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Ineedacatscan
07-29-2008, 10:30 PM
Hi everybody,

I'm very new and am sure to ask some stupid questions in the not too distant future.

I was completely blown away by the videos of the Motion-tracking paintball turret that has been circulating the internet. Right then and there I decided I must build one.

For me this is purely a learning project. I'm going to start by building a R/C operated turret. Once the kinks are worked out I'll move to programming the motion detection control scheme. When it comes time to move to computer operated I'm looking at the Phidgets 4 servo controller.

As it stands now it's a pile of components with a rough idea in my head.

I've got a lot of learning to do, and this site looks like a great resource.

Adrenalynn
07-29-2008, 11:45 PM
Welcome aboard, CTScan!

Maybe describe how you're thinking about putting it together and people can chime in with their sage words of wisdom and save you a few dollars before you go order-crazy? :)

Regardless, welcome to the TRC!

I'm going to move this to General discussion until you get your project going.

4mem8
07-30-2008, 12:09 AM
Ineedacatscan: Welcome aboard, This is a great forum to be on, Many great minds here, and providing that you explain your idea's in detail you will generally get results.

Ineedacatscan
07-30-2008, 07:52 PM
I'd like to say I hadn't gone order-crazy......I'd like to be able to say that.

:veryhappy:

Here's what I'm envisioning. Forgive the crude MS Paint drawing. I'm completely open to suggestions.

Unfortunately the paintball gun I have is semi auto. So I'm thinking about switching that servo to a motor. I'm also not sold on the tilt mechanism. I think it'll work but I wonder if a chain drive is a better way to go.


Not shown is the CO2 canister or the paintball hopper. Forgive the scale of the drawing I quickly through it together

Adrenalynn
07-30-2008, 07:56 PM
Have you weighed everything you want to move up and down?

I've built chaindrives with the #25 roller chain parts here at Trossen, and the Banebots motor, but i don't think you're going to get the accuracy you want that way.

Ineedacatscan
07-30-2008, 08:08 PM
I haven't weighed anything yet.

Gun weight is just shy of 3 pounds. Call it 6.5 with tank

Let's say for the sake of argument the mount weight is 2 pounds.

Total tilt weight will be in the 7-9 pound range.

The servo I'm planning on using has a torque rating of 343 oz/in (HS-805BB)

Adrenalynn
07-31-2008, 12:06 AM
Yeah, just no way that's going to work well without gearing that servo a BUNCH.

I have an 805BB here and it will handle 1.5/2lb tilt by itself, at 2lb it's really sloppy, at 1.5 it's almost acceptable accuracy.

Maybe you'll find it to be OK if you take the tank off the gun and put it on the base with a steel braid hose. I used to have a two tank setup on my back for the autococker that way, back in the very early days of the autoblender - err - autococker.

robot maker
07-31-2008, 02:03 AM
might look at the pan and tilt systems at servocity,that where i get most of my servo's gears and parts from

Adrenalynn
07-31-2008, 02:17 AM
I think the highest load rating I saw at first blush there was 5lb recommended last time I was there. Do they have some that fit the design criteria?

They're also pretty pricey at the higher end for my budget. If I could add $7 worth of braided hose and not have to swing half the weight around, I'd be inclined to go there first.

Ineedacatscan
07-31-2008, 08:03 AM
Yeah, just no way that's going to work well without gearing that servo a BUNCH.

I have an 805BB here and it will handle 1.5/2lb tilt by itself, at 2lb it's really sloppy, at 1.5 it's almost acceptable accuracy.

Maybe you'll find it to be OK if you take the tank off the gun and put it on the base with a steel braid hose. I used to have a two tank setup on my back for the autococker that way, back in the very early days of the autoblender - err - autococker.


I'm by no means a physicist but if the pivot point is at the CG wouldn't the actual load the servo is subjected to be much less than total weight.

I'm picturing a seesaw. It takes much less energy to lift one end the farther you are from the fulcrum.

Electricity
07-31-2008, 11:52 AM
Thats probably true. however I think Adrenalynn has a good idea with going with a remote line instead of a direct feed bottle. You could also look into either a q-loader, or a warp feed for the loader system, as they don't need to be attached to the gun. The advantage or the warp feed too, is that you could have a very large supply of paint, so your turret isn't as limited in its shots.
Also, what type of gun are you using? I'm guessing a spyder of some sort. if thats true, you can pick up an e-grip for it for >$30, which would give you the full auto capabilities your looking for.
Also, for weight reduction, again if its a spyder, you can cut of a TON of the body, probably upwards of 1.5lbs if you go very drastic, closer to 1 lb if you just take off a bit.
I can tell you how to do this, if your interested.

