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Air Gun Home Forum Index » Rifles » QB 78 Power Adjuster (New Adjuster Update) Goto page 1, 2  Next    View previous topic :: View next topic  QB 78 Power Adjuster (New Adjuster Update)   Posted: Sat Jul 19, 2008 6:03 pm Alstone Moderator & Site Supporter Joined: 01 Mar 2007 Posts: 4139 Location: Linconshire, ENGLAND Looking around the internet for a power adjuster for a QB78 turned up just one, this entailed drilling and tapping a hole in the valve tube end plug, the pin is removed from the cocking block and a screw is then used to add more compression to the cocking spring, this system works all right apart from the fact that you have to pull the bolt to cock the gun instead of it being done by closing the bolt, also I think it looks a bit unsightly. So I have designed my own system of varying the power on a QB, it does require a lathe to make the parts and is a bit more complicated, but retains the cocking on closing the bolt which I like, it works by the cocking spring being adjustable with the cocking block remaining in its normal place, this is accomplished by making a new cocking block drilling and tapping a hole through the middle to allow the spring to be adjusted without moving the block. I still have to finish dimensioned drawings but if anybody wants to have a go at this then just pm me for a full AutoCad drawing or a large jpeg. Al Last edited by Alstone on Tue Mar 31, 2009 6:13 am; edited 2 times in total _________________   Posted: Sat Jul 19, 2008 6:16 pm cw Banned Joined: 10 Feb 2008 Posts: 1771 Very nicely executed!   Posted: Sat Jul 19, 2008 6:20 pm broommaster2000 Moderator Joined: 10 Mar 2007 Posts: 5714 Location: City of Groningen, Groningen, The Netherlands That's a very nice little gun with some very nice little parts on it. _________________ BIG GAP   Posted: Sat Jul 19, 2008 8:01 pm 23ib0d0n Moderator Joined: 21 May 2007 Posts: 757 Uhhmmm . . . that isn't the original bolt handle either, is it? Very nice design. Were you a design engineer also? Or is it just a hobby?   Posted: Sun Jul 20, 2008 3:29 am Alstone Moderator & Site Supporter Joined: 01 Mar 2007 Posts: 4139 Location: Linconshire, ENGLAND 23ib0d0n wrote: Uhhmmm . . . that isn't the original bolt handle either, is it? Very nice design. Were you a design engineer also? Or is it just a hobby? Hi J I changed the bolt handle I didn't like the oval ball on the end or the stright shaft, so I made the whole thing bigger so it was easier to use, plus to my way of thinking "If it looks right then it is right". As for the engineering I was the chief engineer of one of the UKs largest textile manufactures for many years, and that involved design engineering, tool and die making, machine tool practice plus along the way I learnt printed circuit design and electronics. I started my working life at an armaments factory in the late 1950s doing a five year apprenticeship in engineering, this entailed working on all types of guns from browning aircraft turret guns up to naval 4” twins, and now I’m back to airguns, “life is just a circle “. Al _________________   Posted: Sun Jul 20, 2008 2:09 pm 23ib0d0n Moderator Joined: 21 May 2007 Posts: 757 Alstone wrote: I was the chief engineer . . . Al Yessir, that explains the constant tinkering . . . I was a construction field engineer for a couple of decades, and mainly specialized in shutdowns. Saw alot and never got boring, but 21 days on at 20+ hours a day for months at a stretch can start wearing on a fella after he hits 40 . . . Since the property and buildings are paid for, and there is enough residual to cover bills ~ I've just been tinkering as well . . . Not much profit margin in it though . . .   