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Canuck Bob · New Member

I'm researching a DIY spring tune kit for my new HM35E. I have the tools and plenty of steel stock to build a metal guide. I won't be using it for the piston top hat, too heavy.

I've read some folks prefer them and they were very common once.

Slavia · Moderator

Metal should be fine. My springers have metal guides, some original and some fabricated. The guide should fit in the relaxed spring with some drag, but not so much you have to force it in. Coil springs expand in diameter when compressed, so when you cock the gun it will be loose on the guide. When you shoot it the spring clamps back down on the guide, helping to reduce vibrations - "buzz" and "twang."

The coil also twists as it compresses. If the ends of the spring can't slip and rotate, then the twisting forces are translated into kinking and bending. Polish the spring ends and the surfaces they contact. Some people put a stack of thin, greased washers at either end to let it slip. This can add a little power, but at the expense of making the shot cycle harsher. You can also add so many washers that the coil binds (wire turns touch) before the trigger latches. Keep it thin.

Canuck Bob · New Member

Thanks Slavia,

I've noticed some tuners prefer Nylon 66 cast plastic to Delrin due to being stiffer and less prone to break. I'll take your advice to heart, specially the advice regarding spring torque.

garththomas · Veteran Member

My spring guide is made of acetron GP a product similar to Delrin. My .22 puts out a little over 10.6 fpe, I have put about 4000 pellets through it since installing the spring guide and yesterday I tore it down and I see no wear on the spring guide. I haven't heard of nylon being recommended for spring guides and I know its harder to get a good finish turning. I made my guide as tight as I could so that I wasn't distorting the spring to push it in since the spring will never be that tight again after compressing. Plastic is lighter than metal and may be quieter and less chance of galling.

Alstone · Moderator & Site Supporter

I use Nylon 66 for the top hat on my TX200 only because it gives me a faster lock.

Here are some wave form charts I did when testing to new top hat which I made 50/50 metal/Nylon, it has had around 16000 shots through it since and still performs well.

As for the spring guides I used Nylon 66 but it wore out fast, so I now use steel and a light molly lube.

Have a look here:

http://airgunhome.com/agforum/viewtopic.php?t=2566&highlight=sound