The Portescap RG4 is reborn!

If you are making something new or have found something, announce it here.
hollybeau
Posts: 91
Joined: Thu Jul 30, 2009 10:03 am

The Portescap RG4 is reborn!

Postby hollybeau » Tue Jan 01, 2013 2:43 pm

Whilst browsing the Slater's catalogue (yes, I know it is mainly 7mm stuff but they do produce some interesting other things) I came across this in their "motors and gearboxes" section (bottom right -also check out the specification/drawings on the second page).

https://slatersplastikard.com/assets/pd ... xFlyer.pdf

Interestingly, it is termed the "SG4" as opposed to the "RG4".

It raise three questions in my mind.

1) How much?
2) When will it be available ? (not sure how long the "flyer" announcing "coming soon" has been on the web)
3) and most importantly - have they resolved the noise from the bevel gears? I bought an early model RG4 some 30 years ago and it is still fairly quiet. However, one bought at the back end of the run, when I believe the moulds that produced the nylon spur gears were begining to wear out, sounds like a dentist's drill at anything over a crawl and no amount of toothpowder and Duckham's as suggested by Ted Scannell can quiten it.

It will be interesting to see if this does comes on to the market. In their day they were head and shoulders above any other motor/drivetrain around but the products available now probably put them in the shade. Nevertheless for a simple ready made solution I can see them having a following. I only hope that pricing is not influenced by the silly money that the old RG4's go for on Ebay.

Incidentally the final drive boxes shown are also worth inverstigating. I have a FD01 3 to 1 box and it is beautifully made and can be "back-driven". Alas it is too large as yet for any prototype I am likely to build. However, I can see a use for the newer, and smaller FD03. Mated to say a Faulhaber or Maxon motor with a set of ceramic planetary gears would make for a powerful, quiet and silky smooth drive train for any model.

All in all this is good news for the New Year.

Bryan

User avatar
grovenor-2685
Forum Team
Posts: 3918
Joined: Sun Jun 29, 2008 8:02 pm

Re: The Portescap RG4 is reborn!

Postby grovenor-2685 » Tue Jan 01, 2013 3:54 pm

I can see a use for the newer, and smaller FD03.

Actually not new at all, it was the final drive for the micro-metalsmiths microdrive unit which Slaters took over and stopped production.
See http://www.scalefour.org/forum/s4-digests.php#41.
Mine are still awaiting their round tuit.
Regards
Keith
Regards
Keith
Grovenor Sidings

User avatar
Horsetan
Posts: 1371
Joined: Tue Jul 29, 2008 9:24 am

Re: The Portescap RG4 is reborn!

Postby Horsetan » Tue Jan 01, 2013 3:55 pm

It will be interesting to see if the initial stage is:

- a pair of bevels, or
- a contrate-and-pinion, or
- subminiature crossed helicals.

These three types will permit drive-back in the same way as the old RG4 did.

If, however, Slaters resort to a worm and wheel as DJH did (yuk!), then I'm not interested!!
That would be an ecumenical matter.

hollybeau
Posts: 91
Joined: Thu Jul 30, 2009 10:03 am

Re: The Portescap RG4 is reborn!

Postby hollybeau » Tue Jan 01, 2013 4:33 pm

Keith,

I believe the Micrometalsmiths box was the forerunner to the FD01. I don't believe they did a smaller box like the FD03. This is evident by comparing the specifications and drawings on Page 2 of the Slaters pdf with the one from the Scalefour archive. Like you I have the larger box, and indeed the Microsmiths motor and gearbox. It can be seen in the photos of my Spinner tender on the "Alan Gibson brass centred wheels" from about a year ago. In the end I could not get the FD01 box in the loco so gave up and fitted a High Level set up in the loco. If I was doing it today I would use the smaller FD03 box mounted upside down on the rear axle of the loco.

Horsetan,

I don't think it will be a worm as the multi stage gearing below would make the overall gearing too high. My guess is that it will be another set of bevels but it will be intersting to see if they are in metal (noisy!) or nylon/plastic (wear problems over time). Perhaps they will be made of ceramic as used in the better gearboxes from Faulhaber and Maxon.

Bryan

User avatar
Horsetan
Posts: 1371
Joined: Tue Jul 29, 2008 9:24 am

Re: The Portescap RG4 is reborn!

