7mm 'Denton Brook' an industrial whimsey

Giles

Western Thunderer
I looked at the GE70, and i wondered how efficient the linkage would be (particularly at extremes) as it manoeuvres the table around - sometimes from quite acute angles . It was for this reason that I passed one up and went for the GE20.

I quite agree with Steph about the lack of measurable or repeatable cutting depth - but that was something I was quite happy to accept under the circumstances. A proper TH would be a much better machine - however, this has revolutionised how and what I can do ( particularly in conjunction with the laser)
 

Giles

Western Thunderer
I've done new cylinders for the Bagnall, as the ones supplied are the righf type for Babnall-Price valve gear, and im fitting Walschearts - they'll use the original castings for cylinder end covers and valve chest cover, and I need to drill them to take the for the valve spindle, once I've worked the position out.
It was a bit of a faff bending the wrappers to the correct shape, but that was the only fiddle. The two end plates were held in the correct position for silver soldering to the back plate by using a frame spacer, shortened down to give the correct length.

The wrapper was also silver soldered, and this has given a really strong unit to which I will solder the other bits. The wrapper was fitted slightly over size, and then trimmed down afterwards.

Also shown are the milled Conn rods.

B1958DA9-939A-447C-821C-BD519F893B5C_zpslumz7zon.jpg
 

Giles

Western Thunderer
Pantograph Milling by giles favell, on Flickr



Milling the valve gear for the Bagnall with Proxxon Pantograph. it gets very small indeed...



The anchor link is only 1.0mm wide, and I had to be careful to mill it leaving one side attached so as to get clean ends, before milling the final side.



Milled Link by giles favell, on Flickr



One side of gear fully assembled. The pins are the small type of dress making pins (steel) that you get with new shirts (0.6mm dia) with their ends spun down in my drill with a needle file. All joints are silver soldered, which, once you get into the swing of it is easier and more reliable than soft solder, with no cleaning up.

Valve Gear Bagnall by giles favell, on Flickr
 

Giles

Western Thunderer
Apart from some final painting, the RC Bagnall's chassis is now finished. I'm pleased to say it appears to work well, with the milled valve gear (the second set) coming out nicely - giving me a better appearance than an etched equivalent, being thicker (0.028") but finer in section - and certainly massively better than I could achieve by hand! The motor/gearbox/worm combination also seems very satisfactory, giving me exactly the sort of speeds I was after,

Videos of the chassis under its own power


this one is at the full 3.7v


and this one is at 1.5v

 
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Giles

Western Thunderer
I'm sorry - I hadn't realised I had left this cold.....
The Bagnall was completed without fuss a year ago and entered service. It certainly does a full day exhibition without recharging, and makes things very easy. If I were doing it again, I should probably just use a conventional motor, as the 1:5 ratio gear motor is weak at the bottom end


IMG_2049
by giles favell, on Flickr

2017-09-28_01-44-28
by giles favell, on Flickr
 

Giles

Western Thunderer
The latest project has been a self-propelled crane for Denton Brook. It needed to be narrow gauge, which meant that some careful weighting/balancing was necessary to make sure it would operate without tipping over!

Again, it has Deltang receiver, and four micro gearmotors to do the business, two of them being the 'flip' type for the hoists. Laser cut gears are used to drive the second axle from the first.


2018-11-06_09-10-28
by giles favell, on Flickr


2018-11-06_12-53-07
by giles favell, on Flickr
 

Scale7JB

Western Thunderer
I'll definitely come by and see it when I get some free time from operating Love Lane.

Very clever with the gears!

JB.
 

Giles

Western Thunderer
Between other things, I'm having a play with this to see if it's viable. It's the standard whitemetal kit (7mm), but of course needs hacking about to make it working.
The trailer needs the wheels to go round - and in opposite directions! (when spinning round, one goes forwards, the other backwards), and of course the '5th wheel' mechanism needs to be more secure than it has to be for a static model. Likewise a home has to be found for the battery (carving out the load-bed - a false floor will go on top).

I'm going to use a smaller motor gear unit on this - only 6mm x 8mm in section, but still plenty of power. The problem is small bevel gears... I bought these on Ebay a while ago, printed by the vendor, so we'll see how they go.

Lord knows how I shall sort the front wheel, but we'll get to that eventually!


2018-12-17_05-05-02
by giles favell, on Flickr
 

Giles

Western Thunderer
Rear Tractor wheels now fitted,, thus completing the driving axle. Motor also fitted. It is my habit to make a rough cradle, and then epoxy the motor in, meshing by eye. (it has always worked well so far!). Should removal be necessary, it is not a massive job to cut the epoxy away, although this Gorilla stuff is runnier than I'm used to, and has travelled further round than I would have liked...... I always use 5 minute epoxy for this job, not at decent 24hr type, which would make life difficult!

I have put some volts through this to make sure the wheels actually do go round!


2018-12-18_04-52-34
by giles favell, on Flickr
 

Giles

Western Thunderer
The front wheel needed a severe re-think regarding making it operable. I haven't used the suspension castings, but fabricated from new using 1.6mm silver steel, silver soldered to brass tube bushes (S Soldered as a single piece, and then the middle section cut out, to make sure both sides are square.. a new axle of 1.6mm silver steel is used, which is a nice fit in the original white metal cast wheel.

To go with this, a new head-stock of a tube sleeve and brass plate has been fitted to the white metal chassis, so the wheel gets good support and a nice close but free fit.


2018-12-19_05-05-52
by giles favell, on Flickr


2018-12-19_05-06-31
by giles favell, on Flickr


2018-12-19_05-06-58
by giles favell, on Flickr

So this now looks more or less like this. The servo has to go in, roughly where the engine should be, and there will need to be a steering arm fitted to the top of the steering head


2018-12-19_05-08-31
by giles favell, on Flickr


2018-12-19_05-08-05
by giles favell, on Flickr
 

Giles

Western Thunderer

2018-12-20_07-09-34
by giles favell, on Flickr

Steering is now all in and works - indeed, I have fitted the receiver and wired the tractor end up, and it all works extremely well, and monoevres beautifully. The only pain is that with the servo being the 'wrong' way up, the steering is reversed, and I can't correct it either on the receiver or on the transmitter I'm using, so I've had to order a more sophisticated transmitter that allows servo reversing....
 

Yorkshire Dave

Western Thunderer
The only pain is that with the servo being the 'wrong' way up, the steering is reversed, and I can't correct it either on the receiver or on the transmitter I'm using, so I've had to order a more sophisticated transmitter that allows servo reversing....

Could you not correct the steering with and additional linkage to reverse the 'swing' or would this be too obvious in the cab?
 

Giles

Western Thunderer
Hi Dave, I had considered a relay lever, but there simply isn't room, sadly....! At least there is a solution available!
 
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