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Help Stuck Dowel
carnut - 17/11/06 at 05:15 PM

Hi,

Ive got a dowel stuck in a blind hole and cant remove it. Its flush with the surface so cant get a grip on it. Its hard as hell so cant drill it. Tried heating ali casing in the hope it would expand and leave the steel dowel slack. I think the dowel is in a tapered bore at the bottom so its well and truly jamed.

I havnt got a welder handy either. The dowel is about 6mm in diameter.

Please post any suggestions so i can tell you that ive already tried.

thanks
Mark


DIY Si - 17/11/06 at 05:17 PM

Got any pics?


carnut - 17/11/06 at 05:21 PM

Sorry but ive you have seen the dowel in a bike gearbox output shaft bearing/case. Its one of those.


DIY Si - 17/11/06 at 05:23 PM

Might not be locost, but get a bike shop to pull it out?


carnut - 17/11/06 at 05:27 PM

Im not sure what they can do that i cant. I would get some1 to weld something to it but i'd have to wait till monday for that.


stevec - 17/11/06 at 05:34 PM

I reckon Japanese bike dowels are case hardened so that will cause extra probs if you try to drill it out.
Steve.


Hellfire - 17/11/06 at 05:52 PM

Araldite something to it, to give you something to pull??

Phil


JB - 17/11/06 at 05:53 PM

Can you drill in from the "back side" then tap it out?

Alternatively you may have to leave it and drill another dowel hole else where.

John


russbost - 17/11/06 at 05:58 PM

Possible to machine a "stepped dowel" & insert this inside the stuck one, or insert smaller dowel to fit & put another of the existing size into the outer half of the case?


Hellfire - 17/11/06 at 06:03 PM

Powerful magnet?


carnut - 17/11/06 at 06:04 PM

It cant be drilled and its been rammed into a cast hole at the bottom of the machined hole which will have draft on it so its bloody tight. Dont want to drill the cases to get it out or add another dowel either as it might weaken the structure.


DIY Si - 17/11/06 at 06:08 PM

Is another case expensive? Otherwise machining the centre out to allow it to be removed, or to fit a smaller/stepped dowel may be the only way.


carnut - 17/11/06 at 06:13 PM

If i could machine it, i could remove it. I have more cases but they are 100miles away and need stripping. And my other cases dont have the engine no. to match the VIN.


flak monkey - 17/11/06 at 06:14 PM

You either need to have it spark eroded out if its that hard, or buy a solid carbide drill to drill it out.

If you can drill it and tap it you can use a slide hammer to pull it out.

David


hector - 17/11/06 at 06:27 PM

IF you can drill a hole through it....... you can remove it by filling the hole with oil and using a snug fitting punch (in the hole you just drilled) gently tap with a hammer and the hydraulic pressure will drive it out! It really does work.


rusty nuts - 17/11/06 at 07:04 PM

Cobalt drill bit ? Find them very good , masonry drills are very hard if you can get one to start . Failing that as David says spark erosion


froggy - 17/11/06 at 08:45 PM

find a tap which will just about go in and try to get the tap started then wind a nut onto the tap to gve you something to pry against with a heel bar , its worked for me in the past just thought is it a hollow dowel?


owelly - 17/11/06 at 09:57 PM

Chew out as much as you can with a Dremmel. Try to grind a slot into it and try to colapse it inwards.


ReMan - 18/11/06 at 08:25 AM

quote:
Originally posted by owelly
Chew out as much as you can with a Dremmel. Try to grind a slot into it and try to colapse it inwards.


I'd second that, dremel is probable the kindest option, so with a small grinding stone, the mountes ball type you could almost drill it out.
Actually I'm not sure its clear wether this is a solid or a hollow type dowel your talking about here? either way still dremel if hollow then slot as abovw, if solid then grind top, you may even find it drills once case hardening is broken through


carnut - 18/11/06 at 11:23 AM

Its a solid dowel else it would be a doddle. Im going to the hardware shop to see what they have in the way of drill bits/ grinding bits. I dont want to break the top off it else it would leave me with a worse problem with it below the surface.


BenB - 18/11/06 at 11:26 AM

Soak in release agent for a few days then drill a small hole and use a stud extractor (gently)?? You do have to be careful though- those extractors can shear and they're bloody hard metal as well....
I had to drill through rock hard steel a while back.. My old bits didn't fancy drilling through it but a new shiny set of titaniums starting small and working up got there slowly. Helps if you've got a powerful low speed drill. I used a 12v portable drill wired up to a car battery.... which was just about perfect for drilling steel (and V powerful)...

[Edited on 18/11/06 by BenB]


Peteff - 18/11/06 at 01:15 PM

this will go down as a classic, ironic isn't it. Welding something to it may be difficult if the dowel is only small and risks arcing to the aluminium, is it only to locate the casing?


carnut - 18/11/06 at 04:07 PM

The dowel is to hold a bearing outer from spinning.

Ive made some progress. I ground a slot across the dowel with a dremmel and i can now rotate it with a screwdriver. Next stem is to epoxy something to the top of it to try and pull it out. Will be a pain as theres likely to be the suction problem as i pull it out.


flak monkey - 18/11/06 at 04:26 PM

If you can turn it with a screwdriver its not that stuck.

Degrease it well and gluing something on might just work.

David


carnut - 19/11/06 at 09:11 PM

Tryed gluing something to it and it didnt work. Next stage is to weld something to it unless any1 has any bright ideas.


02GF74 - 19/11/06 at 09:43 PM

can you tap the casing against a block of wood - may take a bit of time..

I wonder if yioiu can get some water past it then heat it up so the steam pushed it out?

.... but try warmiing it up and tapping first.

small magnet?

I woldn't try glue in case you glue it to the casing


DIY Si - 20/11/06 at 10:39 AM

If you can drill a small hole down the middle(ish) of it, try pouring some oil down it. Then get something matching the hole and hit it slowly in. The resulting pressure should lift it out.


02GF74 - 20/11/06 at 10:44 AM

quote:
Originally posted by DIY Si
If you can drill a small hole down the middle(ish) of it, try pouring some oil down it.


... but if the dowel is spinning, may not be easy

what about using a vacuum cleaner or your gob to suck it with a piece of plsatic/rubber hose? (with vaccum cleaner would need to use duct tape to make a good seal)


liam.mccaffrey - 20/11/06 at 10:54 AM

depending on how easy it is to turn with a screwdriver, i woud make somthing with a bladed end like a screwdriver. epoxy it on and then turn it in a drill will gently pulling out.

OR

I am sure there is somthing fairly innocuous you can buy from the chemists which dissolves carbon steel but doesn't attack ali. I can't for the life of me remember where i read it or what the chemical is sorry


David Jenkins - 20/11/06 at 03:07 PM

If you're not in a hurry, get some boric acid from a chemist - it eventually dissolves steel, but leaves the ali untouched.

Make a dam around the piece using plasticene, pour in a strong solution, then go away for a day or two.

David

BTW: It's not dangerous stuff - just keep it away from your eyes and mouth, and don't let it get in contact with your skin too much. It's used as a wound disinfectant and ant killer!


carnut - 23/11/06 at 06:38 PM

got it out, tigged a small screw to it


Peteff - 23/11/06 at 08:09 PM

It is actually antiseptic and is used as an eyewash and to treat cold sores, I was prescribed it for eye problems. It's used in artificial tears and industrial eyewash solutions. (It's also used to treat Thrush in women but we won't talk about that)