Postby Horsetan » Tue Jan 01, 2013 5:06 pm

hollybeau wrote:....My guess is that it will be another set of bevels but it will be intersting to see if they are in metal (noisy!) or nylon/plastic (wear problems over time). Perhaps they will be made of ceramic as used in the better gearboxes from Faulhaber and Maxon.


I've never seen ceramic bevels before. However, I think someone should give Slaters a call and see whether this SG4 really is going to be produced, or whether it is merely a nebulous intention - timescales being notoriously elastic.
That would be an ecumenical matter.

User avatar
Andy W
Posts: 884
Joined: Thu May 21, 2009 8:11 am

Re: The Portescap RG4 is reborn!

Postby Andy W » Tue Jan 01, 2013 6:51 pm

But is a Portescap really that much better than, for example, a Mashima with an HL box?
Make Worcestershire great again.
Build a wall along the Herefordshire border and make them pay for it.

User avatar
Tim V
Posts: 2868
Joined: Tue Jul 29, 2008 4:40 pm

Re: The Portescap RG4 is reborn!

Postby Tim V » Tue Jan 01, 2013 6:56 pm

In my experience no.

They have a limited range of gear ratios (well one actually).

In fact I pulled all my Portescaps out of my engines some years ago, to replace them with can motors. The Portescap's sold well on the bring and buy.
Tim V
(Not all railways in Somerset went to Dorset)

User avatar
tommallard
Posts: 11
Joined: Mon Aug 10, 2009 8:14 am

Re: The Portescap RG4 is reborn!

Postby tommallard » Wed Jan 02, 2013 4:56 pm

I expressed a very strong interest in these to Slaters some months ago whilst looking for a back driveable gearbox that didn't use 7mm scale gearbox components or those from the portescap unit.

The timing of product release is said to be around about now, so fingers crossed. Please don't quote me on this, but my understanding is that the first stage will be the highly desirable crossed helical type followed by spur drive. So long as the motor is top grade - ie coreless, then a price somewhere around £100 would be in line with equivalent 7mm scale stuff.

Slaters also have the resources to make this in house, so I have high hopes for this product.

Best regards

Tom

hollybeau
Posts: 91
Joined: Thu Jul 30, 2009 10:03 am

Re: The Portescap RG4 is reborn!

Postby hollybeau » Wed Jan 02, 2013 5:12 pm

But is a Portescap really that much better than, for example, a Mashima with an HL box?


It all depends on what you mean by "better". Is better more powerful, smoother, quieter? The Mashima motors are streets ahead of the Anchoridge D11/D13, the "go to" motor of 25 years ago and they in turn were universally considered to be better than the Triang X04 and the K's motors of the generation before that. In my view the Swiss made coreless motors (Faulhaber/Maxon) we have today offer another significant advancement in motor performance. They are amazingly powerful for their size, have considerable torque and unless run at their maximum are virtually silent. They have two problems - they need a pure DC supply to run them (they are too sensitive for some of the electronic wizardry seen in some controllers - but see below re DCC) and they cannot take the end thrust from a worm drive. (in practice the length of protruding shaft is in any event too short to fit a worm on). The RG4 (and its equivalents at the time) attempted to solve this latter problem with the use of bevels (and in part to change the axis of rotation through 90 degrees) but being the first in the drive train they spin quite quickly and are/were noisy. That to me has always been the weakness in the concept.
Tim has raised a fair point about the lack of flexibility in the gear ratios but this does not overly concern me as the amount of torque available is so high they are flexible in their use. For those using DCC the CV's can be tweaked so that top and mid speeds (and indeed everything in the speed table in between) can be changed, along with the matching of CV's to the motor (available in the Zimo decoders for example so as to accurately control back EMF) so that "perfect" control is now available.
The HL boxes are superb and offer such flexibility that they take some beating. What would be good would be to mate a Faulhaber or Maxon motor with a flexible drive to one of Chris Gibbons boxes using the remote extender facility which is built into the etches.
I have just seen Tom Mallard's post and if the first point in the drive train is indeed to be crossed helicals then this is very welcome, even at that price. I believe the reborn RG4 will have a market for some modellers and for some models. More variety and choice can only be a good thing.

