S
SteveO
Guest
Cheers Steph
Trade SDMP/Finney7 - Driving a Geep?
- Thread starter Steph Dale
- Start date
flexible_coupling
Western Thunderer
Since I got a pretty sensible answer to the last complete-noob question, I'll ask another.... Markits vs Romford (and.... others out there?) in the choice of gears; is it simply a personal choice thing - or are there significant/important differences that might influence ones' choice? Or is the "difference" more with regard to the physical gearbox dimensions and simulating size/shape/proportions of popular alternatives?
S
SteveO
Guest
Cheers Steph. Incidentally, how many Romford 40:1 kits did you get etched? Also, do you know who the Mashima wholesaler is? I can't this information anywhere.
Overseer
Western Thunderer
Steph, the gear boxes look very useful. Much better than the alternatives and I won't need to solder on various bits of etch waste and wire to make them rigid as I have done to other etched gear mounts. One suggestion, could you add a dimension or two to the planning drawings so we can check that we have printed them to scale?
ZiderHead
Western Thunderer
I was going to ask the very same, Steph could you please explain the differences (and bear in mind that my next 7mm loco kit will also be my first …)
Steph Dale
Western Thunderer
Happy to help
It's a case of presenting options. I've chosen gears which I think present good value for money, are likely to remain available and give me options (remembering all this stuff is developed, in the first instance, for my own use)
The Branchlines/Ultrascale gears are exceptional, but if you're building a diesel drive that uses the architecture I suggest (gearboxes/propshafts) you need exceptional gears otherwise the noise and losses become too much.
The Romford gears are surprisingly good for the money, but need some care in set up to get the most out of them. Their main advantage is their small size.
The Markits gears have a good reputation, which is thoroughly deserved and they represent a good workhorse gearset; simple to set and with useful dimensions for many locos. The 'idler' version I've developed just adds an extra dimension and allows the use of the gears in larger locos.
I've got an initial buffer stock of 9 (I used one to write the instructions!). I don't know who the Mashima wholesaler is, but you could try contacting Brian at Branchlines.
Hmm, good point
- setting your print options to 100% scaling should do it. I agree it's not obvious though!Does my answer above help?
Steph
Steph Dale
Western Thunderer
Richard,
Broadly, yes. I'll PM or email you over the weekend, if that's okay?
Steph
Broadly, yes. I'll PM or email you over the weekend, if that's okay?
Steph
ZiderHead
Western Thunderer
Thank you yes I think it has made it clearer for me. So for a Sentinel I'll need a 40:1 which means Romford or Markits, and as a first build Markits would be easier for me to set up to run smoothly?
Steph Dale
Western Thunderer
Job,
Basically yes, just watch the wheel diameter to make sure the gearbox doesn't hang lower than the wheels. You can get away with Delrin drive to couple the axles on Sentinel locos, but the chain will usually be visible.
It is one where I'd look at the Romford gear box box though as it'd be less visible.
Steph
Basically yes, just watch the wheel diameter to make sure the gearbox doesn't hang lower than the wheels. You can get away with Delrin drive to couple the axles on Sentinel locos, but the chain will usually be visible.
It is one where I'd look at the Romford gear box box though as it'd be less visible.
Steph
flexible_coupling
Western Thunderer
Thanks Steph, that clears it up!
Steph Dale
Western Thunderer
Jeff,
To be honest as they're already out there (from three sources I can think of) I don't think there's much market in developing equivalent drives. I'm happy to buy from one or other of these sources for my larger locos and will continue to do so. The main weakness associated with the use of helical gears is their size, they will always need either multiple stage gearboxes or a very large output drive gear; this affects both the cost and volume of the gearbox.
Where I'm sure there is a market is in a good quality etched motor mount for simple worm gears. Supporting the axle (output shaft) on ball races does a great deal to reduce noise and increase efficiency; the bearings themselves redirect some of the peculiar thrust angles prevalent in worm gear drives. Adding in the effect of a truly rigid gearbox etch and you've overcome the main issues with etched gearboxes and worm gears. They also have the advantage of being very compact when assembled.
Steph
Steph Dale
Western Thunderer
Jon,
Sorry for the delay in getting back to you, I've only just checked the thread again in preparation for an update.
Anyway, you've raised a couple of interesting issues there. No, I'm not planning a bevel box in any fashion. The main reason is that the 13:1 Blines 'boxes were designed for exactly the sort of situation you describe. With miniature bevel gears you hit on problems with supply (cost), the need for a primary step-down 'box (cost), noise which would mean using helical bevels (loadsa cost) and so on. Mainly cost. If you specifically want them, I can do them, but don't expect much change out of around £75 a gearbox.
Oh and back-driving is a bit of a red herring; why would you want a gearbox to back drive? I'm guessing you're thinking in terms of efficiency; some even relatively inefficient gearboxes can back-drive, while some very efficient gearboxes (those with zero-backlash gears) generally won't. Incidentally the 13:1 Blines 'boxes do back-drive; but I really can't recommend trying it as you'd be quite likely to tear or scar the acetal worm.
