Planet Airgun

General Airgun Categories => Maintenance, Modifications and Upgrades => Topic started by: svendogg on January 20, 2018, 10:05:18 PM

Title: Started on the SYNSG.....
Post by: svendogg on January 20, 2018, 10:05:18 PM
Made a start on the synsg, stripped the whole thing down, gave everything a basic clean up. Piston is reasonably well polished, few burrs in the slot which I've smoothed off already. Quick polish with wet and dry and some metal polish and should be good to go. As expected, piston seal was a tight fit and had a few chunks missing from assembly. I'll fit the Aussie seal I have now, rather than mess about reusing the stock one. Spring is straight, one end is reasonably well finished and flat, just needs a polish. The other is just roughly chopped and sharp, so that needs attention. Rear washer on the spring guide is bent, so I'll replace that, probably put an extra one in there to add a bit of preload. I'm gonna bin the metal piston liner and replace with plastic or ptfe. Also, the trigger unit had a black rubberised sleeve around it which I wasn't expecting, is this normal?
Title: Re: Started on the SYNSG.....
Post by: Gambo on January 21, 2018, 12:10:09 PM
the trigger unit had a black rubberised sleeve around it which I wasn't expecting, is this normal?

From what I remember, yes......but it was a good few years ago that I last stripped one down. :-\
Title: Re: Started on the SYNSG.....
Post by: svendogg on January 22, 2018, 12:07:21 AM
Managed to squash the rough end of the spring almost flat, realised last time I did a Springer I used the gas hob to heat it..... We've since got an induction hob..... DOH!
Luckily my gas soldering iron has a blowtorch tip attachment, which took a while but got me there in the end. Hopefully the bench grinder at work is still set up and I can grind it flat tomorrow, then just needs a polish up.
I'll then re-measure the spring to see how much length has been lost by squashing the coil, the find some suitable washers to preload it up to the original length, maybe even add an extra 2mm or so. Don't want to replace the spring as yet as it's in decent enough condition, but probably end up with a tinbum kit in there eventually.
May start with the piston tomorrow night depending on whether I manage to get the spring ground down or not
Title: Re: Started on the SYNSG.....
Post by: Gambo on January 22, 2018, 06:04:32 PM
Thanks for the update sven.

Induction hob...hehe......but seems like you managed to sort the spring OK in the end (no pun intended). Hope the bench grinder is still there and working. ;)
Title: Re: Started on the SYNSG.....
Post by: svendogg on February 11, 2018, 08:03:54 PM
So finally put this back together earlier..... Piston was, in all honesty, pretty well finished, just polished a couple of minor marks out of the skirt and it was pretty good to go. Seal was a decent fit straight from the pack, so I decided to leave the thing alone. Smear of moly dry slide on the outside of the seal and skirt, lightly lubed spring, PTFE piston liner made.... Couldn't get hold of any suitable washers to make up a small amount of preload, but I'll test it first without any and see how she goes. Just need a replacement screw for the arrestor plate as the head was chewed up by previous owner..... Anyone know what size it should be?
Title: Re: Started on the SYNSG.....
Post by: Gambo on February 11, 2018, 08:30:18 PM
Just need a replacement screw for the arrestor plate as the head was chewed up by previous owner..... Anyone know what size it should be?

I'll see if I can find out for you at the club tomorrow. ;)

Good to know it all went OK. What does it shoot like now Sven? ???
Title: Re: Started on the SYNSG.....
Post by: svendogg on February 11, 2018, 08:37:57 PM
Thatd be great if you could find one mate, I'd really appreciate it.

Not shot it yet as been mad busy this weekend but cocks really smooth
Title: Re: Started on the SYNSG.....
Post by: Gambo on February 11, 2018, 08:50:50 PM
I've already send a text to someone who may possibly have one......I'll let you know as soon as I get a reply.  ;)
Title: Re: Started on the SYNSG.....
Post by: svendogg on February 17, 2018, 10:10:52 AM
Any joy gambo?
Title: Re: Started on the SYNSG.....
Post by: Gambo on February 17, 2018, 10:44:50 PM
Yeah.....he's gonna check to see if he has a spare, and if so, will bring it to the club on Monday night.

If he hasn't, he'll at least tell me the thread pitch and length, so a correct screw can be sought.
Title: Re: Started on the SYNSG.....
Post by: svendogg on February 18, 2018, 09:43:30 AM
Great stuff, thanks very much :)
Title: Re: Started on the SYNSG.....
Post by: Baggawind on February 19, 2018, 10:45:03 AM
Do you know you can also turn that so-so trigger into a really good fully adjustable one ? And it,s easy to do too.
Title: Re: Started on the SYNSG.....
Post by: svendogg on February 19, 2018, 04:13:44 PM
Largely depends on how difficult it is to do haha
Title: Re: Started on the SYNSG.....
Post by: Baggawind on February 20, 2018, 09:58:53 AM
It actually depends if you have or access to a drill press. If you take the trigger blade out you,ll notice , just behind the pivot hole, a small bar running across the top of the blade. This actuates the first stage travel and is, by it,s very nature, not adjustable. What you do is to mark a line on the side of the blade in line with that pin and parallel to the second stage screw. Then you cut the pin in half and pull it out. Then you drill a 2.5mm hole in line with your mark and tap it out with a 3mm tap. Then insert a 3x10mm grub screw and there you have it. It allows you to adjust the first stage and , consequently, the second stage to make a much lighter and more predictable let off. I got the idea from a guy on the Chinese forum and, I have to say, it totally transformed the trigger on my 208.
Title: Re: Started on the SYNSG.....
Post by: Baggawind on February 20, 2018, 06:45:35 PM
Oh I forgot, it also helps to fit  a weaker trigger spring.
Title: Re: Started on the SYNSG.....
Post by: Gambo on February 20, 2018, 08:50:50 PM
Good news Sven......I've got you a new arrestor plate screw. :)

Please PM me your name and address, and I'll get it posted out to you. ;)
Title: Re: Started on the SYNSG.....
Post by: svendogg on February 21, 2018, 12:30:45 AM
Great, thanks gambo! I'll pm you now 👍
Title: Re: Started on the SYNSG.....
Post by: svendogg on February 21, 2018, 12:37:21 AM
Thanks for the advice baggawind, think I may have read about it ages ago on the Chinese forum now you mention it. It may be something I attempt in the future but I wouldn't be confident tackling it at the moment. In all honesty I don't think the trigger is too bad as standard, I can live with it for the time being 👍