Posted: Sun Jul 20, 2008 2:33 pm Alstone Moderator & Site Supporter Joined: 01 Mar 2007 Posts: 4139 Location: Linconshire, ENGLAND 23ib0d0n wrote: Alstone wrote: I was the chief engineer . . . Al Yessir, that explains the constant tinkering . . . I was a construction field engineer for a couple of decades, and mainly specialized in shutdowns. Saw alot and never got boring, but 21 days on at 20+ hours a day for months at a stretch can start wearing on a fella after he hits 40 . . . Since the property and buildings are paid for, and there is enough residual to cover bills ~ I've just been tinkering as well . . . Not much profit margin in it though . . . Yes thats the word for it J "Tinkering" I certainly do a lot of that, and as for making a profit I think it would kill the interest chasing it, although when someone walks in the door with a fist full of bucks you don't turn them away, as long as it's a one off. Al _________________   Posted: Sun Jul 20, 2008 9:41 pm Slavia Moderator Joined: 31 Mar 2008 Posts: 4382 Location: Waseca, Minnesota, USA That explains a lot. I suspected you were not a retired florist. Nothing wrong with that profession, but they don't make steel widgets that are also a thing of beauty. _________________ ¡Listo! ¡Apunte! ¡Fuego!   Posted: Mon Jul 21, 2008 4:05 am broommaster2000 Moderator Joined: 10 Mar 2007 Posts: 5714 Location: City of Groningen, Groningen, The Netherlands If I ever get a QB, I'd pay for parts like that, but since I don't have one... _________________ BIG GAP Update   Posted: Wed Dec 17, 2008 5:22 pm Alstone Moderator & Site Supporter Joined: 01 Mar 2007 Posts: 4139 Location: Linconshire, ENGLAND I had to change the adjuster knob on the QB as I kept trapping my sleeve in it, also I cut rings around the adjusting rod so that I can tell which setting it is on, apart from that the rest remains the same. The hole through the shaft is to put a rod throught to hold the shaft, while screwing on the knob. Al Last edited by Alstone on Wed Mar 25, 2009 5:27 pm; edited 2 times in total _________________   Posted: Wed Dec 17, 2008 8:32 pm Mar Veteran Member Joined: 21 Sep 2007 Posts: 428 Location: Victoria, BC Oh Al, please stop teasing me with your handiwork if you're not gonna share. My list keeps getting bigger and bigger every time I see things you make. PM me for my shipping address Nice work and looking forward to getting a 78D when available.   Posted: Thu Dec 18, 2008 2:17 pm Alstone Moderator & Site Supporter Joined: 01 Mar 2007 Posts: 4139 Location: Linconshire, ENGLAND Sorry about that Mar. when are you getting the 78D, before Christmas? Al _________________   Posted: Thu Dec 18, 2008 9:39 pm Mar Veteran Member Joined: 21 Sep 2007 Posts: 428 Location: Victoria, BC Hopefully order it before X-mas anyway. Whenever the new shipment arrives from the dealer I like to deal with.   Posted: Fri Dec 19, 2008 2:00 pm cw Banned Joined: 10 Feb 2008 Posts: 1771 Printed circut design? Do you also etch them?   Posted: Fri Dec 19, 2008 3:41 pm Alstone Moderator & Site Supporter Joined: 01 Mar 2007 Posts: 4139 Location: Linconshire, ENGLAND cw wrote: Printed circut design? Do you also etch them? I certainly do CW mostly copper clad fibre glass using ferric chloride or ammonium persulphate, I have done a bit of photo etching but it is only worth while when doing quite a few of the same, plus it costs more per board. I did used to make a lot frequency shifter piggy back boards for Hi-Gain CBs, when pirate SSB was in vogue Strangely enough what started me off was when I was asked to repair the air conditioning on a Cadillac, and the problem was that original unit’s were potted in a plastic box, the connecting leads would break off with engine vibration, so I made replacement units for £25.00 ($50.00) which in the UK was cheap, a replacement from the USA was as far as I remember about $150.00. Al _________________ QB 78 Power Adjuster (New Adjuster Update)     Air Gun Home Forum Index » Rifles You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum All times are GMT - 5 Hours   Page 1 of 2   Goto page 1, 2  Next All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First  Select a forum Main Forums----------------AirGunHome Q&AGeneral Air Gun Questions and TopicsPicture GalleryTarget Shooting: Casual, Fun and CompetitionHunting, Pest Control, Varminting People/Events/Airgun Issue Discussion----------------Introduce YourselfThe BS TopicClubs/Events/Regional/Political Airgun Issues Maintenance, Modification and Reviews----------------RiflesPistolsAntique, Collector and Novelty AirgunsBB GunsPellets/AmmoOpticsAccessoriesAirgun Smithing Buy, Sell or Trade Forums----------------For SaleWant to Buy   Note: If you are seeing "Please enter your username and password to log in." 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