Proxxon PD250/E mini lathe - upgrading the fiddly gear wheel nuts скачать в хорошем качестве

Proxxon PD250/E mini lathe - upgrading the fiddly gear wheel nuts

The standard M5 nuts which Proxxon provides are fiddly to mount and they quickly start to dig into the grooves of the gear arm. The nuts shown here distributes the contact forces over a much larger area. They have 7 mm thread length compared to 3 mm for the standard nuts. They are much easier to fit. Their "bling factor" should not be under estimated. ------- Contents of this video ------------------------- 0:00 - Intro and problem description 0:50 - The solution: wider nuts! 1:43 - Mounting the gear wheels on the lathe 4:16 - Test run Dimensions ---------- Height: 7 mm Major diameter: 12.7 mm The parallel flat sides of the nut end has to fit in the groove of the gear arm: Diameter: 9 mm and 7.9 mm wide over the flat sides. Height: 2 mm above the base. No more than the gear arm groove depth. Thread: M5 The nut used for the 17 teeth wheel that sits on the lower track has to be reduced slightly for the teeth to engage properly with the 20 teeth lead screw gear wheel (L). As shown in the video I milled off a straight part from the perimeter that contacts the hub of the gear arm. (The nut shown in the first part of the video had to much material removed and was replaced during the making of the video. The correct one is shown in the section 1:25 - 1:42.) Procedure (Assuming that you have access to a lathe. ;-) -------------------------------------------------------- Put a piece of round brass rod, or whatever your favorite material might be, into the three jaw chuck. Face off the end and drill a center hole with a center drill. Turn the diameter to 12.7 mm. Why 1/2" ? Maybe it is a homage to imperial units from a metric guy, I'm not sure. Make three shallow cut off grooves. Drill a 4.2 mm hole for the thread and use a M5 tap. Your tap may be to short to tap to full depth, in that case continue the threading when one or two nuts have been cut off. Reduce the front end diameter to 9 mm, 2 mm deep. Tidy up the edges. Cut off one nut, and so on ... To make the flat sides of the 9 mm part I used an end mill, but it should be straight forward to make it with hand tools. The dimensions are not very critical. The part should fit in the gear arm groove and run smoothly, even across the kink.