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Member postings for Doubletop

Here is a list of all the postings Doubletop has made in our forums. Click on a thread name to jump to the thread.

Thread: The Chocolate Fireguard as designed by Mercedes Benz
20/05/2019 11:15:09

The link V8Eng provided led to this governemet strategy document. It may well be what I've been asking for


It looks like it is worth reading and right at the back 218 endnotes with links to other papers......


Edited By Doubletop on 20/05/2019 11:17:46

20/05/2019 10:57:43
Posted by V8Eng on 20/05/2019 10:11:47:
Posted by duncan webster on 19/05/2019 19:07:39:
Posted by V8Eng on 18/05/2019 00:22:19:

I read recently that EV charge points installed using a Government grant will have to be “smart” in the very near future.

I have just found the article again so add a link.

Charging points


Does that imply that when the wind isn't blowing (no wind generation), or it's dark (no PV) you won't be able to charge your car?


I kind of assumed that it meant something like that as well, maybe not on a dark cold winter evening when power demand is very high either!

I think it means that if your neigbours have got home and plugged in before you you may well have to wait your turn alternatively they will load share and you may not get as much juice at the rate you expected. Broadband style.

Edited By Doubletop on 20/05/2019 11:00:29

17/05/2019 23:21:05

Those of you in the IET may be interested in joining in on the discussion here. (not sure if others can access it)


One of the contributors provided this link


You may find it interesting

09/05/2019 06:03:53

The previous post was made 12sec before mine but I can't modify the Scalextric reference now. However, it does look like they are on to it....

09/05/2019 02:44:45
Posted by duncan webster on 09/05/2019 00:14:43:

PS Before I get a storm of derision, I'm not being totally serious, but it might work for HGVs

Edited By duncan webster on 09/05/2019 00:15:29

At the risk of undermining the serious debate going on here "Scalextric" rails? Stranger things have been the past. Atmospheric railways come to mind.

However, I am more interested in the planning for the immediate future rather than esoteric long-term options. It all seems a bit piecemeal at the moment, maybe Sainsburys can come up with a plan of their own?

08/05/2019 11:02:39
Posted by not done it yet on 08/05/2019 10:40:25:



The Hyundai Ioniq will travel as much as 174 miles (6.2 miles per kWh). I expect the average is lower, but nowhere near the rediculous 1 1/2 miles quoted in a previous post! The latest model quotes 4.8m/kWh which should be easily attainable. Yes, real mileage is less than the quoted figures in winter, but newer models fare better than your estimate of only 2/3rds. Summer mileage can easily exceed the quoted figures by an appreciable margin, too. It rather depends on the skill of the driver a lot of the time!

So 174 miles at 6.2 miles per kWh is 28.06kWh from a 240v supply 116.9Ahrs. As 35amps have been quoted, as a charging rate, that's 3.35hrs to recharge.

We are not being Luddites here, we know something needs to be done and EV's look to be a promising solution. But the point being made is what is the plan to harness whatever energy source is going to be used and build the infrastructure to get the power to where people will need it?

There does seem to be a lot of “trust us” “she’ll be right” but not a lot of detail about any practical engineered solutions, short, medium or long term

07/05/2019 21:15:58

We all know that electric vehicles in one form or other are here to stay. Every day we hear the virtues of this technology or that and benefits and features of one manufacturers approach as opposed to another’s

So, like any project, we’ve seen the brief, we’ve got some sort of business case, we are seeing the proof of concept, you can go and buy one. What we haven’t seen is any solid on-going forecasts or plans for how this is going to play out long term, particularly for the power infrastructure. Which is the point I’ve been making and we are now discussing.

I agree; my calculations are very ‘fag packet’ I cobbled them together from the information I had available, just to make the point. I could well be way off. I would expect that the power companies are working on this but would suspect that the answer could be too unpalatable to be made public. No doubt there are a number of our members from the power industry. Are they aware of anything in the public domain that they can share with us particularly around power consumption forecasting for the introduction of EV’s?

Maybe we should lobby the IET and get them to do an issue of Engineering and Technology (E&T) on the subject?

07/05/2019 11:32:23

Once everybody in the street is charging their vehicle when they get home the peak period will be at night and the daytime will be off peak.

As pgkpgk pointed out 35amps for an hour to do 21miles. lets say charge to do 100miles thats 44Kwh being drawn at night time, for one property. The cables will be glowing in the dark in the commuter belts

Edited By Doubletop on 07/05/2019 11:34:43

05/05/2019 00:04:27

Mandatory GPS trackers on vehicles opens up many possibilities

  • Missing vehicle searches
  • Road user charges
  • Automatic speeding fines
  • Automatic crash detection (tied to airbag triggers they'd know how major a crash was before anybody managed to get out of their cars)

Big Brother is certainly with us. The 'Thought Police" will be next

04/05/2019 10:16:27
Posted by FMES on 04/05/2019 09:31:49:.......................

The two main points raised were: 1, the availability of 'Economy 7' meters will be phased out as there will be no surplus of power during the off peak periods, and 2: the position of the government with regard to lost fuel duties from fossil fuel burning vehicles, the general concensus was that additional dudies (tax) would be placed on EV charging rates in order to recover the losses.

