Short question topic

[ramses]

That depends on the units your meter reads in (should say on the mode dial, mA or A).

I would guess you are in amps, in which case, the motor draws .62A or 620mA. This will go up A LOT as the torque load on the motor increases. Try dragging your finger on the shaft if it is a small motor.

The negative just means that you connected the meter backwards, which really doesn't matter.

[Zeus]

Good advice Fnord.

GF, so what you're saying is, you don't know anyone with a car?

[Gun Freak]

Alright I tried putting load on the shaft and with a 1.5V battery it drew .5 before and .9 after the load, with 9V it drew .6 before and .9 after. So I need like a 1A source.

Zeus, just because I have cars doesn't mean I can take the batteries out of them besides I want this to be wall powered, not by some hunky battery.

[Zeus]

GF, hook it up to a car battery, doesn't matter if it's still in the car...

If you want to buy one on Ebay, here's a perfect one for you.

I really hope they teach reading comprehension over in 'Murrica. The point was, a car battery is a readily available source of 12VDC, you don't have to buy anything. If it runs well on a car battery, then the plugpack I linked should run it.

[Gun Freak]

I didn't know you meant just testing with the car battery, my bad.

But I found some on amazon anyways, I can't buy off eBay.

[kydavies]

excuse this revival but I have a short question what is gives a stronger joint with standard copper fittings; just for copper or soldering?

Thanks

[Gippeto]

Soldering/sweating is IMO more reliable than any form of epoxy could ever hope to be.

I use 95/5 Tin/Antimony. Joints to 1" are rated for 1000psi...believe JFC claims 500 or 600psi but not certain.

http://www.google.ca/url?sa=t&rct=j&q=c ... wB3yLmPGBQ

[qwerty]

Also JFC is bloody expensive too. Especially in the UK.

[Lockednloaded]

Which of these: Propylene, ABS, Nylon, Acetal Resin, UHMW, or Delrin, could hold the most pressure if it were a 1" OD tube with 1/4" thick walls. And would tapping a 1/2" thread into the opening fo the tube severely weaken it?

[wyz2285]

I have used a nylon valve body for my pcp and have taken it to 50 bar. But Gippeto told me that nylon is not a good choice, delrin/acetal are safer, so I resume that nylon is weaker than delrin/acetal. About the rest I don't know. For me screw a 1/2 fitting will not seriously affect the strength, but you need to but threadings on it first.

[velocity3x]

http://www.machinist-materials.com/comp ... astics.htm

[inonickname]

Anyone know of a calculator to give a rough idea of linear force applied by a given screw thread for a given amount of torque?

[wyz2285]

Hi, just got some questions:
For a .22 is it worth to use a counter-balanced hammer valve? The pressure it will use is >3000 psi
I´m designing a .144 and .22. I have no problem about any of the parts but long rifled barrel is something I can´t get. So, if I use a 4.5mm smooth stainless steel for main barrel and a section (about 10 cm) of rifled barrel in the beginning of it, will it improve accuracy noticeably? For the .22 I can do the same but the barrel is very expensive, so can a smooth bore pellet gun be accurate? Both guns will be very well machine made, so I want them to shot as good as they looks.

[Goats spudz]

i get roughly 550 ft/s at 1000 psi with a normal hammer valve and a leaky smoothbore barrel and yes it can be accurate, i dont see the point in having a barrel with an unrifled part at the end

[wyz2285]

The point is having a section of the barrel rifled to give the pellet a spin.