Mecharius

My plan is to take a 1/35 scale model of the M1A2 and make it control.
Originally i was planning on using Arduino for this, so i could set it up for bluetooth, giving me the ability to control the little machine with a ps3 controller (plus i am decent enough with the arduino language to be capable of making it work), but after actually stopping to think about the size of the model, I decided against that. Arduino would require far too many extra parts to get the job done.

Both treads need to be controlled seperatley, one stick for left, and one for right. I want the turret to be able to rotate, and i want the (mini) 120mm cannon to be capable of moving up and down. These are the things I require for my machine.

ThingsI would want to do, but not neccesarily going to have on this, i would like to add a wireless camera. That one really is only affected by room within the body and money.I would like to also be capable of turning the headlights on and off from the controller (i could do this easy with arduino, not so sure about radio).

I acquired the model for this a few days ago, but only tonight after i finally make my way home shall i begin working on it. I will build the base of the body, get dimensions and from thereI shall move onward.

I am something of an obsessive progress reporter when it comes to internet influenced projects, so every step of the way shall include pictures and words.

Hopefully through this website i can get the help i need (having never done rc work before, the amount of help i need is more than l;ikely going to be far greater then even i can guess at).

I figure this will requirefour channels (one for each tread, one for the turet turning, and one for having the gun move up and down), plus an additional fifth if i truly want the light switch.

But other than figuring out what my available space is, I have no idea where i am going to begin with this.

Rebellion13

First off Welcome to the forums.



You might want to have a look here http://www.35rctank.com/ Although a little pricey, some neat stuff for 1/35. Hope this helps a little. This is the link to the M1A2 on the same site http://www.35rctank.com/html/k3.html

Cheers,
Wade

YHR

You have our interest. Hello and welcome.

Mecharius

I appreciate the welcomes and the wed link.
I intend on buidling this, not buying a kit, but being capable of seeing how others did what i plan on doing is not only educational, but is also encouraging.

The first place i am going to start will be suspension of working tracks. This is a mechanical problem, and one which i should be able to overcome with a small amount of research and a good bit of work.

The video on the page for the Abrams shows how i want the suspension to be. I also like the working recoil.

My model kit was made by Dragon.


I found this gearbox online (http://www.sparkfun.com/products/319), although the page does not provide profile dimensions, the picture of the gearbox on the bread board leads me to believe that it would be small enough to fit within the body of my Machine. 

Picture on the body and dimensions will come tonight. I apologize, I did not have time yesterday.

Mecharius

http://www.scalehobbyist.com/catagor...ct.php?kw=m1a1

I found this, I will order it though i am not sure if it will be good enough. We shall see.

then there was also this:
http://www.sparkfun.com/products/321

The second of the two would be more work ready, though I imagine to get it to fit would require more work.

It order to conserve space I may modify a pair of servos to do continuous motion so they can drive the wheels.

I post up the ideas which I am actually considering with the hope that I shall be given some suggestions.

Mecharius

So i have pictures, being far later than i had planned. Dimensions will be up in a few hours.


This is the kit I have to work with.


Here are the various parts on sprue


The body laying next to the other sprues.


http://www.scalehobbyist.com/catagories/Detailing_and_Display/AFV00035012/product.php?kw=m1a1
I ordered the tread yesterday along with a suspension kit. The suspension will take a decent amount of modification on the tank body to make it fit, it was designed for a different maker's model of my tank.
http://rbmodel.com/main.php?action=p...=c_bm&sub=35ME

Mecharius

For the body the internal length is 8 1/4", width is 2 1/4", and the depth is 1". This does not give me any where near as much room to work with as i would like.

http://www.sparkfun.com/products/319
 I am trying to decide if i should go with this gearbox, though i am no longer sure that it will fit in the available space.  A small amount of room can make things complicated. I will find a solution.

Mecharius

This site gives the gearbox (tamiya twin) as being three inch in length. I can't find the width or height.  I am going to see if i can find some one else on this website who has used this box and ask them.

http://www.pololu.com/catalog/product/61

i dont even think i could fit two servos in this body piece if they are to be placed side to side.

Mecharius

From tip to tip the of the shaft the gear box is aproximatley 4", assuming that the shafts each extend from the box by 2/3", that would leave the box at 2 2/3", making it still too big. If I want it to fit I will have to modify the body of my machine. This estimation was given to me by some one who has worked with rc tech far more that I ever will.

