My First Build!

[Lex Dangler]

Thanks for your response dude. The battery seemed good, around 7.9v but I'm charging it fully as we speak, I did try two, both almost full and got the same result. Spring is the same, I've not checked fps, the gearbox is only in the lower at the moment. 

I didn't count all teeth, the bevel has 10 and sector has 16

[Lex Dangler]

When I shimmed I had the tiniest amount of play on each gear, less than .05mm (I thought it would allow for them to roll a little better) I noticed that after putting the gearbox together completely, there was zero play with the sector. I don't know if that might flag anything? 

Okay, update, freshly charged 1450mah 30c 7.4. Rps up to 16, still not as much as I was getting with 13.1 and the jg blue 🤷‍♂️ 

Amp draw seems quite high? I've attached a screenshot with the details... 

[Lex Dangler]

Since the screen shot, temps have risen to mid 20s

[Davegolf]

You should have clearance on all your shimming, to allow for lubricant ingress, heat expansion etc.

Typically 0.04 - 0.10mm.

And you need to do this with the shell halves bolted up properly.

 

Once all gears are fitted, shimmed up, you should be able to whiz them round with your finger driving the sector gear.

Driving from the bevel gives you great mechanical advantage, in your case 12x as much

 

Aaaand check for tight spots during rotation, which could point to tooth profile faults, casting marks, burrs etc

[Lex Dangler]

36 minutes ago, Davegolf said:

You should have clearance on all your shimming, to allow for lubricant ingress, heat expansion etc.

Typically 0.04 - 0.10mm.

And you need to do this with the shell halves bolted up properly.

 

Once all gears are fitted, shimmed up, you should be able to whiz them round with your finger driving the sector gear.

Driving from the bevel gives you great mechanical advantage, in your case 12x as much

 

Aaaand check for tight spots during rotation, which could point to tooth profile faults, casting marks, burrs etc

Thanks, I'm opening it back up! I'll take another .05 off each gear and give it a whirl 😬

[Lex Dangler]

Okay, I think I've found the culprit! Shimming seems bang on until I pop the cylinder set in, the Tappet plate presses against the sector gear, I'm assuming that with the gearbox closed it's squeezing against the sector and creating drag, there are marks on the Tappet to suggest this. It also explains why there is some deliberate play in the sector gear until I complete the gearbox fully then none at all. I've tweaked the shimming all round to allow the tiniest amount of clearance and still maintain good meshing, sector and spur are as close as can be without touching and bevel is still bang on for pinion height. Gears have .05mm of play except sector which has a minute amount if any, it can't move in either direction or it will bind against either the Tappet or the spur 😬

 

If you hear loud shrieking hopefully it's me with joy rather than my gearbox imploding!🤞

[Davegolf]

Haha! Seems like you’ve learnt you have to build the box up and down many times as you go along, testing clearance and motion at every step!

[Lex Dangler]

15.6 rps now 🤷‍♂️ I'm giving up for the night. I think I might revert back to 13:1 🙄

[Sitting Duck]

Really really daft question....

 

But when you swapped the 13:1 for the 12:1 set...

if you short stroked the sector in 13:1 - did you do the same for the 12:1

coz if not then you will compressing the spring more etc...

and thus lose a bit on ya rof etc...

 

Silly question but thought I'd ask just in case...

Also if your 12:1 set has a 9 tooth bevel as opposed to a 10t one,

(if you use a 9t bevel on a set that came with a 10t bevel then the ratio

increases by 10% so a 12.65:1 becomes 13.91:1 or slower than the 13:1 set)

Your motor could be mislabelled - try the JG or something ???

 

The difference on 12:1 & 13:1 is fuck all as I said previously

 

me personally I'd say the 12:1 is 12.75:1 & 13:1 is like 13.5:1

according to brill armoury/armory (damn yanks & their own English)

according to them they are 12.65:1 & 13.65:1 - well whatever...

like the 16:1 (17.25:1) to 18:1 (18.65:1)

the difference in ratio is about 8% (13.65/12.65 or 18.65/17.25 = about 1.08)

this 8% difference in ratio will not yeild 8% in rps as the slight increase in load from ratio

so realistically expect only about 5% increase to the final rps

which if you are hitting say 16~17rps on 13:1, or say 13rps on 18:1...

then switching to slightly faster gear set won't even gain 1 single round per second

(again the difference is really fuck all)

 

with regards to amp draw & stuff...

amp draw on Leviathan/Titan's differ to what power meters say

so I personally stick with a meter that I test all guns with

the fancy bollox mosfets can tell the exchange rate, sunrise in Mongolia, the latest share prices

but it is fucking useless at informing me the amp draw of another gun or stock gun with no Titan in it

