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Accurascale Class 55 Deltic - 4mm scale


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53 minutes ago, atom3624 said:

Shouldn't there be 2?

 

Anyone see the Deltic being 'moved' last night - some tight squeezes there!!

 

Fantastic beast of a locomotive and can't wait to see the AccuraScale one .... Q2 2020 still?

 

Al.

 

Hi Al,

 

Yes, late Q1 2020 is a possibility even, should have EP1 by the end of this month.

 

50 minutes ago, G-BOAF said:

Looks lovely.

But the spec on the Accurascale website specifies helical gearbox, but the drive train in the CAD looks very much plain gears.

https://accurascale.co.uk/blogs/news/class-55-deltic-in-4mm-our-first-locomotive

 

The helical gearbox is there and the gears will be helical. the angle is slight, but enough to be effective. We cant wait to test it in both our Metro Vick and Deltic to see the benefits. 

 

Cheers,

 

Fran

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1 hour ago, Accurascale Fran said:

The helical gearbox is there and the gears will be helical. the angle is slight, but enough to be effective. We cant wait to test it in both our Metro Vick and Deltic to see the benefits.

So what are you going to measure? One measurement I would like is how far it coasts on straight and level track when at whatever is full speed from 12V DC. The best worm drive circa 600g OO mechanisms that the manufacturers have geared for scale speed circa 120% of rated maximum service speed, manage 1200mm coasting.

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7 minutes ago, 34theletterbetweenB&D said:

So what are you going to measure? One measurement I would like is how far it coasts on straight and level track when at whatever is full speed from 12V DC. The best worm drive circa 600g OO mechanisms that the manufacturers have geared for scale speed circa 120% of rated maximum service speed, manage 1200mm coasting.

 

Hi there,

 

We will be doing a series of tests including what you have mentioned above. Top end speed for both has been given consideration for over 100% of max service speed you'll be delighted to hear! After all, Deltic's were known for spirited runs. 

 

Cheers!

 

Fran

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16 minutes ago, Accurascale Fran said:

 

Hi there,

 

We will be doing a series of tests including what you have mentioned above. Top end speed for both has been given consideration for over 100% of max service speed you'll be delighted to hear! After all, Deltic's were known for spirited runs. 

 

Cheers!

 

Fran

 

But hopefully we can avoid expensive prototypical overspeed related flashovers...!!!!

Edited by Phil Bullock
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13 minutes ago, Phil Bullock said:

 

But hopefully we can avoid expensive prototypical overspeed related flashovers...!!!!

Surely these should be included? With a bank of spare motors available for swapping out. Hopefully just a few screws to undo to drop one motor out and another in!

After a while, if motors are hard to source, they can be repurposed from model boats!

 

Seriously though, mechanically it is looking quite a beast. Can't wait for my KOYLI, but also happy to wait to make sure everything is 100%

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Rotating fans would be great - but 4 of them?

4 motors?

2 motors linked with gears?

 

It would be very nice 'though - I love 'extra details' - opening doors, glowing instrument dials, driver in #1 end, etc ...

 

Main thing is that it must perform well - decent weight, SUPER smooth low speed, scale load pulling and maximum speeds - Deltic was no slouch!

 

Al.

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4 hours ago, atom3624 said:

Rotating fans would be great - but 4 of them?

4 motors?

2 motors linked with gears?

 

It would be very nice 'though - I love 'extra details' - opening doors, glowing instrument dials, driver in #1 end, etc ...

 

Main thing is that it must perform well - decent weight, SUPER smooth low speed, scale load pulling and maximum speeds - Deltic was no slouch!

 

Al.

Indeed the Deltics were fast. Perhaps not quite as fast as an A4 at its fastest but the Deltics could sustain 100 m.p.h. as long as the track allowed it, which the A4s could not. I believe that when the Deltics were shortly to be withdrawn, the men at English Electric very sportingly removed the speed limiters, just to see how fast they could go. It was done on the quiet but I believe one touched 125 m.p.h.

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I would like to believe that, but that 100 mph operating maximum 'anywhere straight' has been etched in my memory since I first set eyes on one .... years ago.

 

Just did a little 'Googling' .... and .... OK, all I can say is WOW!!

 

Fran, you've got to make this thing perform, and VERY WELL INDEED!!!

 

http://www.delticsounds.com/deltichowfast.html

 

Al.

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1 hour ago, atom3624 said:

I would like to believe that, but that 100 mph operating maximum 'anywhere straight' has been etched in my memory since I first set eyes on one .... years ago.

 

Just did a little 'Googling' .... and .... OK, all I can say is WOW!!

 

Fran, you've got to make this thing perform, and VERY WELL INDEED!!!

 

http://www.delticsounds.com/deltichowfast.html

 

Al.

A very enjoyable read – thanks for posting the link.

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3 hours ago, No Decorum said:

Indeed the Deltics were fast. Perhaps not quite as fast as an A4 at its fastest but the Deltics could sustain 100 m.p.h. as long as the track allowed it, which the A4s could not. I believe that when the Deltics were shortly to be withdrawn, the men at English Electric very sportingly removed the speed limiters, just to see how fast they could go. It was done on the quiet but I believe one touched 125 m.p.h.