Think about adding another 40% cost (Based on current fuel duty) to eack KWH of charge time - plus VAT of course.


I had asked the same question about the government’s loss of fuel tax as everybody switches over to EV's. It was pointed out to me that we already have a system working in New Zealand. We don't pay tax on diesel fuel but diesel vehicles are subject to Road User Charges. You pay in advance depending on the type of vehicle you own. In an attempt to encourage take up EV's don’t pay RUC at the moment but it would be easy to tag them on

Removing the off-peak electricity charges will be the tip of the iceberg. The generation and power transmission infrastructure will need beefing up and that will need to be paid for. That will be by all users not just the EV's owners.

01/05/2019 01:49:24
Posted by Bazyle on 30/04/2019 13:51:25:

The solution: reduce the population drastically by removing all safety features from cars so the idiots all remove themselves and their gas guzzling machines for recycling of course (soylium green sandwich anyone?)

Ah! The. I was discussing the same topic with some RAF buddies and the "Injector Seat" evolved. Back to the retinal scanning proposal. If a driver stops being attentive for extended periods a bloody great spike comes out of the seat. Rather than being a pain in the arse they get a pain in the arse....

30/04/2019 09:03:56

Tesla not looking too good in the commercial sector



29/04/2019 11:52:18
Posted by pgk pgk on 29/04/2019 03:31:49:....

Recharging at home on a 230v line @32A is just over 21miles 'summer range' per hour. On Teslas supercharger system one can pull huge power when the car's battery state is between 20-70% but then starts to taper down as the system balances cells. The latest generation of Model3's are capable of top intake of 250KWH on the newest range of chargers when they are deployed and the 300+'ish mile range model3 has a 75KWH battery.


It is interesting to see pgk’s charging details, 35 amps per hour on a domestic power supply that’s about 7.5KWh and for only 21miles

Some time ago I wondered where all the power was going to come from and how it was going to get distributed, and did some rough estimates. The New Zealand Transport Agency publish annual spreadsheets of all the vehicles registered here. They have very comprehensive details of each vehicle including the engine size and power.

Taking 2018 as an example (the stats for 2016 and 2017 produce similar results)

There were 214,000 vehicles of all sizes, scooters to HGV’s registered in NZ in 2018, of which 164,000 were powered. The average power of the vehicles was 128Kw. If the average annual mileage is assumed to be 16,000km (10,000 miles) at, say, an average speed of 50km/hr then the average usage is 320hrs/year. Those vehicles aren't going to be driven at full power so let’s say they are driven at 20% of their max power.

Had all the vehicles been electric that would have been 164000 vehicles, 128Kw at 20% for 320hrs = 1,343,488 MWh of power consumed per annum. With 8760 hours in a year that would require a 153MWh power station running 24x7

New Zealand currently has 5 million vehicles and the government has stated that they are expecting 80% of all the vehicles to be electric by 2050. So 4000000/164000 x 153MWh = 3,732GWh of additional power generation plus the transmission line infrastructure to move the power to where it’s needed.

The real concern is what is all this going to do to consumer power prices in order to pay for the build the required infrastructure? In the UK the problem must be 10 times that of New Zealand? Then again pgk's figures seem to indicate the numbers could well be higher if it takes 7.5KWh for 21 miles 10,000 miles would need an annual consumption of 3600KWh for one vehicle.

Edited By Doubletop on 29/04/2019 11:54:04

Edited By Doubletop on 29/04/2019 11:55:01

Edited By Doubletop on 29/04/2019 11:55:30

29/04/2019 02:22:54
Posted by V8Eng on 28/04/2019 22:31:31:

Autonomous Cars are on a six stage progression and we are part way along that process, this not random as some people appear to believe.

Not random but in a way organic. Various sensors from as far back as ABS, traction control, stability control etc are being developed and tested by all the manufacturers with the long-term intent to integrate them into their autonomous vehicle programme. As part of this development programme they separately or jointly become features on new models.

The technology may well work but at times the human factors seem to be overlooked, unless what is really happening is all the owners of these vehicles are unwittingly guinea pigs. It shouldn’t be a surprise if we found out that all the usage stats for these features were being recorded and downloaded at service time as ‘engineering’ data.

The biggest issue with autonomous vehicles is going to be the legal and moral aspects particularly in the transition period from old to new, when 'gaming' AV's could become a problem.

And then there is this from Elon Musk



Edited By Doubletop on 29/04/2019 02:26:05

28/04/2019 22:08:28

Oooo!! one of my grumpy old git topics

I think that the camera on these systems needs to be turned around and pointed at the driver. When it detects that the driver isn’t paying attention to their driving, fiddling with their, phone, satnav, radio, or just chatting to the passenger then the car slows down. That would prevent many more accidents than checking speed limts.

I’m of the opinion that the addition of these ‘features’ in the quest for autonomous vehicles is contributing to accidents. Drivers are relying on the gizmos too much and are not actually in control of the car.

The other month I watch a driver backing out of a parking space eyes glued on his reversing camera. He backed straight into the path of another vehicle coming down the down the road.

