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User avatar
By Dave the Bass
#88732
Hello Hitchcocks forum peoples,

I usually frequent the Midland Bullet Riders forum but seeing as this time I'm not playing with a Bullet I thought I'd pop in here to ask the occasional question. Hope thats OK with everyone.

A few months ago I bought this pile of bits...
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...some which I'm hoping to rebuild into a nice useable 1966 RE Continental GT250.

The frame is causing me problems, apart from the fact its bent and I need to get it straightened/re-aligned by a grown-up...
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...there's this lug thats been cut off...
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...but see how the 'hole' is still blocked?
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Now, from the 'inside' view of the frame it looks like there's a threaded portion...
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I've very carefully attempted to drill out the metal blocking the threaded section but its amazingly hard, I'm wondering if it's actually weld?

I've not seen a GT250 close up in person but looking at various photographs of other folks GT250's I believe that this is the mounting point for the riders left side foot rest and also where the rear brake pivots too. Am I correct?

Anyone got any ideas what I can do here? It's the original frame, I don't want to scrap it of course.

Ta,

DTB (Dave the Bass).
User avatar
By stinkwheel
#88734
Ideal thing would be to weld a bolt to the stub then use that to undo it. The intense heat should loosen it.

It's fairly easy to accidnetally harden a stuck stud by drilling on it too fast, annealing it by heating red hot then cooling again can soften them up a bit. Or even simply punching the drilled surface. Or use a carbide-tipped bit, slowly. Or a new bit and make sure you use plenty of coolant on the drill bit. Even water or sprays of WD40 will help. Start small, start central, drill slow. If you have a drill press, use it.

You might even stand a chance dremmeling a slot in that and using an impact driver.

In the meantime feed it lots of penetrating fluid. A 50:50 mix of acetone/paraffin and ATF is good.

If you think you are getting too close to the edges, stop. Better to pay an engineer to mill/spark-errode it out than trash your frame.
By vince
#88739
Hi,your correct it is the footrest/ brake pivot. The stud is very hard metal. I would be inclined to work from the inside of the frame has you have a nice recess to fill with wd40etc. Regarding the bent frame I would first try and fit the crankcase into the frame as it may stress it the other way. Vince :D
User avatar
By Dave the Bass
#88740
Thanks Gents.

I've persevered a bit more, and bizarrely these popped out the hole where the broken stud/lump of weld(?) lives...
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It leaves this...
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Erks!

I'm not sure it is a stud stuck in there TBH anymore although it does look like it from the inside of the frame. Also , that last picture in my 1st post shows what I think are the marks of a star locking washer that once lived there.

I'll try and resize the picture files, I've just realised how big they are, ooops. Sorry about that folks.
User avatar
By stinkwheel
#88741
Genuinely, if I was dong that from the point you are at now, I'd take it to my local light engineering guy and get him to clamp it up on his big mill and mill/bore me a nice round hole in the centre of that, then re-face it and press-fit a top-hat insert with a threaded hole in to take it back to spec. He's even done this for me with steel bolts sheared off in alloy.

If I was going from your first picture, I'd have tried the welder trick and if that failed, got a nice small, cwentral pilot hole drilled on my pillar drill.

Part of the trick with a rennovation is to leave some jobs alone before you make repair even harder. I can almost see the frustration in the repeated drilling attempts. Being blunt, you obviously don't have the equipment to properly fix this and are clearly digging yourself a hole. My advice is walk away from that job and find something else to do for now. There's plenty to go at. It'll be quite some time before you are in a position to be assembling cycle parts anyway.

Top tip. When you are next at the shop, buy a big tub of cheap white vinegar. It's excellent for getting rust off corroded fittings.
User avatar
By stinkwheel
#88743
One way out of that situation with home tools would be to fabricate a bolt-on drill guide out of a piece of thick plate you can bolt to the back with the existing holes in the mounting plate. This will help you get a perfectly central pilot hole to reference from. I wouldn't do that now though. Take a break. Clean up some other bits.
User avatar
By Dave the Bass
#88745
Good point well made Mr Stinkwheel, you're right. I'll leave it for now. I do have (and use!) a drill press/pillar drill. Working from inside the frame on the back (inside) of the stud is very difficult as there's not a lot of room, its where the swingarm pivot normally sits, so about 8" gap of work room.

I even played very loud Jazz music to it and still didn't budge :o :)
User avatar
By fernf5
#88763
DTB-First post here. Been following your dilemma and wondering how I would proceed if in your situ. Honestly I ran out of ideas. Stinkwheel gave some good advise.
I was intrigued by Adrians suggestion of spark erosion in the MBR forum though. :o Totally new concept to me. So, since I have the time(thanks Covid 19) I consulted the shadetree mechanics best friend youtube. In case you haven't already educated yourself or for anyone who is following this thread:

https://www.youtube.com/watch?v=fxx5lIGesjg

and other new concepts to me (though not as cool as Adrians spark erosion)

https://www.youtube.com/watch?v=fxx5lIGesjg

Now where would I ever find one of those spark erosion machines? :shock:
By mart
#88766
If you are looking for a grown up to straighten your frame you could try Avondale Welding in BS37 9XD
Phone: 01454 228889
they are old school ( i.e. no computer controlled jigs ) but they made a good job of my Crusader frame.
By RoSy
#88771
Hello Dave, I can also recommend Avondale Welding, almost on my doorstep but a long way from your place.

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