RUMCars Forum

General Category => Unusual Microcar Discussion => Topic started by: Bob Purton on October 01, 2010, 08:30:30 AM

Title: Isetta counter weight
Post by: Bob Purton on October 01, 2010, 08:30:30 AM
Thought I would enter this under a new topic as it has nothing to do with Jeremy Clarkson although we could try dropping one of these on him to see if it has the same effect as a piano on a Morris Marina.
The RHD counterweight weighs 21.5kgs and is about 7.5 inches wide.
A battery of this size would be too feeble to service an isetta.
Title: Re: Isetta counter weight
Post by: Chris Thomas on October 01, 2010, 08:50:40 AM
Dear Bob

You are a mind of technical information.

However I note an interesting mixture of Imperial and Metric measurements in you note. If it is a German made Isetta should you be quoting all metric measurements, and if it is a pre 1974 British made Isetta should you be quoting all Imperial measurements?

We seem to be in that limbo stage where we should be using all metric dimensions, yet because the government are unwilling to expenditure some Imperial dimensions (MILES) still linger making both systems run together. I know older people find metric measure confusing and some young people find some Imperial measure confusing, but distance and weight seem to be the most used and confused of the measurements we use. What should the convention be in Rumcar?

Chris Thomas
Title: Re: Isetta counter weight
Post by: steven mandell on October 01, 2010, 09:53:57 AM
Thank you very much for taking the time to locate, weigh and post pictures of the counter weight.
Is there some way that I could see exactly where it was mounted in the car?  I'm interested in how the physics of its placement allowed a 47 lb weight to effectively counterbalance the combined weight of an Isetta's engine and driver.
You are right in that a conventionally constructed lead acid batterry of similar dimension would not be up to the task of servicing an Isetta.  However a batterry of that weight could service several of them.  So the confines of the acceptable locations where it needs to be placed to achieve the desired effect becomes critical in determining how practical it may be to attempt to duplicate the counterweight's beneficial effect with parts that would also serve another primary functional purpose for being in the car.
Actually Odyssey makes some very compact  rectangular long life gel type batteries with a tremendous cranking ability that are close to that size range.  It is also very usefull that they can be mounted at many angles without negative consequence.  I put one in my AZ-1 instead of the full sized Honda type batterry that it came with.  It both looks and works great- albeit at near $200 it is quite expensive.
Title: Re: Isetta counter weight
Post by: steven mandell on October 01, 2010, 10:08:59 AM
This just in- Wilkepedia says that the counterweight was 27 kg or approx. 60 lbs.
Title: Re: Isetta counter weight
Post by: Bob Purton on October 01, 2010, 10:26:25 AM
Ah, the plot thickens then, I lifted the 21.5 off the Isetta forum. It seems a little light to make much difference. I have an optima spiral tech battery in my Inter but none of these were around when the RHD was developed. I think its mounted inside at the sill just behind the left front wheel arch, you can see the sill shape in the weight.


Chris. Decimal inches were used in engineering for decades as alternative to imperial fractions before the uk had mm forced on it by the EU. Are you confessing to being one of the elderly confused?
Title: Re: Isetta counter weight
Post by: marcus on October 01, 2010, 01:17:41 PM
I have my own unit of measurement, for estimating heights: the Double Decker Bus. Usually around 15 feet high. Imagine how many would stack up to be the same height as a building. Much more useful than yards or meters.
Title: Re: Isetta counter weight
Post by: Bob Purton on October 01, 2010, 01:45:25 PM
What about smaller items? Corgi double decker buses?
Title: Re: Isetta counter weight
Post by: marcus on October 01, 2010, 01:54:36 PM
What about smaller items? Corgi No. 233 Heinkel Bubble Car
?
Title: Re: Isetta counter weight
Post by: Bob Purton on October 01, 2010, 02:01:25 PM
How many of these to the foot?
Title: Re: Isetta counter weight
Post by: marcus on October 01, 2010, 02:03:27 PM
Hang on a mo, I will go and measure my ones.....
Title: Re: Isetta counter weight
Post by: marcus on October 01, 2010, 02:11:05 PM
...

L:   4.8 to the foot
W:  9.6 to the foot
H:   9.8 to the foot

(counter-weight not included)


Title: Re: Isetta counter weight
Post by: Bob Purton on October 01, 2010, 05:53:10 PM
Ah, I see you are using imperial decimal as well! We must be of the same age group of "engineers". What are you working on at the moment? I'm floor mounting a WW2 U boat telegraph, next week I'm on a Georgian Kaleidoscope. All fun!
Title: Re: Isetta counter weight
Post by: Bob Purton on October 01, 2010, 06:22:36 PM
Whats this all obout?

http://cgi.ebay.co.uk/TROJAN-Bubble-Car-BMW-Isetta-BALANCE-WEIGHT-Original-/200525837385?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item2eb0457449
Title: Re: Isetta counter weight
Post by: marcus on October 01, 2010, 06:40:54 PM
Ah, I see you are using imperial decimal as well! We must be of the same age group of "engineers". What are you working on at the moment? I'm floor mounting a WW2 U boat telegraph, next week I'm on a Georgian Kaleidoscope. All fun!

