Any Question Answered

[Valentin]

I am looking to purchase some M0.2 gears from Mikroantriebe (KKPMO) for a small chassis; regarding the material, there are there choices:

• Polyacetal (POM) - white
• Polyacetal (POM) - black
• Brass MO58

Which one to choose? I know that if using brass gears, the resulting chassis is noisier - this doesn't bother me.

[Dave Searle]

13 hours ago, Lacathedrale said:

Regarding bench height, I was watching a woodworking video where the gent built a mini-bench to sit ontop of his work surface for exactly the purpose described. I've taken to using an upturned desk drawer with a cutting mat on-top recently and it's helped significantly in back strain.

 

I've been using a mini worktop based on a breadboard balanced on top of a box. It has a mini precision vice, a jeweller's bench pin and a tufnol worksurface.

 

I'm now building it into a more complex mini-bench based around an 8" square lab-jack and lighting:

 

 

 

Cheers,

 

Dave

[Alex Duckworth]

3 hours ago, Valentin said:

I am looking to purchase some M0.2 gears from Mikroantriebe (KKPMO) for a small chassis; regarding the material, there are there choices:

• Polyacetal (POM) - white
• Polyacetal (POM) - black
• Brass MO58

Which one to choose? I know that if using brass gears, the resulting chassis is noisier - this doesn't bother me.

 

I've had lots of MO.2 gears from Mikroantriebe, all white Polyacetal and I haven't had any problems with them at all.

 

Alex.

[richbrummitt]

15 hours ago, Valentin said:

I am looking to purchase some M0.2 gears from Mikroantriebe (KKPMO) for a small chassis; regarding the material, there are there choices:

• Polyacetal (POM) - white
• Polyacetal (POM) - black
• Brass MO58

Which one to choose? I know that if using brass gears, the resulting chassis is noisier - this doesn't bother me.

I’d go for POM too. They ought to prove to be hard wearing and not require lubricant 

[Kylestrome]

21 hours ago, CF MRC said:

My students found this source of loupes:

https://www.amazon.co.uk/dp/B077QGGXFX?psc=1&ref=ppx_pop_dt_b_product_details

The ones I have seen are pretty good, and excellent value for money.

 

Tim, am I right in assuming that these will only be of use to someone who doesn't have to wear prescription lenses?

 

David

[CF MRC]

Afraid so, as I think the frames are not very adaptable for normal

lenses.  
 

Tim

[Nigelcliffe]

16 hours ago, Kylestrome said:

 

Tim, am I right in assuming that these will only be of use to someone who doesn't have to wear prescription lenses?

 

David

 

 I found them easy to adapt.   Two screws hold the binoculars to the frame at the nose bridge.  Remove those, and the clear plastic "wrap around" can be removed from the frame with a bit of gentle flexing to release it from the outer corners.   Use a bit of scrap plastic as a packer, and re-fit the screws.   That leaves just the upper frame band and the binocular parts.   Wear them over existing frames with prescription lenses in those frames.  

 

There's a certain amount of messing around with the nose-feet of two pairs of glasses so they don't clash and fit smoothly.   But once worked out, I've found I can lift the binocular frame away, with the nose-feet pressing on forehead for temporary "full normal vision" through my glasses.    An individual's nose and head shape, plus their glasses frame design will be a factor.    The supplied head-band cord to hold the weight of the binoculars seems essential.  

 

A friend had bought a set after Tim's posting some months ago, and I tried them at his house, dismantling and being content it would work, then bought my own set.  

 

- Nigel

 

 

[Izzy]

I’ve worn prescription varifocals for 30 years now. My current ones have the maximum magnification used +3, and the last time I changed them this was queried as being much more than normal. When I explained why I wanted this high level, for model work, it was agreed it was a good idea as long as the actual lens depth was enough to cover the range from normal down, not too squashed and thus worthless.

 

If you are also like me, and can’t cope with any great weight on the bridge of you nose, needing the lightest glasses with gel cushions, then you may find those magnifier types discussed might not be suitable, adding too much weight. It’s very much trial and error I have found.
 

So, for my workbench I currently use an anglepoise lamp made by the Daylight Co. This is like those you see used in labs etc, has a ring of LEDS and two levels of illumination. The magnification is 1.7x. This allows it to be far enough away from what you are working on that tools, soldering iron etc, can be used underneath it. You can of course vary the distance and that between you and it as well, so it’s quite flexible to use. Any higher magnification than this would be very restrictive. You could see closer, but it would be too close to the work to do anything with it. I discovered this when testing the different options. 
 

