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Other Vacuum Cleaners & Site Suggestions => Sebo Vacuum Cleaners => Topic started by: beko1987 on May 14, 2017, 10:18:05 pm

Title: Opening up and repairing a Sebo Height Adjustment Module!
Post by: beko1987 on May 14, 2017, 10:18:05 pm
What with this being Sebo week in my house, I got a little box on friday

[attachimg=1]

Containing a jigsaw puzzle!

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Thanks to Dilys at Autovac for this! I've always wanted to see how they work, but was too chicken to try it out on my good ones, so she sent me this, which was broken (not sure how though), she got it apart but couldn't get it back together, meanwhile the customer paid for another module and life moved on!

I'd had a blind go at putting it all back together at work, but pulled it all apart for this

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Ickle motor

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It's from August 1999

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Anyway, that's all very well and good, but I haven't the first idea how it all goes together, and I think it's one of those boring jobs in life that can't be worked out with a hammer, so enter stage left, the module from the X1 I picked up on Thursday!

[attachimg=7]

Sliding the black plastic frame that surrounds the PCB up releases the PCB, so we can have a peek. Oooh look, cogs!

[attachimg=8]














Title: Re: Opening up and repairing a Sebo Height Adjustment Module!
Post by: beko1987 on May 14, 2017, 10:25:34 pm
I'd had tips on opening these up, which is DO IT VERY SLOWLY! So out came the screws

[attachimg=1]

And gingerly, I popped it open a crack with a screwdriver in the join. All good, so I very slowly lifted the lid off

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It's very pretty. There's a hole in the lid of my toolbox that is perfect for sitting the thing in

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The lid has bits to accept the axles, and the motor itself, with it's main drive cog

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Couple of more reference images

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Then I took Dilys's one apart fully!

The first thing off is the end piece, which contains tracks that tell the main PCB where abouts the assembly is on it's rotation. I think maybe when a contact rolls off the track that's a 'height', and that a Sebo height control only has 4 heights it goes to, rather than an infinite position between low and parked. This becomes important later...

[attachimg=7]

Next is a cog with a metal peg in it

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You can see the serrations this sits in on the contact wheel. I think this is the final drive cog, that peg locking it into the position wheel, but I'm not sure why there are so many positions available. Either way, the metal staple looks like this

[attachimg=9]















Title: Re: Opening up and repairing a Sebo Height Adjustment Module!
Post by: beko1987 on May 14, 2017, 10:32:38 pm
Next off is the plastic bush that those two parts sits on. It's keyed along with the shaft at this end

[attachimg=1]

With that removed, the 4 normal cogs slide off

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The felt dust barrier and metal washer slide off the other end of the axle/wheel holder. I then got intrigued about the little motor, and found that with only a bit of destruction it came out (and goes back in perfectly happily too!)

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There's no markings at all though bar made in china

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This is the other side of the PCB, which contains the fingers that run along the contact wheel

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This is the side you can see

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I laid every component out. The tiny axle, tiny washers and tiny cog take the drive from the motor to the first other cog, I'll show that in a sec.

[attachimg=7]

I cleaned the contacts up with contact cleaner and a cotton bud

[attachimg=8]

I later found out that all contacts in place is High, or the parked thing it does where it raises up when upright

[attachimg=9]

Moving down to the last step which is Low, or short pile stuff. These contacts don#t move the unit itself, they tell the PCB what 'height' the unit is, and the PCB then *i think* applies forward or reverse voltage to the motor to spin it whichever way it needs to go (or however forwards and backwards electricity works...)






Title: Re: Opening up and repairing a Sebo Height Adjustment Module!
Post by: beko1987 on May 14, 2017, 10:38:29 pm
So, we had best get this back together! The metal washer does sit that side of the dimple, it does on my assembled one! Dust barrier in next

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The motor pushed in utterly fine

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The axle sits in the main end casing like so

[attachimg=3]

and there's a little plastic bit that clips over the other side (but not brilliantly, it opens up with movement which caused head scratching when all the cogs went on the piss at the end...)

[attachimg=4]

I greased the shaft very slightly, and dropped the 3 white cogs on

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Popped the metal staple into the final cog, which only goes in one way

[attachimg=6]

Then remembered the plastic bush so fitted that

[attachimg=7]

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Then the contact wheel

[attachimg=9]














Title: Re: Opening up and repairing a Sebo Height Adjustment Module!
Post by: beko1987 on May 14, 2017, 10:48:55 pm
I did not have any on friday (but do now) but Lithium grease would have been better than actual grease but meh, it's slippery enough. Thin smear on the cogs for good measure

[attachimg=1]

Onto the next layer of cogs, and I went wrong here and put the first one like this

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When it should go UNDER the first one

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Right at the bottom was a metal washer which was a pain as it kept slipping out. The axle pushes through the middle of all of them, no washer on top.

