Will some sort of glue be good enough for this...

I think the first thing I ever made when I got a lathe was a chaotic (aka double) pendulum. Partly as an excercise in basic turning, partly because they're fascinating things to watch, and partly because I was teaching at the time - actually seeing such a simple mechanism exhibiting chaotic behaviour is quite enlightening for some students.

I found the thing again recently - apologies for crappiness of the pic below, I've just 'upgraded' to a laptop with Win10 which doesn't want to talk to anything else, so I used the laptop camera.

The 'struts' are connected to the 'bobs' by screwthreads with knurled locking collars. It goes OKish, but eventually things work loose (even with threadlock) and it has to be readjusted. A friend was so entranced by seeing the thing going that he asked me to make one for him, but he's a total klutz with anything mechanical, so wouldn't be able to tune it up himself.

So, finally, I get to my question - can I use some sort of glue (CA?} to fix it together with a reasonable lifespan? If so, what would be the best product, given it's brass?

Rob.

If the parts are all brass, just use rosin flux and soft solder it. Or if you're brave about the quality of the brass, use flux for silver solder and silver solder it. JD

Red Loctite is forever.

Its good advice but i'd make sure you've got a decent blow torch before you attempt it, your typical soldering iron wont cut the mustard. Not to mention the ensuing firescale that may develop. CA is fine if you want to.

Michael W

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Robin,

Your original choice [or usage] of threadlocker must have been wrong. Like Hopper, I would simply use one of the stong grades of Loctite anærobic retainers ... 601 or 638 should be entireley adequate; they are, to most practical purposes permanent.

MichaelG.

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Edit: This is a very useful guide to the use of Loctite 'Retainers'

Edited By Michael Gilligan on 03/07/2016 09:27:15

Too late to edit my last post:

This guide from Permabond is also very useful.

MichaelG.

Loctite wont be a good idea if it needs adjusting to get it to do what you want. Grub screws going into the side of the threads that hold it together should work out.

If no adjustment is not needed I would have thought that a loctite retainer and plain holes would be fine. Or drill through and knock in roll pins - they wont ever work loose or move around done that way.

John

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As a genuine amateur in all of this, once I discovered Loctite and had used it correctly in a number of different 'challenging' circumstances (sticking cams on a cam shaft, sticking washers to the lathe face plate to thin them down etc), my perception of 'glue' was changed forever

There is bound to be a grade of Loctite perfect for this application.

Steve

Thanks all, seems like Loctite should be OK - I guess I must have used the wrong grade on my previous attempts. I had considered soldering, but it would take me as long to clean the thing up afterwards as to make it - and the chap I'm doing it for is more interested in the aesthetics than the physics, so it has to be shiny bright.

I'm now interested in how to do an æsc without copy/paste - an academic question for MichaelG!

Rob.

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Rob,

It's a little luxury of Apple's iOS on-screen Keyboard

Press and hold the 'a' and a menu of special characters pops-up

... Similar behaviour on several other keys.

MichaelG.

Change the knurled locknuts for hex so you can get a spanner on them, they will lock far tighter than a hand tightened knurked nut.

Thanks Michael

I've just discovered this works on Windows Phone and the on-screen keyboard for Windows 10 PCs (I use it when my real keyboard is buried under papers) as well. I have no excuses now for using OE instead of Ö.

Brian

I agree fully Steve. Lol, worthy of a new thread.

* Danny M *

Not only that but you can heat it up again to remove it for when you need to make special parts to fit perfectly together, in terms of alignment to one another.

Michael W

Just had a quick look at Google, and found at least 16 manufacturers of shaft lock, and thread lock adhesives, and there are others too as Toyota, and other car makers have their own brand.

Look at BearingBoys.co.uk For Loctite info, and a whole lot of other useful gen.

IanS C

Edited By Ian S C on 05/07/2016 07:04:25

Ah, same as on my (Android) phone then. Doesn't seem to work on the Win10 on-screen keyboard, and I'm heading Linuxward, anyway, so I'll live without ligatures etc. If only browsers did LaTeX, 'twould be as simple as $\ae$ iirc .

Jason, yeah, hex nuts would be better - the thing in the pic was a prototype and at the time I was trying to teach myself various techniques while making something of interest - hence the knurled locking rings. I suspect that the guy I'm making this for doesn't even possess a spanner though, shocking as the thought may be. It has to work out of the box.

Thanks for pointers to info about thread locking and retaining adhesives - looking at the figures given on those sites it's amazingly strong stuff when used correctly. It's obviously the stuff to go for here.l I'm still a bit confused about the difference between thread locks and shaft retainers tho - it seems to my naïve mind that they are basically fulfilling the same function.

Rob.

Edited By Robin Graham on 05/07/2016 23:26:05

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You're quite right there, Rob

Yes, it is basically the same function, but the shaft retainers are inherently stronger ... To the extent that you would almost certainly shear a screw if you use them as a thread-locker. The finesse comes in selecting a grade which does what you need. [Have a look at 222 ScrewLock for example, and compare its spec with 638 Retainer.]

MichaelG.

In addition to all the other good advice re thread-lockers, take the admonition (in the instructions) to thoroughly clean the parts first, seriously.

I dont know about anyone else but i've had a fairly easy time with thread lockers, The brand i buy has never caused strength problems for me and find it acts rather quickly, i have a locking handle on my QCTP for the lathe which gets tightened up and loosened so often and yet the critical parts are only held together by threadlock, never come undone.

Even some parts on the bushes for a compound gear train i made are only held fast by "threadlock" albiet i wouldn't call it a threadlock as such more of a bearing lock. 

Michael W

Edited By Michael Walters on 06/07/2016 02:08:49

I think most people are not aware that there is many types of Loctite thread lock with different purposes and strengths tey are colour coded i think

Cheers Martin