Erbauer 18 V screwdriver- Works once, sometimes does not (interesting, video)

Hello, I bought an Erbauer 18 V screwdriver as a new one, which took me 2 days to cheer up and the engine gave off smoke. Burned rotor diagnosis. In my search, I supported the Asian side where I bought a motor with the same dimensions for 18 V screwdrivers. The only thing I had to replace was the rack at the end of the rotor because although it had the same number of teeth, the diameter was about 1 mm larger. I managed to replace it, although it was not that easy because everything was delicate and small. Well, after connecting, the engine does not always start, i.e. it starts but only from selected places, if it does not want to start, I have to turn it by hand and it always does not start from the same places , changing the direction of rotation does not matter. There is more than 18 V on the terminals after pressing the button. What to do with it?
Movie

Hello
You just have a break in the rotor winding.
You can dismantle the motor and check if the winding wires are correctly pressed into individual commutator plots.

Thanks for rep. If I find a break, can I fix it?

Added 20 [hours] 20 [minutes]:

I was at the guest of the engines and said that there is no cage and it can not be fixed. I bought the next interesting what will come.

Added after 19 [hours] 19 [minutes]:

I was able to fix the engine, I am grateful to a colleague above to direct the case. Despite the advice of a motor specialist, I opened this engine out of curiosity, disassembly was quite simple, simpler than the original because nothing had to be broken, diagnosis lack of continuity on one winding and more precisely no connection of wires to one section of the commutator, I was able to solder and glue it epoxy so that it doesn't spread. I have assembled everything exactly and now the engine is working ok. It is already mounted and the screwdriver is running, I wonder how long it will last. I will have a second engine in stock or if someone needs it, I could sell it. Thanks for the help.

You're welcome
And seriously this is a commutator motor, not a squirrel cage motor (so he was right)
Screwdriver motors are increasingly appearing in screwdrivers but for now only on more expensive models.
With this epoxy glue and exactly the amount I would consider for two reasons:
The first is impeller imbalance (applies to high speed operation).
The second is the temperature to which the commutator can warm up when working with heavy loads.

Hello
In this model of a screwdriver, the commutator of the motor breaks down, but you can buy for 25 PLN (for ALLEGRO) the RS-550S replacement with a 3.17mm full (non-phase) axle and install a gear from the old motor.
To do this, cut it off with the axle (angle grinder - disc 1mm) at the bearing and then using two M5 nuts and M3 screw with a flat large head (e.g. from a computer) and a vice (or crimping tools) squeeze the rack and press on the new motor ( lean on the rotor, not on the stator !!!). Braze the capacitors under the contacts and put their other legs under the slightly crushed (reduced) spring ring from the old motor.
ATTENTION!! Since the replacement has a smaller outer diameter of 37.5mm than the original ~ 40mm, I recommend sliding the outer armor off the old engine and installing it on the new and engine (protrusion in the existing gap). The engine will not fly in the housing and will have better cooling.
BEFORE CUTTING OUT STRAPS, MEASURE THE DISTANCE FROM THE BEARING.
TO DISCONNECT THE ENGINE FROM THE TRANSMISSION, YOU SHOULD HOLD WITH ONE HAND FOR THE TRANSMISSION AND A SECOND FOR THE ENGINE (IMPERATIVE WITH THE ENGINE UP), SCREW AND PULL (BAGNET CONNECTOR). TRANSMISSION HEADS CANNOT BE TURNED !!!! BECAUSE THE GEAR WHEELS FALL OUT. FOR THE TIME OF REPLACING THE ENGINE, IT IS BEST TO INSTALL IT VERTICALLY INTO THE MUG.

All right, and when they fall out? Has anyone maybe a diagram of this gear? Or maybe write which parts should be placed where? I lost one external and 2 internal gears, 3 larger gears and 5 smaller ones.

The differences between planetary gears of most manufacturers are insignificant and you can use:
https://www.youtube.com/watch?v=1ZjCb_bydAw
or others on youtube
Erbauer has a circular wire to change gears and you should make sure that its ends (drivers) enter the groove of the toothed ring.

Thank you, somehow I was able to put it together and it works properly.

Hello,
I will also add a few comments about this equipment, because I cut myself.
Two months ago I bought an Erbauer 18 V 2x 4.0 Ah drill and screwdriver. After a few uses, the fur broke. It jumps, rattles and can't be unscrewed or twisted. Anyone else had such a case?
I took it to a warranty repair, sent it to the service, it came back after a week with the same damage and still all tied up with some grease. Massacre. Today I sent it to the site again and I'm curious if they will do something about it. In general, the equipment looks solid at first glance, but I will not buy such a mess for the second time. Better to pay extra and buy something decent. By the way, PLN 650 is a lot for a screwdriver that breaks down after a few uses.

You probably bought the screwdriver at Ciastorama and it is a new type of EXT. You did not specify the type because it can be brush or brushless. In brushless brushes that are stronger, the first gear falls quickly because the metal ring of the gear engages with the plastic splines of the body. The electronics are lousy and also break down frequently, and moreover, they are sunken and impossible to rummage in. In the brush, you can put a universal switch or motor replacement. Fur damage is rare and you must be unlucky. There are many defective Erbauer EXT screwdrivers on Allegro, brushless ones that are dead (electronics) and those that pass in first gear.

budro2 wrote:

In the brush, you can put a universal switch or motor replacement

Could you give this universal switch replacement?

It can be with led:
https://allegro.pl/oferta/wylacznik-wlacznik-wkretarki-z-dioda-oswietlenia-9584853876
However, it takes a little work to get the Dremel in. You can also try to replace the key so that the replacement is not visible outside.

budro2 wrote:

It can be with a led: ...
However, it takes a little work to get the Dremel in. You can also try to replace the key so that the replacement is not visible outside.

Switch from Allegro. Little modifications and works perfect. Even better RPM control than the original. I recommend
https://allegro.pl/oferta/wylacznik-wlacznik-...DM2MTc3MjNmOTUyMGQyMDg5ODU0NmQ1Y2QyMGRiMDQ%3D

The switch as above fits many 12-18V tools with brush motors: Erbauer, Titan, JCB, Guild, Einhell, Worx, Ryobi, Macallister, Blackdecker. Some Einhella even fit the dimensions.