After checking again, the double gear box is 60mm in width, making it 2.362", and the twin gear box is supposed to have a smaller width than the double. So the twin may fit leaving zero room to either side. I am going to order the Twin Gear Box made by Tamiya, and will provide dimensions when I receive it.

Mecharius

Received the tracks in the mail yesterday, didnt have time to work with them. Over the next couple of days I will have a large amount of free time, I'll put the tracks together and throw up some pictures and a quality report.
It would be better if i could find 1/35 m1a2 metal treads...

Im also going to be going through the model parts to get a better idea what all I have to work with, will be providing more pics of that as well.

Mecharius

I have been looking at the Spektrum DX5e for my transmitter and receiver. From what i have read online, this could be a perfect fit for what I need. Though knowing as little as I do about rc tech, i may be way off on this.
http://www.rcsuperstore.com/ProductD...PM5500&click=2

I have been looking at prints to make an rc switch, so that I may use the fifth channel to turn on and off the headlights on my machine.
Here is one that could be built:
http://www.extremecircuits.net/2010/...switch_04.html
I found this page online which gives the print and parts list for an rc switch:
http://www.ef-uk.net/data/rc-switch.htm
But then I came across this horrible idea:
http://www.rcgroups.com/forums/showp...8&postcount=24
If all else fails, then i would go with something like that.

Then over on this other site, post #9 of this thread, i found an interesting idea of using parts from a servo:
http://www.rcgroups.com/forums/showthread.php?t=251671
Here is a better example of that.
http://rc-monster.com/forum/showthread.php?t=26088
And here is another person who did that, has a video in the post showing that it does work:
http://www.daddyhobby.com/forum/showthread.php?t=40921


Currently I think I will go with breaking down a servo to use as a switch. It seems like it would be easier, making it less likely that my tank will not function as I want it to.

I get the feeling that by the time I am done building my machine, this thread will be something like a Complete Idiot's Guide to Building an R/C Tank.

Mecharius

Started putting together the tracks. seems like a large amount of wasted space, the box could have been half the size it is.


Here is a comparison of the tracks that came with the model and the tracks that i bought. The ones I bought are individual pieces, where the ones which came with the model and non-flexible sections.


Although the tracks which I bought for my machine are 'workable', they feel like they will fal apart if i use them. I have to find a way to attach the smaller pieces to the bigger ones(the smaller hold the bigger together) so that they will still move without falling apart.

Panther G

I would concentrate on the internal workings more. They are going to be the real challenge. Traverse of the turret and elevation of the gun are going to very very complicated in such a small scale. gear boxes are going to be an issue as well. Then you have to fit all the ELECTRONICS in it. A very daunting task.

Mecharius

Working on the tracks is mindless labor. Its just eating time while feeling productive until the remainder of the ordered parts arrive.

the tracks are not the only progress That I have managed. Also put together the wheels (because gluing together two pieces is so complicated that it requires a sense of accomplishment when the task has been completed).


I actually did receive the twin gear box.




I think largely I have been avoiding working on the tank its self so that I don't really have to worry about how i am going to fit all of the parts in side such a small space. I know how much space i have available within the body, next, I guess it would be smart to check to see what the turret will give me. Panther G is correct, I need to work out how i am going to get it to move, then worry over the less complicated matters.

Mecharius

Digging through my scrap box I found a few options for a power switch.
I have three switches like this, all rated up to 12v. two of which are lighted. i am thinking i will place it in the commander's hatch.


Took a trip over to the local hobby and picked up two servos.The larger of the two, a JR SPORT mini servo, I believe will work to rotate the turret. The smaller of the two, a HITEC Feather servo I am going to use for the elevation of the main gun barrel. That is, so long as it is small enough.


Now, on to progress. I but the gear box together, took overall, about half an hour. All in All, far more enjoyable then working on the tracks. I built it for what the instructions call Standard speed, a gear ratio of 58:1. The gearbox has a profile of 3" length, 1 3/4" width, and 1" thickness.




The gearbox fits almost perfectly within the body of the tank. I am going to have to shorten the shafts.

heavyaslead

I have built an RC Gephard in 35th scale using the 35rctank kit (http://www.35rctank.com/)

And it was quite successful. It has accounted for the space and the fitting of all parts in the conversions.

The best thing about it is it comes with the electronics for all the functions you are looking for in the M1A2. I see you have started your path with the Tamiya twin motor kit, well if you get stuck try them.

Mecharius

I am keeping the 35rctank kit as a back up plan, but really I want to pull it together as much myself as I can. Though last time I checked, that site is sold out of the abrams kit.