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Thread: Spring Gun Tuning

  1. #136
    Join Date
    Mar 2012
    Location
    wakefield
    Posts
    479
    I might just give this a go,many thanks for all the info.

  2. #137
    Join Date
    Nov 2013
    Location
    Leeds
    Posts
    31

    spring tune

    Just stripped n re lubed tx 200 nothing else and its made a massive difference read loads what said don't bother vmach just re lube.

  3. #138
    Join Date
    Nov 2013
    Location
    Redditch
    Posts
    50
    I agree, very good tune up guide.
    Tried it on an almost 'new' HW 95, what a difference (power up to 11+lbs & smoother). I also discovered that weihrauch (like most companies) make their guns down to a price. If you have the ability take them apart and clean them up, even if new!!
    As for the degreaser, your local Motor Factors should stock aerosol cans of 'Brake Disc Degreaser' or suchlike. very strong solvent (clears most everything) & dries quickly, certainly worth a try.
    Howard

  4. #139
    Join Date
    May 2011
    Location
    manchester
    Posts
    8
    Quote Originally Posted by Paul Hudson View Post
    Hi Robert

    I found that dropping the power of a 12fpe HW80 down to 10.5fpe and using 7.9g pellets (Mosquitoes) made a huge difference. The rifle was much more tolerant of different holds, simply because it exhibited MUCH less recoil.

    Also, putting the action into a heavier stock further reduced recoil. It's the only 80 I've shot that let me keep the crosshairs on the target throughout the firing cycle.

    I've since sold the rifle to Adam77K on here, so it might be worth having a word with him...

    Paul.
    Totally,10.5 flbs in a medium to heavy springer is perfect imo. I have a prosport .177 running at 10.8flbs. I made the spring myself from a oteva grade material,bliss to shoot.

  5. #140
    Join Date
    Dec 2014
    Location
    orpington
    Posts
    10
    Glad i just read this thread . Just got myself the vmach kit to fit an old Hw 77 and had completely overlooked de-greaser. So many thanks.

  6. #141
    Join Date
    Apr 2016
    Location
    Rickmansworth
    Posts
    5
    great thread, will assist my airsporter rebuild greatly

  7. #142
    Join Date
    May 2016
    Location
    Bruton
    Posts
    77
    I have a BSA Meteor Mk3, I don't have Dry slide/Gun slide or Molykote GN paste, would it be suitable to use a fine wet & dry and polish (or just polish) with Autosol in the compression cylinder plus polishing the piston cylinder and finally coat sparingly with moly grease as suitable plan B ?

  8. #143
    Join Date
    Apr 2012
    Location
    Retford, Notts
    Posts
    16,936
    Yep, a caring application of moly grease is more than fine.
    THE BOINGER BASH AT QUIGLEY HOLLOW. MAKING GREAT MEMORIES SINCE 15th JUNE, 2013.
    NEXT EVENT :- APRIL 7/8, 2018. BOING!!

  9. #144
    Join Date
    Sep 2016
    Location
    Banbury
    Posts
    5
    Quote Originally Posted by Supermick View Post
    Thanks to Hsing-ee for the following :-


    Tuning The Older Springer

    --------------------------------------------------------------------------------

    ALL WORK DONE USING THIS INFORMATION IS AT YOUR OWN RISK - APPLY COMMONSENSE TO YOUR WORK AND SEEK ASSISTANCE FROM A QUALIFIED GUNSMITH IF YOU GET OUT OF YOUR DEPTH. Use a spring compressor and be careful!

    If you want your old or new-to-you old spring-piston rifle to give you its best then you could try the following tune-up. It takes a bit of patience and elbow-grease and dosen't involve any drastic modifications but if you follow it carefully your rifle should shoot sweetly afterwards for a good long time.

    The following is a basic tune for spring-piston rifles which was common in the late 1970s and early 1980s. The idea is to make the rifle as smooth and consistent as possible, and does not involve modifying the rifle in terms of piston weights, top hats, etc, that is for the more advanced airgunsmith. I used this on a Feinwerkbau Sport recently and it would cut 7mm groups at 25 yards from a rest, and in my 30 year old BSA Meteor which does 10ft/lbs and 20mm groups with a standard spring so it seems to work OK. The guide refers to a rifle with a leather washer, obviously don't soak the washer in silicone oil if it is of a synthetic material, just wipe a small drop of SM50 over it before assembly.

