# Stripped screws on burr grinder.



## Davnt

So, I need some advice from anyone who knows a thing or two about Metalwork/hardware. I was giving my Rocky a good clean and decide to change my burrs (new ones arrived from the states!). I opened the whole thing up and found myself failing to unscrew the screws brings the top carrier with the burr. Fast forward a few minutes after, I managed to badly strip 2 out of the 3 holding screws ..

I bought a screw extractor (grabit) and gave it another try. Drill isn't going in, maybe it's too slow, or whatever but I'm running out of options.

Phones up a local handyman, said price to get em out will be £45, really?

Any ideas? I'll post a video showing this soon.

Edit: video added:


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## johnealey

Had heard they could be a bit tricky to get out, so got some food safe HT silicon in to try and get some into the threads in a similar way to WD40 would (only less toxic).

At this stage with the burrs and screws trashed only other option if nothing left of the screwhead may well be to carefully drill out the remainder of the screw(s) taking care not to drill the carrier of course, as you will need to trreplace the screws anyway ( am sure someone has mentioned the screw sizes on here before might be worth a search).

Someone else may come up with another answer so hang in there to see the consensus before attacking them again as may get some sage advice in the morning when the less caffeinated arise









Hope of some help

John


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## No big name!

What make drill bit are you using...presumably the usual generic brand?

Buy a 'Dormer'

Probs only a quid or 2 on Ebay and is proper engineering kit quality.

It'll drill your screws like a knife through butter!

Ask me how I know.... ;-)


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## MooMaa

Hi, I have just had the same problem with my Anfim Super Best, I wanted to give it a thorough clean before selling. The burr screws were totally stuck and I stripped the heads off.

On some of the screws I very carefully drilled from the back of the screw (not the head end) part way through the screws with a very fine drill bit on a dremel, then used a slightly larger drill bit and this forced the screws to actually unscrew out.

On some others i drilled out from the head end a bit dremel then the cross head screw driver I used actually got some purchase and I was able to unscrew.

PROBLEM, I cannot get any burr screws with small enough heads to re attach to the burr carrier, I sent off for some and these are what I got see below.









If anyone knows where to get small headed burr screws from I would really appreciate it. They are M4x8mm with 5mm dia heads that are 2mm deep


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## Davnt

No big name! said:


> What make drill bit are you using...presumably the usual generic brand?
> 
> Buy a 'Dormer'
> 
> Probs only a quid or 2 on Ebay and is proper engineering kit quality.
> 
> It'll drill your screws like a knife through butter!
> 
> Ask me how I know.... ;-)


Haha, how do you know this? 

What do I do after I drill a hole? I'm assuming dormer makes a clean hole? Then what?


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## NJD1977

Screwfix do a little screw extractor kit for £4 that should sort it. You have to use a fairly large bit though, bigger than you'd think. And of course make sure you are drilling anti clockwise!

http://m.screwfix.com/p/screw-extractor-5-piece-set/18643


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## wilse

Don't know if this helps, but I've just replaced the burrs in my Mazzer, the screws look very similar to yours, I presume yours are not fully tightened?

I haven't started the grinder up yet, as I'm removing the doser, but the screws don't look like they will foul the other burr.

I've attached an image, so you can see how the screws sit.


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## MooMaa

wilse said:


> Don't know if this helps, but I've just replaced the burrs in my Mazzer, the screws look very similar to yours, I presume yours are not fully tightened?


Hi,

In the second image (new screws) I couldn't tighten the screws as the heads wouldn't fit into the holes for them, as the head size is 8mm diameter and 3mm deep as opposed to the original screws 5mm diameter and 2mm deep.









Would it be possible for you to measure the screw heads?

@ Davnt, sorry to have jumped on your thread


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## wilse

The screw head is 3 mm thick in total, the side of the head is 2mm, with the domed bit around 1 mm

Diameter is around 7.5 mm.

Length 13 mm.

These were on the machine as standard.

Any use?

w


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## MooMaa

Thank you for the measurements, to big though.

I tried some hex screws from ebay (smallest heads I could find) with a head depth of 2.8mm but they just caught, but did fit the holes at 7mm in diameter.


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## Davnt

MooMaa said:


> Hi,
> 
> In the second image (new screws) I couldn't tighten the screws as the heads wouldn't fit into the holes for them, as the head size is 8mm diameter and 3mm deep as opposed to the original screws 5mm diameter and 2mm deep.
> 
> View attachment 13606
> 
> 
> Would it be possible for you to measure the screw heads?
> 
> @ Davnt, sorry to have jumped on your thread


No worries!


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## mremanxx

You have pobably done this already so just ignore me,, what about phoning a company who sells your burrs.


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## MooMaa

mremanxx said:


> You have pobably done this already so just ignore me,, what about phoning a company who sells your burrs.


I cant speak Italian







, so I emailed Anfim instead.


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## espressotechno

Contact the Rancilio UK agents - http://www.coffeemachinecompany.co.uk - who should be able to help.....


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## No big name!

You would drill down the middle of the screw, and if it didn't come out during that process, then use your stud extractor (anti-clockwise!). Looking at your video, you might stand a chance with a decent punch and hit it in an anti-clockwise direction.

