Giles

Yes, I gather you can do that - indeed Technobots sell a continuous rotating servo - which I presume is basically the sames beast. Very useful. I'm just amazed at what you can buy nowadays - and therefore what one might be able to put together, given time, patience and good eyesight!

I'm planning on the motor/ gearbox going underneath the load-bed, running forward into the back of the cab (at low level) driving through bevel gears. The battery I think will either fit sideways inside the cab - or just underneath the load bed, above the motor.... I really want to avoid havingg to carry a dummy load or any thing! Giles

and looking better with bumper..

Just changing the appearance..... You can just see the servo arm underneath, in the first picture. (rather cruel to photo this close up on something that really isn't very big.... )

I want to try really hard to get the drive under the load bed so I don't have any body at all (it leaves the way clear for all sorts of fun!), but if I can't manage it, it's certainly an idea..... Very nice idea about the dual motors - a very sound principle - but I'm struggling to fit one motor/drive at the moment. I'm looking for a scale 15 - 20 mph @ around 4 volts, wheel diameter 18.3mm PS Cab is blue now, and starting to look much more '50s

Quite brilliant - and should be extremely useful somewhere down the line. I can see this would be perfect for motorising a digger or a crane - for instance....... I'm now committed to the Minor Tiny, which I think is probably the smallest - and therefore suits me best for this particular job (it's on order). This cheapcontrolsystems doesn't appear to give a size - but I think it's a little bigger. Perfect for operating multiple servos!

I've added the steering servo - since they're only £6 a go, I've araldited it in place, and if it fails, I'll simply break it out and replace it. In this location it sits where the dashboard goes. This is the 3.7 gram servo, but you can get a 2.8 gram (I think it is) which is fractionally smaller (I would get this next time...) and this may fit under the bonnet longitudinally, which the 3.7g won't. I've committed to getting a sub miniature combined receiver/speedcontroller - the 'Minor Tiny' made by MicroInvent which is only 17mm x 8mm x 4mm !!!!! This provides forward and reverse, proportional steering and speed control, and I think, even a facility for brake lights! Its not cheap at around £75 or so, but if it makes an interesting model, I'm up for it.... There are some LiPo batteries whichwould fit under the bonnet, together with the receiver/speed controller, leaving only the motor hanging out.... Delivery will take a bit of time, so there will doubless be a pause!

A couple from 'The Loop' (it's always a grey day in Wales....! )

Thanks - like you, it's a wish to have a little more realistic movement around the scene (....but certainly realistic!), and like you, I'm not an electronics whizz..., but it'll be fun if we can pull it off. I'm not anticipating any real trouble driving the rear axle (famous last words - after all, one can approach it in the same way or similar way as locos. There are lots of miniature ball bearings available on e-bay, which helps a great deal, so the difficult thing is the steering axle - which I think I've cracked now, and putting together a package of teeny radio control bits. I've found that conventional servos go down to 2.5 grammes, - I've got a 3.7g to steer this, and the 2.5g is a little smaller (not very much, but every little helps) - but I'm still untangling the rest of the kit....... Meanwhilst, track rod is on. The wiggle is deliberate, as allows for adjustment of tracking (which a straight one with fixed ends doesn't). The loop at one end is to take the steering link from the servo - which drops down through the big hole in the floor.

I've built up the front axle (fairly crudely, but successfully) and mounted it on it's front plate It's not got its track rod yet, so the wheels point in any old direction. The fiddle has been making sure the wheels are in exactly the same place as they were on the original - i.e. same spacing apart, same position front-to-back, and giving the same ride height. anything different will give the game away! As you can see, the wheels happily steer (though not together, yet). I've got a beautiful micro servo to do the steering, and I'm in the process of organising a receiver and bits and pieces (thank you Stephen), so it's coming on.... The front axle is articulated so it will always keep all four feet on the ground.

