I recently had a problem with one of my HO steam locomotives. This locomotive had been painted in such a way that paint has adhered to the 4 axles of the drivers. The drivers would not move, I removed the superstructure and the electric motor in an attempt to try to turn the drivers. I had to loosen the bottom plate and pull each axle and manually turn each of the drivers to break the bond with the paint. I cleaned out the paint next to the axles and oiled the drivers/journals. I had removed a couple of the bolts holding a couple of the rods.After I had cleaned each of the axles and oiled them I replaced a couple of the bolts holding the rods, as well as the bottom plate and placed the locomotive on the track and moved it by pushing with my finger, it would just barely move. It still was not loose enough to roll without having to use more weight.I then took the engine off the track and moved it back and forth on a piece of cardboard for about 10 minutes. It was now loose enough that I could push the engine on the track and the drivers would turn. I replaced the electric motor and superstructure and attached the tender and the engine was now running fine.I now have a problem with one of the bolts holding one of the rods, it now loosens itself to the point it falls out. I had checked very carefully as I disassembled these bolts and there were no tiny washers or keepers in place that I could see.As the engine moves forward the pressure on this bolt from the rod is anti-clockwise, which of course is how this bolt is loosening itself.Any suggestions?
Don7,
Have you thought about using a product like Loc-tite thread adhesive? One of their products that I used to use on micrographics production equipment had a "service removable" type formula, so it would hold screws/bolts in place in applications prone to lots of movement and vibration, but still allow removal when needed. I don't know if Loc-tite still makes such a product, but somebody likely does. Maybe an auto parts store might sell something like this. Good luck.
Wilton.
I would try a tiny drop of Loctite on the threads of the bolt and then thread it back in and adjust the tightness.That should hold the bolt but allow it to be removed if needed.
Joe
Along, with loctite,there is a product, called, thread-loc, basically the same thing..
Cheers,
Frank
Don7.
The screw in question should be a shouldered screw. Tightening with a screw driver should be plenty tight enough. Is there paint on the rods that is interfering with the rotation? Cleaning out the hole in the rod and making sure the shoulder of the screw turns inside it freely should work.
I am always reluctant to use thread lock on such tiny screws I will need to remove later for maintenance. I do use the red high strength Loctight for holding drivers on the axles and flywheels on motor shafts.
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!
Wilton
Yes I immediately went looking for loc-tit or a similar thread adhesive. Just my luck it has to be ordered in.
The joys of small town life.
locoi1sa Don7. The screw in question should be a shouldered screw. Tightening with a screw driver should be plenty tight enough. Is there paint on the rods that is interfering with the rotation? Cleaning out the hole in the rod and making sure the shoulder of the screw turns inside it freely should work. I am always reluctant to use thread lock on such tiny screws I will need to remove later for maintenance. I do use the red high strength Loctight for holding drivers on the axles and flywheels on motor shafts. Pete
The screw is indeed a sholdered screw, it seems to tighten quite well, then later it is loose. I wonder who would be a good source for these shouldered bolts. At least it is on the last set of drivers so If the loc-tite arrives and does not do the job I will be able to use an oversize bolt/screw
JoeinPA I would try a tiny drop of Loctite on the threads of the bolt and then thread it back in and adjust the tightness.That should hold the bolt but allow it to be removed if needed. Joe
Yes, that is the route I will take. Had to order the stuff in so will take a few days. No hurry. this was one of my last winter HO projects, Will not do much more on the layout until the fall.
Clear nail polish on the thread of the bolt. Its cheap if your married and works as well as Loctite.
"The true sign of intelligence is not knowledge but imagination."-Albert Einstein
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One of the suggestions I received was to use a washer.
Apparently this would tighten up the connections.
I am confused by this, I had thought that the washer would be placed between the head of the bolt and the rod that as being held in place.
or would the washer be placed on the driver wheel next to the rod, with the bolt going through the rod, the washer and threaded into the driver?
Since this a shouldered bolt, adding a washer under the head is going to tighten up the drag on the rod. I would not do it.
Your problem is a very common one. You have correctly determined that the direction of the rod is loosening it. The fix is a drop of blue Loctite.
Jim
Soo Line fan Since this a shouldered bolt, adding a washer under the head is going to tighten up the drag on the rod. I would not do it. Your problem is a very common one. You have correctly determined that the direction of the rod is loosening it. The fix is a drop of blue Loctite.
Thanks for the reply, the use of a washer confused me. I could not understand how it would be benifical.
Yes the loc-tite is the route I will go.
There are two types of loc-tite, the red label for permanent placement and the blue, which will allow the bolt to be re-positioned in the future.
