Hi everyone,
I have a problem with the couplers on my two RMT Budd cars and two Beeps. When activated by the Lionel remote control track I have found that the pistons on the RMT couplers will not move down by themselves but, due to free play in the pivot point mounting of the coupler arm, the piston actually pulls the complete coupler arm down. Consequently the piston does not move with respect to the coupler body and the coupler does not open. This happens on all four RMT units. The pistons are free to move when activated by hand.
I suspect this is not a problem unique to only my RMT units so I am wondering what other people have done to overcome this?
Thanks in advance,
Neil
Neil, I have not experienced this problem with my Beep. You might try using some powdered graphite (available where keys are made) to help the plunger slide easily.
Dr John,
Thanks for your comments. I don’t think it is a lubrication problem. Last night I took a close look at everything.The problem is that the uncoupler piston is too close to the track so when the magnet is activated the head of the piston touches the magnet before the piston moves far enough downwards to allow the coupler jaws to open. It looks like the solution is to machine the shaft of the piston shorter by about 0.050".
Both Budds and both Beeps have the same problem. The head of the piston only clears the magent by about 0.020 to 0.030" whereas the movement required is about 0.050" to open the coupler. By contrast my Lionel switcher and cars have about 0.100" clearance. If I shim the entire Beep up on the track by about 0.040" then the coupler works perfectly.
As further proof some of the heads of the piston have scuff marks on them from dragging on the frog while crossing my track switches.
Looks like I will have to fire up my lathe and machine all of the piston shafts shorter. I guess that your units must have been made to a different specification. Or the quality control on these components leave a lot to be desired.
Neil
Good morning Neil, I believe I understand what you are talking about. But so we’re on the same page, your coupler has the following parts: the main coupler body arm, the rivet to hold the knuckle and the knuckle itself, the plunger armature or coupler arm (which can be one solid piece when it is made of metal) and a metal thumbtack which inserts into the coupler arm.
There are two things that can be a play here. One is the thickness of the thumbtack piece: when these are made of metal, the “thumbtack” part can be of varying thicknesses depending on the manufacturer. The other is the type of uncoupler track you are using.
I run cars from all differing companies and have noticed that some work better over uncoupling tracks than others. Sometimes it is the thickness of the “thumbtack” and some times it can be the thickness of the pin on the very end of the coupler arm that inserts into the knuckle itself and holds the knuckle closed. Sometimes these pins need to be filed down to allow better operation of the coupler.
Neil, you are right in the space observation between the thumbtack and the uncoupler track. But this can also be blamed in some part on the uncoupler track. I use 027 track and have noticed the metal stub in the center of the solenoid assembly on the newer 027 uncoupling tracks sticks up higher than it does on older postwar Lionel uncoupling tracks. Therefore, some cars uncouple better on the older PW uncoupling tracks than they do on the modern ones.
You could try grinding down the metal “thumbtack” if the coupler arm is all metal. Or you could try using a flatter thumbtack inserted into the plastic coupler arm if this is the case. This is hardly a unique circumstance to RMT products.
Take the older MDK K-Line classic line of cars with die cast sprung trucks and a plastic coupler armature. These cars have adequate clearance between the thumbtack and the uncoupling track, but don’t always operate well when over the UC track. The prob
Hi Brianel,
Thanks for your comments. I probably was not using the right nomenclature for the various parts but what I called the piston is what you called a thumbtack.
My thumbtacks are not varying in thickness of the head but rather the shaft of the thumbtack is too long so there is insufficient gap between the thumbtack and the magnet head.
I have one post-war Lionel uncoupler track and two new Lionel uncoupler tracks. I did compare them and they are all the same height for the magnet head.
I plan to grind off the rivet portion of the thumbtack shaft, chuck it in my lathe and shorten the shaft by 0.050" That should give me enough freeplay for the uncoupling action to work.
Neil