Most of their lamps are (very) expensive but there is the ‘budget’ one I got, which is about £75. Most are 3/4x that upwards!

 

Izzy

[Sithlord75]

I got specific modelling glasses done up when I last went to the Optician - I took a model to show him what I was wanting to see which helped him help me.  I ended up with a set that I could read the text to calibrate his machine with.  I can't see my feet with them on, sitting in my chair but I can see the 0.2mm hole I am trying to put the 0.15mm wire into which is the main thing!  Best part was I was able to get a buy a set of frames get the second pair of equal or lesser value free deal as I wasn't picking them for looks!

[Valentin]

Does anyone know if the straight piano wire sold by Eileens Emporium is straight enough to be used for axles and layshafts? I want to use the 1.2 mm diameter wire for wheel axles, and the 2.0 mm diameter as a layshaft.

[Guest WM183]

Hi folks. Been a while since I've been in the 2mm section!

A while ago I started building a Worseley Works etched 42xx. I am at the stage now where its time to build the chassis! I am going to cut the existing chassis in half and solder it to gapped PCB spacers. My question is, the shop stocks 2 widths; 6.4mm and 7mm. Instinctively I feel like wider is better, but wanted to ask what others have done. Also, my stash of little 1015 and 1020 mashima motors seems a bit too big. Are the coreless motors sold by the association store good for this build? And should I direct drive the axle gear from the worm, or should I use some sort of reduction?

I guess that's 3 questions!

Amanda

[Joseph_Pestell]

43 minutes ago, Valentin said:

Does anyone know if the straight piano wire sold by Eileens Emporium is straight enough to be used for axles and layshafts? I want to use the 1.2 mm diameter wire for wheel axles, and the 2.0 mm diameter as a layshaft.

 

I expect that it is straight. But I doubt that it would be anything like rigid enough unless you have a solid chassis block rather than frames..

Edited August 29, 2020 by Joseph_Pestell

[richbrummitt]

28 minutes ago, WM183 said:

Hi folks. Been a while since I've been in the 2mm section!

A while ago I started building a Worseley Works etched 42xx. I am at the stage now where its time to build the chassis! I am going to cut the existing chassis in half and solder it to gapped PCB spacers. My question is, the shop stocks 2 widths; 6.4mm and 7mm. Instinctively I feel like wider is better, but wanted to ask what others have done. Also, my stash of little 1015 and 1020 mashima motors seems a bit too big. Are the coreless motors sold by the association store good for this build? And should I direct drive the axle gear from the worm, or should I use some sort of reduction?

I guess that's 3 questions!

Amanda

Question 1: wider is probably better; 6.4mm is meant for use with the rather thicker p/b material and 7mm for thin (etched) frames with p/b bearings added. However if you have tight corners then this 8 coupled chassis might benefit from the extra side play you could achieve with narrower spacers as long as you remember to narrow the muffs sufficiently also. 
 

Question 2: I would expect that the 1015 would fit with a bit of judicious hacking at the interior of the tank internals. I’ve not built a 42xx but have put together the 72xx and I’d have thought they were identical from the front buffers to the rear of the cab, just like the real things. 
 

Question 3: Your choice! I usually find it is convenient to have a worm to lay shaft and secondary spur gear reduction to get the motor to a suitable position. The smallish diameter wheels also limit the maximum reduction available with a single worm gear reduction since the worm wheel needs to be a smaller diameter than the wheel it is mounted on. 

[Guest WM183]

Hi Rich,

 

I will place an order (Once I rejoin, I stupidly let my membership lapse this spring due to RL concerns) for the 7mm wide PCB board, some 9mm wheels, and a set of gears. I will have to manufacture a gearbox of sorts to hold the motor, layshaft, and all in position - fun!

[Chris Higgs]

On 26/08/2020 at 23:42, Dave Searle said:

 

I've been using a mini worktop based on a breadboard balanced on top of a box. It has a mini precision vice, a jeweller's bench pin and a tufnol worksurface.

 

I'm now building it into a more complex mini-bench based around an 8" square lab-jack and lighting:

 

 

 

Cheers,

 

Dave

 

Looks like building workbenches is a hobby in itself.

