Rich,
A job well done.Your patience and perseverance paid off.
Are you sure you don't want to try the swing bridge???? HA HA.
Frank
rich
After watching my bridge through several cycles, I have noticed the following conditions. Note that all references to a right or left side is made from the A-frame end.
1- the right side rack beam does all the work during the lift cycle.
2- the beams are inserted into the pinion gear housings the same amount, but the bridge and A-frame assembly is slighty skewed. This results in the left end of the long rack gear rod [part #114] being displaced toward the A-frame. To correct this the left side rack gear beam would have to be moved 2-3 teeth further into the pinion housing. This can't be done, as the pinion housings are glued togeather.
3- the skew condition causes more binding during the lowering cycle, possibily because the beams go from tension load when lifting, to compression load when in lowering mode. The loaded beam may flex slightly when pushing the bridge down. The bridge may be more sensitive to counter balance weight if the skew condition exists.
4- both rack beams load about the same when the bridge is fully down, and some motor load is applied. This could affect track alignment when in operation.
zstripe Rich, A job well done.Your patience and perseverance paid off. Are you sure you don't want to try the swing bridge???? HA HA. Frank
Thanks, Frank. As for the swing bridge, I will still resist. I have had crazy thoughts over the last 48 hours of scratchbuilding a lift bridge, but I am sure that I will come to my senses before it is too late.
Rich
Alton Junction
barbender rich After watching my bridge through several cycles, I have noticed the following conditions. Note that all references to a right or left side is made from the A-frame end. 1- the right side rack beam does all the work during the lift cycle. 2- the beams are inserted into the pinion gear housings the same amount, but the bridge and A-frame assembly is slighty skewed. This results in the left end of the long rack gear rod [part #114] being displaced toward the A-frame. To correct this the left side rack gear beam would have to be moved 2-3 teeth further into the pinion housing. This can't be done, as the pinion housings are glued togeather. 3- the skew condition causes more binding during the lowering cycle, possibily because the beams go from tension load when lifting, to compression load when in lowering mode. The loaded beam may flex slightly when pushing the bridge down. The bridge may be more sensitive to counter balance weight if the skew condition exists. 4- both rack beams load about the same when the bridge is fully down, and some motor load is applied. This could affect track alignment when in operation.
barbender,
The more experience I gained while building this bridge, the more I realized how critical the racks are to the lifting and lowering process. Your observations are all appropriate. In the instructions, Walthers says to "place the rack, tooth side down, on the gears, as close to the end of #46 (i.e., the gear box, or pinion housing, as you call it) as possible". "As close to the end (of the gear box) as possible". That's all they say. But, it is absolutely critical to align both racks, left and right, identically, so that the racks, the truss bridge and the A-frame are all square. Otheriwise, binding is inevitable.
Each rack must be installed so that the gears on each rack sit on the same tooth on the left rack and on the right rack. As you point out, once the two sides of each gear box (pinion housing) are glued together with three gears inside each gear box with the rack attached, it is too late to make adjustments because the gears and the rack are locked in place at that point.
I came across this thread where someone kitbashed the bascule bridge into a three track behemoth. It is the 11th post down on page 1 of the thread.
http://forum.atlasrr.com/forum/topic.asp?ARCHIVE=true&TOPIC_ID=54824&whichpage=1
I wonder if it actually operates because he, like me, reversed one of the walking beam supports which caused the bridge to jam halfway up.
No matter, that is an amazing piece of kitbashing.
Rich, my head just exploded.
Don
HobbyDr's Workbench
There's an article in a previous issue MRR on how to expand your Bascule to a double track.
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
DigitalGriffin There's an article in a previous issue MRR on how to expand your Bascule to a double track.
Do you recall the month and year of that issue?
That article on converting the Walthers bascule bridge to double track was in Mainline Modeler Magazine. It ran in two parts in the November and December issues, 2002.
Jerry
Someone just bought the bascule bridge new on eBay for $220.49 - - - 7 bidders, 11 bids.
Here are some preliminary photos of the bascule bridge installed on the layout. It sits atop a lift out section spanning an aisle to permit trains to crossover and reverse directions. The lift out is, in fact, a reversing section. You can see the auto-reverse unit on top of the surface. I need to hide or camaflouge the unit. I also need to determine a final position or placement for the bridge tender house which is visible on the left side of some of the photos.
Next step is the finish the track work and wiring. At the moment, the bridge is not operational until I work on the track and wiring on the lift section. Then, the landscaping, ballast and stone piers. Lastly, I will install some railroad bridge lighting. The first photo is the original lift out before re-engineering it for the bridge.
Next are some closeup photos of the bridge from different angles.
Lastly, these are the very first photos of the Santa Fe Super Chief navigating the bridge over the soon-to-be waterway.
