Member postings for Ron Laden

I went into our local engineering supplier today to get some nuts and washers and the assistant that served me I,ve known for over 30 years. When I was working the company I worked for bought all its fasteners and engineering supplies from them.

We had a chat and he asked if I was into model engineering, he had noticed me in the shop quite a few times over the last couple of months, I told him I was but quite new to it.

Its not a massive supplier but they are great, as you can go in with a shopping list and get small quantities of various sizes and types of fastenings. You dont have to buy minimum qty,s or full boxes, they will supply you with one screw if thats all you need.

I said, I bet you get quite a few modellers in dont you but he said no, not any more. He said if he thinks back 30 years and compares it to now, model engineering for them as fallen off a cliff. As well as fastenings, they used to stock some items and materials popular with modellers but those days are long gone.

From what he said it would seem that model engineering is nothing like as popular as it once was, which made me wonder, is that just local to me or is that the situation in general.

Ron

Edited By Ron Laden on 16/08/2018 20:50:29

I wonder..?

If you read up on the characteristics and technical spec on the different battery types then the obvious choice for an electric loco would be a deep cycle (traction) battery.

What about in practice though..? there are lots of examples of things that work with no problems when theory tells you it shouldnt or wont perform so well.

The majority of electric locos I have seen are running on leisure batteries and I think I am right in saying that there now seems to be leisure batteries that are listed as "deep cycle", whether they are actually any different or not I dont know.

As I understand it, it seems to be how much capacity you take from the battery that is key. If you take a leisure or car battery down to 25% on a regular basis then it will start to have problems. So I wonder, are users of leisure batteries not taking them down any further than say 50% and that is why they have no problems.

I spoke to someone yesterday and he uses leisure batteries in quite a large loco and he said that the batteries are 3 years old and never been a problem. He doesnt measures how much they use but an afternoon at the track is probably no more than a total of one and a half hours running on and off. I am guessing that he probably doesnt take them down any further than 50-60%.

So could it be a case of "theory says.... but in practice...."

Ron

Edited By Ron Laden on 15/08/2018 09:55:47

Edited By Ron Laden on 15/08/2018 08:51:54

Edited By Ron Laden on 15/08/2018 08:55:41

A couple of weekends back I visited a model rail exhibition, the first one in a long time. Over the years I have been to dozens of them as well as RC aircraft shows.

The one recently was very good with some lovely layouts and nice models, but I came away thinking that some things have not changed. I wondered if there should be a compulsory dress code before you can be admitted i.e. full body armour like that worn by American footballers. Also should there be large warning signs placed around the show "DANGER beware of people with monster size rucksacks". The number of times you get swiped by rucksacks with people barging past or spinning around.

On a more delicate note I wonder if some of the visitors have ever heard of "a shower or bath and deodorant" The wife left after 10 minutes saying she couldnt stand it.

I wondered are model engineering shows the same or does everyone smell of oil and cutting fluid, I would be quite happy with that...LOL

Hi Jon

I have quite a bit of experience with brushless motors, I used them in my RC aircraft days. I know of one 5 inch loco that is powered by one of the RC truck brushless motors. I have thought about it in the past but for now with the class 22 I will stick with brushed motors.

Cheers

Ron

Edited By Ron Laden on 14/08/2018 09:43:23

Thanks guys,

After Neil suggested traction batteries I did quite a bit of reading yesterday on the different types of batteries, Yuasa have some very good technical info on their site.

From what I read it is quite clear that deep cycle (traction batteries) would be the way to go. They can deliver high amps and the capacity can be taken down to quite low levels. It would appear that the same usage would shorten the life of a car or leisure battery, the leisure battery less so than the car type. If I understand it correctly the key is how low the capacity is taken down. Deep cycle batteries can be taken down to 30% whereas car and leisure batteries would suffer if regularly taken down to those levels.

I have to say that I have seen car and leisure batteries powering electric locos, probably more leisure than car. I never thought to ask how much capacity they take from the battery and if the batteries have a long life I just assumed they must be fine.

Bazyle, "Am I going to use the loco that severely" no, far from it but I want a loco that has good performance i.e. a reasonable top speed and not too pedestrian but I am not looking for a rocket ship. Also with "silly" numbers of passengers it would be good to have a loco that can pull away from a standing start without the need of a push which I,ve seen on a couple of locos.

Ron

Thanks Dave,

Oh well, traction batteries it is then, I had better start saving..

