Model Railway Forum banner
1 - 16 of 16 Posts

·
Registered
Joined
·
34 Posts
Discussion Starter · #1 ·
Hi is anyone else having problems with the running of the class73 at low speed my unit start's slipping
badly saying that I'm not sure if it's wheel slip or it's the gears slipping it has the same motor as the
class 121 which I think was very light I'm not to sure if this is the problem with the 73
please don't think I'm picking on Hornby but I picked up a Hornby chip up to fit in the 73 unit but at all speeds it ran very poorly so I fitted a Bachmann EZ chip and it ran a lot better still slipping like mad but better.
The one good thing is I think!!!! is that as my good pals at Hornby have not changed the 73 body
all the Lima bodys I need not dump should still fit
BILLY
 

·
Registered
Joined
·
34 Posts
Discussion Starter · #2 ·
Hi I'm back
A friend phoned me about the problem I was having with the Hornby 73 he seemed to think the
slipping problem was nothing to do with the wheels or gears in a nut shell what he said was give the loco a good run in on DC and note any slipping after this try a number of chips to see if the problem cleared
1/running in DC on a rolling road no sign of slipping
2/fitted with a Hornby chip slipping very bad
3/fitted with a EZ chip slipping improved
4/fitted with a Lenz silver chip no slipping at all
I'm not sure where to go from here I 'm not keen on fitting a multi function chip in a loco where
only the motor is being controled
as an end note I fitted the Hornby chip in to a Class 60 and it ran no problem
any idea's where I go from here please keep them clean
BILLY
 

·
Registered
Joined
·
763 Posts
I'd be tempted to add some weight over the bogey if possible. It could be that the various different decoders you are using have different acceleration characteristics which are masking or increasing the problem. I've not seen one of the new 73's running yet but have one on order and they don't strike me as particularly heavy loco's especially compared to more modern ones (my lima one weighing 400grams fully boxed)
 

·
No Longer Active.
Joined
·
13,319 Posts
If adding weight does not cure the problem then it could just be that the H or B decoders do not have a good enough motor control for the motor fitted to your loco - checking the acceleration/deceleration CV's could also be worth a try.

Yes, the Lenx Silver is about double the price of the H or B decoders, but maybe you'll just have to bite the bullet with this one.

Be good to know the outcome.
 

·
Registered
Joined
·
34 Posts
Discussion Starter · #5 ·
Hi
Well I've add a fair bit of weight to the loco and I'm still seeing a lot of slipping
but with or without I've found it only seems to slip at low speed .
I've refitted the lenz chip till I work out what the problem is
It was said to check the acceleration CV I'm not to sure what I'ed be looking for so I may need a
little help in this area
BILLY
 

·
No Longer Active.
Joined
·
13,319 Posts
Billy,

When you accelerate with the B or H or L ecoders fitted, if you set the speed immediatly to the max does the loco accelerate gently or full speed more or less straight away ?

Let us know so that we can help further.

For your information ;
I'm not too sure about the CV's for the B or H decoders, but with Lenz starting voltage is CV 2, acceleration is CV 3, decelleration is CV 4 & max speed is CV 5.

It may also be worth checking on Dennis's suggestion regarding the back EMF.

If you get really confused send me a PM & I'll let you have my phone # & talk you through it. I had the same sort of thing in my early DCC days & as soon as I had sussed the basics, never looked back.
 

·
Registered
Joined
·
34 Posts
Discussion Starter · #8 ·
Hi
The loco is at max speed at once but there is just the start of a slip just as you turn the speed up
once past this the slipping clears but by then the loco is on the floor
about the chips (EMF) I'm not sure about the Hornby chip but is the EZ chip not fitted with this?
thank you all for the time out your taking to help me with this
BILLY
 

·
No Longer Active.
Joined
·
13,319 Posts
Billy,

I'm certain that the Hornby decoder has back emf. What you need to do is to set the max speed to a realistic level & then set the acceleration CV.

What control unit are you using ?
 

·
Registered
Joined
·
122 Posts
Subject to finally getting my 'N Gauge' layout started in the new year, I intend getting a Class 73 as I have liked these for years, but never known much about them. I like the design and what they are capable of, then saw a model of one at Spalding MRE this year and it has convinced me to get one. I have chosen to go for 'N Gauge' because of lack of space I have to endure. If I get a 'OO' one, I could always run it on my Club layout when it is finished.
 

·
Registered
Joined
·
20 Posts
Hi Billy, have you tried running the 73 on analogue? Grab a normal controller and try running the loco up a slope and the cause of the problem (to me at least) seems to be a lack of traction tyres. You could possibly try sourcing a replacement set of axles that are fitted with tyres and see if this cures the problem, I have no idea if the older lima style axles would fit though due to the new motor block - the gears may well have a different number of teeth.
 

·
Registered
Joined
·
34 Posts
Discussion Starter · #12 ·
Hi
I run my layout with a Digitrax system without any problems up till now as to adjusting the CV's
this will have to be looked into as every chip I've used has worked ok in a different loco so it may
be a case of me picking one trying to adjust it till it work's (it work's in the movies)

the loco was ran in on DC control without any problems so sadly the wheels are not the problem
BILLY
 

·
Registered
Joined
·
34 Posts
Discussion Starter · #14 ·
Yes right-de-oh I think this problem seems of have ran out of ideas I'll keep on at it and pass on
anything I find
thank you all for your help
BILLY
 

·
Registered
Joined
·
106 Posts
Although this thread is about the 00 hornby 73 id like to add a bit about the N gauge variants.
The dapol DCC ready 73 isnt a patch on the non DCC version when it comes to running,the DCC ready loco is just far too light as they have subsituted the metal chassis block for plastic,so if anyone is thinking of getting a N gauge 73,get the non DCC version,they look fantastic and perform very well indeed.
As to the hornby 00 version,well i dont model in 00,but i am planning a small end to end layout in 00 and the hornby 73 was top of my list in the loco dept,are they any good ?
 

·
Dogsbody
Joined
·
1,387 Posts
I don't know about the Hornby chip but I've got a few 101's and a couple of 121's which have the same motor bogie controlled with the 3 function Bachmann decoder 36-553. The initial problems were solved by setting the cv's as follows :

cv 2 = 5
cv 3 = 1
cv 4 = 1
cv 5 = 12 (I run my stuff slow !)
cv53 =50
cv54 = 12
cv55 = 36

The most relevant ones are cv's 53, 54 and 55 since they alter the chip to suit the motor.

Please try them and let us know the result/
 
1 - 16 of 16 Posts
Top