gun turret

[phyrelord]

does anyone have any ideas for making a remote controlled gun turret. it needs to support 25-50 pounds Capable of moving about 90 degrees from left to right and about 90 degrees up and down. All I need is a basis for the stand i'll mount my firing device on it. Should i use a motor or hydraulics/pneumatics. It doesn't have to be RC but i will probabely have a line running from it with which to control the turret. Any input is greatly appreciated.

[nbk2000]

What you're referring to is called a "telesniper". It's already a manufactured product ($50,000). Look in the archives for an existing thread about it (pictures and all) by me.

[Anthony]

Building one of these is on my list-of-things-that-will-probably-never-get-done. I'd go for motor driven linear actuators (like car scissor jacks, satellite adjusters etc). They're cheap, strong, simple and will hold position indefinitely. Depending on the speed you drive them at they are pretty precise too, even with a plain cheap dc motor (as opposed to steppers).

[xoo1246]

Reminds me of what was the name of that movie again, the jackal(modern version). Someone with access to a workshop, some technical knowledge and the resources could build one. You could use one of these closed circuit cameras and connect it to a microwave link to give it a few hundred meters range in open terrain at best. What would the cost be to build one, no weapon included? My guess is less than 2000$.

[PYRO500]

Remember now, your turret has to be strong enough to hold a weapon and manage it's recoil possibly many times. I think that you'd surely need some kind of gearbox attached to a stepper motor and you'd need an brake of somekind to hold it in place.
I think that if you had some threaded metal shafts going through something like the bottom of a scissor jack you could slowly adjust the verticle angle of the gun while keeping it very secure (for sniping not rapid fire) there would be jacks at the front and rear of the gun and some kind of hinge in the middle to allow it to move up and down but not side to side. The jacks would hold the gun in place securely with some kind of hinge mounts of their own.
The left/right angleing of the shot would simply be controlled by turning the platform the gun was on.

[Eliteforum]

Although you probably have good intentions, roguesci does not encourage members to reveal personal information, such as their postal address, tel/fax number.

<small>[ August 20, 2002, 01:35 PM: Message edited by: Anthony ]</small>

[xoo1246]

Something like this could be used for the elevation:
It can pull/lift 300N an operates at 12 or 24 v, although it's expensive, around 170$. Possibly you could build something like it yourself.
<a href="http://w1.478.telia.com/~u47802930/electromechanic01.jpg" target="_blank">http://w1.478.telia.com/~u47802930/electromechanic01.jpg</a>

[Energy84]

I believe the greatest problem to overcome will be dealing with recoil. Unless you're mounting a rocket launcher on the platform, or using a small caliber rifle (smaller than a .50B) you're going to have to build some rather heavy duty mounts. I'd also recommend using bearings for all the pivoting joints to ensure smooth operation.

[Arkangel]

The mounts would be a piece of piss I reckon. Make the structure pretty strong, if you can deal with the weight, and then sit it on some anti vibration engine mounts. There are loads of that type of thing available, especially for boats. You could even pick a load up at a scrapyard

[zaibatsu]

Surely for smaller calibre rifles you could weight them to decrease the recoil, and have the actions of the rifle on a sled, so when the rifle fired, the action travelled backwards along the sled, compressing a spring or extending one. This would decrease the recoil, or at least spread it out over a longer period of time. I've read about a similar mechanism in some mortors and also recoiless air weapons. I guess what I'm describing is a recoiless rifle :)

[xoo1246]

Too bad most of us are into chemistry and not into electronics, programming and mechanics. Someone sufficiently skilled in the above arts could make a gun mount controlled from a laptop via an internet connection. That would be interesting, remote controlling a weapon from the other side of earth. <img border="0" title="" alt="[Wink]" src="wink.gif" />

[parabolic]

well,well, this sounds like a good project :) . would your turret have a gattleing gun attached or a single shot rifle mounted which would require you to load up after each shot? as iam an engineer i find that you would be more concerned about the type of action you would use if using a self loading gun, as this would require alot of careful thought into making, as the chamber pressure produced from a rifle is around 3000 bar to 5000 bar i would make sure my action would be able to cope with these pressures. but if using an existing gun which has been "proofed" at a proofing house, then it should be ok, and you need not to worry about that, as for recoil you can use a method like what zaibatsu described by having a slide with travels with the gun when recoil takes place, we have a rifle mounted on a type of sled, but instead of springs to absorb the recoil,
we use a ram, much like what you get on the back of a car boot, the parts that hold the boot open, you notice how the boot doesnt fall down because the ram cylinders stop it, and no matter how quickly you try to shut the boot the rams only let it close at a certain rate, the quicker you try to shut the harder it is to shut. i would personally go for this type of system to take the recoil out. but be very careful when trying stuff out.
we also used an electric trigger, which was basically a small electrical solenoid, which pressed against the trigger of the action.

