Crest train engineer help please

P

paul delany

Registered
30 Mar 2018
91
3
53
Dublin Ireland
Hi folks I installed a Crest system in my three truck shay ,while testing in on a rolling road,I noticed that when I advance the hand controller throttle ,the middle truck starts turning well before the front and end truck do,anyone any suggestions please
 
PhilP

PhilP

G Scale, 7/8th's, Electronics
5 Jun 2013
25,884
1,462
Tamworth, Staffs.
I think you will find this is just 'slop' in the geared drive-chain?

There is a lot of slack in the drive system on these models.
 
P

paul delany

Registered
30 Mar 2018
91
3
53
Dublin Ireland
I think you will find this is just 'slop' in the geared drive-chain?

There is a lot of slack in the drive system on these models.
Hi Philip thankyou for your reply,do you have a shay with a train engineer fitted?
 
PhilP

PhilP

G Scale, 7/8th's, Electronics
5 Jun 2013
25,884
1,462
Tamworth, Staffs.
Hi Philip thankyou for your reply,do you have a shay with a train engineer fitted?
No, but I have had to fit decoders to them in the past..

If you put the loco on its side. - A folded towel (get permission!) is good.. You can see how much the wheels on the front and rear trucks can rotate, before the slack in the drive is taken up.
All the sliding rods etc. are quite lose, so that they do not bind and jam when cornering.

A good source of information:


Search the site for Crest information as well..

PhilP.
 
P

paul delany

Registered
30 Mar 2018
91
3
53
Dublin Ireland
No, but I have had to fit decoders to them in the past..

If you put the loco on its side. - A folded towel (get permission!) is good.. You can see how much the wheels on the front and rear trucks can rotate, before the slack in the drive is taken up.
All the sliding rods etc. are quite lose, so that they do not bind and jam when cornering.

A good source of information:


Search the site for Crest information as well..

PhilP.
Hi Philip I take on board what your saying my concern is that the middle truck starts running before the other two when small power is applied ,it takes more power to get the front and back truck wheels to start moving,my concern is ,if the middle motor can be dammaged while running on the track over time
 
PhilP

PhilP

G Scale, 7/8th's, Electronics
5 Jun 2013
25,884
1,462
Tamworth, Staffs.
Whilst in a perfect world, all the forces would be balanced, and the motors/gearboxes exactly the same.. We live in a real world.

You have to make a call on how bad the problem is? - A force called Back EMF will tend to even things out when the loco is on a solid rail.
This should mean that the middle motor will be held back, and the other two will join in the effort to move the loco.

As long as (when on track, not rollers) the middle truck does not spin, whilst the others are stationary, you should be OK.

If the problem is really bad, after running for a while, the centre motor would get quite hot. - This might indicate a problem with the outer two motors/gearboxes. - Usually only one motor/gearbox will have problems, unless the loco has had a really hard life.

Do read the link, and take special note of the lubrication regime..
 
P

paul delany

Registered
30 Mar 2018
91
3
53
Dublin Ireland
Whilst in a perfect world, all the forces would be balanced, and the motors/gearboxes exactly the same.. We live in a real world.

You have to make a call on how bad the problem is? - A force called Back EMF will tend to even things out when the loco is on a solid rail.
This should mean that the middle motor will be held back, and the other two will join in the effort to move the loco.

As long as (when on track, not rollers) the middle truck does not spin, whilst the others are stationary, you should be OK.

If the problem is really bad, after running for a while, the centre motor would get quite hot. - This might indicate a problem with the outer two motors/gearboxes. - Usually only one motor/gearbox will have problems, unless the loco has had a really hard life.

Do read the link, and take special note of the lubrication regime..
Hello sir thankyou for taking the time to reply in detail,I appreciate the advice and I will let you know how it runs on the rail.many thanks

Paul d