    For the full works you will need:

    new spring
    new piston washer and buffers if fitted
    new breech washer

    Can of Dri-Slide (or Gun Slide from Chambers) or tube Molykote GN paste
    Abbey LT2 molybdenum grease (J.S.Ramsbottoms has this)
    Abbey SM50 oil (J.S.Ramsbottoms has this)

    Solvol Autosol metal polish ( a car accessories shop like Halfords or a hardware store)
    Methylated spirit or white spirit
    Very fine abrasive paper
    Cheap toothbrush (unused)
    18Ē length of broomhandle
    Couple of packets unused ĎJí cloths or similar

    The idea of the tune is to make sure the bearing surfaces are smooth and appropriately lubricated, with the aim of consistent mechanical action giving consistent velocities without dieselling and so giving good accuracy. The molybdenum in the Dri-Slide binds to steel giving a very slippery hard surface.

    IT IS ABSOLUTELY ESSENTIAL THAT YOU CLEAN ALL THE PARTS COMPLETELY AFTER POLISHING THEM WITH ABRASIVE PAPER OR METAL POLISH. Use newspaper under the parts as you work and throw them out as they are soiled. Have a clean area to put your clean parts and donít do Ďdirtyí work next to them. Be careful with naked flames and the hair-drier, the methylated spirit and the carrier element in the Dri-Slide ar e both highly inflammable. WORK IN A WELL VENTILATED ROOM OR WORKSHOP.

    1. Place the new piston washer in a pellet tin or similar receptacle and pour over Abbey SM50 to cover it completely. Leave to soak overnight.

    2. Disassemble the rifle, taking care to store small parts so they donít get lost.

    3. THE COMPRESSION CHAMBER

    A. Degrease all the parts and the inside of the compression chamber using the meths. The broomhandle should have a 3Ē slot cut in one end so that a stip of J cloth can be slid in and wrapped round to give a cleaning head. Be very thorough, and keep using fresh strips of J-cloth until they start coming out completely clean. Check that the transfer port is clear by using a non-metalisc implement like a cocktail stick and examine carefully by eye. Use the toothbrush and methys to clean the threads that the rear cylinder block screws into. Dry the inside of the compression chamber using further J-cloth strips.

    B. If you feel it necessary you can remove the sharp edges on the inside and outside of the cocking-slot. Pack the compression chamber with cloth and using a spatula or table-knife with the fine abrasive paper wrapped around it smooth the inner and out edges of the slot. Donít overdo this, just remove the sharp EDGES from the slot. Degrease again and be meticulous about removing all the metal filings and abrasive dust using methys and J-cloths. Remove the packing cloth and degrease again until you are sure all the dust has been removed.

    C. Using a hair-drier, warm the compression tube by blowing hot air inside and outside the tube body. When it is warm, pour a tablespoon-size amount of Dri-Slide into the compression chamber and roll the chamber around so that the liquid coats all of the surface of the chamber and also further back in the area above the cocking slot. Be careful not to lose all the Drislide out of the transfer port! The chamber can be left to dry for a couple of hours or overnight. Alternatively, rub in some Molykote GN paste onto the whole surface of the inside of the compression chamber.

    D. When you are ABSOLUTELY SURE IT IS DRY, use a tightly-wound long piece of J-cloth on the broom handle, burnish the surface of the compression chamber thoroughly. A lot of the Dri-Slide will appear to come off, but it is leaving behind a layer so don't worry.

    4. THE PISTON

    After disassembling the piston, degrease it inside and out as above, using meths and J cloths. Polish any scratches on the piston body out using the fine abrasive paper, using a rotary action i.e. turning the piston on its axis and holding the paper still so the mark is polished out in a ring around the piston. Polish the whole of the outside of the piston with Solvol Autosol, particularly the back of the piston where it makes metal-to-metal contact with the cylinder wall. Use a J-cloth and to apply and polish off the Solvol. Carefully polish the surface of the bent (part of the piston which engages the sear) with Solvol on a J-cloth drawn tight over something flat and rigid (e.g. a small file). Degrease and clean with meths. Heat the piston up with the hair-drier and coat the inside AND the outside of the piston with Dri-Slide as with the compression chamber, except you donít need to polish it in afterwards, just leave the coating as it is.