Ron

I dont know if I am looking in the wrong places but 12 volt traction batteries are expensive, or at least the ones I,ve seen are, didnt expect them to be those sort of prices.

Hi Nick,

Thanks for the link and the side elevation is useful it shows some good detail.

To be honest I didnt realise there was a society intending to build a new 22, that is some undertaking and I will keep my eye on progress.

Regards

Ron

I thought that leisure batteries deep discharge but obviously not.

Thanks Neil

Working from a scale drawing of the class 22 loco I have put together some dimensions and figures for a 5 inch version.

Overall length: 48 inches.

Body width: 9 inches.

Height: (from top of rails to top of body): 13 inches.

Weight: (including 2 x 12v / 75amp leisure batteries) estimated 65 kgs.

Gearing: 6/1

Power: Will depend on which motors I go with but the ones I am leaning towards will produce approx 1000 watts (1.3 hp) across 4 axles. Seems high I know but I am hoping to carry 10-12 passengers and thinking that its better to have too much than not enough, plus I think it will need reasonable power for pulling away with a full load of passengers.

Speed: 7 - 8 mph (max)

Well thats about it for now, I had better get back to the 0-4-0, just about to start building the body.

Ron

Edited By Ron Laden on 13/08/2018 10:26:01

Its steel track Bazyle.

Thanks Michael and Andrew,

I now know what PWM is, not that I understand it despite your explanations. I think it a case of coming from a mechanical background and thinking electronics a mix of magic and wizardry...lol.

Appreciate you both explaining it though.

cheers

Ron

Edited By Ron Laden on 12/08/2018 14:02:47

Thanks Dave, the last time I did any technical drawing was back at school which was a long time ago. I just find graph paper easy to layout, I would like to be able to use CAD but I fear I would be hopeless at it and can probably finish a drawing (good enough for me to work from) quicker than I could manage a couple of lines on CAD.

Ron

Thanks Bazyle, you have told me before about track debris, the club track is raised and I was assuming it would be cleaner than ground level track but I will take a look at it. I would rather stay with gears if I can plus there is a limit to how far I could raise the motor without it clashing with the upper chassis/batteries etc.

Ron

Although I am still working on the 0-4-0 loco I have in between jobs given some thought to my next project a Class 22 (baby warship). The 0-4-0 is a test piece really and my first attempt at a 5 inch loco, its not a model of any real loco but more a fun model which I hope will pull 2 or 3 passengers. The class 22 will be semi scale and hopefully a reasonable representation of the real loco.

A grubby and well used Class 22.

Early days but a sketch below of how I may approach the build of the bogies and drive assembly. The loco is twin bogie with four axles all of which will be driven. Apologies for the state of the sketch but hopefully it shows how the axle/motor frames pivot on a shaft mounted across the centre frame. The axle suspension is via springs mounted to a pair of bars, a fixed bar between the axle frame sides and a pivoting bar mounted to the centre frame.

Nothing is set in stone, just ideas at the moment.

Ron

Thanks NDIY, I will be giving the controller fuse protection and allthough I have no spec details I did read that the controller does have some inbuilt protection.

Ron

Thanks Dave,

That all makes perfect sense so I will go with the full 24 volt and as you say the amperage can be controlled via the throttle and been able to read the amps and watts level via a cab ammeter.

When the loco is ready I can run some track tests and get the best balance between performance and amps/watts whilst checking I,m not cooking the motors. Once I find the maximum throttle position it wouldnt be difficult to fit a mechanical stop to prevent this been increased any further.

The controller in the picture does have a central neutral position on the forward/reverse switch, the 100 amp version controller is the same. I cant find any useful data on the 100 amp version but its spec gives 12 to 50 volts, 100 amps max and a continuous rating of 60 amps. The 60 amps continuous is convenient as I was looking at 15 amps for each of the 4 motors.

Thanks again and thanks to all the guys for their input.

Ron

Edited By Ron Laden on 11/08/2018 20:13:52

I doubt it helps much but a picture below of the 60 amp controller I am using on the 0-4-0 loco. Dont ask me anything technical about it as I cant tell you. All I know is it rated at 60 amps (40 amps continuous) 12 to 36 volts, it is wired with a forward/reverse switch and a rotary speed control.

The picture of the 100 amp version looks just the same but I will try and track down some technical info on it.

Sorry Les, but what do you mean by a PWM controller..?