[ranch vermin]

This all stems from the fact that i havent got anything to screw onto my motors to chain them together for a body.

My first attempts to make a "tilt+pan kit" of 2 dc motors (connect them at 90*) were pretty dismal,    but the more I did it the stronger they got.

At the moment the way I do it is I solder a blob on each of the motors separate, and at this point they both take quite good hits without budging or coming off the motor.  so im proud of it up to here.

But when I put them in the 90 degree formation, and try to connect them together, this seems to be harder to get more solid.

I have a feeling that the solder has to be very hot for it to form a better bond,  so I get the iron really hot here and then I smoosh over it all very carefully yet quick like a chinese ink artist and thats the best bond ive got so far.

It took a fall test.  (and even the motors themselves fall apart if you drop them.)  But I still can pull them apart with my hands pretty easily.

Ill keep doing it today, and Ill see if I can get a better bond.     Its not over yet.

[ranch vermin]

update on this unorthodox technique ->
<url="https://www.youtube.com/watch?v=sa6mdhY0KzY&feature=youtu.be">

[Korrelan]

You will need a reduction gear box on each DC motor.

To build the mounting structure, get some polymorph, easily mouldable and cures to a hard nylon like consistency.  Can then be easily sawn, drilled, etc… I use it all the time for quick projects.

https://www.amazon.co.uk/dp/B00P89M3GM/ref=asc_df_B00P89M3GM52681520/tag=googshopuk21&creative=22146&creativeASIN=B00P89M3GM&linkCode=df0&hvadid=214522367922&hvpos=1o1&hvnetw=g&hvrand=13627990435397187676&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1007083&hvtargid=pla-422831376435

or…

https://www.ebay.co.uk/i/352062536302?chn=ps&var=621543849602&adgroupid=50809222926&abcId=1133936&adtype=pla&merchantid=101765778&poi=1007083&googleloc=1007083&device=c&campaignid=1057753625&crdt=0

 

[ranch vermin]

Korrellan, how did I know it was going to be you to comment...

Guess what I just soldered a good one!
I just have to encapsulate the ends and I cant snap this one. (yet to give it the full bort test tho.)

But on your comment.
Ah yeh... I didnt think of gears.   
But without the gears saves alot of space, so itll be quick, but it wont be as strong. but itll fit in a tighter space and is a simpler machine.
So im being mad again arent I... missing things.

Thanks VERY MUCH for the link on the magic goop.
That water meltable plastic probably is what im after,    im still only a beginning at hard forming, I dont know where the real cheat is yet.

I could definitely do what im doing here with the plastic as well, thanks.
Ive got given an AB epoxy but i didnt try it yet.  because i wanted to see if the solder works in the end if your tricky enough with it,  and it does. :?)

Just comicly, I was exploring using sugar to connect things, and ive got all these sand+sugar rocks out the back I was trying, but its not that strong and it snaps under pressure.

[Korrelan]

Hi Ranch.

Ok… given my engineering background, the thought of using sugar to connect mechanical structures together makes me both cringe… and smile lol.

Whilst I applaud your ingenuity dude… no… just no lol.

DC motors alone are not designed to provide the fine movements/ accuracy required for a pan-tilt mechanism.  The only way to use DC motors for this type of setup is with reduction gearboxes and preferably some kind of readable feedback/ positioning schema.

https://hobbyking.com/en_us/hxt900-micro-servo-1-6kg-0-12sec-9g.html?countrycode=GB&gclid=EAIaIQobChMI1qWCm8ab2wIVrL_tCh1Y2Q6oEAQYAyABEgL9MvD_BwE&gclsrc=aw.ds&___store=en_us

Or use stepper motors, no gear box required but the drivers are a little more complex.

https://www.accu.co.uk/en/nema-17-stepper-motors/394336-NEMA17-40-1-2-1-8?uk_google_shopping=1&c=3&mkwid=s_dc&pcrid=209417175255&kword=&match=&plid=&gclid=EAIaIQobChMI15KUiceb2wIVQ7DtCh0-PwZ1EAQYASABEgKvb_D_BwE

I presume the pan-tilt is required for a bot of some kind? 

With HD cameras being cheaply available these days perhaps just a 360' camera?

 

[ranch vermin]

ha, glad to make u laugh, im a funny beginner idiot all the time.

Oh shit,  I thought you meant by "reduction gearbox" a torquing gear that slows it down.   Ah I see its in those "servo motors" ive seen around the place.

Ive got the positional feedback covered using my own technique,  im going to be using hand made rheostats that wrap around them,  ive got one already put together its not too hard, i just notch a bit of a plastic folder cover on both sides with a knife evenly, then wrap toaster wire around, and then i just solder a brush to the motor end, which gives me the readable angle of the motor.

The circuit im looking at.  (and have made a linear drive to test it.  and doing it discretely cause im a showoff ) is very simple, its a voltage divider between the position of the motor, and the target its going to, with a balancing resistor considering the fact it is a divide not a subtract which is what it should be, but it should work in a similar way and i just have to fudge the resistor right to get it working.

I had alot of resistor heat problems just coming out of my 18 watt battery, and i think i need to do the voltage divide on a 9 volt, and then high watt transistor it into the motor instead of running the whole thing hot, which is wasting the battery.

I fried alot of components working it out. >X)

[ivan.moony]

Maybe if you bake sugar bonds in an oven... 

[ranch vermin]

Maybe if you bake sugar bonds in an oven... 

There might be some way to do it,  sometimes things only work if they are done just right.   (like mixing sugar with something and getting something more than a hard ginger nut.)  ginger nuts are pretty hard, but there could be a way to get it tougher,  takes many iterations and experiments. =)

[Art]

There are many searchable videos/articles on converting recyclable plastics like milk containers and such to solid, usable plastic items that can be repurposed for a variety of things.

Solder is nothing more than a bridge between two metallic points in order to maintain or allow conductivity, not structure.

Many of those low-cost camera gimbals might do the trick for your needs.

Lastly, there is the ever trusty J.B.Weld here in the states that even turns clear after being mixed and hold with something around 4,400 psi of strength yet remains, fileable, sandable, drillable and paintable. Fairly cheap as well!

Good luck on your project but no structural solder. A lot of it is still made with lead.

[ranch vermin]

yeh art, probably not a good idea to solder the motors together,   but use of lead could be in the design if it wasnt used in a critical bearing point.

Im not sure what to do,  maybe the plastic is a better bet,   i think making a good cube between the 90 degree motors would be strong enough, then u cant shake the robot apart.

bit by bit,  the body is coming together,  the brain is more important to get,  its what all the robots you see are missing today.

[ranch vermin]

I looked at the prob again, and im looking at it from how many vantage points there is to break it.

And I think once the handles go on it,  (i make an x handle, and a y handle) and if i sacrifice a bit of freedom on one of the dimensions by putting it on both sides ill stop 2 breaking actions.    I have to get the handles organized but then ill get another strength test,  and see what I come up with.

maybe solder isnt too bad if you do it right with supportive metal,  have to find out for sure.

Im thinking about chopping up aluminium cans to get the semi circles,   but its too hard to cut, and im hurting myself trying to make the damn thing!

hardware is hard.