Hello :o)
I have been working on this little engine for a few weeks now and its progressing along quite nicely. The problem is I have now reached a point where I need to step away for a bit and think through what, and more importantly how, to do the next bits. That plus I am feeling a little guilty for not working on Highclere so I have now packed it up, ready to move onto the next thing this weekend. Below are a few pictures showing what it looked like before it was bagged up...
One of the problems which I had to overcome was the fact the slidebars for the cylinders covered a wheelset. I got around this by drilling and tapping the chassis and bolting on the cylinder block with a single M1 screw. I still need to work out how to add the slidebar bracket to the chassis which will also need to be removable. The main problem with this bracket is although the wheels are 4mm diameter, the flanges are still oversize and therefore the wheels are bigger and the bracket cannot be fitted in its 'correct' position. The photo also shows me testing the motor fit, its a 6mm diameter motor from Nigel Lawton but I haven't figured out how to hold it in position, I am leaning towards some sort of formed Brass tube with a spring clip of some sorts. You can also see that I had to cut out the chassis around the worm because I didn't realise until I tried it that the worm is 2mm diameter, not much use when the chassis only has 1.5mm clearance between the frames! The final problem worth mentioning which I also didn't realise until they came was the fact I had ordered 1mm thick gears for the drive. Not thinking about it too much I then realised I needed to get two gears side by side within the frames. Of course now I have placed another order to get some 0.4mm thick gears...!
The above shows how the chassis looks at the moment. The wheels have been temporarily fitted so I don't loose them. It also shows how the cylinders look fitted. I am pleased with how the wheels have turned out, especially as I have made them from scratch.
And this is with the body (badly) fitted. I had to cut away the body a bit around the cylinders as the cylinders are a little bit wider than the prototype (to accommodate non scale wheels). I have noticed that I have made the cut out on this side too big (I didn't notice it on the model itself) so I might replace that bit and try again.
So thats how it looks, the size of the thing is making it a little harder than normal to build. I think I am going to do something less demanding like some more scenery.....
Julia :o)
A good idea to pause for reflection - I do it often. I like your approach of taking the various problems as they arise and working out the solutions as you go, rather than trying to address everything at once. Perhaps you could tell us a little about the background to this model (or am I the only one who doesn't know?)
ReplyDeleteMike
Thanks for your comment Mike. As much as its painful to do I think you are right and it will help if I leave it alone for a bit. Its just not nice to have yet another half finished project sitting around. I should stick to my 'layout takes priority' for now.
DeleteThere is not a specific reason why this engine came into existence really. At the time I was putting some bits and pieces together for an etch and I had the time and space to add something else to it , it just so happened I found a drawing for the engine so I drew up and etch for it. The original intention was never for it to actually work at the time!
J.
Hello Julia,
ReplyDeletegreat work on the loco, it's looking very neat too. I regularly pack away models that I'm working on whilst I think around problems that have arisen - one of the reasons why I like to have two or three projects on the go. I find that a bit of scenic work is a great relief after tiny loco construction.
Thank you Alex, I am trying my best with it although looking at those photos it shows up one or two little bits where I could do better!
DeleteI am struggling a bit though with the scenic stuff right now, my mind is still very much on this engine!
J.
P.S. See you next Saturday
The loco is looking fantastic, I thought building small OO9 locos was a challenge but this is something else entirely.
ReplyDeleteQuick question. I've also been using the 6mm motors from Nigel Lawton but so far have used belts and pulleys. I do, however, have a drawing for a loco I'd like to build where there wouldn't be enough space for the main pulley so had wondered about using gears. My problem though was that I wasn't sure the best source of worm gear sets that would fit on the 0.8mm drive shaft of the motor. So the question is where are you getting worms/gears from and do you have any specific suggestions of part numbers etc. that you've found work well?
Hello Mark and thanks for the comment :o)
ReplyDeleteI get my gears from a polish supplier called Mikroantriebe (http://www.shop.kkpmo.com/) and have been happy with the service from them. He does a huge range of gears but the ones I have used for this project are 0.2mod. The worm I used is a 2mm OD worm (http://www.shop.kkpmo.com/index.php?cPath=21_35) but there is also a range of ready made gearboxes too. I quite enjoy designing and making gearboxes and that site is like a proverbial sweet shop to me!
If you have any more questions then let me know.
J.
Thanks Julia, that looks like a very useful shop to know about. I've never designed a gearbox before, I've always stuck with a belt drive, so I may well be back at some point to pick your brain :)
DeleteHi Mark.
DeleteIts not that scary once you figure out what you are doing, the important thing is to get the spacing between the gears right. I use AutoCad to design mine and its a very useful tool but you don't need it.
I did an article for the now deleted RMWeb Showcase which went into a bit of detail on how I design them but I could do a blog post on here and repeat it if you like?
J.
I think a lot of people would find a blog post on how you design gearboxes to be very useful. It would certainly get my vote!
DeleteOk Mark, I will put something together. Watch this space!
DeleteJ.