BBUMB Mods

Okay then, just as the title says, these are some mods for the BBUMB.

First, you want to open up the blaster. This is what you should see.(This pic borrowed from Nerf Mods and Reviews due to lack of before pic)

Now, remove the orange bit at the front. This isn't necessary, but it does get in the way of an RSCB or hopper. Next, remove the pump from the pump tube, and plug the OPRV. This is pretty important as stock, you can only get about 4-5 pumps before severe hissing starts up. I used hot glue.

Next, you want to dremel out the front on both sides of the shell where the barrel comes through. This is to fit the coupler.

After this, cut the black barrel off completely, wrap the bit left in e-tape until a coupler fits snugly on there, and glue the coupler on.

Now, your internals should look like this.

With the shell on, this is what you should have.

Now, stick a big-ass RSCB on there, and you're good to go.

Now, your coupler may not look the same as mine. I prefer threaded couplers. The put less stress on the bond because you don't pull forward to remove attachments. This is now pretty much my favorite blaster(sorry snow camo recon) because with the coupler, it now offers much more versatility than any of my other blasters. As for ranges, I haven't yet tested with the RSCB(just finished tonight) but with my absolver attachment, it gets about 60' with 6 pumps. If you want to see my other attachments for this, look here.

So an RSCB (what does it mean anyway?) enables multiple shots fire without having to load one at a time right?

I'm just wondering if it decreases range significantly because I can hit 70-80ft with my BBUMB just with a brass barrel fitting nicely over the existing barrel (minus the orange end bit)

RSCB is the name of the four Nerfers who devised it. It's a magazine system that allows, as you surmised, one to load multiple darts and fire them one-at-a-time.

Basically, you have a PVC tee, the breech side with a length of PVC that ends in either a cap or a valve so you can load it. The 'muzzle' end of the PVC tee has a short length of PVC, long enough for a single dart to at least lead into the tighter barrel (CPVC, 12mm brass or PETG. Pressurized air comes up the tee, and out the muzzle, clearing the dart with it.

The RSCB needs to be pointed down after each shot to drop a dart into the front section of PVC.

There are some people who put a 'tray' across the air intake hole portion of the PVC tee to keep the dart from straying into that hole. Other people mount the tee below the air supply.

With my rscb bbumb which only holds 3 streamlines I can consistantly hit on average 75 feet but the more dead space in your clip the more you will find the range decreases.

I would recommend you leaving the orange tip on there just for publicity purposes. It looks like a pipe gun LOL. You're choice though.

Or gluing a chunk of LongShot faux barrel over the business end of the RSCB.

Well, actually, I got bored waiting for my purple PVC to come in, so I wrapped most of my RSCB in brightly colored string, to make it less boring.

*...and now, a video: - added Apr 3, 2011

Okay, a little back story: I was injured the other day playing Dodgeball (that's right, laugh it up). A teammate and I ran into each full force. He tripped and fell flush against the side of my knee. Another teammate said he saw me knee bow sideways. It hurt like a bitch!!! Anyway, it looks like I'm out of commission for at least four weeks with a sprained knee. Which means I most likely won't be attending Vengeance 4. I was bummed... But when Life hands you lemons you make lemonade!!!!

Enjoy the ridiculousness! I give you, the [size=150]"Hop 'A' Long"[/size] Haha!


By makeitgo

By makeitgo

By makeitgo

By makeitgo
at 2011-03-29

Ultimate Missile Blast, nested in a crutch with an aluminum and acrylic RSCB. The pump is not plugged. My co-workers think I'm NUTS!! They're probably right.

Mods:

• Stock pump's OPRV releases at low pressure, so it has been augmented with the OPRV from an SSPB (eputtied over the stock pump head's OPRV hole.)
  
  
  
• Stock pump's check valve has been drilled out. Pump head has been attached to the back of the pump tube, turning it into a tank expansion.
  
  
  
• Stock pump handle is fixed to the back of the blaster via screws.
  
  
• Primary tank has been moved back, allowing the hopper clip to enter via the B-blaster slot.
  
  
  
• Bicycle frame pump attaches below the blaster, secured by a reusable zip-tie.
  
