how to get electronic sachse rotor down?

mkavci9

mkavci9

Full member
Location
Slovenija
Hello!
I have one question or better, I'm asking for suggestion. I want to remove the cover on the left of engine, to repaint it, because the engine is "pity" painted. I want also to change the chain inside.  I have Electonic Sachse ignition. When I want to remove the rotor, i can't because I made "round" that small inbus screw, bescause was to tigthten up. 
Look the picture. I think that this screv is insurance, that rotor dont unscrew? right? What you suggest me to do now? To drill screw out? To block engine and force the rotor to unscrew? But, how to block engine??

img20150427181752.jpg


thanks for any suggestion
 
Do not use force.
It looks like some force has already been applied to a screw fixing the ignition cover and another fixing the primary chain cover!
Paul
 
Ouch! That's quite a difficult situation there.  A badly made part that should have had a keyway in the inner rotor like the original.

Sometimes a TORX key can be hammered into a stripped out hex and if the sizing is just right it can sort of 'cut' it's way deeper into the corners of the old hex get quite good grip. 
Something like this:
008236064476lg.jpg

You can then fit a 1/4" spanner onto the bit once it is driven into the stripped hex.
Hopefully the grub screw is not too tight.
Good luck, this will need a bit of mechanical 'feel' to do without creating more problems.
 
PS When I say 'hammered into', that only applies when access is much easier.  In that housing I would guess the best way is to use some sort of clamp around the rotor to pull the bit into the hex.  As I said, great care required so as not to make the problem worse.
Maybe others have a better idea.
 
Yes I think  have a better idea

Seens as you have been the instigator in causing this problem you should take it to someone that has the ability to fix the problem

will be cheaper than you fucking the ignition rotor and your pickups....




 
Go easy lads, looks more like crash damage to the cover to me, my eyes aren't what they were but from the photo it seems the bottom of the housing is missing/patched.
So in fact, if the patch section of the cover was removed and crank was rotated then the grub screw could be (carefully!) drilled out.

Mcavci9, the screw is only to locate the rotor relative to the crank.  It is a shortcut, probably because it was easier to make that way.  The original rotor had a 3mm keyway groove.  There isn't even any real point to the screw since the outer part of the rotor needs to come off to clear the pickups anyway, and it is free to rotate 360deg on the inner rotor part.  With all due respect to the sadly departed maker, it's a crap design.
 
Right angle drill or dremel www.dremel.com/en-au/Attachments/Pages/ProductDetail.aspx?pid=575
 
Two suggestions:

1.  Have a look at your hex key, as the "teeth" may be slightly rounded.  Often happens if the hex key is not of good quality.  If this is the case, then the key will be inclined to spin, more so if the grub screw is worn.

2.  You could try carefully heating the grub screw.  This will help, especially if it was fitted with threadlock.  I had a similar problem on the Sachse rotor on my 3C and I used the small butane torch shown in the attached pic.  The heat releases the threadlock bond.

Tom
 

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It's most likely Loctited in place so the heat should help free it.
 
I'd try the method Steve suggested with the Torx bit and perhaps some screw grip glue in the rounded off allen head (inbus). As you're in Slovenia try looking for a product called Schraubendoktor, it has worked for me in the past.

good luck
Gerald
 
first off all thanks for some really good advices..

Second.. housing was broken 10 years ago, between little crash, nothing serious, so now only two screws are holding it, and that black plastic is glued with silicone, to prevent water goes inside.

This problem cause.. that i had bad "allen head" (inbus) tool. Was worn, rounded. When i changed it with a new, proffesional one, was already to late.

I will try with some of your methods, if there will not be success, i will drill this screw out and cut new screw thread.

If someone has any other idea, is welcome.
thanks
 
breganzane said:
Ouch! That's quite a difficult situation there.  A badly made part that should have had a keyway in the inner rotor like the original.

Sometimes a TORX key can be hammered into a stripped out hex and if the sizing is just right it can sort of 'cut' it's way deeper into the corners of the old hex get quite good grip. 
Something like this:
008236064476lg.jpg

You can then fit a 1/4" spanner onto the bit once it is driven into the stripped hex.
Hopefully the grub screw is not too tight.
Good luck, this will need a bit of mechanical 'feel' to do without creating more problems.
Click to expand...

Hi Steve and all

Steve, what is required to actually cut a keyway inside a rotor like that? I have a similar rotor that has the same sort of grub screw arrangement, would much rather have a keyway. Amongst other things, even if the grub screw keeps the rotor from moving on the crank end, the issue exists of having to reset base timing from scratch with a degree wheel any time the rotor were to be removed, rather than just sliding the rotor back on to a fixed location keyway.

for the original poster in this thread, I have used Steve's idea of a TORX key with success. As the grub screw is metric, and in all likelihood has been Loctited in place, use some heat, and I have sometimes had success using an Imperial sized hex key just so very slightly larger. I have also seen people use something like JB Weld to hold a new hex key in place. Otherwise, just pull the patch in the outer cover so you can rotate the crank to actually get at the grub screw on the rotor with a drill and drill it out.

Paul LeClair
 
mkavci9 said:
I will try with some of your methods, if there will not be success, i will drill this screw out and cut new screw thread.
If someone has any other idea, is welcome.
thanks
Click to expand...

email me your address and we will send you a new rotor adaptor, fairly certain I have a couple left to suit the optical trigger
 
Paul,

Specialist tools needed to make a keyway... unless you have a couple of small sharp files and loads of patience enthusiasm. :D

piet

 

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broach will not work, is a blind hole in the adaptor
will need to CNC the keyway when they are being machined

 
Hello!

one more question, before "operation". Someone said that this small screw is glued..    I' mounted this ignition by myself, and I didn't use glue for sure. But I really don't remember how I mounuted this stuff, so I preasume that I screw this small screw on position. Is possible to mount this alloy rotor, to engine rotor without touching that small screw?  Stupid question, but I really forgot how this parts are put together.  my logic tell's me that alloy rotor is tighten with a "19" key till end, and than this small screw is a safety screw, that rotor  cant unscrew because vibrations and so....  enlight me please:) 

thanks, by
 
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