para

<small>[ October 15, 2002, 03:30 PM: Message edited by: parabolic ]</small>

[NoltaiR]

Well to add to the idea of being able to control the gun with the internet, wouldn't it be nice to have it somehow controlled by a cell phone? I mean technically this is an age-old idea, but if you could take it a step further so that there some sort of automated operating machine onboard that would answer your phone call similarly to how a calling card service does? For instance when you call a calling card number you get something along the lines of:
'press 1 for english, 'press 2 for spanish, 'press 3 for assistance.'
But if you could set up your answering machine to say something along the lines of:
'please enter access code'....[pause while you enter code]...
'access granted. press 1 to shift gun 45 degrees to the right; press 2 to shift gun 45 degrees to the left; press 3 to fire'...
and so on.

But I guess, in essence, with all the currently available technology, anyone with the mind to do so could make a remote out of anything.

Anyways I don't think recoil is as big of a problem as most think unless he really is planning on working with anything that a single man couldn't fire while holding either under his arm or on his shoulder. Just as the 'neck' which holds the gun and its armor up rotates easily by a sufficient motor (which wouldn't require much if the neck was well lubricated), I think the turret should be able to fire as much as needed without problem.

Also a thing to think about (although this would probably be more for looks than anything unless you were planning on taking your turret into war) is the overall armor. This may seem a bit obvious, but it is always important that you armor has no side on it in which an enemy bullet would have a (what I call) a maximum efficiency hit. Meaning that the bullet should never direct all its force to the place it was aimed. By making your armor slanted, the bullet will always be deflected (usually in an upward direction) so that only partial force from the bullet is actually given at the point of contact.
In fact, if slanted enough and by possibly putting some heavy duty grease on all the sides, an enemy weapon such as an RPG could be fired at it and it would simply slide up and over without contacting enough force to detonate.

But then again many of todays newer RPGs (and similar weapons) have timers built in that correspond to the scopes on the firing gun, so that whether the RPG hit anything or not, it would still detonate.

<small>[ August 21, 2002, 03:56 PM: Message edited by: NoltaiR ]</small>

[xoo1246]

A wireless LAN(around 2Mbit/s) can have a range of 5 km with propper antennas, that way you could have laptop on each side of the LAN and send everything on one channel(using TV-in, a PC-controll card and some extensive C++ knowledge). The question is what uses it would have(except costing alot of money and time). Using a a semi automatic cal .50 rifle it could be used for sniping as well as taking out armoured limousines. I have read you americans can buy them without too much trouble. <img border="0" title="" alt="[Wink]" src="wink.gif" />

[phyrelord]

what i have so far is a small scissorjack, a windshield wiper motor, a barstool swivel a sprocket off a bike, and an electrical engineer who is going to wire it for me. I'm using an sks and a motor to drive the trigger. I'm going to work on a sled system for the recoil, and the engineer is going to hook up motion sensors for the time being later we will experiment with types of remote to drive it. Ideally i want to hook it up so i can use a nintendo pad to control it. So far i have the top half made once it's done i will post pics. It may be a while however. I also want to be able to put a paintball gun on instead of the sks. Thanks for all of the help. Any more input is appreciated

[Eliteforum]

Hehe, A to fire, B to aim! :D

[Die Another Day]

I agree with zaibatsu...
Using spring(s) to deal with the recoil of the gun. I remember seeing a spud gun on xinventions.com that used springs because it had so much recoil.

[Keref]

NBK2000 you said that telesniper had already been discuted before and was in the archives with plans to make one. But more than half of the arcives are not accessible so maybe could you post that stuff again ?
By the way is it normal we can't access archives later than july ?

[nbk2000]

I'm not in charge of the archives, so I wouldn't know. You could download the complete archive as a .ZIP file from the FTp...if you had a password...which you're not going to get till you've proven yourself as a worthy member here.

Search the 'net dude. It's out there (telesnipers).

[Keref]

I gonna do that. But since you had told it was in the archives, why looking elsewhere ? i've not much time.

Don't worry about the FTP access, i'm not planing to ask one right now.
But check in the archives, in january 2001, contributions by Arthis. It used to be my pseudo, someone else has it now (fun !). I'm not a Kewl nor a newbie. But thanks for answering.