Ineedacatscan
07-31-2008, 12:18 PM
I'm definitely going to look into the remote bottle. That could also solve a concern I have about clearance when the gun is tilting. It would also improve the weight distribution.

I may have to see if I can't find a full auto kit for it as that DRASTICALLY simplifies things and should improve battery life. The gun I have is the Spyder TL

Electricity
07-31-2008, 12:20 PM
Heh I've got 2 TLs sitting on the wall here. The remote line really is your best bet. let me know if you want help chopping the gun down.
-E

Adrenalynn
07-31-2008, 01:09 PM
For every action...

You mount it close to the cg, but you have rotational mass. Once it comes time to stop the rotation of that mass the gear-train takes the load. At best you have slop and slap which effect your accuracy drastically. At worse that swinging mass keeps right on going and those cute little nylon gears just became less cute expensive nylon bearings. ;)

A worthy engineering challenge is to try to cut your rotational mass whenever possible. A remote line (thanks for the technical term, E'!) is one way that is cheap and easy. Drilling/milling the gun is a kinda permanent solution that is drastic, but if you're willing to dedicate the gun to it, that's not bad. A lighter barrel can make a huge difference because that's out there at the end of the swinging arc so "counts for more". We used to do Delrin bolts in our autoblenders too. Heck, wouldn't be that hard to machine the upper receiver either...

Electricity
07-31-2008, 01:27 PM
You can do whats called halfblocking of a spyder, where you basically remove the back end, and half of the bolt. You can get delrin internals to reduce weight, and friction. And you can get a carbon fiber barrel, which will drop barrel weight by 200% or more. If your not going to be playing with the gun, and just dedicate it to a turret, you can also use said warp feed/q-loader, and direct connect it to the body of the gun, eliminating the feed neck. I suspect you could also remove the entire grip frame as well and work something out. You can also remove the front grip, as its nothing but something to hold onto.

gdubb2
07-31-2008, 01:47 PM
Hi Ineedacatscan,

If you haven't found them already, there is a group of folks making 1:6 scale paintball shooting tanks. (me included)

They have a lot of info available on their website about things like turret elevate and rotate. Along with mounting the markers in turrets. Look at the build reports of the various tanks.

Check them out at : http://www.rctankcombat.com/

Good luck with your project
Gary

Ineedacatscan
07-31-2008, 03:07 PM
I'd like to leave the gun as is for the most part. I will be getting the remote tank hose which will go along way to reducing the overall weight.

Adrenalynn....

What are your thoughts then for operating the tilt mechanism? Move up to a metal geared servo? I really like the plug and play capability of the servos... Are the karbonite gears worth it?

Adrenalynn
07-31-2008, 03:21 PM
Have you considered stepper motors? IMHO they were really designed for tasks like this.

Matt
07-31-2008, 03:48 PM
Hi Ineedacatscan,

If you haven't found them already, there is a group of folks making 1:6 scale paintball shooting tanks. (me included)

They have a lot of info available on their website about things like turret elevate and rotate. Along with mounting the markers in turrets. Look at the build reports of the various tanks.

Check them out at : http://www.rctankcombat.com/

Good luck with your project
Gary

There is probably a lot to be learned from their track designs too I imagine.

Ineedacatscan
07-31-2008, 04:26 PM
Have you considered stepper motors? IMHO they were really designed for tasks like this.

I have but Servos seemed drastically easier to work with.... I'm not sure how to interface a stepper controller with R/C.

Alex
07-31-2008, 05:12 PM
I have but Servos seemed drastically easier to work with.... I'm not sure how to interface a stepper controller with R/C.

I know you want to use R/C, but have you taken a look at the newer PhidgetStepper Controller (http://www.trossenrobotics.com/phidgetstepper-unipolar-usb-4-motor-stepper-controller.aspx)? It's a pretty sweet controller for Unipolar Stepper Motors and fairly easy to use if you have some programming experience.

jes1510
08-08-2008, 11:07 AM
I'd like to say I hadn't gone order-crazy......I'd like to be able to say that.

:veryhappy:

Here's what I'm envisioning. Forgive the crude MS Paint drawing. I'm completely open to suggestions.

Unfortunately the paintball gun I have is semi auto. So I'm thinking about switching that servo to a motor. I'm also not sold on the tilt mechanism. I think it'll work but I wonder if a chain drive is a better way to go.


