{"product_id":"polarstar-hop-up-thing","title":"PolarStar Hop Up Thing — CNC V2 Hop Unit for AEG and HPA","description":"\u003cdiv style=\"background:#edfaf1;border-left:4px solid #27ae60;padding:12px 16px;border-radius:0 6px 6px 0;margin:0 0 16px;font-size:13px;\"\u003e\n\u003cstrong style=\"color:#1a6b3a;\"\u003ePolarStar Hop Up Thing.\u003c\/strong\u003e A CNC-machined hop unit for standard V2 M4 and M16 gearboxes, running either an AEG or an HPA engine. 6061 T6 aluminium cut in-house to a two-thousandth of an inch, with PolarStar's TDC slider doing the adjusting.\n\u003c\/div\u003e\u003cp\u003eHop units are where accuracy is won and lost, and most of them are cast parts that arrive slightly off-spec and loose in the barrel. PolarStar machine this one themselves from 6061 T6 aluminium to a tolerance of two thousandths of an inch, and the reason that matters is fitment: a unit that sits snug in the outer barrel and square to the gearbox face cannot rotate or creep, and a unit that cannot move puts every BB on the same line.\u003c\/p\u003e\u003cp\u003eThe adjuster is the part worth understanding. Older sliders push the nub from an angle, so they drift under vibration and lose their setting over a magazine. PolarStar's TDC — top dead centre — arm applies pressure straight down through the centre line of the barrel instead. Vertical pressure on the nub gives a flight path that stays where you set it, and it takes the common 3x4mm nub rather than something proprietary.\u003c\/p\u003e\u003cp\u003eThe design is modular so the same unit suits both an AEG and an HPA build, and PolarStar make a short line of parts for tuning it further: alternative gearbox lips in tighter inner diameters to stop a nozzle deflecting, barrel slot bushings to take out rotational play, and a fine adjustment ring that halves the sensitivity for R-hop and flat-hop setups. Those are separate items and our supplier does not currently carry them — \u003ca href=\"\/pages\/contact-us\" style=\"color:#1B3A6B;\"\u003eask us\u003c\/a\u003e if you want one sourced direct.\u003c\/p\u003e\u003ch2 style=\"font-size:16px;color:#1B3A6B;margin:18px 0 8px;\"\u003eSpecifications\u003c\/h2\u003e\u003ctable style=\"width:100%;border-collapse:collapse;font-size:13px;margin:0 0 18px;\"\u003e\n\u003ctr style=\"background:#1B3A6B;color:#fff;\"\u003e\n\u003cth style=\"padding:7px 12px;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"padding:7px 12px;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eCompatibility\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eStandard V2 M4 \/ M16, AEG and HPA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eMaterial\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eMachined 6061 T6 aluminium\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eMachining tolerance\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003ePlus or minus 0.002 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eAdjustment\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eTDC slider system\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eNub compatibility\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003e3 x 4 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eGearbox lip supplied\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003e0.305 in, standard for most AEG nozzles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eColour\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eBatch 01, Medical Metal Gray\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eManufactured\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eMade in the USA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eIn the box\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eHop unit, 0.305 in gearbox lip, 3x4mm round nub, axle retaining O-ring tool, five shimming O-rings and a moulded barrel clip\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eBrand\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003ePolarStar\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch2 style=\"font-size:16px;color:#1B3A6B;margin:18px 0 8px;\"\u003eGood to know\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eWhich gearboxes does it fit?\u003c\/strong\u003e Standard V2, which covers M4 and M16 platforms. It is not a V3 part, so an AK will not take it.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this an AEG part or an HPA part?\u003c\/strong\u003e Both. PolarStar list it for AEG and HPA builds, and the fitment is modular so you can tune it to either.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is TDC and why should I care?\u003c\/strong\u003e Top dead centre. The arm presses the nub vertically through the barrel's centre line rather than at an angle, so the setting holds instead of wandering as the gun vibrates.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I keep my own nub and bucking?\u003c\/strong\u003e If the nub is a 3x4mm, yes. The supplied lip suits a typical AEG nozzle; a narrower engine nozzle is better served by one of the tighter lips PolarStar sell separately.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDo I need the Direct Attachment as well?\u003c\/strong\u003e Only if you want to mount an F2 or JACK engine straight onto the hop unit and do away with the upper shell. As a straight hop unit replacement this works on its own.\u003c\/p\u003e\u003cdiv style=\"background:#fffbe6;border-left:4px solid #f0d060;padding:12px 16px;border-radius:0 6px 6px 0;margin:0 0 16px;font-size:13px;\"\u003e\n⚠ \u003cstrong\u003eFitment is the whole point:\u003c\/strong\u003e measure your outer barrel slot before assuming a drop-in. A hop unit that is loose in the barrel undoes everything the machining buys you, which is exactly what the bushing set exists to fix.\n\u003c\/div\u003e\u003cdiv style=\"background:#1B3A6B;color:#fff;padding:12px 16px;border-radius:6px;margin:18px 0 0;font-size:13px;\"\u003e\n\u003cstrong style=\"color:#fff;\"\u003e💡 Titan Forge Airsoft tip:\u003c\/strong\u003e It pairs with a good bucking and a matched nub — both sit in our \u003ca href=\"\/collections\/spare-upgrade-parts\" style=\"color:#cdd6f4;\"\u003espare and upgrade parts\u003c\/a\u003e. If this is part of a conversion, our \u003ca href=\"\/pages\/hpa-tech-service\" style=\"color:#cdd6f4;\"\u003eHPA tech service\u003c\/a\u003e can build and tune the whole gun.\n\u003c\/div\u003e","brand":"Polarstar","offers":[{"title":"Default Title","offer_id":55696832430456,"sku":"77139322","price":84.95,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0562\/8097\/3450\/files\/PolarStarHopUpThingV2M4_TitanForgeAirsoft.webp?v=1791726754","url":"https:\/\/www.titanforgeairsoft.com\/products\/polarstar-hop-up-thing","provider":"Titan Forge Airsoft","version":"1.0","type":"link"}