153 replies to this topic

[PyroSam]

Has anyone contemplated building one of these?

http://www.ctpyro.com/

I found the patent and it appears to be a United States only patent.

http://www.freepaten...om/6571675.html

With the high cost of international shipping it seems it would be viable candidate for a do it yourself project for those of us outside the US.

Mechanically I don't think it's that complicated of a machine. Figuring out the algorithm to use to create the pattern to lay the gummed tape down with and the actual CNC programming I think would be the stumbling blocks.

There's a freebie CNC controller program that runs on Linux that seems well reviewed.

http://www.linuxcnc.org/

Do we have any members talented in math to figure out the taping algorithm?

Do we have any members talented in CNC programming?

Do we have any members skilled in CAD drawing?

Do we have any members with a WASP willing to take pictures & measurements?

[phildunford]

Yes, I've often considered making one of these, but never got round to it...

Think it would be fairly strightforward to program a microcontroller to run it.

The main costs would be some fairly large stepper motors.

As far as patents are concerned, can't think this would be an issue if you were mking one for yourself, but would be if you were going into production...

[PyroSam]

Ned Gorski has written an operator's manual for the wasp stinger, it's chocked full of good information.

A copy can be downloaded here:

http://pyrotechnics....nger manual.pdf

[PyroSam]

Hi Phil,

I'm seriously considering trying to build one as I'm just tired of handpasting ball shells.

I imagine it's not too complicated of a program to create, either as G code for a CNC controller pc program or for a dedicated microcontroller, but I have zero experience with CNC programming and I'll venture a bet that's the case for most of our members so the software I think would be the major stumbling block for most - hopefully we have someone here on the board that can help.

I agree - the stepper motors, controllers and power supplies will probably be pretty pricey but still much cheaper than purchasing a wasp and having it shipped over.

Reading some threads on the net, I think patents within the United States are kind of an issue as their patents ban any duplication, even if it's only for your own personal use. As near as I can tell though, the patent is only a US patent so there should be no issue for anyone outside the US.

[cooperman435]

I toyed with the idea a while ago, tot he point of starting to price motors. Not cheap for the size I wanted thay would cope easilly with even bigger shells but definately a lot cheaper than buying one.

If anyone can PM me with the knowhow of stepper controlling I did some work on the algorithms but some programming would be needed to make an adjustable set of inputs write it for you.

Mechanically I can make then so I can suply that part of the job, including the electrical but not electronics unless pre built and supplied

[PyroSam]

Hi PyroPDC, I've seen the videos of the Chinese machines but it appears to me they would leave a weak spot at the poles where the wasp moves the poles around to negate that. I think the wasp would just be easier to construct also. It's neat to see other machiens though - just shows there's more than one way to skin a cat!

[PyroSam]

The OEM motor on the wasp stinger is a 570 oz motor, Keling part # KL23H2100-50-4B (NEMA23), about $55 US (I haven't found a source for them over here yet).

[cooperman435]

I know they struggled with even a light 8" shells though so wanted bigger ones if making my own to be very sure.

[PyroSam]

From what I understand the 570 oz are enough but the machine must be adjusted properly so the shell sits in the middle of the drive rollers. Also, the angle of the drive rollers is important - it's 120 deg.

[cooperman435]

yep we got it all set up fine but the motors stalled regualally, I prefer to over engineer as then you have redundacies

[cooperman435]

If Im right then 570oz is about 4.5 to 5 Nm of holding in which case I found some awsome 12.5Nm over at very little cost over the origionals?

[PyroSam]

It's interesting the motors stalled on you, in the all the posts I've read about them no one has mentioned that. The machines have used a couple different motors though so I imagine something prompted the changes.

The WASP 3, which I can't find much information on so I don't know it's shell size range, used a 381 oz-in motor - a Keling KL23H2100-35-4B (NEMA 23).

The WASP IV used 970 oz-in motors though I don't have the part number of that one.

The Super Stinger is using the 570 oz-in listed earlier.

381 oz-in = 2.69 Nm
570 oz-in = 4.02 Nm
970 oz-in = 6.80 Nm

Do you still have access to a WASP? If so could you assist me in making some CAD drawings by providing some measurements?

[PyroSam]

A friend of mine wondered if a stepper motor was really needed? His thoughts were that basic stamps and servo motors are used a lot in amateur robotics so he thought it may be easier to refresh myself on basic programming than learn CNC programming, hmmmm, I've never looked at basic stamps or robots. Has anyone on the forum?

[phildunford]

Have not looked it up, but I think RS Components had suitable motors - but RS are rarely the cheapest...