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My First Build!

I appreciate that the fet might skim a little but then it would have done the same with the 13:1, so I still would have expected a slight climb in rps.

One thing I had considered was the motor is struggling more to pull the spring (pdi 150) with the 12s than with the 13s? But had read that the u22000, and the jg blue for that matter are more than capable of pulling that load with both set ups?

And yes, rof is set to 100%, that was one of the first things I checked when I was trouble shooting.

Is there a particular affordable amp meter you would recommend? 


agree the skimming would be the same with any gearset - I was merely pointing out these fancy bollox mosfets

do shave a tiny little off the max possible performance - this is offset by the fancy features like precocking

which compensates for any minor drop in overall rof on full auto

Nonetheless - this shaving needs to taken into account when expecting say a max rof

of say 25rps on 7.4v, 30k & 13:1 - you might only hit 22rps no matter how perfect you build 2 similar guns

(1 old school 16awg & other Titan bells & whistles)

Any expected ROF is simply just that, there are so many variables that can effect slight difference in rof

and as always there is always a mild sprinkling of luck or good fortune is things go well or really fucking well...


than what the Titan says the amp draw is

The Amps don't really alter much on 7.4v or 11.1v, not really

they might be a smidge more or less on a different battery - if one has higher C rating or capacity

basically if one battery can supply the current under load slightly better

and the amps roughly remain the same or in that area on 7.4v or 11.1v I've found

(or again not a MASSIVE difference)

You are looking at amp draw to see how efficiently it is all running (drive chain wise)

Wattage is Volts x Amps of course so obviously will alter depending on battery

but you are checking for amp draw of a build

(worry/work out watts if you wish later if you wish, we're just checking amps)

High speed motors like 40k & up REALLY up the amps like 24 amps

so me personally stick to around 25~30k rpm motors at about 12~16 amps say

apart from higher amps, them faster motors in theory will wear brushes quicker

(motor is spinning faster = more wear, in "theory", though depends on how gun is used/sprayed)

but will deffo drain battery quicker & stuff runs hotter on high speed motors

variations in motors - similar specs can still vary as no two motors/cars/guns are the same

but also with slightly used motors a bit of carbon build up soon lowers the max possible rof

so if the commutator/motor a bit blacked with carbon then the rof/rps will lower

not an enormous amount but still a factor to taken into consideration at times

 
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Seriously don’t get hung up on the amps, your leviathan will tell you enough, just a reference point / ballpark device really.

Youre not going to get more the 18rps tops out of 7.4, 12:1, 22k.

Take it back to bare shell.

Does the piston freely fall in the rails when the gearbox halves are bolted up tight?

Shimming should be good by now.

Tappet plate is not binding.

Assemble the cylinder head and cylinder, put the piston assy inside.

Blank off the nozzle with your finger.

Does the piston pull back without vacuum?

Next assemble compression set without the main spring and gears into gearbox, properly bolted up can you easily cycle it all turning the bevel with a screwdriver?

This is checking the sector isn’t binding with the piston.

Lastly check electrical connections are solid.

Let us know what your results are ?

 
Seriously don’t get hung up on the amps, your leviathan will tell you enough, just a reference point / ballpark device really.


agreed - but my point being that taking the 18.8 or near 19 amp auto draw as gospel

is not the same as what a meter will report

imho the figures they report are higher than meter

and though as said they offer a reference point for THAT GUN

the figures these mosfets report should not be taken as a figure to use in comparison to other builds

19 amps is like a 35k motor draw or where the bevel is being rammed into shell/bushing

when in relation that build should be sitting at say 13 amp on a meter - so a 50% increase

but rof is getting near the expected performance though he said he hit 16.7rps on 13:1/JG

now dunno if he noted what the Leviathan dooberry reported for amp draw back then

but the point of using a meter is so it can be benchmarked for all builds

there is no urgent rush to get one right now

though tbh the way these mosfets reports stuff I would look to get one

so you can see the difference and make comparisons across all guns Titan'd or not

Yes benchmark the gun based on the history of stuff you tried in it

but still what that thing reports, can not be used when comparing what other guns say on a meter

For this reason anybody saying the amps (according to Leviathan/Titan) are a bit high

can not be taken as true reading when making comparisons/judgements of actual amperage

even my meter could be out a little but I'd say close to what most people find the draw is on a meter

I feel these dooberries do skim the juice a bit and add to amp draw though

Mind you, I've only quickly tested the M904G and the amp draw was a bit high at 14.5a

which on say 360fps, 18:1 lame motor (likely 18k rpm) I think is bit high

mind you the AB is always on as piston stops asap even on 11.1v

so with 12:1 maybe the reading of near 19 amp is not THAT high considering

though I would like to run it through a meter to be sure what that reports

these fancy mosfets do add amps imho, perhaps report stuff differently to meters

and skim off a bit of juice too, offset by added features but still might see a bit more draw

(and slight drain on battery)

Not knocking them - just pointing stuff out

*** arguing of my case/defense over ***

rest of your post I fully concur with btw

 
Oh they completely serve a purpose, but he can use the leviathan for apples to apples results - IN THAT GUN, or if he built another gun with another leviathan.

And the inbuilt metering is way more sensitive than an inline doohickey, unless your on lab spec kit.

I mean a BTC is more accurate regarding actual peak current on start up than my Fluke clamp meter.

That not a C clamp - damn jarheads

 
edit: TL-DR

New Year Resolution, cut down on the waffle

 
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