Loctite and wheels

[David B]

To secure wheels, for example Sharman or Ultrascale, with plastic centres to an axle, which Loctite would be recommended? Looking through this Forum, several numbers are mentioned (which suggests personal preference) though one more commonly.

Many of the posts are a few years old. Has the Loctite numbering or technology changed in recent years to make the earlier posts less reliable?

[Guy Rixon]

You might refer to Loctite's documentation to identify the various types. E.g. the page for the 600-series retainers: http://www.loctite.co.uk/retaining-9171.htm.

AFAIK, the number haven't changed and all are still available, but there may have been some introductions.

If choosing among the 600-series retainers you might consider:

- close fit vs. gap filling (probably close for P4 wheels);

- temperature tolerance required (low, because nylon centres);

- oil tolerance required (depends on how you lubricate your engines).

[dal-t]

You might refer to Loctite's documentation to identify the various types. E.g. the page for the 600-series retainers: http://www.loctite.co.uk/retaining-9171.htm.

Always worth checking out these things - I've used 601 for years, but only just discovered that it "fluoresces for presence monitoring"! As it happens I stumbled across my UV torch a few weeks ago, so now I can sit in my darkened workshop and confirm all wheels are properly retained - or not.

[Philip Hall]

I have always used, with varying degrees of success, Loctite 601 and latterly 603. However, if you read Chris Pendlenton's article in MRJ a while back about wheels, and before that his piece on converting a Hornby 8F, he says that Henkel (the manufacturers) are doubtful of its efficacy in such situations.

I only use Loctite on Ultrascale wheels, and then after employing Chris's dodge (not sure if he still uses it) of turning a tiny ring about 1mm in from the end of the axle, which seems to provide somewhere for the stuff to get trapped in rather than being squeezed out as the axle goes in. I also slightly abrade the axle end by rolling it in the bench under a file. Another opinion on this comes from David Rogers, who told me once that he thought that, under a microscope, an axle looks a bit like the foothills of the Himalayas, and the Loctite goes into all these humps and hollows! Notwithstanding this, I have tried the turned ring idea on three engines now and it does seem to give increased grip, so much so that I don't pin them on anymore. Time will tell with this one...

Alan Gibson wheels have always been a sufficient grip on the axle to not need any retainer, ditto Sharmans, because they are made of a bendier sort of plastic which kind of shrinks down on the axle when they settle down. A recent set of AG wheels were a very tight fit indeed, and I had to set the GW press in a big vice to push them on. The only exception to this is when they have been on and off the axles too many times, in which case I have had to resort to pinning when Loctite just didn't hold. This was a repair, I hasten to add, and I think they had been off many times before the engine came to me.

With all these retainers the most important thing is for the surfaces to be scrupulously clean. I clean off the axles with acetone, and use a baby wipe to clean out the axle hole if it's been contaminated in any way. New wheels should not need to be cleaned out. Use these cleaners with care, though, for once I accidentally cleaned out some axle holes with the same stuff I was using on the axles and you will understand why the next action was a phone call for a new set of wheels...

[Le Corbusier]

The only exception to this is when they have been on and off the axles too many times, in which case I have had to resort to pinning when Loctite just didn't hold.

How do you pin wheels ..... I have yet to come across this in the learning curve that is my modelling adventure!

Tim

[David B]

Thank you, chaps. Very useful and much appreciated.

[John Fitton]

Loctite 603 has the added advantage it is resistant to lubricants.

John Fitton

[Philip Hall]

Tim,

When I pin wheels there are two options. One is to drill a 45 degree hole in the end of the axle which comes out of the side of the axle midway through the bore of the wheel. Once the quartering is set and tested, a drill is run through the hole into the wheel and a wire pin inserted - I use nickel silver wire for this. The advantage of this is that you are drilling through the metal axle into the soft plastic, so there is less tendency for the wheel to move during drilling.

The second option, which was Guy Williams' method, and which I have recently returned to, is simply to drill through the boss of the wheel between the spokes into the axle. With decent (free cutting) axle steel and a sharp drill, you only have to go into the axle a short distance. Because I am drilling through a soft material into a hard one, I scribe or draw a pencil line across the face of the axle and the wheel boss. That way if the drill slips as it meets the axle I can see if it's drifted the quartering. This is not as elegant a method as the first described, but has the advantage that if the pin is left sticking out a little it can usually be removed. Yes, it can be seen, but you have to look closely.

Now, with both these methods I have found that it is only a reinforcement of the quartering. A sharp twist of the fingers and it is possible to break the pin at the joint between wheel and axle. This is why I have gone over to nickel silver pins - steel would be even better.

As I said earlier, I now tend to use pins only if I have to, preferring to turn the little ring in the end of the axle and abrade it a little before using Loctite. You don't need a lathe to turn the little groove, putting the axle in a mini drill and touching the surface with a triangular needle file will do the job just as well.

Sometimes when doing a repair the second option is the easiest as you don't have to take the wheelsets apart to drill. I have also used pinning on outside cranks, as they seem more likely to move for some reason.

Philip

[Le Corbusier]

Thanks Phillip,

Very helpful. A useful thing to have in reserve.

Tim

[Will L]

There is also the Don Roland's method. With your trusty piercing saw, cut a slot across the ends of the axle at 45 approx degrees to the end so that it cuts half way down the wheel depth on one side of the axle and not at all on the other. Fit and quarter the wheels, then drill 0.5mm down the slot into the wheel. Glue a pin in this hole and cut it off flush with the end of the axle and fill the end of the axle. If you ever need to remove the wheel you can pull it strait off, but it won't turn on the axle.

[Jol Wilkinson]

I've always been concerned that the drill would wander when it got to the axle, enlarging/widening the hole it has just made in the wheel hub.

Tony Montgomery of Ambergate fame told me that he cuts an angled narrow slit into the end of the axle. When the wheel is fitted, he then drills up the slit into the wheel boss.

This has the advantage that the drill can't slip as it's held aligned by the harder material and if you need to remove the wheel, the locating wire will pull out of the slit. A No. 8 blade is .5mm wide so would take a .5mm drill.

I haven't tried it yet but it seems like a good idea.

Edit. Beaten to it by Will while I was typing.

[Will L]

Snap