Well, i did a search in Google as nbk2000 kindly told me...
I'm gonna search more but there is 1 answer to the search (at that time). This is a link to this one page, the summary is Nbk2000 who dreams about his PDF and a way to use a
telesniper ...
:D
thx for advises nbk...

[EDIT: i searched on Google...]

<small>[ September 06, 2002, 11:49 AM: Message edited by: Keref ]</small>

[nbk2000]

Try this instead:

<a href="http://www.google.com/search?q=trap+remote+rifle&hl=en&lr=&ie=ISO-8859-1" target="_blank">trap remote rifle</a>

Or, you could have right clicked on one of the pictures, copied the URL, and pasted it into your browser, where hence you would have been taken directly to the manufacturers homepage. I leave that to you. Really, learn some basic web skills, eh?

[Axt]

I had a simular idea years ago.. though on a far smaller scale. My intention was to rig up a small gun on a r/c turret and a small wireless IR camera so that it could be set up over my yard.

The point being, when TV got boring one could turn it onto the "shooting channel" and comb the yard for cats, a noble cause, though one that didnt happen. I got as far as making a very small single shot gun ( .096 cal!!) but was turned off the idea by the cost of the camera.

This thread re-kindled some interest in the project, since im now loaded with cash.

What sort of radio gear would be needed? I dont know much about what is available but I expect a 3 channel transmitter for turning, elevation and firing, but it aint that simple.

Is there servo's available that would turn 360° and keep their position?

I tried searching but their doesnt seem to be any such thing available off the shelf .. but what 'may' work is a winch for a r/c sailing ship??? problem is I havnt seen a r/c boat before and dont know how they work. Any ideas on the radio gear needed?

[Anthony]

You can modify off the shelf RC servos for continuous rotation. One could be used to rotate the (very light) gun platform and the other one using a spring returned winch to tilt the platform. The trigger solenoid could act directly upon the trigger or via a linkage.

Although personally, I'd have the servo arm make/break microswitches to control far stronger pan/tilt mechanisms.

I was going to find you a step-by-step for modifying servos but my ISP has had it's routing table corrupted again so I can't access Google.

[Axt]

Thanks,

Im just looking for something very simple or it wont happen. I searched google and found a few step by step's for modifying bought ones so its a valid option I guess, though im pretty simple minded.

A servo will be plenty for the gun I made, ill try find it and post a pic, you could well call it a "pen gun".

Since its so small I was just going to attach the elevation servo directly onto the trunnion .. very easy, though it wont hold its position.

[Anthony]

Considering the probable weight of a pen sized gun, I'm surprised a servo won't hold its elevation when not powered. A simple friction lock might help the problem.

[nbk2000]

See how the <a href="http://www.spawar.navy.mil/robots/resources/gunpod/gunpod.html" target="_blank">Big Boys</a> do it.

[Axt]

Dont all servos reset to centre once the nob on transmitter has been let go? thats what I was refering to when saying that it wont hold position.

I was actually the one that posted that robotics site in the link/lit section. While it would be fun to have a huge turret .. I know I cant do it :( + a "Ultra Motion Smart Actuator :confused: " sounds a bit high tech ...

<small>[ January 29, 2003, 01:43 PM: Message edited by: Axt ]</small>

[Anthony]

They do return to centre stick position, unless you switch off the transmiter before releasing the stick. Although that'd be pretty useless if you wanted to then press the fire button :p

I hadn't thought of this because it's not a problem in an actuator switched by servo system.

<a href="http://www.motionshop.com/pr/ultrala.shtml" target="_blank">http://www.motionshop.com/pr/ultrala.shtml</a>

Those actuators with the big name are just a regular linear actuator (nut moving along a thread shaft), but is controlled by an EEPROM. It probably also runs from a stepper rather than a brushed PM motor giving finer control.

It's a neat solution, as you could plug your RC straight into it (no servo), the IC could interpret the PWM signal given by the reciever and relate transmitter stick position directly into an elevation position.

It certainly doesn't need to be that complicated though. As with a camera as a feedback you just tilt till you see your target and then stop it.

[Axt]

Well personally im looking for something that I 'will' do, that doesnt include these actuator thingys but I guess if you were going for a serious weapon they are what you would be looking at using.

Im pretty set on servos, as I know I can get them. Also if I tried to make an actuator thing it would end up noisy, which isnt a big problem with servos.

Ive had a thought, the transmitter has them "trim" things under the sticks. Using the trim one could aim and it would hold position - though does anyone know over what movement range the trim will adjust to?

[Anthony]

I did briefly think of the trims, but they only move the servo by a few degrees, maybe 5 degrees. They really are only ment for fine adjustment.

