Hi all, I need to replace the small metal screw (that holds the motor to an Atlas Alco S2 locomotive) with a plastic screw in order to isolate the motor from the frame so I can add a decoder for DCC. Anyone know where I can locate small plastic screws? I've tried EBay and Amazon, but can't find them anywhere. I think the screw may be metric as the Atlas engine was made in Austria, but I can't be sure. The threaded shaft is 5mm in length and with the flat head, add another 1mm for a total of 6mm.
both ebay and amazon have plastic screws, both inch and metric
Does this look like your Atlas S-2?
https://tcsdcc.com/installation/ho-scale/1900
This only shows three pieces of kapton tape to "isolate" the motor pickups from the frame, no mention of using a nylon screw.
Maybe yours is older?
As long as each brush holder does not touch the frame or if it has a can motor you don't have to isolate any further.
Good Luck, Ed
The motor in the P2K Alco switchers looks exactly the same, and when I did one of those, the metal frame of the motor did not touch either brush holder, so the metal screw holding it in place did not violate any isolation. However, multiple sources have said the motor used int he Atlas model does short the metal case throught he brush. I have an older Atlas (made by Roco) S2 that I have yet to take apart and look into to see if this is the case or not.
Easy enough to test - meter on continuity, touch the probes - should beep. Touch one probe to the metal frame part of the motor where the screw goes in (in the screw hole migth be best - that way there's an area cleared of paint) and touch the other probe to each brush cap one at a time. If no beeps - then there is no reason to use a nylon screw, a metal screw holding the motor in place won't connect the chassis to the brush. If it does beep (and only one side would beep - if both sides beep, thent he motor is always shorted, in which case it never would ahve run), then a layer of kapton tape plus a nylon screw will be required to keep the brush isolated from the chassis.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Hello All,
Check out Micro Fasteners.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
You might try using some Kapton tape to insolate the motor from the frame then use some glue like Amazing Goop to hold the motor using the metal screw to keep everything in place until the glue dries then remove the screw. I’ve been using Amazing Goop to mount motors for years and it not only holds very good but it also absorbs motor noise and vibration.This motor is attached to the frame using Amazing Goop.Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
Using standard measurements, I show 10 tpi (5/16 in length) by 1.5mm (diameter). The hole size is 2mm. Yes, a very small screw. I already have Kapton tape covering the frame where the motor will sit, but the screw was meant to secure the motor. I guess I can use glue to do that as one other modeler suggested. Because I'm installing a new LokSound decoder, I do not want to risk frying $85.
Thank you.
JRP
Sounds easier. Thanks Mell.
Do test it with a meter, that way you will be sure.
Agree. Thanks Randy.
The Amazing Goop can be really messy to work with, sticky and stringy, but it’s my go glue for mounting motors. Great glue and has terrific holding power. If you error or for some reason want to remove the motor a firm grip with a twisting motion the motor will come off.Both the Canon EN22 motors in my Mel Rivarossi Cab Forward brass frame are mounted with Goop.Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
I did the meter test and did not get a beep sound when I touched the probes to the screw in the frame and the brush cover. I do have Kapton tape covering the frame base and narrow sides where the motor sits, so I think I'm good.
To isolate or set the motor in place, I glue two strips of plastic on the frame using CA, leaving space bewteen them, and I used silicone caulk to glue the motor. The space betwen the plastic strips allows the silicone to reach the frame directly for a good firm grip. The strips are really there to prevent the motor from touching the frame despite the use of caulk. I like caulk because it is very easy to remove in case I need to disassemble it for some reason. It happens...
Simon
JRPI do have Kapton tape covering the frame base and narrow sides where the motor sits, so I think I'm good.
Keep in mind Kapton tape is a relativly thin material and subject to wear through repetative movements. It also doesn't have a high-tack strength like other tapes.
I use Kapton tape too but when I need to be absolutly sure of electrical insulation and longevity I use 3M doubble sided foam tape- -if there is room. Air is one of the best insulators- -the air bubbles in the foam, along with the foam it's self, acts as an insulator.
The resilency of the foam also provides a cushion between the parts being insulated during repetative motion.
When there is not enogh room for doubble sided foam tape I use Liquid Electrical Tape. This is available at most hardware & home improvement stores.
Be aware that this product is spirit based and should be used in a well-ventilated area while applying and curing with no open flames.
Silicone caulk is also another good insulator with less volitile fumes. The fumes that silicone caulk emits during curing can be a deal breaker for some.
Keep in mind electricity is the lazyist force in the universe- -second only to water.
It will always seek the path of least resistance, no matter how small.
Any breach in the insulating material will allow the electrons to flow and release the "magic blue smoke" that make the component(s) work.
Even just doubbling-up on the Kapton tape will provide a little more insurance against the electronic gremlins.
Post Script: This is why I use Digitrax decoders. They have a "no questions asked" return policy. Even if the malfunction is your fault they will replace the blown decoders. H.T.H. J.J.D.I.
Last thing I learned to do is use the program track, FIRST.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.