7mm Steph's 'Western' - real workbench...
- Thread starter Steph Dale
- Start date
Steph Dale
Western Thunderer
Delivery number 2 arrived (in two consignments) it looked something like this:
And now we can crack on. First job is to strengthen up the frames after removing material earlier in the build. For this I used a piece of 40thou" plasticard 22*12mm, with a cut out to clear the Branchlines drive shaft. This was stuck in using Zap super-runny superglue (pink label):
(there's a little more required if fitting CSBs, which I'll come to later).
The other means of strengthening the frames also supports the back of the motor. This is an idea I've use a good few times in my HO modelling to strengthen up scale bar frames, which can otherwise be pretty weak. This uses the fine tube (o.7mm id) with pins (0.65mm shaft dia) to hold the frames in registration. For this job Devcon 2-ton epoxy was the adhesive of choice:
This then gets us a set of strengthened bogie frames looking something like these pictures. They are now as stiff as they ever were, the extra fillets around the tube being pretty key to the build:
While all this was going on the (split) axles have been prepared and a start made on assembling the gearboxes. This loco uses a 2mm dia epoxy-dipped hardened steel pin to maintain the strength in the axle. Here they are after cutting to length, keying up, hardening, rubbing down and cleaning (in that order). The axles are drilled through 6BA tapping (2.3mm):
The axles are then coated in epoxy and wrapped in masking tape, the aim is to put a thin insulating later of epoxy on all the pins:
The final assembly and cutting of insulation gaps is then completed as for the axles which use a GRP pin. (See http://www.euram-online.co.uk/tips/splitaxle/splitaxle3.htm)
Once the axles are made they can be assembled in to the gearboxes and torque arms attached:
The final assembly stage for these gearboxes is to attach the Branchlines drive shafts:
The motor/gearbox unit were built at the same time, but unfortunately I forget to photograph them...
Steph
And now we can crack on. First job is to strengthen up the frames after removing material earlier in the build. For this I used a piece of 40thou" plasticard 22*12mm, with a cut out to clear the Branchlines drive shaft. This was stuck in using Zap super-runny superglue (pink label):
(there's a little more required if fitting CSBs, which I'll come to later).
The other means of strengthening the frames also supports the back of the motor. This is an idea I've use a good few times in my HO modelling to strengthen up scale bar frames, which can otherwise be pretty weak. This uses the fine tube (o.7mm id) with pins (0.65mm shaft dia) to hold the frames in registration. For this job Devcon 2-ton epoxy was the adhesive of choice:
This then gets us a set of strengthened bogie frames looking something like these pictures. They are now as stiff as they ever were, the extra fillets around the tube being pretty key to the build:
While all this was going on the (split) axles have been prepared and a start made on assembling the gearboxes. This loco uses a 2mm dia epoxy-dipped hardened steel pin to maintain the strength in the axle. Here they are after cutting to length, keying up, hardening, rubbing down and cleaning (in that order). The axles are drilled through 6BA tapping (2.3mm):
The axles are then coated in epoxy and wrapped in masking tape, the aim is to put a thin insulating later of epoxy on all the pins:
The final assembly and cutting of insulation gaps is then completed as for the axles which use a GRP pin. (See http://www.euram-online.co.uk/tips/splitaxle/splitaxle3.htm)
Once the axles are made they can be assembled in to the gearboxes and torque arms attached:
The final assembly stage for these gearboxes is to attach the Branchlines drive shafts:
The motor/gearbox unit were built at the same time, but unfortunately I forget to photograph them...
Steph
Steph Dale
Western Thunderer
Hehe, yep. More soon.
It should be pretty good yep; and run well too.
Steph
Steph Dale
Western Thunderer
Umm, how about 'to see if I could'? I found a couple of references to forming split axles in this way in 4mm scale (using 1/8"od stainless steel tube) on the Scalefour forum. The idea appeals for some axles, particularly those which may have strange forces applied. As an example I have got one of the axles in my LSWR G6 made up in this way; it was going to have a compensation beam on the axle and I was concerned about the bending force along the axle. Similarly, diesels with Delrin drive put a force radial to the axle (the tension in the chain when under power) and I'm not sure of any long-term failure issues; I suspect they're only imagined though as Cynric had built a few split axle/delrin drive locos made using the GRP rod method and reported no issues.
Incidentally, one advantage of the drive I'm using is that they don't have any of those whacky forces, so they should work fine with just the GRP rod.
I'd stick with the GRP method to be honest. There's a fair bit of faff with using the steel pins; at the very least you're looking at three adhesive stages in the manufacturing (glue coat on pins/glue pins in to axle/fill slot in axle) against two if using GRP rod (glue rods in to axle/fill slot in axle), plus the heat-treatment of the pin. In all honesty I expect to continue using GRP rod in most cases, because it's easier, quicker and perfectly strong for my needs.
