It was a decent day out yesterday, may be the last until Spring so I had to get the Garrett out for a track test and video of the run.
There is still lots to do and the number one thing is to setup the support wheels under the boiler and cab so they don’t derail so easily.
In some shots you can see them bouncing along.
Excellent and totally convincing US take on the B-G locomotive. I’m very taken by the colour scheme - very reminiscent of the EAR. To look correct you’ll need a Sikh engineer and fireman, and a boxcar full of native polishers and oilers for the stops.
tac
Ottawa Valley GRS
Are those wheels under the boiler necessary? They seem to spend an awful lot of time on the ground.
I like the colors. Beautiful job!
Ken, since the pivot point is above those wheels, instead of just forward of the last driver, they would be necessary to support the boiler. I mean visually they would be needed.
Thanks Tac.
Those extra wheels are not needed, they are all about the looks. I have them on a tongue which pivots at the same point where the boiler/cab attaches plus it pivots on a screw above the wheels with a spring on it. I had them setup another way and they always jumped on a curve. I need to go back to the drawing board a third time on these.
The thing is I need this loco to go through a 5’ diameter horseshoe curve.
Could you use larger and heavier wheels and add some weight to the pivot arm? That may help them track better.
Or another thought I had while watching the video again, mount that pivot arm rigid with the drive train and narrow and have the wheels slide side to side as it enters the curves, that way it won’t hop. That’s how the rear truck on the B’mann K-27 works. It doesn’t move up and down or pivot, just side to side.
The tongue is best for a single axle, you need shocks! A downward dampening force to eliminate the bounce. Perhaps a spring with a slider pad to press against the frame or underside.
John
What about something like this. This is the pilot truck I made. It works as sort of a plunger. The bolt is loose in the hole in the truck and slides freely. The spring gives it tension and the loco rides on the nylox nut. The spring provides constant down force to the truck, as the loco presses down the bolt is pushed down through the truck. and the spring pushes back. In essence it is a strut like on your car. Tension is somewhat adjustable. by tightening the nut but only limited so because you don’t want the bolt to protrude through the nut. Mine is loose and will likely require a longer bolt.
Anyway That’s how I am tackling the problem. Of course it is untested as of yet but I am very confident in it.
Todd
Hmmmm I tried some different configurations tonight. I setup a snaking S curve with 5’ diameter curves and put the front drive unit of the Garratt on it but the trailing wheel set still eventually hopped off the track.
Looking at a LGB 2-4-0 I have the front wheels are on a tongue that is attached to the frame with a screw and spring. I have the opposite setup but it is not good. It would seem simple enough to build and install a device similar to the one like Devon posted but I need to figure out how to attach it.
The wheels and tongues are now off and they will be put on the back burner. I would like to get the headlights working next.
Todd,
Just in case it isn’t clear, the pivot point to the truck is on the right. the black (actually blue) piece of plastic on the left is actually gone now. So not really sure how you can do it but if you can create a pivot point near as close to the drivers as possible then some sort of place for the nut to ride on then you can do it. Easier said than done since I can’t really see what your working with.
Greg Hunter contacted me with a tip on how he has set up extra pilot wheels on his locos and I tried it and so far so good.
The idea was to use a thin piece of brass that is strong enough to hold a bend but flexible enough to act as a spring. It is about 3" long and is securely fixed to the wheel and pivots at the frame. If the pilot wheel set has 2 axles Greg recommends having it pivot at the wheels and the frame.
I sent the Garratt on a winding S curve test track and those pilot wheels stayed on the track so Gregs idea is a good one.
Good deal. Sounds like an easy solution which are the best ones.
Todd Haskins said:
Greg Hunter contacted me with a tip on how he has set up extra pilot wheels on his locos and I tried it and so far so good.
The idea was to use a thin piece of brass that is strong enough to hold a bend but flexible enough to act as a spring. It is about 3" long and is securely fixed to the wheel and pivots at the frame. If the pilot wheel set has 2 axles Greg recommends having it pivot at the wheels and the frame.
I sent the Garratt on a winding S curve test track and those pilot wheels stayed on the track so Gregs idea is a good one.
I’m glad it seemed to work Todd. Always great to see another Garratt in action.
The few times that the Garratt has been on the track this Winter I decided it was too tall for its own good so I cut the top of the coal tender down by 1/2" and reworked the mounts and rear platform on the boiler cab section so that too would sit lower and be more appealing. Yesterday I tried it out and going through a few 16000 switches in the train yard one of the wheels came off the pilots then the other did too.
Back to the shop! It seems that when I lowered it 1/2 inch I now have pieces that are pinching and not allowing free movement through a 8’ diameter curve which is bad news because I have a few spots on the main that have 5’ curved sections.
I set up a “S” curve test track on the floor and got to cutting and grinding pieces off to allow a greater swing. There is now a plug and wires in the way that need to be moved.
It is crazy what a difference 1/2 an inch makes.
Todd,
Glad you revisited this thread. This is a great build make sure to show some more pics and videos
Hey you say your having trouble with it pivoting and pinching? Is any of it related to the actual pivot points. I was watching the video again (I love this build such a cool loco) and wondering if the threaded bolts as pivots could be giving you trouble with maybe the threads cutting into something. I wouldn’t think so but it just crossed my mind.
Devon Sinsley said:
Hey you say your having trouble with it pivoting and pinching? Is any of it related to the actual pivot points. I was watching the video again (I love this build such a cool loco) and wondering if the threaded bolts as pivots could be giving you trouble with maybe the threads cutting into something. I wouldn’t think so but it just crossed my mind.
I need the bolts so I can thread nuts on to hold everything together. The boiler/cab has 3/4 inch or so nylon spacers glued in that accept the bolts.
When I dropped the boiler/cab down it started to hit on things that it once cleared so I took my dremel and started operating on the inside of the frame where it won’t be seen. On the back of the bachmann chasis are 2 plugs and a switch that are now in the way. This needs to be moved into the tender since this is how I link the drive trains but of course that won’t be easy as it sounds due to stuff being in the way.
I now know why engineers get so much money when they design things.
Great sounds like your moving forward Todd. Can’t wait to see it run again. I have always thought I wanted to build a Mallet but that Garrett is just very cool.
