Monster XL fixed - armoury stats wrong??

[pritch]

Hi all,

Looooong time since I checked in on this site. Heh, I'm all grown up now - haven't got the time for water wars of the teenage years.

But... in my job now I often work with young people. My colleague had a group who recently wanted to end their project with a water fight - well, that brought my old guns out of the shed - XP310, CPS1500... and the MXL I rescued from a friend's trash can 7 years ago.

Anyway, I used the 310 in the fight. It was easily better than these crappy new pump-only guns that seem to prevail now. What happened to all the decent blasters? I just did a look at what's for sale here in the UK and it is woeful - where have all the good water guns gone?

I didn't use the 1500 because it leaked badly from the pump when I tried pumping it - it always did this a bit even when new but now it's pretty bad. I never did like that pump. The MXL my friend binned all those years ago cos the QFD was broken - on pumping water just shot out the QFD. I tried once or twice to fix it, or glue it up, nothing worked. I decided this time to do it, whatever it takes. I took it all apart, filled the QFD inlet with expanding foam and let it set, removed all excess then put it all back together. How many screws?? The odd droplet comes out now under chamber pressure but the soaker retains charge now, and fires its full load.

What a ridiculous, awesome thing it is. It is such a crazy water gun, I still love the madness of it. it's not even a particularly efficient or effective weapon, but for sheer coolness, nothing beats it IMO.

I've been checking out the MXL stats at the armoury out of curiousity. I was interested to see the water output measured of two nozzles the same versus one.

So, 5x = 180ml/sec, but 5x + 5x = only 220ml/sec? So one nozzle fires 81% as much water as 2?

The ratios for 8x+8x and 11.5x+11.5x are one nozzle firing 61.1% and 60.7% as much as two, which seems much more realistic. Is the 5x+5x figure wrong?

I was going to try and work out the values of all nozzle combinations (I count 26 possible?) as isoaker only did the data for the 9, based on the isoaker data (bit of maths involved). But if you do a curve respecting the 5x+5x figure, you end up with 5x+8.5x putting out slightly more water than 5x+11.5x, which can't be right.

I know, I know - why am I doing this? Well, why not

Happy blasting y'all

[Silence]

Welcome back pritch.

You may be able to fix the CPS 1500's pump. I was just going to link to this article, but it links to iSoaker's even better CPS 1500 repair article. Hope that helps.

Good to hear you could plug up the Monster XL's quick-fill port easily enough – I'd have thought foam would leak because, you know, it's foam. Guess that's not the case after all.

Those are weird numbers about the Monster XL's output. I was thinking of ways to justify them until you noted that the 5x + 8.5x has more output than 5x + 11.5x. That's strange indeed...good catch.

[isoaker]

Yup, those are some really odd numbers on the Monster XL review page. Then again, those were what I ended up measuring at the time I did the stats and never really thought about why the numbers ended up being that way. Stats were measured in triplicate and averaged, but as my MXL is now in deep storage, I am not able to re-measure those output stats (not to mention the blaster is now over 8 years old).

At any rate, welcome back! Sorry can't really better explain those stats. I just measure 'em! *hah*

[pritch]

Re: the CPS1500 fix - thanks for the link, very interesting I did have the screws out this morning but of course the 1500's nozzle selector is glued on to the two sides of the body so you can only tease it apart so far anyways. Then I looked at the article saw how easy it was to get the pump out

At the end of my pump is the two washers in place. That is all there is - that end of the pump features like an inverted flat screw head which the washer comes over. I may take a photo later if you don't know what I mean. Isoaker - can you remember if that is correct of missing something? When I look down the pump shaft I can see a thin rubber washer at the end, but it doesn't look out of place really so I'm not sure if it is where it is supposed to be. Should I fish it out?

Thanks!

@Silence re: the foam - it's expanding foam so it dries, increases in mass and forms a watertight seal after ~30 mins. It's used mostly when you make a big hole in an outside wall to run a boiler vent out of etc. You can paint and decorate it, it's weird stuff, but it works! Think it would be good in some blaster repairs as with a bit of force you can unstick it, unlike epoxy.

Re: the MXL figures, well it may just be one of those weird things! I'm sure you measured it properly, but dude, don't leave the MXL in deep storage, use it! It will only deterioate in time anyways, enjoy it while it lasts!

[HBWW]

He probably takes it out seasonally to test, clean, and/or maintain it. The bladder has to be exposed to water every once in a while to prevent it from cracking up.

[pritch]

That's worth knowing - I'll make sure the 1500 and the xl get a bit of water through them now and then.

With regards to the 1500, I still can't see if there is actually anything "wrong" with the pump itself. Both washers are on, there's no yellow bit as in isoaker's pics, but I can't see that down the pump either. Is it possible we have different versions? I know this particular soaker was released a few different times wasn't it?

I got it fully loaded in the bathtub today, even though it leaked another 10-20% of the resevoir getting there, and was pleased to see it still packs a very good punch with some kick-back and gets close to the quoted shot duration times. If it wasn't for the major pump leakage it would be a terrific blaster.

I wonder if the washers and/or plastic flange in front of them just aren't making a tight enough fit tbh. The design is very poor, you can flex the pump handle so much it's asking a lot for any washer to hold the water in considering the full pressure load into the firing chamber is happening right behind it. I'm considering making up a little rubber band to go between the proudest parts of the two washers - I'll use rubber strips spare from bicycle light clamp kits. Thing is, it will need to be very tight, and still be able to pump without too much friction.

What do you guys think? I'm open to better suggestions from the pros!

[isoaker]

When it comes to trying to make a better seal, as opposed to using rubber strips or a little rubber band, I believe some have had luck using carefully wrapped electrical tape.

So if my understanding is correct, basically the pump can pull water into it, but when you push it, it leaks like crazy? Definitely sounds like a seal problem. Well, either that or, in addition, the other check valve is not behaving properly, making it much more difficult to push water from the pump into the PC. If there's a check valve problem, there is no easy fix for that.

[HBWW]

In homemade guns, pumps leak while pulling instead of pushing. The water shoots out along the side and in a poorly designed pump, it happens a lot.

If the seal on the pump isn't bent or damaged in any way, I'm not sure what would cause it. Perhaps it's simply worn out. Is there plenty of frictional resistance?

[pritch]

There's resistance, in fact when you start pushing it back in, it does try and push the pump back out again as the pressure rises. The way the washer placement is designed, it's almost like it depends on the pressure to expand the lip, creating the watertight seal with the pump tube. Except it doesn't It's not that difficult to charge the PC and the gun does perform fairly well minus the leak so I'm hoping there isn't a check valve issue? I would love to take the 1500 right apart as with the MXL but the nozzle selector is so well glued I can only see that ending in diasaster

The pump leaks in both directions - when pushing it in water is forced out, when pulling it out it streams straight down the pump into the pump handle. I tried fix attempt #1 last night which was wrap rubber around the pump handle directly in front of the plastic bulge before the washers. No joy - well, actually maybe a slight reduction in the amount coming out.

Thanks for the tape hint, I think the key location to go for might be the middle bit of the two washers as in your pics. I'll let you know if I have any joy, but it's going to be tricky, it has to be watertight but it also has to travel up and down the tube without too much force and I'll have to get it in to the tube in the first place!