Steph
Ressaldar
Western Thunderer
Hi Steph,
is it the intention to supply the ready built gearboxes with the option of split or solid axles or will there be no issues by mixing the pick-up system? I'm thinking of the DMU scenario with the gear boxes in Wayoh bogies with the trailing bogie fitted with wipers, connected via a paxolin type bus-bar arrangement, thus sticking to the 'old fashioned' insulated wheel boss principal and not having to worry about insulated spacers etc which might be somewhat 'slim' in a DMU bogie.
cheers
Mike
is it the intention to supply the ready built gearboxes with the option of split or solid axles or will there be no issues by mixing the pick-up system? I'm thinking of the DMU scenario with the gear boxes in Wayoh bogies with the trailing bogie fitted with wipers, connected via a paxolin type bus-bar arrangement, thus sticking to the 'old fashioned' insulated wheel boss principal and not having to worry about insulated spacers etc which might be somewhat 'slim' in a DMU bogie.
cheers
Mike
Steph Dale
Western Thunderer
Mike,
Yep, I can supply the 'ex works' gearboxes with (Slater's) split axles if you'd find that useful. I understand the desire to keep things simple and perhaps use conventional pick-up arrangements in metal-framed bogies. I'll be using Easybuild bogies in my DMU which, as you know, are plastic. So no split axle problems there.
For a metal framed bogie I can think of a couple of ways you might achieve a desired level of splitness:
1. Rebuild the bolster and end beams using paxolin to insulate/replace provided parts.
2. Use paxolin washers between wheel bearings and frames to insulate the two.
Confidence, time and the presence of brakegear would seem to be the main considerations.
Steph
OzzyO
Western Thunderer
I would have thought that the photo in post #20 show how the motor and gearboxes fit in. But to help you.
S
SteveO
Guest
This demonstrates precisely how so neat and tidy this solution is. Very nice.
I've somehow ended up with a JLTRT Clayton kit (don't ask) and because of the very restricted space in the bonnet area, which was highlighted very well by Brian in his RMWsaga thread, this is the perfect solution.
I've somehow ended up with a JLTRT Clayton kit (don't ask) and because of the very restricted space in the bonnet area, which was highlighted very well by Brian in his RMW
OzzyO
Western Thunderer
Hello Steph,
after going to all the trouble of making the gearboxes with roller bearings, I'm a bit surprised that you have not fitted roller bearing into the resin frames on the driven axles. As it looks like there should be enough resin around the axle holes for them to fit in.
I hope that you do not mind me reposting the photos of the boige.
after going to all the trouble of making the gearboxes with roller bearings, I'm a bit surprised that you have not fitted roller bearing into the resin frames on the driven axles. As it looks like there should be enough resin around the axle holes for them to fit in.
I hope that you do not mind me reposting the photos of the boige.
Steph Dale
Western Thunderer
Ozzyo,
Split axles, ball races and DCC are not a good combination! I'll stick with plain bearings in the bogie so they provide me with low-friction pick-up.
Feel free to re-post away!
Steve,
Thanks for the comments. I hadn't thought about the space issue with the Clayton, but yes I guess there isn't much height or width. Incidentally, things are afoot in the 8'6" bogie department (as in; guess what I'm doing at this exact moment...)
Cheers,
Steph
alcazar
Guest
Thanks Ozzy....I'm following so many threads at the moment, I tend to forget what I've seen and where I've seen it, especially if the thread is slow moving, (not updated daily, LOL).
For example, somewhere I replied to someone asking about glazing with a link to Dikitriki's warship on the "Building O gauge online" site...but can I find that thread now? Nope.
For example, somewhere I replied to someone asking about glazing with a link to Dikitriki's warship on the "Building O gauge online" site...but can I find that thread now? Nope.
daifly
Western Thunderer
Steph Dale
Western Thunderer
Hehe, okay so I'll take the hint! Truth is that it's not the only thing on the workbench at the moment:
LSWR G6 0-6-0t in 7mm
Southern Pacific S10 switcher in HO
Canadian Pacific RDC4 in HO
Etches for FP7/9 details in HO
An Easybuild Bubblecar
More SDMP design work...
Etc...
Steph
Osgood
Western Thunderer
I'd not thought of that, but now you mention it yes it seems obvious that current flowing through roller bearings is, over time, inevitably going to cause arcing and deterioration of the rolling characteristics - if not total seizure!
What is the additional effect of DCC in this scenario - increased liability go arcing?
S
SteveO
Guest
Steph, I'm just wondering if these gearboxes would suit Roxey's 13:1 or 26:1 gear sets?