7mm Possible GT3 model
- Thread starter Compton castle
- Start date
Eastsidepilot
Western Thunderer
Always liked the idea of scratch building a GT3 with one of these JetCat P20-SX micro turbine for small model jets with a thrust of 24 Newton or 2,4 kg to power it. 
Col.
Col.
Boyblunder
Western Thunderer
Well Colin I wouldn't try pulling any plastic carriages with it, may get a bit blobby.
Eastsidepilot
Western Thunderer
Eastsidepilot
Western Thunderer
On a serious note I wonder where or if you would get a sound file, out of interest what does a model turbine engine of that size sound like ?, I have never heard one.
Col.
Eastsidepilot
Western Thunderer
I think I'd need a marine version like this JetCat 2-shaft Marine Engine SPM5 ,turbine for speed boats although this one is too large.
Col.
oldravendale
Western Thunderer
Perhaps they'll use this:
I saw this running at a couple of Model Engineers' exhibitions. It's mightily impressive and is probably as close as one would get to the real thing. I've not been to Model Engineers for a few years but at my last visit they were starting work on either 18000 or 18100 - I can't remember which one.
Brian
I saw this running at a couple of Model Engineers' exhibitions. It's mightily impressive and is probably as close as one would get to the real thing. I've not been to Model Engineers for a few years but at my last visit they were starting work on either 18000 or 18100 - I can't remember which one.
Brian
Steph Dale
Western Thunderer
They whistle. More so than full size versions. The small size reduces internal inertia enormously, so like a small motor the speed is higher and torque lower. So the harmonic frequencies of their acoustic output moves up in sympathy...
The only downside is that the higher frequencies are much more directional, so the sound is focused on the 'output' side of the turbine. The narrow dimensions of the exhaust don't help, but you certainly don't want to be downstream of one of these wee things.
Pardon?
Steph
adrian
Flying Squad
you don't want to be down stream of the larger ones either.
Steph Dale
Western Thunderer
In the case of the little ones, I think I'd add that I wouldn't really want to be beside one either. 
In fact probably best avoided altogether. Bring back steam! Or clockwork...
Steph
In fact probably best avoided altogether. Bring back steam! Or clockwork...
Steph
oldravendale
Western Thunderer
I've been up close to that loco (I think Steph has too) - in fact they used to run it up on a rolling road pretty much every hour at Model Engineers' Exhibition. The crowd gathered around for the demo noticeably expanded with those at front trying to get to the back as soon as the loco started. (I exaggerate, but only a bit). I seem to remember (although I have no notes about it) that the engine was running at something like 23,000 rpm, but I'm probably wrong and Steph will doubtless put me right.
Many moons ago a friend and I were at the same exhibition when there was a display of one of the first miniature jet engines. It was run behind industrial netting and as soon as it started up the operators ran away.......
Brian
Many moons ago a friend and I were at the same exhibition when there was a display of one of the first miniature jet engines. It was run behind industrial netting and as soon as it started up the operators ran away.......
Brian
Eastsidepilot
Western Thunderer
The old biker in me would probably end up building this instead
.............and 'ave a real burn up
Col.
Col.
Last edited:
Steph Dale
Western Thunderer
............and 'ave a real burn up
I didn't think 'burn up' meant self-immolation..?
Steph