Im converting an old Walthers GP40(I think its a GP40, theres no model number on the frame). Am I correct in thinking that when Im done the motor should not be touching the frame?
http://mwcohio.blogspot.com
They key is that the terminals where the two wires for the motor must be isolated from the frame. This does not necessarily mean that the motor shell can't touch the frame as it may not be electrically connected to the terminals.
Here is an installation photo set from the TCS site http://www.tcsdcc.com/public_html/Customer_Content/Installation_Pictures/HO_Scale/Walthers/GP382/Walther_Gp382.htm
is it similar to what you are doing? If so, it looks like this might be a split frame installation where the motor terminals touch the frame? In this case the frame conducts the current and you have to wrap the motor terminals with insulation tape once you have soldered on your new wires.
What you need here is a meter with an Ohms reading so that you can make sure there is no connection. Fully isolating the motor brushes/terminals is an essential part of the decoder installation.
Simon Modelling CB&Q and Wabash See my slowly evolving layout on my picturetrail site http://www.picturetrail.com/simontrains and our videos at http://www.youtube.com/user/MrCrispybake?feature=mhum
Thank you Simon. I now have my first working DCC locomotive! Cant wait to do a few more and PLAY!! Mark
simon1966 They key is that the terminals where the two wires for the motor must be isolated from the frame. This does not necessarily mean that the motor shell can't touch the frame as it may not be electrically connected to the terminals. Here is an installation photo set from the TCS site http://www.tcsdcc.com/public_html/Customer_Content/Installation_Pictures/HO_Scale/Walthers/GP382/Walther_Gp382.htm is it similar to what you are doing? If so, it looks like this might be a split frame installation where the motor terminals touch the frame? In this case the frame conducts the current and you have to wrap the motor terminals with insulation tape once you have soldered on your new wires. What you need here is a meter with an Ohms reading so that you can make sure there is no connection. Fully isolating the motor brushes/terminals is an essential part of the decoder installation.
While I don't disagree with anything Simon has said, wouldn't the safer practice be to completely isolate the motor from the frame, that is, not have any part of the motor touching the frame?
Rich
Alton Junction
Rich.
I thought we covered this in the prior S1 thread?
The shell or outside frame of the motor DOES NOT need to be isolated from the frame Unless one of the motor brushes can not be isolated from it. I have open frame motors that are screwed to the loco frame but the brushes are isolated from the frame by just a piece of wire insulation. I have seen one can motor that had a little copper contact crimped into the rim of the metal case that was contacting one brush contact. All you need is to cut it and solder the motor wire to the brush contact. Like Simon said, (Sorry Simon no pun intended) an ohm meter will be your best friend. Count on it for a confident isolation.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
Rich, agreed in the absence of a meter to verify that the motor shell is not electrically connected to the brushes it would be a precaution. On the other hand, if you know for sure that the motor terminals are isolated then it won't make any difference,
mwcohio Thank you Simon. I now have my first working DCC locomotive! Cant wait to do a few more and PLAY!! Mark
Excellent. Just apply the same basic principals to any other installation and you should have lots of success! Not sure what DCC system you use, but it is also good practice to first check the locomotive in the low current environment of a programming track. If you get shorts or problems there, they can be rectified before the loco gets to the high current environment and fries the decoder.
locoi1sa Like Simon said,
Like Simon said,
I would not mind that game so much if it actually worked!! The Wife and teenage boys don't seem to understand the concept
simon1966 locoi1sa: Like Simon said, I would not mind that game so much if it actually worked!! The Wife and teenage boys don't seem to understand the concept
locoi1sa: Like Simon said,
Simon.
Yes I have the same problem. Its tough when the dog is the only one who listens to you.
locoi1sa Rich. I thought we covered this in the prior S1 thread?
We did, but there was an ongoing concern expressed about even having a metal screw protruding through the frame, and that was even after using Kapton tape to isolate the motor shell from the frame.
Further 'complicated' by the fact that those motors mount the brushes in a plastic end cap, so even with a metal screw holding the motor in palce there's no way the frame will be in contact with the brush and therefore the motor lead fromt he decoder, which is the cause of the decoder going poof.
The key factor for isolating the motor in any decoder install is that the BRUSH wires are not in any possible contact with the track pickups, be that wires, clips, or the whole frame being connected to one rail. Sometimes this is more easily achieved by completely isolating the motor fromt he frame, other times it's easier just to isolate the brushes themselves. Either way is valid and safe.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
rrinker Further 'complicated' by the fact that those motors mount the brushes in a plastic end cap, so even with a metal screw holding the motor in palce there's no way the frame will be in contact with the brush and therefore the motor lead fromt he decoder, which is the cause of the decoder going poof. The key factor for isolating the motor in any decoder install is that the BRUSH wires are not in any possible contact with the track pickups, be that wires, clips, or the whole frame being connected to one rail. Sometimes this is more easily achieved by completely isolating the motor fromt he frame, other times it's easier just to isolate the brushes themselves. Either way is valid and safe. --Randy
Randy, I agree with you and Pete, and maybe it is overkill on the side of caution, but there were some dissenters on that S1 thread who still insisted that the motor mount screw be nylon. What can I say?
Ive successfully converted 2 Locos and am having a ball running them at the same time! I have a Digitrax System and am looking forward to discovering all of the different things this system allows me to do. Thank you guys, this is why I joined! My last layout was when I was 18, and at 52 Im amazed at the progression of our Hobby! Mark.