[Axt]

If the trim idea is crap, I guess one could always pull the springs off the sticks on the transmitter so it will hold position, and use a large gear onto a smaller one to give 360° rotation (though you will lose fine adjustment).

[Stoic]

<a href="http://www.anycities.com/user/thestoic/stoic001.html" target="_blank">http://www.anycities.com/user/thestoic/stoic001.html</a>
<a href="http://www.anycities.com/user/thestoic/stoic002.html" target="_blank">http://www.anycities.com/user/thestoic/stoic002.html</a>
<a href="http://www.anycities.com/user/thestoic/stoic003.html" target="_blank">http://www.anycities.com/user/thestoic/stoic003.html</a>

"The main idea of such a weapon is to keep a sniper out of the line of suppressive fire, while maintaining his own superior accuracy on one target or several targets.

The whole system consists of the following main components:

(A) T-2 remote platform with rifle and surveillance camera;
(B) T-2 Controller, with viewer (CP-076), Screen Switch, Aim Joy-Stick and Trigger;
(C) T-2 Interface Control Unit, with the Video Control Capability."

Intresting, as in another thread we were talking about GPS and cell phone jamming.

Now could the same be applied for the interface control unit and video display, jamming the signal both to and from the T2 unit?

Or perhaps overide it all together, and use it for your own needs! :D

Also, if there is a video display being broadcast. Would there be any way of piggy backing off it? So you could see what they see and thus, stay out of harms way as it were?

[nbk2000]

You couldn't jam a TRAP since it's hooked up to the controller by a cable, not an radio, connection. Thus it's immune to jamming or eavesdropping.

[Jake Ellwood]

Just a heads-up on the servo modification, the current issue of NUTS & VOLTS has a complete how to for several popular models.

The author recommended using the Hitec brand because of low cost and ease of modification. <img border="0" title="" alt="[Wink]" src="wink.gif" /> <img border="0" title="" alt="[Wink]" src="wink.gif" />

[Energy84]

Do you have a scanner by any chance? It'd be awful nice to have a copy of that article.

[Axt]

Jake, does the two winks on the end by any chance mean you wrote the article? if that is the case be good if you would upload the file.

I just pulled apart a transmitter, removed the springs and tightened a screw, so now it will hold its position. So in theory one would move the sight to near the target, then fine adjust with the trim - should work.

I also contacted a hobby shop about sail winches, heres the reply -

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica"> Hi

We have a sil winch for $110.00 but they rotate 3 1/2 turns and are not proportional otherwise servos rotate 60 degrees.

Budget Hobbies </font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">So they will rotate plenty, and hold their position when the stick is released, im not sure what effect the trim would have it though.

[Jake Ellwood]

Sorry I didn't write the article but I do have a scanner and it's only a four page article so I will get around to scanning it this week,but I don't have access to the FTP yet so I can't upload it there.

Have a look at <a href="http://www.balsapr.com" target="_blank">www.balsapr.com</a> look at the bp148t rated at 100 oz.-in it should do the trick for you.
Also for further servo mods, look at alsrobotics.botic.com

[concrete feet]

on the subject of remotely controlling a _device_ over long distances i have a few ideas.
i am not claiming them to be the most practical, or even verry practical at all, but they are feasable.

first off, i like the idea of using celular transmission, as it can be done over long distances with less consideration to geography between A and B than wireles LAN, though the limitations become clear when you want to stream vidio so you can see what is going on in front of the _device_ to be operated.

i also like the idea of using a laptop controller because of the ease of protability, it's opperation on independent power, and the fact that you can often pick up old laptops (Pentium 1-2 or similar) for verry cheap. it is also easy to implement either a wireless LAN or a cell dialup as the software is already there and requires no custom development on that side.

actual comunication between the laptop and the _device's_ electronic controllers is as easy as developing a simple device driver for SCSI comunication. although such a task is beyond the scope of my programming ability (meaning that i could not give much specific advise), it is a simple matter of basic proficiency in any low level language (like c/c++) and a desent understanding of ASPI standards, not too dificult for many.
i'm also giving some thought to the recoil supression mechanism and the hardware to make adjestments via electronic controll in real time (someone mentioned linear actuators).

[edit: edited for poor spelling, and gramar]

<small>[ February 13, 2003, 03:18 PM: Message edited by: concrete feet ]</small>

[Jacks Complete]

Couple of things:

If you use a mobile phone, you might be found to have links to Ally Keeda (recently of Spain).

Sail winches are very powerful compared to other servos. They are also slower, and less accurate. Digital radio controllers will let you store positions, settings, adjust rates of swing, etc. and, of course, you get to keep a hold of the expensive bit!