If you'd like to see more the planning sheet for the 13:1 Blines 'boxes is here.
Steph
Steph Dale
Western Thunderer
Guys,
In other news, the fret for the Mkits gearboxes is now drafted. Some unfortunately haven't made it to the production tooling. The ones which have made it are:
13:1/26:1 12mm motor fixings
13:1/26:1 15mm motor fixings
13:1/26:1 'remote'
20:1/40:1 10mm motor fixings
20:1/40:1 12mm motor fixings
20:1/40:1 15mm motor fixings
40:1 'idler' 12mm motor fixings
40:1 'idler' 15mm motor fixings
The ones which haven't made it to production are:
13:1/26:1 10mm motor fixings (no perceived application for Mashima 14xx/16xx use with such a low ratio)
20:1/40:1 'remote' (worm-gear clearances result in a gearbox which is large and tricky to assemble)
10mm fixings are for Mashima 14xx and 16xx series motors, 12mm fixings are for Mashima 18xx series motors, 15mm fixings are for Canon 1833.
I expect that, as intended, these gearboxes will be available for order from Cleckheaton. Then we're on to the next iteration...
Steph
In other news, the fret for the Mkits gearboxes is now drafted. Some unfortunately haven't made it to the production tooling. The ones which have made it are:
13:1/26:1 12mm motor fixings
13:1/26:1 15mm motor fixings
13:1/26:1 'remote'
20:1/40:1 10mm motor fixings
20:1/40:1 12mm motor fixings
20:1/40:1 15mm motor fixings
40:1 'idler' 12mm motor fixings
40:1 'idler' 15mm motor fixings
The ones which haven't made it to production are:
13:1/26:1 10mm motor fixings (no perceived application for Mashima 14xx/16xx use with such a low ratio)
20:1/40:1 'remote' (worm-gear clearances result in a gearbox which is large and tricky to assemble)
10mm fixings are for Mashima 14xx and 16xx series motors, 12mm fixings are for Mashima 18xx series motors, 15mm fixings are for Canon 1833.
I expect that, as intended, these gearboxes will be available for order from Cleckheaton. Then we're on to the next iteration...
Steph
Steph Dale
Western Thunderer
After a most entertaining discussion with a forum member yesterday evening I felt suitably prompted to get a product and price list created, so I've attached it to this post. It will shortly be making an appearance on the website as a link from the Downloads page. It will be updated periodically as prices change or stock alters.
Thanks to all those who've ordered hornguide sets. They're currently out of stock with the next batch due in a week or so. I'm happy to take further orders now, but will not be able to honour them for Cleckheaton show.
Cheers,
Steph
Edit: Website now updated with price list
Thanks to all those who've ordered hornguide sets. They're currently out of stock with the next batch due in a week or so. I'm happy to take further orders now, but will not be able to honour them for Cleckheaton show.
Cheers,
Steph
Edit: Website now updated with price list
Steph Dale
Western Thunderer
I've spent this afternoon doing a planning template for the Markits-based gearboxes, which is now on the Downloads page of the website. Etch artwork is now with the etchers and I'm expecting the frets back shortly, along with a new run of hornguides. Prices for these gearboxes is in the pricelist...
Steph
Steph
Overseer
Western Thunderer
Steph,
Looking good. Any chance of a cranked version of the Mkits idler gearbox? I am planning a 2-4-2 tank which has the rear driving axle under the back end of the fire box and a version of the idler gearbox could fit if the gearbox axle was a bit further from the end of the motor. As it is the gearbox conflicts with the backhead (with the motor forward of the gearbox). Not sure if this makes any sense without a drawing.
Looking good. Any chance of a cranked version of the Mkits idler gearbox? I am planning a 2-4-2 tank which has the rear driving axle under the back end of the fire box and a version of the idler gearbox could fit if the gearbox axle was a bit further from the end of the motor. As it is the gearbox conflicts with the backhead (with the motor forward of the gearbox). Not sure if this makes any sense without a drawing.
Steph Dale
Western Thunderer
Fraser,
Yes, it's an option. It's certainly possible, just that I wasn't sure I could think of an application. It'd also need thinking about in terms of assembly! I can't say it's a version I'm likely to do imminently as I've got other things I'm working on for a few months, not least getting the die-cutter up and running to deliver commissions already received.
There is also the drive for the inside-cylinder locos to do...
Steph
Yes, it's an option. It's certainly possible, just that I wasn't sure I could think of an application. It'd also need thinking about in terms of assembly! I can't say it's a version I'm likely to do imminently as I've got other things I'm working on for a few months, not least getting the die-cutter up and running to deliver commissions already received.
There is also the drive for the inside-cylinder locos to do...
Steph