I will be back with a video of the bridge in operation once I complete the track work, wiring, landscaping and lighting.
Nice,Nice, and Nice!! Your Service yard gave me some ideas!! Thanks - Looking forward to the video. Chris
Looking at it in its future location, I gotta ask: howcum ya didn't build it as a skewed bridge?
Seriously, though, Rich, it looks great, and so does your layout. The video of the bridge in operation was impressive, too.
Wayne
doctorwayne Looking at it in its future location, I gotta ask: howcum ya didn't build it as a skewed bridge? Seriously, though, Rich, it looks great, and so does your layout. The video of the bridge in operation was impressive, too. Wayne
Oh, Mama. Can you imagine trying to kitbash this guy into a skewed bascule bridge. I am going to leave that project to you, doctorwayne. Please send photos of your progress.
richhotrain Someone just bought the bascule bridge new on eBay for $220.49 - - - 7 bidders, 11 bids. Rich
It's articles like yours on here that encourage people to try to build thier own, after they see how nice it comes out. Not a bad profit for an $80 MSRP kit.
I wonder how much my assembled one would sell for with working marker lights? I'm still not sure if I have a place for it in my final layout.
Great job so far. You have been busy!! When I have time,I will post some pics I have of an actual
derailment on the 21st. canal st. lift bridge. UP power units 8 to be in fact run onto the bridge on their
own.Brake failure.Three of the units derailed on the bridge leaning on the girders. One of my son's
was an operations manager for the UP intermodal yard on canal,2009. Now he is at the Joliet yard.
Here are the pictures of the bridge at 21st and Canal St. Enjoy!
-Frank
Bridge1
Frank,
Great photos, thanks for sharing. That PRR bridge at 21st Street is no place for a derailment. So much for bridge guard rails.
DigitalGriffin richhotrain: Someone just bought the bascule bridge new on eBay for $220.49 - - - 7 bidders, 11 bids. Rich It's articles like yours on here that encourage people to try to build thier own, after they see how nice it comes out. Not a bad profit for an $80 MSRP kit. I wonder how much my assembled one would sell for with working marker lights? I'm still not sure if I have a place for it in my final layout.
richhotrain: Someone just bought the bascule bridge new on eBay for $220.49 - - - 7 bidders, 11 bids. Rich
I think that the trick would be in packing it for shipping so that it wouldn't break. Might have to be for pick up only. My guess for a fully assembled, painted, operational bascule bridge with working marker lights - - - somewhere between $300 and $500 - - - based on the selling prices of NIB kits on eBay.
Yikes, I am nearly four weeks into this project, but I finally completed the bridge tender house today. The base, walls, windows and roof are no big deal. But, the platforms, staircases and handrails are consistent with the rest of the kit. They must be put on the building in the proper order, and the instructions do a good job warning you of that fact.
The inner handrails are attached to the inside of the staircases, but the staircases and platforms must be attached to the building first for proper alignment. In turn, this makes it difficult to put on the inner handrails. So, what I did was to use a 2-part epoxy (JB Kwik), applied with the point of a needle. That worked superbly, and it provided a much better and more secure fit. Ultimately, I secured all of the handrails, inner and outer, with epoxy which also eliminates any spaces between the parts of the handrails that are supposed to join together with glue.
Today, I ordered the stone cut walls and piers (Chooch Enterprises), the bridge track Walthers Shinohara), and a fire department tug boat (Model Tech Works) to put under the bridge in the river. Once I finish the ladscaping (ground cover, piers and abutments, river, and ballast), I will post final photos and a video of the bridge in operation on the lift out section of the layout.
I hope to have that ready by the end of next week. Golf is right around the corner in the Chicago area.
That looks great Rich. Looking forward to seeing the final pics when you get everything all tidied up. The tugboat sounds like a nice addition.
Golf in Chicago after all those snow storms, are you kidding me? LOL
Michael
CEO- Mile-HI-RailroadPrototype: D&RGW Moffat Line 1989
I don't golf, but around here, those who do, do so all winter. I think that they use an orange ball when there's snow, although after a couple of days, the snow on the ground is dirty enough that they go back to using regular balls.
Looks Great! - Pic from layout of Jack Heier in Loveland, Colorado
scoutII Looks Great! - Pic from layout of Jack Heier in Loveland, Colorado
Wow, that is sweet. I love that scene, especially that tug beneath the bridge and its wake.
I plan to place a similar looking tug beneath my bridge, but being on a lift out section, I will have much less room and the length of the waterway will be shortened somewhat as a result.
I will be pressured to match the good look of this scene.
Thanks for posting that photo.
Guys, thanks for the excellent discussion. I am building the bridge with my son. We are having great fun but it is definitely pushing the limits of our modeling skill. I printed out Rich's helpful hints and it is serving as a bible for us.
