I am using digitrax and trying to get Athearn blue box, Athearn RTR, and Atlas engines speed matched. My models were in storage for three years and it seems I have forgotten more than I thought. I remeber a technique were I ran the engines around the layout at 50% and 100% throttle and adjusted a CV on the fly to match them up. For the life of me I can't recall how to do that.
How do I adjust the CVs while the engines are moving so that I can speed match them?
Do other engines need to be off the track while I do it? Like when operational programing...
Any help would be appreciated?
Thanks
If all your locos have decoders that support CV2 for start speed, CV5 for top speed, and CV6 for mid speed, those are your start, 50% and 100% settings.
Ops mode programming only programs the loco that is addressed. You technically do not have to take anythign else off, but if you have 2 with the same address, both would get changed.
If you have one of the bigger Digitrax throttles with 2 knobs, what you do it start one loco on one knob, and the other one you are trying to match on the other knob, then adjust CV2, 5, and 6 as needed. Remember CV6 is the middle speed, CV is the top speed. ANd when adjusting, make sure you tweak the knob for the loco you want to program before pushign the program button to go to Ops Mode - so that you are programming the one you intend to, whenyou switch to Ops Mode it programs the currently active loco.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
They really need to build a device that can develop a speed curve from then simply plop the other loco on it to match the speed curve of the first.
Speed matching is the most raw and difficult part of DCC
some decoders have speed matching in only one direction. Look out!
Chris
CV2, 5, and 6 all apply in forward and reverse. SO do 28 step speed tables. There is even a forward and reverse trim CV for use with the speed tables to take into account variations between forward and reverse.
There IS a 'gadget' to do what you want - It's a script in JMRI. You need some sort of block detection - not sure if it yet works with the Bachrus speedometer so you could do it without a layout even.
JMRI is software. I'm talking a hardware device with rollers that measures the rpm of the rollers and matches locomotive properties. I'm looking for something Completely automated so I can go paint a locomotive and let the computer match the speed curve.
I'm not the only one finding the speed curve capabilities half implemented...
Quoting Gerome from http://cs.trains.com/mrr/f/744/t/139918.aspx
"annoyingly, even if you speed match a pair in one direction, it is usually the case that the units will run at different speeds in reverse. One can only speed match in one direction whenever locos run at different speeds in reverse."
Honestly, Loco manufacturers should be doing more to find a uniform speed curve and matching their DCC decoder equipped locomotives to that out of the box. I couldn't imagine beginners to be expected to speed match locomotives on their own.
There's gotta be a better way. It's easy to spend hours on doing one direction of one locomotive.
Chris Palomarez
The thread below is about speed matching a (TCS non-sound) decoder loco that utilizes CV2, CV5 & CV6 with a Tsunami equipped diesel (Athearn GP9) that uses CV2 but not CV 5 & CV6. Thus, on the Tsunami I had to activate the (straight line) speed table and also use the forward & reverse trim CVs to match up to the other (slower) loco. With help from Randy!
http://cs.trains.com/mrr/f/744/t/218127.aspx
Paul
Modeling HO with a transition era UP bent
Shoofly,
A H/W implementation is going to need to know the diameter of the drivers to start with(it's got to have a base line). Why do you think JMRI & DCC speed curves to be 'half implemented'? I have speed matched over 100 engines at the club, and only a couple have had to go the speed table route. Even the speed table implementation of JMRI allows you to 'fill in' the steps between two outer steps.
No one ever said that this was easy or is going to be easy. We have various gear ratios/driver diameters/motor drag and even copies of two identical locos may be different due to friction losses. At least with DCC we can adjust this kind of stuff. Back in the 'good old days' of model railroading there really was no way to speed match models - We tended to run the Atlas engines together, and the Athearn engine together...
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
Like some above, I use JMRI software. I use my slowest loco that will be in the consist and time it--keep that record as all others will need to run similar. The others I adjust until their timing equals the timing of the "control" unit.
Richard