Bryan

Philip Hall
Posts: 1947
Joined: Mon Aug 10, 2009 7:49 pm

Re: The Portescap RG4 is reborn!

Postby Philip Hall » Wed Jan 02, 2013 5:53 pm

I agree with Tim. A Mashima and High Level box is in my view the modern equivalent of the RG4 when it first came out. But things have moved on. I have taken many RG4s out of engines and replaced them with cans and HL boxes, mostly to get rid of the awful noise that they make in a quiet home environment. Yes, the early ones were much better, but they still whined, and you have to have a controller that likes them, whether or not you use DCC. The later ones were just dreadful, and no amount of mucking about with toothpaste and engine oil has done much to alleviate that on the one I've just taken apart. It runs smoothly, but...

The Slater's development is interesting, but the prospect of paying £100 for a motor and gearbox frightens me, and I suspect many others. However good it is, it can't be that much better.

Philip

User avatar
tommallard
Posts: 11
Joined: Mon Aug 10, 2009 8:14 am

Re: The Portescap RG4 is reborn!

Postby tommallard » Wed Jan 02, 2013 10:40 pm

Yes it is likely to be a case of diminishing returns, Philip.

The motor may well be equivalent to the cost of the gearbox in my hypothetical price bracket, and I was simply comparing what is proposed with the cost of mechanically similar 7mm scale motor/gearbox combinations. I know for the pair of Faulhaber motors I recently purchased, these came out at £60 each or so (including delivery)! That was for a very low order size - things get much cheaper for larger orders I imagine.

Maybe we'll all be pleasantly surprised?

Best regards

Tom

Philip Hall
Posts: 1947
Joined: Mon Aug 10, 2009 7:49 pm

Re: The Portescap RG4 is reborn!

Postby Philip Hall » Thu Jan 03, 2013 4:55 pm

I know it's not Portescap country, but it's gearboxes. It seems that Ultrascale have been looking into 3D technology as well. Looks interesting:

http://www.ultrascale.com/node/41

Also Bill Bedford:

http://www.mousa.biz/fourmm/loco/drives/gearboxes4.html


Philip

billbedford

Re: The Portescap RG4 is reborn!

Postby billbedford » Fri Jan 04, 2013 11:01 am

but also this one, though not really for locos.

hollybeau
Posts: 91
Joined: Thu Jul 30, 2009 10:03 am

Re: The Portescap RG4 is reborn!

Postby hollybeau » Fri Jan 04, 2013 1:05 pm

It is good to see these new products becoming available. Given their long track record and association with gearing the developments at Ultrascale are particularly exciting.

On the question of the price of Portescaps et al I normally buy mine from the States from a chap called "Grandad Eldon Shirey" (only in the good old US of A could you find a name like that) or "The Motorman" whose Ebay shop can be found here:

http://stores.ebay.co.uk/microlocomotio ... 7675.l2563

However, there is VAT and sometimes a Customs handling charge on receipt of the goods here so in an effort to support British business I made enquiries of a company located in the UK who import them directly from the manufacturers. For a Portescap 1328 motor with 1 to 5.5 attached planetary gearhead (a standard item) I was quoted £476.24 + £12.50 carriage + VAT.(Total of £586.49p). That is for one motor, not ten! Suffice it to say I have ordered one from Grandad for just over £40. The price that Tom paid of £60 per motor seems good value!

Bryan

User avatar
Horsetan
Posts: 1371
Joined: Tue Jul 29, 2008 9:24 am

Re: The Portescap RG4 is reborn!

Postby Horsetan » Fri Jan 04, 2013 10:57 pm

tommallard wrote:I expressed a very strong interest in these to Slaters some months ago whilst looking for a back driveable gearbox that didn't use 7mm scale gearbox components or those from the portescap unit.

The timing of product release is said to be around about now, so fingers crossed. Please don't quote me on this, but my understanding is that the first stage will be the highly desirable crossed helical type followed by spur drive. So long as the motor is top grade - ie coreless, then a price somewhere around £100 would be in line with equivalent 7mm scale stuff.....


There should be an option to buy the gearbox only, for those who don't want to use coreless motors, or who have their own coreless stock.
That would be an ecumenical matter.


Return to “New Products”

Who is online

Users browsing this forum: ClaudeBot and 0 guests