 

plus with all them gubbings n shit, I tend to think it reports the amp draw differently to a meter

so I take what them fancy mosfets say about the amp draw with a pinch of salt

simply because I don't think you can compare what a Titan says the amps are Vs a power meter

(same power meter used on all guns when checking/benchmarking)

so nah soz, I reckon a meter will say the amp draw on say 5 sec auto is about 13 amp max

& if it reported the draw being over 20a then the shimming is shit or spring is way overpowered

 

The other issue is that these fancy bollox mosfets do skim a little off the max possible rof

It isn't their fault, you can't help it - every diode has a forwarding voltage

which basically means it needs a small voltage to turn on - about 0.5v

plus all the other gubbings in that board & reporting what time sunrise is etc...

you are having the voltage availbe to the motor terminals slightly reduced

not a mega amount like 7.4v out of a 11.1v, but you are going to have the full capacity slightly skimmed

So what the Titans report on, the overal rof even with 100% rof is going to vary slightly

to what say an old school aeg might achieve or state with a seperate meter on it

 

(another daft question: you have got rof set to 100% not say 90% - just asking)

 

The weird thing about shimming is to ensure you tighten the box up the same as previously...

The urge to clenched fist tighten the screws up - just to be safe...

Nope - finger & thumb on the screwdriver - nipped up moderately tightly

just like you did when shimming....

you tighten the box EXACTLY or with the EXACT same force/torque as previously for shimming

When you try to mega tighten the box you do throw the shimming out a smidge

and if you had very slight play when you shimmed it nicely...

Then expect that slight play to begin to disappear when you clenched ya fist to tighten the box up

So consistancy really matters like most things on reassembly

 

Wiring = wiring can make a slight difference

not saying totally rewire a gun, but for sure ensure the motor connectors are snug

and make good firm contact with motor terminals

as you try different motors and/or reopen the box, them connectors do tend to loosen slightly

so check & if required crimp the contacts with thin nose pliers to ensure a sound connection

 

Ensure that if/when you reopen the box, check motor height with grip, motor etc...

using top half of gearbox shell, your pinion should be sitting just right on the outer edge of bevel

but just making full contact with bevel

If motor is a bit too high, then you need to lower motor and add say 0.1 shim to top of bevel

if motor too low then reduce shimming on top of bevel slightly & increase motor height

hopefully you should see the pinion in right place next time you have the box apart on bench

 

what we all try to acheive is ensure the parts we use are installed as close to perfection as possible

hopefully resulting in close to perfect efficiency & performance as possible

(though due to natures of these fucking shite toy guns - sometimes easier said than doine)

[Lex Dangler]

7 hours ago, Sitting Duck said:

But when you swapped the 13:1 for the 12:1 set...

if you short stroked the sector in 13:1 - did you do the same for the 12:1

coz if not then you will compressing the spring more etc...

and thus lose a bit on ya rof etc...

I didnt shortstroke on the 13:1 or 12:1, I checked all teeth are present and correct which is more than can be said for my own! 

 

7 hours ago, Sitting Duck said:

Silly question but thought I'd ask just in case...

Also if your 12:1 set has a 9 tooth bevel as opposed to a 10t one,

(if you use a 9t bevel on a set that came with a 10t bevel then the ratio

increases by 10% so a 12.65:1 becomes 13.91:1 or slower than the 13:1 set)

Your motor could be mislabelled - try the JG or something ???

Checked bevel teeth too, both have 10.

I considered that maybe could be an issue with the u22000, it looks legit unless guts had been swapped so also tried the jg blue with the 12:1 for comparison and got the same rof. 

 

7 hours ago, Sitting Duck said:

The difference on 12:1 & 13:1 is fuck all as I said previously

 

me personally I'd say the 12:1 is 12.75:1 & 13:1 is like 13.5:1

according to brill armoury/armory (damn yanks & their own English)

according to them they are 12.65:1 & 13.65:1 - well whatever...

like the 16:1 (17.25:1) to 18:1 (18.65:1)

the difference in ratio is about 8% (13.65/12.65 or 18.65/17.25 = about 1.08)

this 8% difference in ratio will not yeild 8% in rps as the slight increase in load from ratio

so realistically expect only about 5% increase to the final rps

which if you are hitting say 16~17rps on 13:1, or say 13rps on 18:1...

then switching to slightly faster gear set won't even gain 1 single round per second

(again the difference is really fuck all)

I wasn't expecting a dramatic gain in rps but a gain nonetheless. Certainly not a drop! It was as much to experiment and learn than anything else. 