See the first post on this thread:

https://www.rmweb.co.uk/community/index.php?/topic/37623-fastest-deltics/

 

Edited by G-BOAF
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7 hours ago, No Decorum said:

Indeed the Deltics were fast. Perhaps not quite as fast as an A4 at its fastest but the Deltics could sustain 100 m.p.h. as long as the track allowed it, which the A4s could not. I believe that when the Deltics were shortly to be withdrawn, the men at English Electric very sportingly removed the speed limiters, just to see how fast they could go. It was done on the quiet but I believe one touched 125 m.p.h.

Deltics were well capable of 100+ MPH for mile after mile. In my time at KX I saw then run Peterborough-KX in HST timings with ease. The fastest I ever had out of one was 113 mph, and that was on one engine. My diary indicates it was 55004 on the 1940 KX to Hull, 25/9/81. We had two engines leaving Kings Cross but had lost one by the top of Holloway Bank,  (it was trying to join us in the cab), so the Driver I was driving for said, carry on with one and don't hang about, the 19.50 departure will be right behind us. So from the top of Holloway Bank to between Biggleswade and Sandy, 42 miles, where we were booked onto the slow line for the 19.50 to pass, the power handle never left the FULL position. I looked at the speedo as we passed though Hitchen and it was showing around the 113 MPH mark, and didn't drop below 105MPH until I shut off and braked for the signals turning us onto the slow lines at Sandy. I did see higher speeds attained with two engines running, but never with only one. Deltics could hold 100MPH that would have a 47 struggling to maintain 90, and having also driven class 50's, I have no doubt they the Deltics would beat a 50 as well in maintaining 100MPH.

 

Paul J.

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On 08/09/2019 at 10:01, No Decorum said:

I see cooling fans mounted on a shaft which goes through a hole in a mounting plate and something-or-other just visible underneath the plate. You’re not intending, are you? Could you possibly be? Wot? Rotating fans driven by servo motors? Eh? Eh?

 

Good morning!

 

Well spotted!

 

Early in the Deltic development we did look to have a separate servo motor operate the fans, well spotted! However, as we moved on it became impractical for us to do. However, we have left the mechanism in place for the most part (without motors) so it could be possible for someone with a bit of ingenuity to power them if they wish.

 

 

9 hours ago, Swindon 123 said:

Deltics were well capable of 100+ MPH for mile after mile. In my time at KX I saw then run Peterborough-KX in HST timings with ease. The fastest I ever had out of one was 113 mph, and that was on one engine. My diary indicates it was 55004 on the 1940 KX to Hull, 25/9/81. We had two engines leaving Kings Cross but had lost one by the top of Holloway Bank,  (it was trying to join us in the cab), so the Driver I was driving for said, carry on with one and don't hang about, the 19.50 departure will be right behind us. So from the top of Holloway Bank to between Biggleswade and Sandy, 42 miles, where we were booked onto the slow line for the 19.50 to pass, the power handle never left the FULL position. I looked at the speedo as we passed though Hitchen and it was showing around the 113 MPH mark, and didn't drop below 105MPH until I shut off and braked for the signals turning us onto the slow lines at Sandy. I did see higher speeds attained with two engines running, but never with only one. Deltics could hold 100MPH that would have a 47 struggling to maintain 90, and having also driven class 50's, I have no doubt they the Deltics would beat a 50 as well in maintaining 100MPH.

 

Paul J.

 

Great story Paul, would've loved to have witnessed that! As we stated previously our model will be geared to over over 100mph scale speeds and be exemplary at slow speed too, as is expected these days!

 

Cheers!

 

Fran

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6 minutes ago, atom3624 said:

All sounding very good.

 

Thanks for the update Fran.

 

Quite a story!  Maintaining >100 mph with a single motor - that was pushing it a bit surely - obviously got away with it!!

 

Al.

Not really. Insted of having two diesel engines to produce traction current, we only had one that day. The diesel engine was doing what it would have done had there been two, and all 6 traction motors were working, so no strain on them. It just took a little longer to get up to 100MPH as there was less HP available, but once at 100MPH, the engine was quite happy to hold it there. Diesel engines, especially the Deltic ones, were a lot happier and economic when run at high revs for long times, as long as the cooling system was designed for it. I can remember working heavy steel trains over  the Marches line with a single refurbished Class 37's hauling 1400 tons. The climb from Shrewsbury to Church Stretton, 12 miles, took around an hour with those type of loads, all with the engine flat out. They never faltered, as long as you could put up with the fire bells ringing every now and then. The biggest limit to the maximum speed a loco could attain was the speed at which the last Field Divert came in, which on a Deltic was higher than other locos. Once the last field divert had done its thing, the point at which the back EMF from the traction motors was matched the output of the main generator/alternator, a locos ability to carry on exelerating was limited. So the higher the speed of the last divert, the higher the speed up to which the loco could keep accelerating. This was shown to me the best when they refurbished and regeared the Class 37's. We had a spell of working 2,000t steel trains out of Llanwernto Dee Marsh with pairs of class 37's. A pair of unrefurbished class 37's could get a 2,000t train up to 60MPH, where the gradients allowed, more often than a refurbished class 37, which had been regeared, thus altering the speed of the last field divert. A refurbished class 37 would start to struggle once above 45MPH. 

 

Paul J.

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