    5. THE SPRING

    Take a peice of the fine abrasive paper and place it on a very flat surface e.g. a suitably strong piece of glass or steel plate. Polish polish the flat ends on the paper until they are shiny. You can make this a mirror finish if you then polish the ends using Solvol Autosol on cloth stretched over the plate. Degrease and clean the spring carefully afterwards.

    6. THE PISTON GUIDE

    Degrease inside and out and polish out scratches using a rotary action using the fine abrasive paper and then Solvol Autosol to give a shiney surface. If you like, pad a vice and use a file to remove the sharp edges on the base of the guide. Degrease and clean as above. Make sure you clean the passage through the middle of the guide and get rid of any old grease and dust in there.


    ASSEMBLY

    1. Take the piston washer that has been soaking in SM50 and squeeze it dry using a J-cloth. Fit it to the piston, avoid getting any lubricant on the screw/bolt attaching it to the piston body. Smear a couple of drops of SM50 around the base of the leather washer (away from its face).

    2. Take a lollipop stick and smear a stripe of LT2 grease about 1Ē in width around the back of the piston (trigger end), be fairly generous.

    3. Fit the piston back into the compression chamber, easing the piston head into the chamber gently. It may be a little bit swollen at this point, but persist in easing it in and donít use hammering or excessive force. Line up the cocking slot in the piston with the one in the compression chamber.

    4. Using a small pad of J-cloth, apply a thin smear of LT2 grease to the outside of the spring and a generous layer to one flat end. Fit the spring into the piston with the greased end forwards.

    5. Apply a liberal amount of LT2 grease to the outside and INSIDE of the spring guide and fit it to the end of the spring.

    6. Smear a little LT2 grease on the threads of the back-block and use this to compress the spring and reassemble.

    7. Reassemble the rest of the rifle using LT2 grease on all the main points of wear. Apply SM50 oil to the trigger by dropping it into the mechanism, allow the excess to drip out before reassembly. Replace the breech washer with a new one, and clean the barrel in the normal way. Make sure all the stock screws are tightened appropriately (not too loose, not too tight).


    The rifle may be a little bit smokey the first ten or twenty shots but should then settle down to be very consistent. All that is needed in terms of lubrication after this is a drop of two of SM50 at the joints occassionally, and once every 1500 pellets or so a drop of SM50 ***BEHIND*** the piston washer, which can be done by removing the stock and putting the oil in through the cocking slot. Leather washers can take a long time to bed in, so I recommend doing alot of plinking, like two or three tins of pellets, before the gun reaches its peak. Then you should be able to shoot the rifle for thousands of pellets without doing anything more than slip a new spring in occasionally and a sparing use of SM50.

    CAUTION: Do NOT over-lubricate. Stick to the amounts indicated here - less is more, especially with polished bearing surfaces.

    --------------------------------------------------------------------------------
    Looks like sound advice there, thank you.

  10. #145
    Join Date
    Sep 2016
    Location
    Tring
    Posts
    25

    Piston seal sizing

    Hi, just thought I'd explain a method which seems to work for me with my old HW77k from the eighties.

    1) Start with a new seal.
    2) Place the cylinder, piston and seal in a pan of boiling water. With the piston with the seal on push the piston in and out of the cylinder. Let the pair rest in the pan for about five minutes.
    3)Get a bowl of cold water (best with ice)
    4)Quickly use the piston to suck up ice cold water then block the transfer port with your finger and push the
    Piston down to create as higher pressure as possible and hold.

    This process first softens the seal then opens the parachute seal and cools it in the perfect diameter. This will not work so well with an old seal. Once done the piston can be pulled to the top of it's stroke and let gravity make it fall but then stopped by covering the transfer port.

    I hope this is of help.

  11. #146
    Join Date
    Oct 2012
    Location
    Hythe
    Posts
    8

    Thanks for the guide

    Useful information, thanks for posting the guide.

    Cheers!

  12. #147
    Join Date
    Nov 2014
    Location
    Burnley
    Posts
    10
    Quote Originally Posted by deadeye dick View Post
    No you cant it is not available to the general public, my wife gets it because she lectures and teaches nails and beauty but I have tried to get some without success I believe you can buy it in the USA over the counter
    Not available to general public ?, I buy mine 5 litres at once from a printing supplies company, it's not a controlled substance or illegal in any way

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