I wonder why I have not run into this before now?
I would advise against the use of Loctite, at least in the manner describe. On a small screw or bolt such as this, that drop of Loctite will be spread over the entire threaded surfaces as the bolt is tightened, and there's a good chance that you will never be able to remove it again. Any attempt to do so would likely damage the head beyond use or break it off.
Instead, insert the bolt and tighten it, then back it out a couple of turns. Working from the inside (rear) face of the wheel, apply the drop of Loctite into the inside end of the threaded hole, then re-tighten the bolt. The end threads will pick-up enough Loctite to secure the screw without locking the entire length of the threads, which should leave the bolt readily removeable when necessary while still keeping it in place in normal operating conditions.
If you don't have Loctite on-hand, put a small amount of contact cement on the end threads of the bolt and let it dry, as per the instructions on the container. There's no need to apply any cement to the threaded hole. Once the cement has dried, simply screw the bolt into place - the semi-hardened contact cement creates enough of an interference fit that it's unlike to wind out of its own accord, yet it remains easily removeable when necessary.
Wayne
It's always possible that the hole in the rod is too tight. Take the rod and the screw/bolt off and test-fit them together. If they're the least bit tight, a VERY gentle reaming with a round file should do the trick. With a shouldered screw, you should be able to crank the screw down quite snugly without binding the rod, assuming the shoulder it long enough. Also, if the rod is drilled even the slightest bit off-target, you can get a bind in the rod. With the rods all on, and without the motor, the chassis should roll very freely, with no signs of binding (hesitation, abnormal slowing) on a piece of plate glass.
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Gary M. Collins gmcrailgNOSPAM@gmail.com
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"Common Sense, Ain't!" -- G. M. Collins
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Thanks for the reply.
That is a great idea of using the bolt hole for placing the thread fastener
As I mentioned I will use the blue label Loc-tite, this variation allows for future movement of the bolt. Whereas the red label is marked as a permanent fastener. It cautions the user to consider if they use it it is a permanent fastner and the bolt will not likely move again. Hence, the blue label alternative..
gmcrail It's always possible that the hole in the rod is too tight. Take the rod and the screw/bolt off and test-fit them together. If they're the least bit tight, a VERY gentle reaming with a round file should do the trick. With a shouldered screw, you should be able to crank the screw down quite snugly without binding the rod, assuming the shoulder it long enough. Also, if the rod is drilled even the slightest bit off-target, you can get a bind in the rod. With the rods all on, and without the motor, the chassis should roll very freely, with no signs of binding (hesitation, abnormal slowing) on a piece of plate glass.
Thanks for the advice. I will double check the fit between the rod and the bolt before I use the Loc-tite. It is very evident that with the shoulder on the bolt that the rod is loose behind the head of the bolt and there did not appear to be any hesitation or binding after I had cleaned out the dried paint and oiled the axels and rod assembly.
Don,
If you find a bolt with loctite is hard to remove, simply heat with the tip of a soldering iron. Loctite is rated up to 300 F and completely breaks down at 480 F.
Wrap the driver with a wet rag to keep the heat from traveling and heat the screw head. Heat with 10 second increments. It will not take much to soften.
You have certainly received a lot of great advice. Doctorwayne was right on to suggest loc-tite on just the rear threads. This loctite product as aptly named. Where people sometimes go wrong is using the "permanent" loctite product not knowing about the "service removable" stuff. I think the permanent-type product has something like CA in it - it can be tough to loosen. Soo Line's idea to heat it to loosen it is worth remembering. This forum is a great resource.
I would like to thank everyone who has responded to this posting. I certainly have received a lot of excellent advice on how to cure my problem.
Thanks everyone
Hi DON7, You should have been able to find Loc-Tite products in small tubes at any good auto supply shop, (Advance, Car Quest, or the Zone.) or a good Ace H'ware. I remember selling lot's of it to the local hot rodders when I worked at Advance Auto. Bill
don7There are two types of loc-tite, the red label for permanent placement and the blue, which will allow the bolt to be re-positioned in the future.
There are quite a few more than two. The red is high temp semi permanent that requires heat and or special tools for removal. The blue is the next grade lower. Green is low strength and can be applied in advance and the fastener installed after it is dry. Yellow is a type of formula that wicks into the threads and is very low strength. These are the most common consumer Loctight products. All in all there are 17 different Loctight retaining products designed for the automotive industry alone. The last I heard from Henkel (owner of Loctight) there were 237 formulas of retaining compounds.
Just a warning from someone who uses and deals with the product everyday. Just a dab will do. I have seen the blue used to excess and end up ripping the threads right out of steel parts.