Jump to content
 
  • entries
    93
  • comments
    685
  • views
    145,388

Tutbury Tractoring

D869

Entry posted by D869

1,180 views

 Share

As you might have seen on one of 2mm threads, the tractor and its test bed put in an appearance at the Tutbury gathering yesterday.

 

Several folks had a try at tractor driving and several politely declined. Apart from hopefully being entertaining for the budding driver it was interesting for me to see what happens with someone else at the wheel.

 

P1060805.JPG.d287c1a84c8c4edd59f8946109d2c167.JPG

Full marks to Laurie Adams for being the only person to attempt and complete the full tractor shunting challenge (swap an incoming full tank with an outgoing empty one).

 

So apart from having a good day out and a deadline to actually make me get things done, what did we learn about using the tractor under the gaze of the public ?

 

  • People unfamiliar with the tractor seem to start off by driving very slowly. This is understandable but I'm not sure it's a good strategy because as well as the tractor moving forward more slowly the response to the steering also takes longer and the driver has time to over correct.
  • People have different 'muscle memory' of what a rotary control should do. It is a bit confusing for a long time model railwayist to be presented with a handset on which the rotary control is a 'steering wheel'. Figuring out which is left and right can also be a challenge when the tractor is pointing in different directions (not surprisingly, radio control modellers tend to be better at this). Things get more fun when you then hand them the other controller so that they can do some shunting with a loco. I don't think there is anything to do here other than to watch knowingly while they get used to it although using a Powercab DCC controller for the trains might be easier on the brain.
  • The test bed was kitted out with more dummy scenery and buildings than last time so there were more opportunities to collide with the landscape. Not unexpected but if the driver keeps the throttle open then the tractor will part company with the magnets underneath. After this happens it is tricky to 'find' the magnets again... the extra stuff on top acting as a disincentive to lifting the lid to figure out where the magnets are. This is a good lesson because it won't be possible to lift the lid when the tractor is installed on the layout proper. I have some ideas about how to make it easier to get out of this pickle.
  • Sometimes the control system's centre position drifts over time. This is probably because friction or collisions up top are creating more resistance than the steppers can handle and they 'lose steps'. This is a job for some more Arduino programming - at the moment it only 'finds' the centre when it starts up but with some work it can also correct for lost steps while it is running.
  • I did managed to get the tractor stuck 'in a corner' once between the limit of lengthways and widthways travel so need to give a bit more thought to the way that the limits work to prevent that embarrassing situation. Luckily nobody was looking.
  • More visual feedback (probably some LEDs) is needed when the magnets are moving without anything visible 'up top' before and after the gravity shunt.

 

On the whole it kept running for the whole day with very few unscheduled stops to lift the lid and sort things out manually. As far as I know it only went completely pear shaped once when the carriage swing arm somehow managed to swing a long way past what should be its 60 degree limit. I thnk I was watching Parkend when it happened so I'm not sure how it got into that state but the bigger concern is that even with a 'standard IT fix' (turn it off and on again) the thing couldn't sort itself out without extra manual help, so some more work needed there.

  • Like 8
  • Informative/Useful 2
 Share

8 Comments

Recommended Comments

  • RMweb Gold
bcnPete
  • RMweb Gold

Good to see you again Andy and meet your son too - I also enjoy following his blog posts on here.

 

Cracking work with the tractor although I didn’t get to grasp the whisky box ;)

 

Really looking forward to see this layout come together as it will be quite unique.

 

Until the next time...:bye:

 

 

Link to comment
D869

Good to see you too Pete (plus Kyle, Meeth, Exeter and Loch Awe) and sorry we didn't have more time to catch up.

 

Yes, the enclosure I've 'upcycled' to house the tractor controls has attracted some favourable comments. A sort of new take on John Greenwood's 'beer can' controller. It was originally temporary but it is quite a nice size so I think I'll probably keep it as it is - I just need to figure out a more long term arrangement for getting the cable out without the tin slicing through the wires.

 

Regards, Andy

Link to comment
D869
3 hours ago, Ian Morgan said:

It's called a rubber grommet.

 

Hi Ian,

 

I think that the thin metal of the malt whisky tin is capable of slicing through a grommet when used on a handheld controller like this so it needs something to protect the grommet from the metal.

 

I already have some things like these in my stash... https://uk.farnell.com/hummel/lcp07b/cable-gland-polyamide-6-5mm/dp/2887516

 

These should prevent the metal from causing damage but they lack any strain relief at the point where the cable exits the gland so I dont think they are ideal either. Something that has both a hard plastic sleeve through the hole and also a flexible strain relief sleeve on the outside end would be ideal but the stuff I've found so far has one or the other, not both.

 

If only the whisky people had foreseen the high probability that their packaging would find a new use as an electronic project enclosure, honestly... :jester:

  • Funny 1
Link to comment
D869
1 hour ago, Graham R said:

Thicken the whisky tin metal by gluing on a suitable washer, then use the grommet :-)

 

I have in mind something similar involving making  something along the lines of a stepped washer on the lathe and using it with a flexible grommet/strain relief sleeve unless I can find something better ready made. It's not very high on the 'to do' list though.

Link to comment
Laurie2mil

Tie a knot in the wires just inside the grommet??

 

I enjoyed the tractor drive - thank you!  Our respective tractor drive systems rather reflect our respective psychi's, I think!!!

 

Laurie A

Link to comment
D869

Cheers Laurie. Good to see you and glad you had fun on the day.

 

All grommet/strain relief suggestions will be stored away for the day when this particular job comes off the back burner so thanks for that. Before that day there are more important things like wood to cut and so on.

 

I was thinking of some flippant comment about our respective mental states but decided that it might be best left as an exercise for the reader.

Link to comment

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...