I ordered some DW Switch Motors SM-903 plus some other manual switch throws for other turnouts. I opened a SM-903 last night and could not figure out from their diagram (nor their website photos) how the 2 smaller parts attach. The two small parts go on the outside of the main parts, but there's a pin on each that could go into something but only one hole in the side of the motor.
Well, today I did what is often suggested here and did a search for images and the 3rd one was spot on. So, I thought I'd share it here (and attach its link) in case the assembly of this item is confusing for anyone else.
https://www.google.com/search?q=railroad+switch+motor+image&rls=com.microsoft:en-US:MIE-Address&tbm=isch&tbo=u&source=univ&sa=X&ei=BVuwUsiuGIjo2AWm-oGQCQ&ved=0CC4QsAQ&biw=1366&bih=753#facrc=_&imgdii=_&imgrc=DsQeUnqzFUh-bM%3A%3BilGXkMwsA4TTaM%3Bhttp%253A%252F%252Fpsdcovers.s3.amazonaws.com%252Fwp-content%252Fuploads%252F2012%252F05%252Fswitch-machine.jpg%3Bhttp%253A%252F%252Fwww.psdcovers.com%252Ftag%252Frail%252F%3B2122%3B1600 P.S. - what glue to use on these white metal parts? CA (I use Superglue gel)? Other? P.P.S. - the left level I can tell is a manual throw. What is the smaller right lever? A dis-engager for the manual or the electric function?
https://www.google.com/search?q=railroad+switch+motor+image&rls=com.microsoft:en-US:MIE-Address&tbm=isch&tbo=u&source=univ&sa=X&ei=BVuwUsiuGIjo2AWm-oGQCQ&ved=0CC4QsAQ&biw=1366&bih=753#facrc=_&imgdii=_&imgrc=DsQeUnqzFUh-bM%3A%3BilGXkMwsA4TTaM%3Bhttp%253A%252F%252Fpsdcovers.s3.amazonaws.com%252Fwp-content%252Fuploads%252F2012%252F05%252Fswitch-machine.jpg%3Bhttp%253A%252F%252Fwww.psdcovers.com%252Ftag%252Frail%252F%3B2122%3B1600
P.S. - what glue to use on these white metal parts? CA (I use Superglue gel)? Other?
P.P.S. - the left level I can tell is a manual throw. What is the smaller right lever? A dis-engager for the manual or the electric function?
Paul
Modeling HO with a transition era UP bent
Paul,
Those DW switch motors are tough little buggers to clean up and assemble, but they sure look good. Like you said the instruction diagram isn't clear. I was going to use expoxy, but ended up using superglue. Not sure the purpose of the smaller lever. There appears to be two shallow holes on the side of the case for the lever pins. I opened the holes up with a drill bit so the pins would fit and go all the way into the case. I suspect there are and were more than one mfg. of prototype switch motors and so different configurations.
regards, Peter
Thanks, Peter. Now that I see that the foot of the two small pieces goes on a tie position I can see which dimples the pin should locate to. I hope I can clean off the flash without breaking the fragile small items. The detail, as you note, is impressive and they will be a nice addition.
I'll bet you're correct in thinking that the smaller lever is the motor disengagement for hand throw operation. I know that motor actuators for valves have a similar disengagement lever for handwheel operation.
Was watching a reality show about the Alaska Railway on TV last night and one segment showed a track crew freeing up the frozen point rails of a switch. The switch motor couldn't move the point rails full travel because the switch heater had failed. Seeing those guys having to sledge-hammer the ice from between the point rails in order to hand throw the switch takes some of the romance out the railroading.
Hello, all. Another question...are the two tie mounts (the base of the SM903) meant to be glued atop the long ties that parallel the throwbar, or cut the two plastic ties shorter and make the metal ("tie mounts" an extension of the plastic. Or, should I delete the tie mount base and glue the mechanism to the plastic long ties? I'd like to do it right if I'm going to do it.
The DW photo is not clear enough on that aspect:
http://www.detailswest.com/images/wpe96778.gif
Though not clear in the photo of the installed SM903 on the DW website, it appears the metal mount head blocks should be an extention or placed at the end of the turnout head blocks. Laying the metal mount head blocks atop the turnout head blocks doesn't look right to me. I wish I'd thought about this placement before I installed and ballasted my turnouts.
Thanks, Peter. I just put two together. I'll test out the placement.
Update: It looks like in real photos that the electrical stuff sits on the ties (headblock). So I plan to go with your advice of using the metal tie mounts as tie extensions. I will need to shorten the plastic headblock ties appreciably and probably also narrow the throwbar extension slightly (by filing) so it can freely move w/o the metal headblock extensions interfering as it looks like the tie mounts are a tad narrow in spacing.
HO-Velo Paul, I'll bet you're correct in thinking that the smaller lever is the motor disengagement for hand throw operation. I know that motor actuators for valves have a similar disengagement lever for handwheel operation. Was watching a reality show about the Alaska Railway on TV last night and one segment showed a track crew freeing up the frozen point rails of a switch. The switch motor couldn't move the point rails full travel because the switch heater had failed. Seeing those guys having to sledge-hammer the ice from between the point rails in order to hand throw the switch takes some of the romance out the railroading. regards, Peter
The small handle is indeed a power off switch that enables manual control. Just be sure to get permission from the dispatcher before throwing it As to sledge hammers, I don't think that's realistic. The hammmer wouldn't fit between the rails. The pick on a switch broom is the correct tool. If that doesn't work then maybe a dull axe is called for! As a 30 year operating employee in Northern Ontario I've unstuck a fair number of switches in the winter!
Dean
30 years 1:1 Canadian Pacific.....now switching in HO
Many years ago I spent the night in a seedy motel across the street from this yard, the yard traffic was neat, the motel, well, that's another story. Anyway, I'm guessing the equipment cabinet in the photo might house the relays for the switch motors? You probably already know that DW makes some nice equipment cabinets to go with those switch motors. I just assembled, painted and weathered two of em' for my switch motors.
mactier_hoggerThe small handle is indeed a power off switch that enables manual control. Just be sure to get permission from the dispatcher before throwing it As to sledge hammers, I don't think that's realistic. The hammmer wouldn't fit between the rails. The pick on a switch broom is the correct tool. If that doesn't work then maybe a dull axe is called for! As a 30 year operating employee in Northern Ontario I've unstuck a fair number of switches in the winter!
Dean, Thanks for the info. My mistake, I carefully rewatched the frozen switch segment of the Alaska Railroad TV show and the crew was using what appeared to be a pick to clear the ice between the rails, not a sledge hammer. Might that be the "switch broom"? I would assume switch heaters have made life a bit easier on the track maint. crews.