....
In the kit there is a small screw which is used to retain the bottom of the tension Spring.
Not wanting to drill and tap a hole for it in the existing Nozzle Mounting Beam I came up with a Plate that sits around the top of the Nozzle Throat, with a location peg for the Spring to sit on. (These are Left and Right Handed BTW). To fit the crank arm there is a Shim that fits on to the Stepper motor body, then a 4mm washer was used between the crank arm and the Shim to get the Crank in position. Lastly, another 4mm washer was used behind the grooved Bearing to finaly aline everything with the Nozzle Throat.
One last thing to do to the Crank was to open out the Filament hole to 3mm, to give the filament some extra clearance.
I'll let the pictures do the rest of the talking... Oh one last thing the Shim Plates are Left and Right handed BTW.