Not shown is the CO2 canister or the paintball hopper. Forgive the scale of the drawing I quickly through it together

As a general comment you should check out google sketchup. It's a 3D package that is really easy to draw concepts with. It's a heck of a lot easier than paint and free for the casual home user.

http://sketchup.google.com/

Electricity
08-08-2008, 11:23 AM
As a general comment you should check out google sketchup. It's a 3D package that is really easy to draw concepts with. It's a heck of a lot easier than paint and free for the casual home user.

http://sketchup.google.com/
Wow, awesome program! Thanks for the link!

Ineedacatscan
08-11-2008, 10:16 AM
As a general comment you should check out google sketchup. It's a 3D package that is really easy to draw concepts with. It's a heck of a lot easier than paint and free for the casual home user.

http://sketchup.google.com/

Never even considered using it. Started playing around with it last night. Thanks for the link!

ScuD
08-11-2008, 10:40 AM
Sketchyphysics is a nice plugin too, although it still has some issues.
Worth looking into once you've found your way around sketchup.

indy007
08-28-2008, 01:39 PM
I cut virtually all of the rotational mass off of mine by using a warp feed mounted above the turret itself, and a steel braided hose (that's all a remote line is, coiled ones are plastic coated & more comfortable to wear) to a high pressure air tank (90ci, 4500psi). If you use co2, pay attention to how you mount the tank. Liquid co2 is the enemy of almost all paintball guns. If you're using a higher end gun like an Angel, you have to run HPA anyways. I also shelved my personal Autococker since it's simply too damn heavy even with everything suspended elsewhere. The best replacement so far as been a Smart Parts ION. Affordable (as far as paintball guns go), very light, effecient, spews tremendous amounts of paint. The servos liked it a lot more. If you try to use a Spyder and start shaving it, pay careful attention. Absolutely do not shave anywhere remotely close to the valve areas, unless you think you need a face transplant. Any electro marker is definately the best option though, and the simplest, fastest, and most reliable method I've found so far is simply mounting a micro servo inside the trigger guard itself to have it bump the trigger. It beats opening it up and voiding your warranty wiring into the switch.

I also switched over from cheap $15 hitech standard servos to their digital, karbonite gear models. Same footprint and dropped directly into the pan & tilt kit from Trossen. I mounted a spare metal plate directly onto the top of it to mount the markers, and built hard limits into the servo position code to keep from the tail of the marker from pitching back into the mount.

The main problem with running Phidgetts USB for a paintball application is the distance limitation. USB range is 15'. If you want more than that, you have to daisy chain USB hubs, or you need to make very long PWM cables, and there's a ceiling on that also. I managed to get 50' out of some cat3 phone wire and boosters, but haven't gotten much further. 65' to a person running at you trying to shoot you while you hide and remotely aim a turret... doesn't work out well for you. Sounds fun on paper, but the reality is harsh and bruising. You also have to be able to transport and effectively deploy it, while a game is going on, and maintain power to every device (laptop, servos, camera, gun, communications...) It doesn't fit in with weekend, recreational paintball. It does fit perfectly into 12-26+ hour scenario events though, provided you plan well ahead on any infrastructure and deployment issues you're going to have (which is TONS of them).

Also, this is just a personal thing, but it seems logical to me. If I saw your turret, I would know exactly what it is, and avoid it, or call up assets to take it out. It would take you longer to set it up than for me to dispatch it. I've found a better mount option to be a fake bush. Literally. Build it on a PVC stand, drill a bunch of small holes in it, and spray paint it. When you get to the field, strip down a common bush, and jam those sticks and leaves into your mount. Use artificial plants from hobby lobby, anything, just break up the outline of it and get it blended in. Leave a wedge of clearing in front of the guns field of fire, but enough overhang to conceal the gun in the shadows. Instant ambush, and your gun will reap an awesome tally amongst the clueless than walk by. They'll also spend awhile trying to find that "1 guy hiding in the bushes". Have 2 or 3 guns like that, and it magically becomes "A WHOLE F*[email protected]&#[email protected] TEAM IN THE TREELINE!". Psychology is a funny thing.


edit: 2 shabby quality vids of the initial software testing are up on my YouTube channel. No gun footage yet. Been so busy. Got engaged & started competing in grappling tournaments since I last posted. I'll get it up there eventually though. The first live game field trial is in October!

http://www.youtube.com/indy007pb