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The last one is the most fiddle one, and always falls out with ANY movement! A drop of loctite on the tiny axle as it sits on the housing would have been so helpful here!

Washer, cog, washer, axle

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Drop of grease in the bits that will soon recieve

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The outer housing slides surprisingly easily onto the whole thing. Dilys sent me no screws, so I had a rootle about and voila!

[attachimg=7]

However, there was a problem. I'd assembled it into the wrong position. When you put a Sebo upright and turn it off, it raises the head... but only if you let it run long enough when upright, if you turn it off before you pop it up, it doesn't do nothing... Bottom one is Dily's, top one is mine from the X1

[attachimg=8]

It's hard to see from that picture, but the wheel carrier bar doesn'g go up and down, it arcs in a semi circle. The X1's one was at it's full height, with all 4 contacts in contact. Dilys's one was not... And it's not what contacts are showing, it's what the fingers touch inside when fitted, as they go in a bit... It took me a while to work it out

But comparing like for like, I got it close enough

[attachimg=9]

What followed was 15 minutes of lowering the cover down enough to see what contacts were showing through the window, lifting it up, moving the cogs 1 notch, try again, move again etc etc DROP IT AAAAH BASTARD and eventually got it sorted! I could not be bothered to go to the car by this point, so got the X4 from the hallway



















Title: Re: Opening up and repairing a Sebo Height Adjustment Module!
Post by: beko1987 on May 14, 2017, 10:58:29 pm
So now I had 3 modules! I got a sharpie out and noted which one was which...

[attachimg=1]

However, upon fitting it to the X4, (and it was like 11.45pm by now so I couldn't run it for long) it lowered down, but would not raise back up... RH one is Dilys's, LH one is i dunno know! But obv you need to look at it as bar up - floorhead down, bar down - floorhead up...

[attachimg=2]

I matched them up again

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And still no luck. I even swapped the motors over, and still nothing. I went to bed.

(No more pics now, I did some small videos but I CBA to put them on youtube, I'll do it properly one day)

The next day, I got the X1 out of the car, and ran it with no module fitted at all. It worked fine (groomed really well actually) but the 'Up' light kept coming on. Obviously the machine was sensing it needed to go up, and was sending the signal but the signal wasnt going anywhere!

I then thought sod it and quickly fitted the rebuilt module, turned the thing on and decided that what happened would happen.

It thought about it for a while, then in double the time went to the high mode... I lowered the handle and... it went down! Back upright, IT WENT UP! I reckon it must auto-calibrate itself, and just spin the motor until it reaches a point on the contact wheel it knows. I wasn't giving it enough time the night before! I used it for half an hour and it worked spot on!

So there we go, it IS possible to rebuild a Sebo Automatic height adjuster module! And if you try and all the cogs fall out we now know how to sort it!

What I want to know from Sebo people is how do they usually fail? What causes them to need replacing? Do they just die? Grinding noise? Only work one way (only up or only down?) I'm struggling to think of ways they break, but TBH my mind is on the motor. I reckon the PCB sends a forward signal down one wire, and a backwards down the other, or reverses the voltage or something.

What I am also going to try, now I know how to manually set one up is buggar the position up completely, set it up at full low, fit it to the machine and turn it on and see what it actually does given time, then I'll know if a manual calibration is needed or not.

It's been fun either way. Dilys - I'll send you the module that was in my X1 for your stock, this one works fine, I'll sell it with the machine and we can get rid of it!

Well that was fun.




Title: Re: Opening up and repairing a Sebo Height Adjustment Module!
Post by: autovac01 on May 15, 2017, 10:26:05 am
 :bow:  :bow:  :bow:
Brilliant work Sam.
Title: Re: Opening up and repairing a Sebo Height Adjustment Module!
Post by: MVacs on May 15, 2017, 07:09:00 pm
:bow:  :bow:  :bow:
Brilliant work Sam.

Yes indeed. I dont think we have ever opened one, just swapped the unit if they go (which being Sebo doesn't happen often).
Title: Re: Opening up and repairing a Sebo Height Adjustment Module!
Post by: beko1987 on May 16, 2017, 10:22:54 pm
I've just tested my theory of it auto-sorting itself out and it doesnt, you do have to manually setup the positioning. I filmed it though, will link up once it's live!

Still interested to know the faults though, my money is on the motor giving up, I can't see the cogs seizing and stripping tbh, although if the machines smacked on the ground on the wheel it could make it jump.
Title: Re: Opening up and repairing a Sebo Height Adjustment Module!
Post by: beko1987 on August 08, 2017, 12:20:30 am
I forgot the video I did too, just noticed this after linking to it in my X1 refurb thread!


Shows how much attention you lot pay... :angryman: