Member postings for Roger Best

Sorry Harry but I have downloaded the Polly catalogue and it conspicuously does not say what size A/F the nuts are, all the fittings are described solely on the nominal pipe size. The same goes for Macc Models and the ebay retailers I have looked at.

Hi folks

I am finding model engineering pipework standards confusing, fittings have a nominal size, but can fit more than one pipe size by changing cones and nuts, and everything is imperial.

I have obtained a mix of nuts and cones, and I don't know what I have.

Is there a table somewhere on the internet where sizes are tabulated so I can identify the nuts? I assume I can identify the cones from their internal diameter.

This sort of question has come up before but it didn't help me in the short term, although I hope to be able to find the reference when I can get to the club and look at the old magazines.

thread link

Thanks for the help.

Rog

Did anyone find anything??

i will start a new thread.

R

Progress delayed due to arrival of a new loco.

Small list of jobs required before spring testing day.

Who knows??

My information:

1/2" is too much to chop off. They are very sensitive to just a few mm plus minus. Just go carefully.

Obviously it varies with size of garter spring, and length required.

i am no longer surprised when I get it wrong.

Jib implies it moves in an arc. 125kg at 2m or rather the test load, of either 1.3x or 1.5x for a hand hoist (if I remember) adds up to a lot of moment, so you may have to dig a foundation of a tonne or two to stop it tipping or ripping your house apart. Jibs are very expensive all in.

Far, far easier is a travelling beam, or fixed-each-end beam, it can be far lighter and easier to move, probably aluminium if you buy one with A-frame and castors.

Another option is a track screwed into the ceiling beams. As you know what its for you can probably think of a few routes that it could follow.

Good luck.

Hi guys

I am not trying to preach too much, but there is a reason for my approach on transport of engines.

A few years ago I was sideswiped on the way how from a show. I transport my toy engines in crates with soft packing and they were all fine, but a metal tray I use to steam them on was bent between the inertia of light toys and the sudden movement of the car as an SUV ploughed into us.

The accident is on my Youtube channel:

skip to 1:50

The point of this anecdote is that a small tap at 30mph can do an enormous amount of harm and damage, 8K of damage to my SMAX plus injury claims, the front of the Kia SUV was plastic so generally smashed.

I don't see much above that will take 3g lateral load let alone a real bang, the box frames look very promising but wing nuts are often a bit soft and wood batten is limiting.

Watching my fellow members secure their beloved engines it was obvious that an accident was not an option. Small screws fixing the loco to not a lot.

Who has survived a real accident with their loco contained safely?

What did you do to hold it down? That would be a good starting point.

Cheers

Rog

Ta guys, I have the means to follow Robert's advice, I like the spit solutions, but that is a big job in its own right and I need this done for testing day.

Transport is another issue entirely.

I am still interested in what people do.

Awesome.

Bins are not expensive but having exactly the right storage, all sealed up and dust proof is wonderful.

I have experience of using vinegar and I liked it, you have to maintain your expectations of how long it takes. Overnight soakings and changes of liquid may be required.

For examples of variable results see my video:

vice restoration video

Times: 01:10, 14:46, 26:43, 29:11

What didn't make the cut was that it took several days to etch out the vice jaws, which were clogged with debris and rust. The crap loosened and came off and they came up almost as good as new which was amazing and very worth while as quality jaws are very expensive - if you can get them.

A big part of this film demonstrates the maxim of not using chemicals if you don't know what you are doing. There might be a bit of that in the posts above.

I am probably going to try some other techniques for other items, I think its a matter of horses for courses and you need to experiment to find the right technique and product for the application and your patience.

A few pictures of my new engine on its trolley, and the areas that need work.

How do you get to the underside of your engine? I need to give mine a good clean and repair the paint, its more than just oiling the motion.

Do you just tip it on something soft?

I am minded to bolt disks of plywood to the buffer beams but I need to know the centre of gravity.

I have a bad back and my workshop is very cramped, so no heavy lifting for me, only controlled and safe. My Polly 4 is about 40kg so one end at a time to lift.

ta

Hi folks

I have uploaded some pictures. My first impression that the taper was an incorrect fit was because it protruded so much more than the original chuck.

So after all the discussion I marked the male taper 25mm up, ignoring the chamfer. This was a mistake, the chamfer is part of the specified dimension, it should have been 24mm so take 1mm off your measurements below. I fitted the chuck by hand and there was a good gap between the mark and the top of the chuck.

I fitted the assembly and forced it together with the mill quill which I videoed. I don't think it got much deeper so maybe a squeeze in the vice or a tap with a hammer, suitably protected, is required.

Lastly for the night here is a simple picture that shows that I needed something to hold small drills.

As Jason says there is a lot of luck on those last few microns of any set up so I will have another try another day. then I will update the video or do a part 2. I videoed the runout of the chuck as jammed on and it was 0.055mm so a little worse than before and worth playing with.

There is also the drilling test to look forward to.

Thanks for all the diverse advice from everyone.

I did make at least one mistake - I now think the chuck is undersize, rather than the arbour too big. Explanation will have to wait till I post the pictures. In short the taper does not penetrate 24mm, only 21 or so. As observed above, it only takes a tiny difference in the diameter to cause that.

However, the very gracious Ian Davidson has persuaded me that its a good product, and I have come home to find other arguments to that effect and that this level of protrusion is normal, so all is well and I feel better about everything.

The only problem is that after jamming it on good and hard the runout is now a little worse, it would be so nice to get it down to 0.04mm.

Loads of great examples here. I have just ordered a hydraulic table myself, in my wife's name as she will sign for it.

I used to do a lot of stuff with cranes and handling aids for my job, both design and use.

Generally its worth remembering that if its too heavy to lift its dangerous so buy bits and equipment that does the job, don't see how little metal you can use, use chunky stuff that fits the hand and survives errors. Its cheap, why not?

Secondly it needs to be held down in the car as well as a person, that means big bolts and brackets. Someone decided to broadside my car once and it shunted everything, its not about you driving carefully.

Thanks guys.

I only pushed the chuck on by hand and it hadn't been used so it came off easily with a tiny slide-hammer action. Bragging rights to DiogenesII.

I measured the arbour diameter and its oversize, 16.0 v 15.7, chuck seems OK size-wise, so I have sent an e-mail with pictures to the vendor and hopefully we can speak tomorrow and they can say what they want me to do with it.

Not being properly seated would account for much of the excess run-out over the fancy chucks, its a matter of leverage and we are talking microns. That's great.

Edited By Roger Best on 16/01/2022 20:24:14

Thanks Emgee, I couldn't find those either on the website or catalogue.

I didn't jam it on tight it should pull off.

I will check dimensions against info here:

tools-n-gizmos

mmm I might have got something wrong. The tapers don't fit very well but it took me a while to work that out.

A quick video:

https://youtu.be/gFDdZaZ0lR4

How do I get the chuck and arbour apart?

I was enjoying all this archaic stuff when i remembered that my first days at uni were spent learning to draw in pencil.

By the time I graduated draftsmen using pens were no more, it was all 2D CAD. Within a few years I was using 3D parametric CAD.

That was twenty years ago now. I haven't drawn a part professionally in all that time as my current employer is a bit backward in its ways, I do powerpoint and spreadsheet engineering mostly.

The good news is that not only can we now get cheap domestic CAD but we can do additive manufacture too on 3D printers. Roll on progress.