Rob Pulham
Western Thunderer
That's the long term plan Steve, photos would be appreciated.
7mm Rob Pulham's Work Bench - Connoissuer J79 Revisited
- Thread starter Rob Pulham
- Start date
Rob Pulham
Western Thunderer
Before going any further I started to make up the bulkheads which are made up from multiple layers. Here the instructions (or my interpretation of them) let me down again and I managed to get the overlay for the top of the front bulkhead out of sequence meaning that I had to cut a section out of it to prevent having to undo a lot of work meaning that it sits around the lockers not behind them (it was quite easy to do with scissors due to it being half etched). It isn't visible in the end result but I know I had to do it.
Front Bulkhead
Fire Iron Tunnel
Front Bulkhead
Fire Iron Tunnel
SteveB
Western Thunderer
Hi Rob
Please see photos below. I got the idea of using Tang Band speakers from someone on WT, but I cant remember who. Sorry. I think it may have been Steve Cook, apologies to all concerned if I'm wrong.
If you're interested, I've only been able to get them from USA. Its quite a painless and surprisingly quick process. Here's a link to where I got them from.
www.parts-express.com/tang-band-t1-1942s-speaker-module-pair-5-1-4-x-2-1-8--264-932
I did wonder about just having the sound coming from the tender, but unless you get really close to it then its not too noticeable. A good friend of mine is investigating an option of adding a tweeter for the loco. The Tang Bands are already 4 ohms which is low as my Zimos will allow.
Hope this helps.
Regards
Steve
Please see photos below. I got the idea of using Tang Band speakers from someone on WT, but I cant remember who. Sorry. I think it may have been Steve Cook, apologies to all concerned if I'm wrong.
If you're interested, I've only been able to get them from USA. Its quite a painless and surprisingly quick process. Here's a link to where I got them from.
www.parts-express.com/tang-band-t1-1942s-speaker-module-pair-5-1-4-x-2-1-8--264-932
I did wonder about just having the sound coming from the tender, but unless you get really close to it then its not too noticeable. A good friend of mine is investigating an option of adding a tweeter for the loco. The Tang Bands are already 4 ohms which is low as my Zimos will allow.
Hope this helps.
Regards
Steve
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John K
Western Thunderer
Sorry for the interrupt Rob.
These Taiwanese speakers are good but while we are still part of the EU it may be easier to buy from Loudspeaker Freaks in the Netherlands.
See bottom line of this page.
TB speaker | Loudspeaker freaks
Best,
John
These Taiwanese speakers are good but while we are still part of the EU it may be easier to buy from Loudspeaker Freaks in the Netherlands.
See bottom line of this page.
TB speaker | Loudspeaker freaks
Best,
John
daifly
Western Thunderer
I may be in a minority of one but I always find it very noticeable, and the bigger the loco, the worse it is. Surely it’s possible to find space in an 8F boiler for a reasonable speaker?
Dave
Rob Pulham
Western Thunderer
Thanks for the input gents, that is one big speaker
Rob Pulham
Western Thunderer
This is what it looks like with the overlays on the body. You get two options included in the kit either welded or riveted. I chose riveted because it adds a little more to the character.
These latter two show the front bulkhead now it's fitted and the fire iron tunnel which fitted perfectly.
These latter two show the front bulkhead now it's fitted and the fire iron tunnel which fitted perfectly.
Yorkshire Dave
Western Thunderer
There should be plenty of room if the speaker is mounted on the boiler/firebox ring. The boiler and smokebox become the sound chamber.
Ideally the speaker requires a response range of 105Hz to 20KHz and this is where the Tang Speakers score. Most speakers available have 150Hz as the lower response level which I have personally found is not low enough to provide the deeper WOOomph, WOOomph sound of a larger steam locomotive when it starts.
As an experiment I'll be fitting a Tang Band T1-1925S speaker at some point into one of my steam locomotives to test this theory (all my previous installations of this range of speakers have been in diesels).
Apologies for the diversion Rob
.
Steph Dale
Western Thunderer
Dave,
Sorry mate, that's erroneous - where on earth did those numbers come from?
Steph
SteveB
Western Thunderer
Sorry to intrude on your thread Rob. Firstly I think I owe Dave an apology, I now suspect I learnt about Tang Bands from his posts.
I've just done a quick experiment with my 8F, my admittedly poor hearing can't really tell that the sound is coming just from the tender unless I'm closer than 3 or 4 feet and then I have to concentrate on the sound. I suspect it's less obvious where the sound is coming from because of the difference in the amount of bass. Really, what Dave was saying. Bass doesn't seem to be as directional as mid/high frequencies. I guess that's why even good surround sound systems only have one woofer.
I'm hoping that the 8F will be running at the Albury S7 meeting on the 21st, so if you're going then you'll be able to hear it for yourself.
Regards
Steve
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Yorkshire Dave
Western Thunderer
They came from the their spec sheet unless I've completely misunderstood for which I apologise.
Steph Dale
Western Thunderer
Aah - that makes some sense. The problem is that you said 'Ideally the speaker requires a response range of 105Hz to 20KHz', which to me reads as a specification. Or 'what you'd want your speaker to have under ideal circumstances'. Well, the CD standard was built upon a belief that human aural comprehension is about 20Hz - 20kHz, so your 'ideal' should be at least that, I'd propose. Tricky enough with lots of watts and cubic inches; in the milliwatts and square millimetres we're dealing with here nearly impossible...
I also cheerfully acknowledge that getting any sort of output down to 105Hz out of an enclosure that size is remarkable!
Steph
farnetti
Western Thunderer
In a previous life I was a recording engineer and so:
Steve, you are correct, mid high frequencies are more directional so a speaker near the front end of a stem loco is ideal. If there is room for a larger lower frequency speaker elsewhere so much the better to add some oomph.
Steph, the 20Hz-20kHz potential hearing range is very dependent on age. At 8Khz most people lose about 30DB at age 60 compared to age 20, presumably more at higher frequencies. As it is a gradual decline we don't tend to notice it and at age 60 or older 20Khz maybe below the threshold of hearing.
Ken
Steve, you are correct, mid high frequencies are more directional so a speaker near the front end of a stem loco is ideal. If there is room for a larger lower frequency speaker elsewhere so much the better to add some oomph.
Steph, the 20Hz-20kHz potential hearing range is very dependent on age. At 8Khz most people lose about 30DB at age 60 compared to age 20, presumably more at higher frequencies. As it is a gradual decline we don't tend to notice it and at age 60 or older 20Khz maybe below the threshold of hearing.
Ken
Rob Pulham
Western Thunderer
I had a very satisfying session on Friday afternoon finishing of fitting the pickups and getting the J79 for a run out at SHildon on Saturday. After a couple of minor hiccups including a crank pin bush and a wheel retaining stud coming undone she ran successfully in both directions. I do need to look at my springing of the centre axle though as there didn't seem to be any movement at all.
I took along a couple of items of rolling stock for a run out too - Connoisseur Midland Milk van and a Dragon S&D Horsebox.
I took along a couple of items of rolling stock for a run out too - Connoisseur Midland Milk van and a Dragon S&D Horsebox.
Rob Pulham
Western Thunderer
Back in 2017 I built a Connoisseur J79 which was painted in early 2018 (video above) and then after some test running it sat in my cabinet with occasional trips out on my demo stand. Somewhere along the line I managed to get a large chunk of paint removed from the bunker. I may have attempted to patch paint this but I also noticed that somehow when fitted the backhead had slipped and moved off centre.
This was one of those thigs that despite being in the enclosed cab one I had seen it I couldn't unsee it and it started to bug me. I popped it in a box on a shelf and tried to ignore it but eventually I decided to take the plunge and strip the paint of it.
Just a reminder of what it looked like in January 2018
Fast forward to a couple of weeks ago and we have this.
You will note in all the photos above that there is an infilled section under the boiler behind the smokebox. I didn't notice this when building and only noted it when I had got it all assembled. Now having stripped all the paint off I took the plunge and cut that infilled section out and I have to say that the loco looks much the better for having it removed.
You will also note that there have been a couple of casualties during the paint stripping process - One of the cab steps broke off, one of the cab handrails came adrift and I removed and repainted the backhead
This was one of those thigs that despite being in the enclosed cab one I had seen it I couldn't unsee it and it started to bug me. I popped it in a box on a shelf and tried to ignore it but eventually I decided to take the plunge and strip the paint of it.
Just a reminder of what it looked like in January 2018
Fast forward to a couple of weeks ago and we have this.
You will note in all the photos above that there is an infilled section under the boiler behind the smokebox. I didn't notice this when building and only noted it when I had got it all assembled. Now having stripped all the paint off I took the plunge and cut that infilled section out and I have to say that the loco looks much the better for having it removed.
You will also note that there have been a couple of casualties during the paint stripping process - One of the cab steps broke off, one of the cab handrails came adrift and I removed and repainted the backhead
Paul Tomlinson
Western Thunderer
Hello Rob. You might like to add a bit of dummy motion? Both it and Jim's Y7 are charming little locos...
Rob Pulham
Western Thunderer
Thanks Paul,
I plan to revisit the chassis because I wasn't too happy with the running so I may well do as you suggest.
I plan to revisit the chassis because I wasn't too happy with the running so I may well do as you suggest.
tomburnham
Active Member
Hi Rob,
You may already have these photos showing both sides of No. 1662 but they should be useful in providing information for those extra little details.
Tom
You may already have these photos showing both sides of No. 1662 but they should be useful in providing information for those extra little details.
Tom
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Rob Pulham
Western Thunderer
Thanks Tom,
I have the second one but a very low resolution copy so your higher res copies are really useful thank you.
Without looking too closely, one detail that I have definitely missed and I am not actually sure what it is, is the curved section in the rear of the cab outlined below.
Any pointers would be gratefully received.
I have the second one but a very low resolution copy so your higher res copies are really useful thank you.
Without looking too closely, one detail that I have definitely missed and I am not actually sure what it is, is the curved section in the rear of the cab outlined below.
Any pointers would be gratefully received.
Rob Pulham
Western Thunderer
I repainted the backhead which had losts its paint in the stripping process.
Another minor casualty of the paint strip was the oil can which sat on the footplate.
Jim thoughtfully supplies a casting for an oil can which I had improved by adding a handle from a piece of scrap etch before painting it and gluing it on..
Initially I planned to repaint it and stick it back in position once the loco is painted, I had even got as far as getting the gunmetal paint out. But then I wondered if I could do better. So I found a few images on auction house websites and had a go.
Buoyed by the result of the first, I made a second for the spares box.
Being nickel I hope that they will tarnish into a nice representation of an oily can.
Another minor casualty of the paint strip was the oil can which sat on the footplate.
Jim thoughtfully supplies a casting for an oil can which I had improved by adding a handle from a piece of scrap etch before painting it and gluing it on..
Initially I planned to repaint it and stick it back in position once the loco is painted, I had even got as far as getting the gunmetal paint out. But then I wondered if I could do better. So I found a few images on auction house websites and had a go.
Buoyed by the result of the first, I made a second for the spares box.
Being nickel I hope that they will tarnish into a nice representation of an oily can.