discussion Small drive chain for use as basis for Small scale R/C tank tracks

[Guest]

Sorry - It's another question from me I'm affraid!

Hopefully when I get back into modelling a bit more in earnest I'll be able to make some more productive posts rather than just asking for advice!

The standard is so high on these forums it's a littl eoffputting posting eary work in progress shots!

I'm working on some scratch built models and as I'm not limited to the parts that come in the kit I can be pretty flexible planning the arrangement and construction of the vehicle I'm working on. Gearboxes, materials etc. I was thinking about radio control as it'd be a good time to try to work out gearboxes and wheel arrangements for the tank I'm doing.

One problem with tank models and especially powered ones is tracks. The model is only 210mm long so it'll be a task getting all the inards in there, but one area I'm a bit stumped on is sprockets and tracks. I didn't want to adapt some rubber tracks from another model as to my mind you can't beat seperate links.

Ideally I'd find some premade metal drive chain, maybe similar to mechano and then adapt those links with my own scratchbuilt track shoes to maybe add a touch more authenticity. The other option is something like lego or fishertechnik track links which have their own matching sprockets. I'd machine my own idler wheels but didn't fancy trying to design and make my own track links and sprockets much.

Can anyone think of a similar product which would be up to the job and not be forever breaking links and spooling broken track links allover?

 

[Guest]

Hi Alan,

This is not as daft an idea as you think and I think it has been covered on here a while back. There is a company out there who makes this very sort of thing, the stuff I remember seeing was not too different to that on My Panzer V except it was metal as opposed to plastic.

I will see if I can find the link and will report back.

As for your pics, get them up on here, we are not snobs...These Forums are all about Modelling and that's what we like to see.

Regards......Mark.

 

[Guest]

Alan, any forum is only as good as the members who take the time and trouble to post. Questions asked by you are just as beneficial to the members as any other postings and are what make for interesting reading for all.

I know we have a vast range of experiences in a great number if different areas of modelling and it is great to see everyone joining in with thier own projects.

As for your chain, the only think I could think of would be have a look at a cheap jewelers. There may be a chance of something that could be uses as a basis for what you want to attach seperate links to.

Another possibility is something like a cloth or rubber backing with sold links glued to the surface.

Just a couple of ideas for you to play with.

 

[Guest]

if you need the lego bits just ask, i may have em in stock !

 

[Guest]

As far as Lego goes, something like this might work:

The track links without the tread plates on would probably be better as I'd fix my own engraved parts to those. If you have those in stock what would you charge for those bits, I'd need approx 1 m in length (500mm for each side)?

Regarding sprockets, the drive wheels measure 22mm in diameter on the model, would a lego technic gear be available in this size, if my memory serves me right the 24 tooth gear was about that size in diameter across the teeth.

EDIT: If you have any of those bits in stock could you measure up one of the links and let me know what the pitch of the links is?

Many Thanks!

Alan

 

[Guest]

Will Check The Database To See If We Have The Bits In Stock, Then Will Physically Go And Check To See If The Database Is Telling Lies !

Hang On A Mo !

 

[Guest]

there is a 16 tooth gear wheel which is small at approx 18mm in diameter, i have loads of stock of these !!!! sadly i dont have the 24 tooth gear in stock right now, so cant measure it...

i have the chain links in stock as shown in your top photo, dont know how many i have its a bag full of individual links... but probably just about enough !-

i can order more if these are what you want as for cost then we get the stuff trade and in bulk so its alot cheaper than buying a box of 35 bricks in your local toyshop that forms a little police car or whatever, i guess the cost would be about a fiver for what you need plus postage....

 

[Guest]

Here's a couple of images of the kind of thing I'm working on. At the moment the rest of it is still on my PC yet to be cut out.

I was figuring out how I'm going to assemble the drive train and then adapt the hull section to fit. Construction is styrene sheet. I'm using acrylic for the wheels and suspension arms, sides of the hull will be 1.5m Aluminium sheet and a couple of bits of 20x20mm angle for the suspension mountings, then lots of turned bits of brass rod for axles and a handfull of m2.5 screws to hold it all together (hopefully!)

 

[Guest]

Lovely job Alan. How do you cut the chamfer on the plate so that it all fits together at the correct angle?

 

[Guest]

Nice work there Alan,

Keep us posted with the pics, Looking forwards to seeing this one !!!

And another suggestion for the small drive chain, Not sure if Meccano still do these and in the size you want, but may still be worth checking out as they will have the sprockets to match too.

Maplin also do something similar which may be just your size with the chain and the sprockets included, check out this link: http://www.maplin.co.uk/Search.aspx?criteria=chain&source=15&SD=Y

Regards.....Mark.

 

[Guest]

Lovely job Alan. How do you cut the chamfer on the plate so that it all fits together at the correct angle?

I've got a couple of engraving bits, one 90 degree and one 120 degrees. I set the depth so it cuts almost through - leaving about 0.2mm remaining. a touch of liquid poly tacks the joints at the correct angle and a bead of poly cement run along the inside provides the strength.

The software I use is called Pro Desktop and I generate the development using Pepakura, a piece of japanese software used to create card models from 3d CAD models. Solidworks will also do the same thing but I've yet to install that on my PC.

The resulting assemblies are very pleasing as being cnc cut fall into place with barely any additional work on the edges needed. I also drill the holes to allow for the parts to be aligned using needlework pins whilst they are glued together. Parts where access are needed will actually use very small BA screws to allow dissasembly too.

I'll also machine some parts at the correct angles where angles other than 90 degrees are needed where the thickness of the material is significant or where you will see both sides of the piece, a gunshield for example.

 

[Guest]

do you have all this stuff at home alan? or do you take advantage of st.marys equipment? lol

Richard

 

[Guest]

I used to try to use the equipment at St Mary's but it's so awkward trying to plan for everything and do modelling jobs during a lunch hour or something. I bought my own CNC Engraver and it's great fun and superb for modelling.

It's small in capacity only 210 x 310mm bedsize it wont be any good at machining a cylinder head from an old escort or anything but it'll cut hardwoods, pcb's, plastics, laminated plastic name labels, it'll machine and engrave brass and cut brass shim, but one thing that is very useful is when working on thicker pieces you can use it to accurately scribe and mark out pieces to be cut, position hole centres for gearboxes etc. A brilliant bit of kit.

 

[Guest]

Superb job Alan and very interesting techniques. Thanks for the descriptions and pictures.

 

[Guest]

Alan,

taking shape and looking good!

 

[Guest]

Here's some images of the little tracked chassis I built to test the drivetrain and control conponents.

I'm using Tamiya Gearboxes at present and although I've been told the mabuchi motors (toy type) are ok for 6 Volts I've already cooked them much to the cat's glee!

I was amazed by the battery duration though as I'm running it from 5 AA NI-Mh pen cell batters and using BEC.

All the drive spins freely and with the gear reduction of 58:1 or so I would have thought those motors would have been up to the job.

I think I'll have to purchase something heftier and redesign the final drive, the only problem will be trying to fit the gearboxes in to the width of the tank, which will only be 70mm or so in width.