If you came to this site from Vike's Complete Guide to Building a Spimmy (click for link) then you understand how thorough I like to be when making these tutorials.
Fortunately, this modification isn't as complicated as the Spimmy. In it's simplest form, it's a marker that shoots, but doesn't recock after firing. You then pump, or push back a handle, to get the maker ready to fire again. Considering that electronics are not needed, nor any fancy type of operating system to make it work, this is a relatively simple gun to make, once you understand the mechanics of it all.
The base for this modification is a Spyder body, of which any one of the older models should work. I would like to say the newer models such as the MR series, the VS series or the RS series will work, but unfortunately I have no experience with these newer models. Because of this, for the sake of this tutorial, I'm suggesting that you use an older style Spyder (older, as in pre-2K5 models) as they should work perfectly fine. The reason for this is that prior to 2005, all the Spyders had the same basic operation with the same internal parts - the only differences between the individual guns were the body styles and colors, with just a few exceptions (the EM1 and the Primal are the ones that come to mind).
These days, Spyders and their clones can be found easily and cheaply. Chances are, you probably have one in a closet somewhere as the Kingman Spyder is the predominant ENTRY-LEVEL marker on the market. Lots of people started with a Spyder (or a Spyder clone) but abandoned them eventually for higher level markers. When I began moving "up" in terms of play and markers, I started to sell off all the aftermarket parts I had added to my own Spyder Sonix, and many of the stock parts as well, just to get back a little bit of the money I put into this sport. Luckily for me, I never sold the Sonix body and it sat in a box for about 4 years gathering dust. If you don't have a Spyder or clone, look around the different forums on the internet, or go to garage sales as a lot are sold extremely cheap in those.
As a side note, I can't guarantee this tutorial will help if you are trying to modify a Tippman (another entry level marker) or a Spyder clone such as a Mongoose, Icon, Pirhana, etc. I don't see why it shouldn't work with a clone, but I haven't tried it with them. You're just going to have to experiment and find out.
Where to start
Well, first of all, you have to have a body to build on. Duh! As I said before, any pre 2K5 Spyder will work, and possibly the newer models. In this tutorial, I'll be using a Spyder Sonix body.
This was how it looked back in it's "active" days several years ago. I had pretty much upgraded it as far as possible at the time - Assault block, Maddmann Rocket Valve, Tigershark bolt, polished stiker, ESP ipi frame with RT mod (I've been modifying Spyders for a long time...), sweetspot trigger, Intimidator detent, CIP medium drop with on/off asa, so on and so forth...however, like most active players, I moved up to the mid-level range of guns after a few months and the Spyder was relegated to the pile of paintball gear in the utility room.
Next, you're going to have to have certain parts. Stock parts work fine for the most part, but it's a bit more flashy when you can say that it's got "such-and-such" aftermarket part on it. Unfortunately, after buying into the mid-range level of markers, to fund my paintball playing back then I slowly sold off all the bits and parts to it, including some of the stock parts. Of course, this made it difficult this year when I wanted to build this pump!
So, this meant I had to find parts. Here's a list of what you're going to need: (Note - this is, by far, the easiest thing to do because there's very little modification involved and you can either use aftermarket parts or the stock parts.)
1. Valve and pin (stock is fine, but you'll have to modify the valve pin. I'll explain this on another page.)
2. Striker (again, stock is fine, but you're going to have to modify any striker you get.)
3. Bolt (stock is fine, but there are many aftermarket bolts you can use. Just make sure it's built for your particular marker, i.e. a Sonix bolt for a Sonix body.)
4. Vertical Adapter (stock is perfectly fine, but you don't need the LPC anymore. I recommend finding one that is high flowing, though, so you don't have to worry about velocity issues later. I had to use a clone VA from an Icon Z since I couldn't find a Spyder one anywhere.)
5. Spring kit (you need both main springs and valve springs for this.)
6. Single trigger frame (If your gun actually came with one, you're one step ahead! However, you can use the double trigger it came with since most markers started using them exclusively. I went with a single trigger frame because in my opinion, pumps don't look right, nor feel right with a double trigger.) I used a Dye .45 Spyder single trigger frame that I found on eBay and got really cheap, but any Spyder single trigger frame should be fine.
7. Pump kit (you can make one of your own, but for the purpose of this tutorial, I'll be using the PMP Trilogy kit.)
8. Barrel (I recommend a kit that uses an insert, such as the Freak kit from Smart parts. The inserts keep balls from double feeding or rolling out of the barrel since this gun will become a "Closed" bolt system. However, any barrel will work so long as it has a good enough ball to barrel fit to keep the paintball from rolling out of the barrel.)
9. Other things you might need - single trigger, safety (with spring and ballbearing), sear with spring, pins, grips, asa (air source adapter), regulator or gas thru grip, air line (stainless steel or macroline).
10. Tools - Allen wrenches, files (I used an Xacto file set), drill press, screw driver, dremel with grinding stones, sandpaper, and paintball lubricant (I used Sl33k lube from Smart Parts, but anything made for paintball guns will work. Other tools needed will be mentioned in that particular section of the tutorial.
First of all, if you buy new parts, please visit your local paintball store if you're lucky enough to have one. Supporting them will keep the sport alive and going in your area. But, if you don't have a store or don't want to buy new, the internet is a great place to find these parts. Different forums BST threads will have these items, some more than others. I'll tell you right now that I had a HARD time finding a single trigger frame, and even a harder time finding the parts to go inside it! I had to resort to cannabalizing my brother-in-laws old Spyder Classic frame...hope he doesn't read this!
Make sure to gather all the parts and equipment you need PRIOR to starting so that when you are ready to build, you can immediately test it and then play with it, because after all, that's what we ultimately build for - the thrill of playing with something we created.