A friend of mine was telling me of a car he hired that he realised that the cruise control adjusted his speed to that of the vehicle in front. When the vehicle moved out of the way it resumed to the set speed. He got quite used to using it. When he got back into his own car and used the cruise control he nearly went into the back of another car....

If you want an insight into the technical, legal and moral questions of about autonomous vehicles have a look at this book on Amazon Free for Kindle


I’ll save electric vehicles for another time…..

Thread: Quality issues with a SIEG SX2.7 mini mill
19/02/2019 20:36:38

Problems like these occur with every manufactured item.

In my RAF days the aircrew would have their favourite aircraft and go out of their way to avoid flying some. There would be aircraft that were forever in the hangar being fixed and others would go days, weeks without anything other than the regular servicing being done. No amount of changing components and fixing things would make a bad aircraft good. Maybe better but not good. The same went for the various components, some units would always be coming back in the servicing bays.

I’d suggest that very piece of equipment in our workshops is a compromise from rulers, through micrometres, callipers to the large machines. Fortunately, there’s enough info out there for us to be able to make an informed decision on what to buy within our budgets. Many of us were beginners and when we outgrew our initial choices we either fixed or replaced.

We purchase this Chinese equipment because it is cheap. If they didn’t supply the market we’d still be using vertical slides on our Myfords and probably not being as accurate or productive as we are now. Fair go to Ketan for fronting up and telling us how the supply chain works many other suppliers would shy away from making any comments.


Edited By Doubletop on 19/02/2019 20:37:59

Thread: Drill sharpener
27/12/2018 09:46:39
Posted by Gary Wooding on 27/12/2018 07:59:15:
Posted by Doubletop on 27/12/2018 02:34:46:

So when doing split point on the Sealey do you reset the drill bit in the jig after doing the basic grind? The Chinglish instructions that came with my clone don't advise to do it but some YouTube videos say you do.

I always reset the drill bit for the split point grinding, and get good results.


Thanks, now I have an idea of the orientaion of the drill bit relative to the grinding wheel and be able to do some juggling to get everything in the correct position.

I also thing I picked up somewet that these machines only do split point for drills 8mm and up, or was I dreaming that?


27/12/2018 02:34:46


I have been working though this. Here are a series of drills I'd done with the machine out of the box. Either a flat relief or going the wrong way

I ground a pointer and installed it in the drill holder and offered the point to the grinding wheel

As I had suspected putting it into the setup jig the there was a gap between the end of the pointer and the touch plate in the jig.

Looking at it the other way round if a drill bit was set against the touch plate the extra material would need to be ground off before the grinding ceased. This would then mean that the cutting lips would be ground beyond the intended location on the flutes.

This should be easily resolved as the grinding wheel can be moved along the motor shaft. However, on my unit flat on the shaft, that the grub screw bears on doesn't allow the grinding wheel to be moved far enough. That is, after the pointer has been set to the correct length on the setup jig, the tip of the pointer should be just rubbing on the grinding surface.

I have tried with the grub screw being clamped directly on the motor shaft and not the flat and using the machine like this I get perfect results with drills from 3mm to 12mm.

I now need to work out how to get the split point to work. I think there will need to be a compromise between the position of the grinding wheel for the basic grind and the split point.

So when doing split point on the Sealey do you reset the drill bit in the jig after doing the basic grind? The Chinglish instructions that came with my clone don't advise to do it but some YouTube videos say you do.



Edited By Doubletop on 27/12/2018 02:41:19

Thread: Drill Sharpeners Compared.
26/12/2018 19:38:46
Posted by peak4 on 26/12/2018 16:57:39:

I've been having a bit of a play this afternoon as the weather wasn't up to much.
Rather than hijack the other thread, which was asking specifically about the Sealey SMS2008 drill sharpener, I thought I'd start a new one for a quick comparison.

Maybe others could contribute some ideas and photos to this thread, so that it could be used for reference and learning.

Doubletop-Pete commented, in the above thread, that he felt that his Sealey was taking off too much metal; so was mine out of the box, albeit a second hand box.

Sliding the wheel towards the motor, will reduce the depth of cut on the primary grind, as it's a tapered wheel.
It's a bit of a fine line as moving the wheel also affects the split point grind.


Edited By peak4 on 26/12/2018 17:19:39

Great thread. I'm going to have a play with my Sealey 2008 clone today. The realisation that the ginding wheel position was adjustable and would affect the depth of cut is the basis of my investigation . I have an idea of an approach to doing the basic setup without making it hit and miss. I'll see it there is a way of ensuring the split point still works. It may be a case of the best compromise position of the wheel to accomodate both.


Thread: Drill sharpener
26/12/2018 10:29:29

I do understand that there are many ways of tackling drill sharpening but the purpose of this thread is really a question about using this particular piece of equipment.

I've been thinking about the problem I raised and an observation that my machine seems to want to take off too much material. When the amount of grind is reduced it seems to get it right. I have an idea I'm going to test tomorrow and if I'm right it will be about correctly positioning the grinding wheel on the motor shaft. It is designed to be adjusted.

I'll let you know how I get on


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