In order to increase the suction power of my Kärcher WD 3.300 M (but should fit all Kärcher vacuum cleaners with standard hose like the WD3) workshop vacuum cleaner, it is possible to increase the hose diameter from the 38mm inside diameter (40 outside diameter) to a whopping 50mm. In particular in connection with the well-known Chinese cyclone dust separators, the suction power increases significantly. But not only with this, even without a cyclone, the efficiency of the Kärcher vacuums can be significantly improved.
I designed the hose adapter as a combination solution. You can either use a 50mm spiral hose or use the adapter with 50mm HT pipes! When using spiral hoses, I recommend additionally securing the hose with a hose clamp. Please note that the hoses that I show in the one photo tend to contract when you turn on the vacuum.
I printed the adapter in PETG from Goedis. PETG is elastic and resistant to oils such as those found in my workshop. Be careful of static electricity and make sure that it is properly discharged! You can pull some earth wire through the hoses to discharge the static charge. This must be laid from the beginning of the hose to the dust container and be earthed.
When printing, please only activate supports from the platform and manually set supports in the locking groove. The internal hollow locking mechanism is otherwise blocked by supports that cannot be removed. (See the sawn part in the last picture.)
At this point I would like to point out the excellent Kärcher WD-Series hose socket to DN 50 adapter from ralondo. The thing is the counterpart to my adapter, it enables, for example, the connection of hoses to HT50 pipes.
Download & more @ thingiverse
I hope the adapter is useful for you. Some of the links are suggestions for parts to replicate the thing and affiliate. If you buy something, I get a small commission. The price you pay is the same. Thank you very much.