  

End result is an UMB that looks stock once the hopper clip and extended barrel is removed. This is a design goal because the official Nerf FB site only allows pictures of unmodded blasters (and no homemades) and many Nerf wars like to conclude the festivities with a group photo they submit to the 'Shot of the Week' contest on the page.

Right now, there are still some leaks I need to fight, but I expect 80' to 90'. Before I replaced the OPRV, firing it immediately after the OPRV kicked in (so to minimize the effect of the leaks), I was getting 60' with slugs.

I know bike pumps vary, but does the addition of that reduce the number of pumps required to reach the required amount of pressure to shoot micros?

It still takes four or five pumps, which is the same as unmoded.

• The bike pump has a longer stroke, but smaller ID, so the volume might be the same.
  
  
• This has a tank expansion, so the volume may actually be greater.
  
  
• Remember, the tank leaks, too.
  
  
• Having the pump in front means the user doesn't have to swap hand position to pump, then shoot.
  
  

I am hoping for 80' - 90', and six or eight pump strokes per shot.

Please don't jack my thread by posting your own mods. Maybe for comparison, or explaining how something works, but not to just post it.

Nerf Doctor wrote:Please don't jack my thread by posting your own mods. Maybe for comparison, or explaining how something works, but not to just post it.

Umm. Your thread was pretty 'vague'. It just said "BBUMB Mods". How would anyone know that it was actually a write-up. Hell, I would of posted how I would of modified a BBUMB too if I had the time. This thread should be open for idea. You're ruining your own thread by trying to stop people from posting their ideas up too.

@taerkitty - Where you attached the 'tank extension' for more power. Is that just part of the original pump? Because I'm pretty keen on doing thatso I can get some 4B ranges.

Yes. You drill out the check valve and it becomes one continuous reservoir.

taerkitty wrote:Yes. You drill out the check valve and it becomes one continuous reservoir.

That's actually quite interesting. I was more afraid that the tank would go 'BOOM' because the pump itself isn't made to hold pressure. Only to take it. I will have to try this out. Thanks for the idea man.

I have a sleeve of 1" thinwall PVC that nicely sheaths the pump tube. While 1" is 2.54cm, PVC ID and OD in the US are only approximately the sizes they state. The point here is that you are right - I have augmented the pump tube with another layer of plastic.

littlebro05 wrote:

Nerf Doctor wrote:Please don't jack my thread by posting your own mods. Maybe for comparison, or explaining how something works, but not to just post it.

Umm. Your thread was pretty 'vague'. It just said "BBUMB Mods". How would anyone know that it was actually a write-up. Hell, I would of posted how I would of modified a BBUMB too if I had the time. This thread should be open for idea. You're ruining your own thread by trying to stop people from posting their ideas up too.

@taerkitty - Where you attached the 'tank extension' for more power. Is that just part of the original pump? Because I'm pretty keen on doing thatso I can get some 4B ranges.

Well, I'm sorry. I didn't realize, that whenever someone wishes to post a write-up, they absolutely must post "Hey, this is a write-up, just to let everyone who can't tell know." And, I also did not realize that people are supposed post "ideas" in other people's threads, instead of in the "Mod Ideas Thread" that those are supposed to be for.

Nerf Doctor wrote:

littlebro05 wrote:

Nerf Doctor wrote:Please don't jack my thread by posting your own mods. Maybe for comparison, or explaining how something works, but not to just post it.

Umm. Your thread was pretty 'vague'. It just said "BBUMB Mods". How would anyone know that it was actually a write-up. Hell, I would of posted how I would of modified a BBUMB too if I had the time. This thread should be open for idea. You're ruining your own thread by trying to stop people from posting their ideas up too.

@taerkitty - Where you attached the 'tank extension' for more power. Is that just part of the original pump? Because I'm pretty keen on doing thatso I can get some 4B ranges.

Well, I'm sorry. I didn't realize, that whenever someone wishes to post a write-up, they absolutely must post "Hey, this is a write-up, just to let everyone who can't tell know." And, I also did not realize that people are supposed post "ideas" in other people's threads, instead of in the "Mod Ideas Thread" that those are supposed to be for.

k

This is a pretty good way of singling this gun, but I rather whoever it was from Adelaide's way. Only because of reasons like how it is cleaner and easier with no dremeling.

That's just my opinion