Hi,
If it’s the new Walthers roundhouse and the turntable, I beleive, you get a plan mockup whith it to lay the track.
When I had layed my turntable and roundhouse (not a new Walthers!) I aligned the bridge to the direction I need following this process…
I cut the adjoining track to lenght following a paper mockup; a few millimeters shorter don’t affect the track look but allow you some adjustements.
If you can, draw the mockup on the roadbed and lay the track to fit the roundhouse stall.
Fille well all the cutting ends of the track and be sure the one coming on the pit is very square, check both rails.
Now take your time, don’t work in a hurry it’s important for the future use of your turntable.
I blocked the bridge and using a steel rule against one bridge rails I carefuly align the adjacent track where it need to go ( an roundhouse stall by example).
I use a small plastic shim to give the very small space between the bridge and the adjoining track. I reuse this same spacer whith all the tracks to be constant.
I lay and spike temporaly my track whith T pins.
Second I checked the level of the adjoining track and the track bridge by again putting the rule on the top of one rail.; both track need to be perfectly on the same level. Trim some ties or file them to get the level.
If you use cork as subroadbed you can sand it carefuly to get the level.
Take an old car truck and roll it from the bridge to the adjacent track and try to not feel through your finger any dump as far as possible.
When everything is checked and rechecked I spike down the track definitively and add the feeder wires if necessary.
Some modelers add gardrails on the brid