Thanks again Stephen, I've taken your advice and bought one..... It'll certainly be smaller... I can't believe how much I'm learning about here - it's great (but a bit alarming as to how much the world's moved on...) Thanks again! Giles

Stephen, all this information is quite brilliant, and rather mind-boggling! I had no idea that decent Radio Control had got this small... At present, I'm planning on driving it with an RG4, like this, which may take maybe 500ma ? Should I use a card from a bigger servo, or, forgive my ignorance... addind a driver transistor ....? I could do with an idiots guide on this one - I have normal common sense, but electronics (as opposed to electrics) is not my bag - but I'm willing to give most things a go! That little 1.6gm servo looks very good, but it's very little smaller than the 3.7gm one? KEEP IT COMMING! Giles.

Hi Andrew, It'll probably end up as a box van, which will give me plenty of room to play with! Yes, as fully functioning as I can get it.... It should be quite fun if nothing else. I must say, as far as donor vehicles go, this Corgi Morris is quite a good one - the wheels are quite easily modified and look good, and it all comes apart very easily. G.

Thanks Stephen, I had thought about driving just one wheel but I wondered whether it might sit there and spin - perhaps I better just try it...! This was the servo I was thinking of using - nice and small at 3.7 grams but so far I've not managed to find a receiver smaller than this - which is about 35mm long x 25mm or thereabouts... I'm afraid you lost me a bit with the speed controller - will the board from a servo (minus the feedback potentiometer) give reverse as well? All very useful stuff! Thanks! Giles

I was planning to pivot the front axle allowing it to rock to give it a little 'compensation', as most of the weight will be over the back end (batteries, receiver, motor etc.) rather than actual springing. This should give four-point contact on normal roads. Of course what I'd really like is a miniature differential, which would make all the difference cornering, but I'm not up to making one (I want to keep this relatively simple!) and I don't think anyone produces one this small - but if they do - let me know...... and I'll think again about the drive train. I absolutely agree that the motion has to be smooth and realistic - otherwise it wasn't worth bothering - but with a well controlled final drive (such as a portescap...), decent proportional steering, and all four wheels on the ground, I don't see why it shouldn't be? (how it copes on any hills is anyones guess....) I'll have a further think about whether I can sensibly incorporate springing into this - I rather think it might be a bridge too far, but we'll see.

Modified the front wheels today - - removed the rear boss, opened out theback slightly and glued them on to the new hubs and watch them spin!

I decided I wanted a van or lorry to provide some movement on my next 7mm layout, (not much room for it on 'The Loop'!) and of course there doesn't seem to be anything suitable or easily adaptable out there - but do tell me if there is....! Finding a lorry suitable for the late '50s isn't entirely easy, but Corgi do this nice Morris, and I picked up a couple on Ebay Since it's possible to put radio control gear into 00 gauge diesels, I reckon it's got to be possible to make something like this go, so we'll see how we get on. It may fall flat on its face and get nowhere, but it's worth a try, and people may find it interesting! First job is to strip it down. Screws in the bottom (the front one underneath a little cover). Kit of parts. It should be reasonably straight forward to make a new back axle, motorised with a Portescap RG4 or modern equivalent, so I'm not too worried about that. The tricky bit will be the front steering axle with the ackermann steering. The first job is to make wheel hubs with bearings. The new hubs are machined out of steel, 8.5mm diameter, to take bearings 3.95mm OD, 1.5mm ID x 1.2mm across - a fairly quick job on my little Unimat 3. Bearings from Ebay. Its all very, very small.... Completed hub. A cruel photo of the two completed stub axle assemblies made from blocks of nickle silver, with king-pins and steering arms of 1mm dia MIG wire (steel). The actual stub axle is 1/16" dia silver steel, run down to a slight taper with a needle file in a lathe, so the 1.5mm bore of the bearing fits snugly on it. It is then retained with a ring of copper tube (again, 1/16" bore). These now spin quite freely, and are ready for the wheels, which need slight modification. More as I do it....

Very nice indeed - I remember those buildings well! I'd very much like to see more of this........... Keep them coming please! Giles