dan jeavons shunter how to quarter
Bob Brown 1 | 15/04/2017 17:09:06 |
![]() 1022 forum posts 127 photos | Posted by Geoff Perkins 1 on 15/04/2017 13:50:02:
Hi Bob, that looks ok for smaller gauges (garden railway sizes) but not secure enough for 5" gauge where the coupling rods are doing all the work of transmitting power to the axles. My cranks also include counterweights and are therefore quite a bit larger. Mine is 5" and as I said 3 motors one on each axle
Edited By Bob Brown 1 on 15/04/2017 17:13:39 |
Perko7 | 22/04/2017 01:50:43 |
452 forum posts 35 photos | Apologies Bob, for some reason I assumed you were working in garden railway size. My loco is probably similar in size to yours but has a jackshaft drive with coupling rods connecting the jackshaft to the wheels as in the photo below: I am using a small petrol engine rather than electric, and for the sake of prototype accuracy have chosen to replicate the jackshaft drive, so my coupling rods are doing all the work. As this is my first loco I'm unsure of the stresses involved so wanted to be sure that it wasn't going to fall apart second time around the club track Having now used Loctite for a few things I'm a bit more confident in it's holding capacity, which along with my steadily improving machining skills may remove the need for 'safety pins'. Cheers. |
Perko7 | 06/09/2018 11:58:06 |
452 forum posts 35 photos | So, after about 18 months of procrastination (well not entirely, i've had a few other things to do during that time) I finally bit the bullet and got around to fitting the external drive cranks onto the axles and quartering them. Wasn't quite as hard as i imagined. First I made a drawing of a jig that would hold the axles and drive cranks in correct alignment and welded it up using 5mm steel strip. This is helped by the presence of dimples in the axle ends from when i turned the axles between centres, so i turned down the end of some M5 bolts to a nice cone shape, drilled and tapped some holes in the jig, inserted the bolts and tightened them into the axle holes. That kept the axle in place while i aligned the cranks. First i drilled and tapped an M5 hole in the side of each crank so that i could insert a grub screw to clamp it to the axle. I then fitted them temporarily onto the axle ends (easy push fit), quartered them in the jig, and tightened the grub screws. After checking that they were in fact quartered correctly, i loosened the grub screws, removed the cranks and drilled shallow holes in the axles at the grub screw locations. Reassembled again and checked for correct quartering when the grub screws were tightened into the holes, then pulled apart, applied a well-known anaerobic retaining compound, re-assembled in the jig, tightened the grub screws and checked alignment one last time before allowing the retaining compound to set. All the above took about 2-1/2 hrs including cups of tea. Axles now re-mounted in the chassis. |
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