Can anyone provide some more details on the switch replacement? Looking at the thing it is pretty clear that it is inadequate as everyone says. I would love a 'switch replacement for dummies' level of detail. I am a bit concerned about how the motor stops when the bridge is fully up or down. Are you all going with a fully manual approach or is there some auto ct off that can be rigged?
Thanks folks.
rjstruble Guys, thanks for the excellent discussion. I am building the bridge with my son. We are having great fun but it is definitely pushing the limits of our modeling skill. I printed out Rich's helpful hints and it is serving as a bible for us. Can anyone provide some more details on the switch replacement? Looking at the thing it is pretty clear that it is inadequate as everyone says. I would love a 'switch replacement for dummies' level of detail. I am a bit concerned about how the motor stops when the bridge is fully up or down. Are you all going with a fully manual approach or is there some auto ct off that can be rigged? Thanks folks.
rjstruble,
Welcome to the Forum and welcome to the club, of bascule bridge builders that is.
Digital Griffin, one of our fellow forum members provided me with a diagram of a setup for using micro switches in place of the reed switch. The diagram is shown earlier in this thread.
The micro switches are referred to as "leaf" switches, but I like to think of them as "pedal" switches. When the bridge strikes the leaf, it is like your foot hitting the brake pedal. The force of the bridge striking the leaf, or pedal, pushes it down, cutting power to the motor.
Digital Griffin's solution was to replace the reed switch with a pair of leaf micro switches, one to stop the bridge at the top of the lift and one to stop the bridge at the bottom of its descent.
The placement of the micro switches is the critical part. The one that stops the bridge's descent is fairly simple. Where the far end of the truss bridge meets solid ground upon completion of the descent, that is where the micro switch should be placed.
The one that stops the bridge's ascent is more challenging. My solution for the placement of that micro switch is at the bottom of the A-frame. As the bridge is raised, the counterweight moves down and inward inside the A-frame. At the top of the bridge's ascent, the counterweight is beginning to move inside the A-frame. That is the spot to place the other micro switch so that the counterweight strikes the leaf, or pedal, cutting power to the motor. A DPDT switch controls the motor and the micro switches.
A simple alternative is to operate the bridge "manually" without micro switches. That's how I started out just to keep it simple in the testing stages. A DPDT switch is wired directly to the motor. I used a Center Off DPDT switch. When the ascent or descent of the bridge was complete, I flipped the DPDT switch to Center Off. If you are afraid that you will forget to turn off the switch in the event of a distraction, then use a Momentary DPDT switch that you have to keep activated with your finger. If you let go, the motor will stop.
Hope that helps.
Thanks Rich, very helpful. Another stupid question which I may get answers to later in the construction: How does the motor 'switch direction' to either raise or lower the bridge, or is that done mechanically somehow?
rjstruble Thanks Rich, very helpful. Another stupid question which I may get answers to later in the construction: How does the motor 'switch direction' to either raise or lower the bridge, or is that done mechanically somehow?
It is done electronically by reversing polarity by means of the double pole double throw (DPDT) switch.
The DPDT switch has six contacts. Two of the outer contacts receive power from the power supply (transformer, wall wart, battery, whatever) through a pair of wires. The two center contacts feed power to the motor through another pair of wires. A third pair of wires cross from the outer contacts on one side of the DPDT switch to the outer contacts on the opposite side of the DPDT switch. In other words, that third set of wires forms an 'X' so to speak. When you flip the toggle on the DPDT switch you reverse the polarity and the motor spins in the opposite direction.
Thanks Rich, so I guess the included switch does all that and the new circuits proposed replicate that. I am an enginner, but it was chemical and a long tme ago, so my head is beginning to hurt.
On another one of your tips, you suggest gluing the gears in place to avoid slippage. Did you just use the standard modeling glue used for the plastic structures? You say put it on the sides, I was wondering if putting it on the rod and then sliding the gear over wouldn't be better. I agree overall that potential gear slippage could be an issue.
rjstruble Thanks Rich, so I guess the included switch does all that and the new circuits proposed replicate that. I am an enginner, but it was chemical and a long tme ago, so my head is beginning to hurt.
Actually, the included switch, the reed switch, is replaced by the micro switch which is more dependable. The reed switch is simply too flimsy and unreliable. Put simply, it doesn't work. After I wrote my checklist earlier in this thread, I was referred to the March 1999 issue of Model Railroader magazine in which a 2-page review of the Walthers Cornerstone Bascule Bridge was published. It is an interesting article, and it addresses the reed switch. The author had fits getting it to work.
Having said that, the reed switch is nothing more than an on/off switch. However, you still need a DPDT switch to power the motor and to reverse polarity. Curiously, the instructions never mention the need for a DPDT switch.