 

7 hours ago, Sitting Duck said:

with regards to amp draw & stuff...

amp draw on Leviathan/Titan's differ to what power meters say

so I personally stick with a meter that I test all guns with

the fancy bollox mosfets can tell the exchange rate, sunrise in Mongolia, the latest share prices

but it is fucking useless at informing me the amp draw of another gun or stock gun with no Titan in it

 

plus with all them gubbings n shit, I tend to think it reports the amp draw differently to a meter

so I take what them fancy mosfets say about the amp draw with a pinch of salt

simply because I don't think you can compare what a Titan says the amps are Vs a power meter

(same power meter used on all guns when checking/benchmarking)

so nah soz, I reckon a meter will say the amp draw on say 5 sec auto is about 13 amp max

& if it reported the draw being over 20a then the shimming is shit or spring is way overpowered

 

The other issue is that these fancy bollox mosfets do skim a little off the max possible rof

It isn't their fault, you can't help it - every diode has a forwarding voltage

which basically means it needs a small voltage to turn on - about 0.5v

plus all the other gubbings in that board & reporting what time sunrise is etc...

you are having the voltage availbe to the motor terminals slightly reduced

not a mega amount like 7.4v out of a 11.1v, but you are going to have the full capacity slightly skimmed

So what the Titans report on, the overal rof even with 100% rof is going to vary slightly

to what say an old school aeg might achieve or state with a seperate meter on it

 

(another daft question: you have got rof set to 100% not say 90% - just asking)

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? 

 

7 hours ago, Sitting Duck said:

The weird thing about shimming is to ensure you tighten the box up the same as previously...

The urge to clenched fist tighten the screws up - just to be safe...

Nope - finger & thumb on the screwdriver - nipped up moderately tightly

just like you did when shimming....

you tighten the box EXACTLY or with the EXACT same force/torque as previously for shimming

When you try to mega tighten the box you do throw the shimming out a smidge

and if you had very slight play when you shimmed it nicely...

Then expect that slight play to begin to disappear when you clenched ya fist to tighten the box up

So consistancy really matters like most things on reassembly

I'm confident that the shimming is good, I used half shell to perfect bevel to pinion/get motor height bang on then went from there. I tightened the gearbox properly (finger tight then just a tweak more every time on every screw) and ensured movement was still fluid and still some play, then checked there was still some play after greased (superlube silicon grease, not too much or little) and fully built with cylinder set etc. In fact, when I shimmed originally with 13:1 there was NO play yet that build achieved higher rof than 12:1 with play 🤷‍♂️

I also checked bevel and pinion meshed well with both motors and they both did perfectly at 90degrees.

I shimmed several times in fact, varying my method each time in case I was at fault but rps was the same each time.

 

7 hours ago, Sitting Duck said:

Wiring = wiring can make a slight difference

not saying totally rewire a gun, but for sure ensure the motor connectors are snug

and make good firm contact with motor terminals

as you try different motors and/or reopen the box, them connectors do tend to loosen slightly

so check & if required crimp the contacts with thin nose pliers to ensure a sound connection

This is one thing I have noticed! The motor terminals have become slightly loose since everything has been taken apart and rebuilt so many times now, so I will crimp the connections a bit and give it a whirl, hopefully that's the problem, I can't think of anything else it could be. I will post results when I've done it.

 

Just to note, all the wiring is in very good condition otherwise and I have ground down the nubs on the gearbox so there are no pinch points.

 

Thank you for your suggestions duck, you've been a great help 👍 

[Sitting Duck]

4 hours ago, Lex Dangler said:

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...

 

 

and no I'm still a noobie like JD than a fucking mad ranting nutter like Dr Cox

just reminding us that no matter how clever or good we think we are

sometimes when shit goes really well - a small part of it can be down to a little bit of luck

(otherwise nigh every build would be close to perfection - when often in reality it isn't & work in progress)

 

a cheap £8 power meter is what I use - it is like chrono though

my amp meter/chrono might say this & others say slightly different

(chrono's do vary only slightly perhaps, but mosfet readings often read higher)

The point is that what Titans & stuff report in there settings/figures take with a pinch of salt

sure you can compare that gun's readings with a different motor etc...

but there can be a bigger difference when comparing what me or others say might read (on a meter)

and that stand alone meter is used for numerous guns to test & compare 5 sec auto draw amperage...

 

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

[Davegolf]

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 😁

[Sitting Duck]

19 minutes ago, Davegolf said:

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

[Davegolf]

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

[Sitting Duck]

edit: TL-DR

New Year Resolution, cut down on the waffle