Dropleaf track joints

[harrym]

I have my dropleaf mechanism working so that it lines up every time. The track joints have been a pain. The track ends have been bevelled so they fit a fingernail thickness apart -- enough so that they swing down without catching. I soaked the roadbed ends with CA to stabilize them for height, weighted down across the tops of the tracks with a flat steel plate while they set up. I hope they stay in these positions. What do the rest of you do to keep the tops of the tracks level across the joint?

[wm3798]

I make periodic adjustments...

I used sectional track laid on cork and plywood up to the tunnel portal,


and I used c-80 Atlas flex on the bridge itself.  I secured the loose rail with CA.  The tunnel portal provides about 3/8" of protection to the track projecting from the side of the layout, so the track actually extends at touch beyond the edge, enough for it to catch on the bridge when it's lifted into place.  There's also some blobs of clump foliage glued to the bottoms of the portal, which compress like weather stripping on the bridge deck to keep things stable.  I have a single barrel bolt that holds the whole mess in place.

On the hinge end, it transitions from c-80 to c-55, so I simply filed down the c-80 rail head to get a gradual transition, since the bridge is on a slightly steeper grade.

Lee

[cv_acr]

Here's a couple in progress shots of our new lift-up entry bridge at the club. It replaces an older swing bridge which we always had problems getting lined up properly. Since it swung outwards, you had to make sure the rails were properly aligned before crossing, and watch carefully for derailments.

Also, since it swung into a narrow aisle, it completely blocked foot traffic in one direction when opened, which could be awkward at times.

The new bridge is designed to eliminate those problems. It uses a very heavy duty metal hinge and swings upwards. We laid spline roadbed right across the bridge and then cut the spline for the joints and the end of the bridge. The sides of the spline at the opening end of the bridge is bevelled and will nestle into a pair of matching bevelled blocks on the benchwork to assure horizontal alignment. An electromagnet will be installed in order to hold things down when in use. Pushbuttons on either side will turn the magnet on/off to open the bridge.

[Chris333]

This is mine. One end has a door hinge so that keeps it in line. For the other end I built stops. Under it is a slide latch and that pinches it into place so it can't move up and down.



Mine runs into a shelf. If it was layout there (and it has been for me) I just half lap the end and pinch it the same way.

[Walkercolt]

I didn't build it, but one of our N-TRAK club memembers built us a lift-up "gate module". Now this guy is an aircraft engineer and it took alot of his knowledge to make the "frame" stiff and strong enough to keep the moving portion in-line with everything else. He used 1/2" all-thread steel rods as "tensioners" to alinge everything, and after the trip to Louisville, it needs to be "tweeked" a bit. With just one track, and a much narrower drop section, you won't have to go to the extreams Steve did, but the hard part is, you need to come back to 1/100th's of an inch in N-scale for the tracks to aligne and work right. Steve hand filed some fairly heavy aluminum stock into "V"s  to aligne things everytime. Think stiff, not heavy. But 1x4's are probably not going to do the job on your vertical pieces, by themselves. The classic door pin-lock has way too much slop in it for horizontal or vertical location by itself. I'd also consider using the rather expensive "European" style multi-wafer cabinet door hinges on the drop-leaf. You also need to be able to adjust for wood exspansion/contraction easily for reliablity. Now have I compleately discouraged you? I don't want to at all, but you need to think "out-of-the-box" a little. Things like 2" aluminum angle really stiffen up wood, with little wieght. I hope I gave you some ideas.

[harrym]

My dropleaf carries three tracks and is 18" wide by 24" long.  It works now, but I'm gathering ideas in case it doesn't stay in alignment.  It will have quite a bit of scenery on it eventually, so I want to be sure before I do any of that.  Thanks for the ideas.

[wm3798]

Simple is better.  For a large panel like that, it might be worth designing a drop in section with positioning pins to hold everyting in line, or a couple of quick drywall screws that can be backed out...

Lee

[Walkercolt]

Lee, you have to make sure your pins stay the same size(metal into wood...not a good combination) and backing out wood/drywall screws a half dozen times will loosen their holes consideralby. Most of the time "simple" isn't nearly as simple as it looks. I like "simple" too. Simple that works and keeps working.

[wm3798]

How about holes drilled through with screws and wing nuts?  That's worked for me...


Lee