As for the replacements, try 'Button head cap screw' which I think will be better than the standard items and nice and foolproof to tighten/loosen, with an Allen key


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## Davnt

No big name! said:


> You would drill down the middle of the screw, and if it didn't come out during that process, then use your stud extractor (anti-clockwise!). Looking at your video, you might stand a chance with a decent punch and hit it in an anti-clockwise direction.
> 
> As for the replacements, try 'Button head cap screw' which I think will be better than the standard items and nice and foolproof to tighten/loosen, with an Allen key


Cheers mate. My drill ran out of battery when I was about to do the deed so I'm charging it now and it'll be a while till I'll be able to tinker around (5-6 hours hmm). I have the speed out extractor but I couldn't get it to go through, I'm guessing I couldn't get a good grip of the thing thus making me subconsciously worried about drilling my fingers.

I'll have to think of a way to get a good grip on it.

Also, I should point out that both of the screws now have a very inconsistent, mountain-ish surface due to my award-winning screw-stripping skills.


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## El carajillo

The speed out type extractors are intended mainly for wood screws, and from my experience with them they do not work well for that purpose.

You would be much better off buying the screw extractors shown by OP, these are for removing engineering screws and bolts, they are also more appropriately sized for what you want.

Use your drill on it's highest speed,

I also recommend the "Dormer drills" NOT the normal "jobber drills" which tend to be softer


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## Davnt

El carajillo said:


> The speed out type extractors are intended mainly for wood screws, and from my experience with them they do not work well for that purpose.
> 
> You would be much better off buying the screw extractors shown by OP, these are for removing engineering screws and bolts, they are also more appropriately sized for what you want.
> 
> Use your drill on it's highest speed,
> 
> I also recommend the "Dormer drills" NOT the normal "jobber drills" which tend to be softer


Cheers for the insight mate. Wasted 9 quid then :/. Any chance youd lend me those drill bits to a poor student? Haha


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## wilse

How can poor students, afford to drink coffee, let alone have their own grinder....?

Kids today

Hope you get it sorted.

PS, why not try the drill bit, as you've got it??


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## mremanxx

Did you get it out?


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## El carajillo

MooMaa said:


> Hi, I have just had the same problem with my Anfim Super Best, I wanted to give it a thorough clean before selling. The burr screws were totally stuck and I stripped the heads off.
> 
> On some of the screws I very carefully drilled from the back of the screw (not the head end) part way through the screws with a very fine drill bit on a dremel, then used a slightly larger drill bit and this forced the screws to actually unscrew out.
> 
> On some others i drilled out from the head end a bit dremel then the cross head screw driver I used actually got some purchase and I was able to unscrew.
> 
> PROBLEM, I cannot get any burr screws with small enough heads to re attach to the burr carrier, I sent off for some and these are what I got see below.
> 
> View attachment 13601
> View attachment 13602
> 
> 
> If anyone knows where to get small headed burr screws from I would really appreciate it. They are M4x8mm with 5mm dia heads that are 2mm deep


These are obviously specialist screws as screw heads are normally proportionate to shank size. Do you have access to a bench grinder ? Grind the periphery of the heads down ?

If you have a piece of dowel and drill a tight hole in the end and thread the screw into it this would allow you to rotate the screw to reduce the head diameter. POSSIBILITY ??


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## Gallant

Just wondering if you managed to solve your problem (or find replacement screws at all), currently looking at all of the screws on the upper burr carrier being completely stripped, and the lower set not being far off, but the burrs in definite need of replacement. I think the only way I'm going to get them off is drilling through, but then that leaves the dilemma of not being able to fit a new set of burrs.


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## El carajillo

As mentioned earlier in the post, you can extract the screws by drilling an appropriate sized hole then using a screw extractor (similar to a thread tap but with a coarse L/H thread which bites into the remains of the screw )) but leaves the threaded hole undamaged .


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## urbanbumpkin

I did see these in Lidl or Aldi recently. Not sure they'd be the right size. I really rate the screw/ bolt extractors.


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## Gallant

Poor phrasing on my behalf I guess. I know I can use a screw extractor to get them out, it's more the finding replacement screws after this step that would be an issue, as they're a non standard fit?


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## MooMaa

Gallant said:


> Poor phrasing on my behalf I guess. I know I can use a screw extractor to get them out, it's more the finding replacement screws after this step that would be an issue, as they're a non standard fit?


Hi, well had great difficulty, tried ordering screws from variuos apparent Anfim suppliers in Britain but they all sent me standard M4 screws with heads that were two large and charged me loads (I sent them back and got a refund).

In the end I ordered these http://www.ebay.co.uk/itm/M4-x-8-BUTTON-Socket-Cap-Head-Screws-BLACK-10-9-20-/400161539075?hash=item5d2b7c8403 (from a different supplier), the head diameter was to large but the head depth was good so I reduced the diameter of the head by filling it down using a drill and file see image below, and it worked a treat.









I did it once with Stainless Steel screws, one got stuck and the head got mangled and was a really really hard to drill out, so I decided to use softer steel screws as they are much easier to drill out if they get stuck again.

Hope it helps


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