I just finished building eight Accurail autoracks and loaded them with vehicles for a test run. I've since tweaked them all I can and they still get into a wobble from time to time. It doesn't affect how they operate, it just looks bad seeing these cars wobbling like that.
There are small raised areas on the bolsters to prevent one truck from moving side-to-side and the other to prevent front-to-back movement, but it just doesn't seem to be enough.
Any ideas how to make these cars sit a little more solid on the track ???
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Have you ever watched real autoracks ??
Boy,,, do they ever wobble from side to side.
So I guess yours are just prototypical. Be Happy.
Long live the "Wobbly" You got to love the WESTERN PACIFIC.
James:1 Verse:5
from Saskatchewan, in the Great White North..
We have met the enemy, and he is us............ (Pogo)
I'm guessing that the wobbling is the confluence of several factors, not just sloppy fitting trucks or just loose ones...whatever. I know that modellers have reported harmonic rocking in their models for no fathomable reason, and that the prototype does this in certain conditions.
Have you tried tightening one truck so that it just swivels and does not rock to any appreciable extent? Leaving one loose and keeping one tight sometimes improves tracking and operability.
Are you sure the axles are well seated? Are the bearing cones free of debris such as grit or lint or flashing? Are they lubricated? Are any of the trucks bent or misshapen in any way such that axles are not very closely parallel in all dimensions? Any bent axles, bad wheels..?
If they SWAYED side-to-side that wouldn't be so bad .... there's a big difference between swaying and wobbling !!! These are acting more like a "speed wobble" - once they start, it just gets worse !!!
selector wrote: I'm guessing that the wobbling is the confluence of several factors, not just sloppy fitting trucks or just loose ones...whatever. I know that modellers have reported harmonic rocking in their models for no fathomable reason, and that the prototype does this in certain conditions.Have you tried tightening one truck so that it just swivels and does not rock to any appreciable extent? Leaving one loose and keeping one tight sometimes improves tracking and operability.Are you sure the axles are well seated? Are the bearing cones free of debris such as grit or lint or flashing? Are they lubricated? Are any of the trucks bent or misshapen in any way such that axles are not very closely parallel in all dimensions? Any bent axles, bad wheels..?
Everything has been gone over with a fine tooth comb .... new metal wheel-sets, all adjusted and lubricated. The biggest problem I can see is the fact the Accurail cars use friction pins to hold the trucks on. When the pin is first pressed in place, it works as it should. However, after some running the pin loosens ever so slightly allowing the car some lateral movement. Due to the design shape of the pin, it would be very difficult to replace them with screws .... I tried turning down some screws to a tight tolerance, but that wasn't the answer. I tried pinching the pin slightly for a tighter fit, but after the cars negotiate some curves and a few bunps through the switches, they loosen up again. Remember, even the slightest amount of loosening, and these things start wobbling !!!
Mark, you may have to remove the trucks and replace them with another make. That will mean rebuilding the bolsters with styrene, if I have read other threads correctly, and then drilling and tapping to get a screw to work for you in place of these split pins...if that is what your are describing.
Can you post a photo?
I've been half tempted to try putting a bit of silicone on the pin before I insert it. This may help keep the pin from loosening, but still allow me to remove it if I ever need to. I'll try this first before going to all the effort of rebuild the bolsters and using different trucks.
A 2/56 machine screw, the same size provided by Athearn with their kits, should be able to be used as a direct replacement for that stupid plastic pin that AccuRail uses, without even having to tap the hole.
I'm surprised to hear that AccuRail is still using those pins - I thought they had changed to screws for everything because the last few covered hoppers I bought had screws, even for their coupler pockets.
If you can get ahold of some thin styrene of the proper thickness, you may be able to cut off those small tabs on one end that are supposed to stabilize the truck bolster's side-to-side motion and glue styrene in place of the tabs, but determining the proper thickness to use would be tricky.
I doubt that a different brand of truck would help. These models are top-heavy, just like their real-life counterparts.
The hole for the pin is larger than a 2-56 screw !!! A screw large enough to thread in to hole has too large a head. I tried turning the head down to fit the truck, but that really didn't work well - probably due to the flat base of the truck bolster hole.
Mark R. wrote: The hole for the pin is larger than a 2-56 screw !!! A screw large enough to thread in to hole has too large a head. I tried turning the head down to fit the truck, but that really didn't work well - probably due to the flat base of the truck bolster hole.Mark.
These pins instead of screws have been a problem from time to time.
To fit a 2-56 screw to the bolster: First you need to fill the hole with a piece of sprue. To make it easier to size, do the stretched sprue thing by heating w/ a match or lighter. CA the plug, mark the center and drill the pilot hole w/ a #50 drill bit. Now tap the hole w the 2-56 tap. Kadee sells kit #246 Tap and Drill Set, #50 tap drill, 2-56 tap and a #43 clearance bit. This set is a worthwhile investment for future work for coupler and truck mounting.
You should also note that if you tighten the screw and still have free movement of the truck, check that the bolster lug is not higher than the flange for the truck screw to tighten. Some slight filing of the pin/ lug may be nec. to properly snug the truck to stabilze the autorack.
You still need some swivel but tightened enough to control some or most wobble of the car. The oposite truck, the one w/o the bolster pads should be much looser to stop any derailmants by allowing the truck to follow any irregularities in track/ turnouts.
Modeling B&O- Chessie Bob K. www.ssmrc.org
I had some odd ball screws laying around that I replaced mine with. Stopped the problem. Can't tell you where I got them. When ever somthing breaks I always strip the screws out of it before I pitch it out. (those friction pins suck)
PS- Do they rock without the autos in them? You might just have too much weight in them.
One post points out that these cars are top heavy. Are you able to bring the centre of gravity down? Perhaps extra weight on the bottom deck or hidden under the ends (as with some intermodal cars) would help?
If they are wobbling they may be acting as pendulums - just upside down. in that case no amount of correcting the wheels and trucks is going to help and tightening the ride may only cause them to derail. The C-o-G should be the answer.
You could try this out just by placing weights in the bottom deck and see how they run. if it works you might even load the bottom deck cars with weights as well as any others you can hide under the car.
Speaking of Screws....
Where can I find 2-56 screws and what length should I buy IF I can get them?
I have some very good quality 2-56 NC taps, I just need to order in a bunch of screws for my stock.
Chris
NYC56 wrote:Speaking of Screws....Where can I find 2-56 screws and what length should I buy IF I can get them?I have some very good quality 2-56 NC taps, I just need to order in a bunch of screws for my stock.Chris
I get mine at Radio Shack. Look for #60-3010. This is a 42-count pack of 2-56 screws in various lengths...for $2.00 (US). Occasionally, you can find similar screws in broken radios and other scrap electronic gear.
NYC56 wrote: Speaking of Screws....Where can I find 2-56 screws and what length should I buy IF I can get them?I have some very good quality 2-56 NC taps, I just need to order in a bunch of screws for my stock.Chris
The standard machinist's tappered 2/56 tap will do fine for threading any hole that has sufficient depth. Sometimes you may find the need for a bottoming tap where you need the treads just about to the end of the hole- tapping couplers/ trucks on flats, centerbeams gons etc.
Radio Shack is a good source as mentioned. Some decent hardware stores will also carry them. Kadee sells Delrin 2/56 screws that I find work great for those odd lengths needed. Just cut to size w/ an Xacto and file or sand the burrs.