doug72

Great news, I was very impressed with their quick reply to my initial e-mail query and the smooth ordering process.

I,ve ordered a basic double crossover from Trixbrix.eu in Poland, £36 cost & shipping. Will be suitable for the GBC train module.

Started building the double reverser unit, and slowly figuring out how it works. Using two shocks but a rubber band version would be easy to install and replace them.

3D Double Crossover Track for GBC module. I contacted TrixBrix.eu to see if there original “open” design of a double crossover is available. It has the spring mechanism for the point blades so ideal for the GBC double crossover track and cheaper. They replied saying they can print one to order for £36 inclding shipping to UK Delivery next week. You need to order the Crossover Basic.

Scroll to top of this page, click, forum in the grey bar, then scroll down to find Train Tech. https://www.eurobricks.com/forum/index.php?/forums/forum/122-lego-train-tech/

@dunes take a look at the Lego Train forum, I started a topic about 3D printed double cross over track. Mentions the Polish version. There,s an interesting reply on how to cut and glue ordinary switches to make a crossover unit. Doug

Make sure the routing of the two PF cables (from battery to switch and from switch to motor ) are not stopping the trip bars to more fully to change switch position.

Elevator MOD: Noticed as train left elevator platform there was a sharp knock as the train moved onto the connecting bridge to the rotary dumper. This is caused by the 90 deg shape of the end of the 15L beams used to guide train wheels and hold train at correct height for 8T gears to engage with the gear racks. Fixed by using two LEGO Beam 4 with Ball Cup Socket (15459 / 31794) which have a rounded end at the cup allowing the train a smoother transition when exiting the elevator. Extended double crossover: Don't think is workable as very difficult to operate switch C from the reverser due distance and slide on wrong side. So probably will used a 3D printed double crossover, time to buy before exchange rate for UK pound / Euro slides any further !!

Thanks, the 3D printed double x-over has four independant switches unlike the Lego one, which has two ganged switches requiring a MOD to use with the GBC module.

Has anyone had experience on using 3D printed versions of the Lego 7996 Double Crossover ? How reliable are they ? I need one for a GBC train module I am building. Found two firms selling them one in the US the other in Poland. 3D printed from £50 to £60. Genuine 7996 selling on Amazone for up to £480.

Got all the parts required except three 4L racks, there’s a snag , how to operate track switch C. The slide bar is on the inside so have figure a way for the R2 reverser to connect to operate it. Also its 7 track units or 112L from R2.

Extended double crossover reverser module: It might be possible to use this track arrangment if one switch can be operated from reverser R2 - see diagram. Dashed red line indictats connection between R2 & switch C. R2 would need a four lobe rotor. Hopefully timing would not be affected to allow two trains pass each other correctly. I have two sets of modified crossovers. Worth a try as much lower cost at expense of larger footprint. Might use shocks as low stock on rubber bands.

Two of these might work for the diamond crossover with modified Lego switches. https://www.4dbrix.com/shop/index.php?route=product/product&path=18_45&product_id=131 appox €22 + shipping

I thought the same but it won,t work. There has to be a cross over configuation in order to work as per Akiyuki video. The switch blades have to fixed in a particular way to operate as per Akiyuki video., the switches are not moved by the two reversers, Try in on paper and you see what I mean. The spring loaded switch blades are forced open by the train in one direction and are set to run the train in other direction when it is reversed. re Saw, a modellers razor saw, with fine teeth, is the best for cutting lego track., watch your fingers as they are very sharp, I have scars to prove it!

Take a look at this website they do a compatible double crossover. https://www.4dbrix.com/products/train/train.php https://www.4dbrix.com/products/train/double-crossover/index.php Update: The diamond crossing parts are available @ USD 10.45 but will not connect to standard Lego switches. A full set parts is €64.95 plus shiping from USA.

Good luck, it will be a challenging build but only uses 24T gears for the reverser units not Z56 T/T. Rubber bands for the reversers should work OK I think the track layout can be made more compact, I will experiment with the tracks switches I have. I have some modified track switches which give a more compact layout. The switch MOD should be on the Train Tech forum. I built the siding module that allows two trains to pass each other. The through module is also useful. Tried your Mac tip and works OK.

Thanks I can now open the file OK. Had to set up the right click on my mouse then right click the "Open with" then select Launcher app.(1.0) and it opens in Stud.io

Having trouble looking at the Stud.io files. Downloaded the Stud.io app for Mac OS but can't open file for Rotary Dumper Mod Z56 rubber bands.io Do I have to register with Bricksafe before being able to open the files ? Every time I double click the file it sends me to iBooks. Doug

Brilliant, great to see another one working well. I see your train car has the same bumpy ride on & off the elevator, I'm working to improve that. Will check your latest LDD files today, suggest that earlier versions be removed to avoid confusion as which to use. @Berthil Shocks V rubber bands - its six & two threes which you use - both versions work OK. I My observations are:- Shock absorber - Takes up more space and has a complicated support structure requiring a thin L shaped spacer to adjust the trip arm correctly. Possible an illegal Lego build as it distorts support framing slightly and can shift during prolonged running upsetting trip release arm. Takes more force to cock the spring and slows dumper rotation down before trigger releases the train. Requires a ballast box to balance dumper rotation. High cost of shock absorber. Rubber Bands - Simple support structure without need for the thin L shape spacer and needs less force to cock trip lever with uniform dumper rotation speed. Will work with only one rubber band but two better for redundency, quick & easy to replace bands without major strip down. Ballast box not required. Low cost for rubber bands.

I assume you mean the four small pully wheels, They are only acting as guides and don't need to rotate. I have changed them but no real difference. Doug.

Three minor mods for the elavator that I forgot to mention ! A. The veretical 5L thin beam was rather flimsy and replaced by a 7L beam. B. 5L beam replaced by a 7L thin beam as trip arm sometimes rubbed the 5L beam as the elevator rose and released the chock. C. Trip arm altered so that it went in the recess when elevator at bottom and extra 2L axle added to the lever to wrap rubber band around to get improved tension.

A file for the elevator mod at the height that matches the Rotary Dumper height should sufice. Its easy to raise both in 4L steps using 4L gear racks. Expect @Berthil will be applying the various Mods to his combined elevator / dumper module he has already built. I think that’s all the mods done now unless anyone else has any issues or problems. I might have an issue with an M motor runnning slow in one direction, will recharge batteries and try again. Might see if a L motor will fit on the train unit now that have put short trip bars on them.

Elevator Modification:- I have had problems with this module as the elevator rises with the train car jumping over the restraining chock causing the elvator platform & train unit to crash back down and jam. I have made a simple fix to prevent this - see image Parts used:- 2 x LEGO Technic Cross Block 1 x 3 (Axle/Pin/Axle) (32184) 2 x LEGO Axle to Pin Connector (3749 / 6562) 2 x LEGO Technic Gear 8 Tooth Type 1 (3647) The freely rotating 8T gears prevents the train unit from riding up over the chock until the elevator has reached full height, latched on & lowered the chock to allow train to move forward onto the rotary dumper. On the train unit return to be lowered the modification does not impede passage.

Rotary Dumper Update:- see video Now installed a rubber band reverser into the rotary dumper, and it works very well. Rotation is quicker and smoother without slowing down as the trip arm is cocked ready to release train unit. Installation was very easy with more clearance between the Z56 turntable and yellow gear ring.

The problem occurs when the trains unit is up side down and starts to compress the spring. The axle 8T gear can lift off the 24T gear slightly and skip. Thanks again for doing the files, did you get the pm about improved connection between hopper and rotating gear ring ?