Member postings for mick H

A question for Neill and his astronomical friends.......what is the star in the western sky that I can see in the evenings. It is incredibly bright and I assume that it is Venus?

The only relevance of this question to model engineering is that I can see the star from my workshop and secondly Evening Star was, I believe, the last made loco of the steam era.

Mick

Thanks gents. Those prices are a bit more like it. I have placed 3 orders to try them out.

Mick

Due to a combination of deteriorating eyesight, reduced manual dexterity and a generous helping of cackhandedness I have made severe inroads into my stock of 1.5mm cutters. Looking around, I am astonished by the terrific increase in the cost of replacements since I last purchased. A familiar cry, I know, but where might I best pursue my quest?

Mick

The Consumer Contracts Regulations require the supplier of defective goods to bear the cost of return.

Mick

I have not got much further on this subject than previously outlined but the following may be useful. After a lot of messing about experimenting with different jets I finally settled on a number 8 for my Gauge 1 V2 loco. The boiler on this loco is about 11 inches long and approx 2 inches diameter. The ceramic burner is approx 2 inches x 2 1/2 inches.

The following notes may also be of interest. As designed, the boiler is of the sealed system type where all the air required for combustion (primary air) is sucked in by the gas jet. A number 8 and a number 10 jet failed miserably and from the fumes coming out of the chimney it was quite evident that nowhere near complete combustion was taking place. I then fitted a number 5 jet which although smaller, sucked in more air as the gas velocity through the smaller orifice was greater. This improved things somewhat but performance was not as I expected. I then decided that I was not happy with the sealed system and remade the ceramic burner to allow for some secondary air to enter the firebox. The smokebox was also altered to give a Stephenson effect. Now there was not enough gas for the air available and so the number 8 was refitted and the whole thing has balanced out quite nicely with a nice cherry red glow to the ceramic burner. The gas used is butane with a liquid feed from the bottom of the gas tank fed to the burner jet via a preheater loop silver soldered to the firebox. This is so much easier to manage than taking gas from the top of the gas tank with the consequent drop in pressure as the tank cools.

In short I would say that a number 8 is capable of delivering a lot more gas than my loco will take and I would certainly not argue with Stuart Models.

If you do come up with any information enabling a calculation to be made matching jet to application I would love to see it. I got rather bogged down trying to research this subject and finally decided that as I had found a solution to my immediate problem my time would be better spent on other workshop matters.

Mick

This is a very interesting question as far as I am concerned. From what I have seen and read, the formulae for steam and exhaust port sizing does not seem to have changed from the days of Greenly and LBSC. Perhaps these eminent engineers were absolutely right but things do have a habit of moving on.

More recently the 16mm groups and the Gauge 1 fraternity have been using "smaller" ports consisting of just a single drilling per port with, by all accounts no discernible effect on performance. I have just completed a pair of gauge 1 cylinders where the steam port is a 1/16" drilling and the exhaust port a 1/8" drilling. Moreover the exhaust cavity in the valve is an easily cut 1/4" diameter, with a slot drill.

Drillings from steam port to cylinder also seem to have been reduced from two to a single drilling of about 2mm. This did nothing to reduce the power of my last loco.

I have previously made some calculations based on the 1/8" steam pipe from the boiler to the cylinders and in some of the older designs it seems to me that the "demand" from the traditional steam port drillings is more than the steam pipe can supply at a given pressure.

Having said that, these calculations are quite superficial and no doubt do not take account of many factors I probably haven't even heard of. I suppose if you are unsure it is best to stick with the tried and tested. It would be great to hear from someone who has looked into these issues with a more informed mind. Meanwhile wish me luck with my newly drilled "scaled down" cylinders.

Mick

Just a thought John, I notice that Reeves sell brass stamped numbers and letters at between 30p and £3 each. These could easily be soldered to a home made nameplate.

Mick

Michael.....the very best of luck and I am sure that you will make the right choice. As a beneficiary of your excellent advice in the past, just make sure that you can keep tapping it out on the keyboard.

Mick

Thank you, gentlemen, for the usual excellent selection of options.

Mick

I have bought a SatNav with a standard suction cup base which I would like to sit in the centre of the car dashboard. Unfortunately, the dashboard, whilst pretty smooth, is not smooth enough to allow proper adhesion. There are plastic discs available to first stick on the dashboard and then the suction cup is applied to the disc. As an alternative I was wondering whether there is such a thing as a "low tack" adhesive which could be applied to the suction cup to enable it to create the necessary vacuum to hold it in place? The ideal substance would also be easily removable from the dash and the suction cup if necessary. Any ideas most welcome.

Mick

Russell......these are my thoughts although I was not aware of the exact statistics. A replacement battery might be a case of jumping from frying pan into the fire......or it might not! It seems to me that a proportion almost everything manufactured goes wrong somehow and who is to know where the next fault lies.

Mick

A couple of months ago I replaced my laptop battery with a new Lenoge battery. Lenoge is a reputable company which are apparently fitted to Dell computers as original equipment. The cells are manufactured by Samsung. Yesterday I received an e-mail telling me that my money has been refunded and not to use the battery but dispose of it according to the correct protocol. Fair enough, I thought, I shall get a new one. Then it occurred to me, which replacement battery should I buy and what guarantees are there that it is safe? Are there any foolproof makes out there?

Mick

I am a Gauge 1 type and invariably use brass for cylinders, but, at this small scale "O" rings are usually used as piston rings so that there is little or no wear in the cylinder walls. Whether this is possible in larger scales I have no idea but I would tend to take the advice given by Julian if I were investing the time, effort and expense in building a 31/2" loco.

Mick

Edited By mick H on 12/11/2016 08:59:21

Edited By mick H on 12/11/2016 09:01:20

All these terrible things are nowhere near as deadly as the motor car which is still killing about 3000 per year. Selling ether to a responsible 10 year old does not seem to be anywhere near as dangerous as the way that driving licences (and mobile phones) are handed out almost willy-nilly to some of the idiots on our roads.

Mick

Thank you all for your valued advice.

Mick

Thanks very much gents.

Mick

I have seen on Youtube type videos, people using what appear to be angle grinders fitted with wire brush cups or sanding discs to clean up exterior timbers. Are they angle grinders with add on attachments or are they a different tool entirely? The only tools that I can find that seem to be similar are rather expensive Hitachi outfits.

Mick

Thank you for all the ideas gents. I will have a go at some of them this morning....but I think that I will leave out the HF suggestion! My fall back position, although not ideal was to cross drill and pin but if I can get it to "stick" by other means then so much the better.

Mick

I would like to secure a 4 or 6BA stud into a piece of PTFE rod......which adhesive can I use? Or am I on to a total loser on this one?

Mick