 

Chris

[Chris Higgs]

22 hours ago, WM183 said:

Hi Rich,

 

I will place an order (Once I rejoin, I stupidly let my membership lapse this spring due to RL concerns) for the 7mm wide PCB board, some 9mm wheels, and a set of gears. I will have to manufacture a gearbox of sorts to hold the motor, layshaft, and all in position - fun!

 

The 7mm is intended for 10thou etched frames, and if you wish can easily be reduced in width using a file or even quicker a bench grinder!

 

Don't forget a set of axle bearings, you'll need those with the thin etched frames.

 

Chris

[-missy-]

Hi.

 

How do you guys normally attach cylinders onto the chassis of a steam engine? Once they are attached they seem to make removing some of the wheels impossible without removing the cylinders?

 

Thanks.

 

J.

[Donw]

Well some etched ones have the end pieces rather like water wings sitting across the frames with the cylinders either side and a wrapper over them . These are not easy to remove if soldered to the frames.  I have seen cast ones with a bolt cast in which can then be bolted to the side of the frame. 

If you could mill and file the shape out of solid piece of metal it would add a nice bit of weight. You could drill and tap a hole in the side to take a screw. I think that could work in 2mm as the work of shaping it wouldn't be too bad. 

Some locos where the smokebox flows out and round the cyclinders just ask to be part of the body which brings up another issue of taking the body off.

Just some thoughts 

 

Don

[CF MRC]

Usually two 16 BA studs and some nuts on the inside of the frames. 
 

Tim

Edited August 30, 2020 by CF MRC

[Caley Jim]

I have usually soldered mine to a separate pcb spacer which sits across the chassis in a recess cut in the frames and is then bolted to another spacer below it.

 

The the case of my 'Crewe type' 2-4-0 ( which is the type Don is referring to), I only had the slidebars attached to the chassis, via double sided pcb with the outside frames and cosmetic part of the cylinders part of the body.  See my article in the February 2005 Magazine, p13.

Jim

Edited August 30, 2020 by Caley Jim
edited to add photos of the 0-4-2

[Donw]

17 minutes ago, Caley Jim said:

I have usually soldered mine to a separate pcb spacer which sits across the chassis in a recess cut in the frames and is then bolted to another spacer below it.

 

The the case of my 'Crewe type' 2-4-0 ( which is the type Don is referring to), I only had the slidebars attached to the chassis, via double sided pcb with the outside frames and cosmetic part of the cylinders part of the body.  See my article in the February 2005 Magazine, p13.

Jim

 

Very neatly done Jim that could be a real pig otherwise.

 

Don

[CF MRC]

On Valour the front end was made removable, as two components, but that was partly to accommodate the use of etched parts. 
Tim

[richbrummitt]

The problem exists on the 28xx where the front driving wheel is behind the slide bars. I designed the cylinder and slide bar assemblies to fix to the frame with a fixed stud and a nut on the inside between the frames. All a bit of a faff but the best way I could figure it would work. 
 

That much I have working but the frames got soldered together on a wonk so it needs undoing so that the chassis is no longer twisted...

Edited August 31, 2020 by richbrummitt
Productive taxed

[Nick Mitchell]

I tend to solder the cylinders to the frames and not worry about it.

Once the wheels are in, they're in forever.

I may yet live to regret this approach, but I've never really understood why so many people want to be able to take their loco chassis apart. It makes sense for locos that run real miles on layouts like Copenhagen Fields, but I'll be surprised and delighted if any of mine have chance to wear their axles out!

[Nig H]

I usually make the cylinder and slide bar support bracket/ motion bracket as one unit that drops into slots in the frames. These slots act as a jig to hold the cylinders and slide bar support bracket in place while the slide bars are soldered to the slide bar support bracket. It gets a bit fiddly if the crosshead has to be fitted before the two sub units are joined. The unit could be bolted to a spacer between the frames, but I keep it all in place via the soldered joint between the return crank and the driving wheel crank pin. This allows the cylinder unit to be lifted up and out of the frames, clear of the driving wheels.

 

Here are some pics of the assembly for a Princess Royal.

 

 

 

 

 

 

In these pics the pcb blocks have yet to be cut through to isolate the left and right sides electrically.

 

Nigel Hunt

Edited September 1, 2020 by Nig H