My godfather was a submarine Captain, we have great chats when we get together. His old sub (HMS Alliance) is now at the Gosport Submarine Museum. With his knowledge of subs and my interest in engines we figured out how the Sweedish Navy's non-nuclear subs are out-smarting the American ones. Making a Georgian Kaleidoscope sounds fun!  
I am getting another radical snare drum design ready for production, due to good interest at a drum show in Birmingham last w/e. You might recognise this Proper English Gentleman trying out my Busker Cajon drum kit. It's John Bly, furniture expert from BBC TV's Antiques Roadshow. There is already a you tube video of Al Murray / "The Pub Landlord"  playing it, (but spelled Al Murrey). Whatever next?!



Title: Re: Isetta counter weight
Post by: Bob Purton on October 01, 2010, 06:56:30 PM
That sounds interesting Marcus. Our old drummer used to stick tea towels on his snare for some unknown reason! By the way, the kaleidoscope is a restoration job, a real one, not a prop this time.
Title: Re: Isetta counter weight
Post by: marcus on October 01, 2010, 06:58:43 PM
I forgot the link:

http://picasaweb.google.co.uk/peakepix/NDF20101?authkey=Gv1sRgCP3uh5GRzonbeQ#5521750076807159746
Title: Re: Isetta counter weight
Post by: Chris Thomas on October 01, 2010, 07:37:18 PM
Dear Bob

I consider myself quite adept at both metric and Imperial but prefer Metric. I find myself still hanging onto some imperial measurements such as miles per gallon rather than litres per 100 km. Whilst L/100 km may be of more use day to day, I find it too fiddly and MPG more accurate. With road distances all marked in Miles it is also more difficult to think in km. As far as weights, loads, volumes and linear measurements I always use metric, however Imperial based UK clothing sizes I still use, as continental shoe, shirt and trouses sizes are not yet in my brain.

So I would not say I am confused, just not yet fully metricated, but easily able to estimate in both.

How about you?

Chris T
Title: Re: Isetta counter weight
Post by: steven mandell on October 01, 2010, 07:39:31 PM
Just when it was starting to seem like it all made sence!  
Now ther is a mere 33 lb weight of generic design that would not allow it to be placed as far laterally or forward.   Both of these vector shifts are necessarry to get the cg closer to the engineer's ideal- the lowest available centerpoint of the greatest source of resistence to roll over- the front "axle."
Perhaps the reduced weight and less ideal location would be less problematic for the Trojan as at least the engine was centrally located.  Have you experienced or heard of this concern form other Trojan owners?
Talk about low brow tech- I think if I had the Tojan and it seemed in need of this type of assistence I would save the money and use some masonary.
Title: Re: Isetta counter weight
Post by: Bob Purton on October 01, 2010, 08:40:36 PM
Steven. I think the ebay listing of the weight it gobbledygook! I have never heard of Heinkels using counter weight, with a central engine what would be the point? Its certainly not from an Isetta. Someone has been leading this guy up the garden path! Unless someone know different?

Chris. I'm much the same as yourself using both. For work on antique stuff I'm in imperial as most of the instruments are English. For DIY around the home I use mm these days. If a doctor asks what I weigh I give it to him in Stones!
Title: Re: Isetta counter weight
Post by: Big Al on October 02, 2010, 08:59:59 AM
If a doctor asks what I weigh I give it to him in Stones!

Yeah I weigh a Kieth, Mick and half a Charlie! Must start by loosing the Charlie on my diet.

The problem is that many imperial units are very useful in practical application as they equate to bits of body etc. Thus when hand constructing they make far more sense than metric. If you are being scientific the metric system is a lot better. Likewise the standardisation of fasteners in the metric system is far preferable to the myriad of differing types used outside that system, as owning a Berkeley reveals, one reason I do not own one. So we are reluctant to get rid of imperial units as many suit our day to day lives, like a pint of beer, a round metric equivalent does not work. Inches, the turn of a thumb, foot, obvious etc. Why do we need to get rid of them anyway? They are ideal in construction as was because things were done by eye locally. Very often the better for it in fact as what looks right often is not square or exact. The French still use imperial measures in the country, in fact, and they invented and promoted the metric system. Much like driving on the wrong side of the road they claim its better. Like measurements the fact is the countryside took a longer time to adapt than those who pushed the idea through thought. Only law forced the issue. Beyond that which metric system do we use? Centigrade, Kelvin etc.

This battery thing I thought I had answered. There is, now I have looked, ample room for a period battery of larger capacity than standard to be sunk into the floor of the Isetta behind the front wheel arch. It does not get in the way. All that is required is the weights of the various components and to then calculate the moments of them in comparison to the original design to see if it can be matched by moving the other parts listed about. This would take about a day with a slide rule as we are being traditional. Even if it were to not be enough the amount of extra weight added that is useless would be far reduced and the overall weight of the car reduced to better performance and economy. Carrying 60lbs is the same as the terror if it were an airdale or something. In the light of being green and performance added weight is bad news and where modern cars fall down very badly. On a microcar added weight is just not minimalist and a cop out against the tenants of the class.
If this counter balance was a clever bit of design could you buy one to match the weight of the driver to give best performance?No it was moulded into the 'sill' in the hope no one would notice it. Botch up for cash and of a subtly and standard of finish railway engineers could make without help from BMW.

The eBay counterweight. It is SS gold - of sorts. A brick painted gold and marketed as a counter balance. Brilliant. The car version of poodle clipped sheep for Japan.
I have an original Messerschmitt 10 inch wheel conversion here as advertised in the Exchange and Mart that is more useful than that but a really cunning use of available technology. It does work as I have tried it. I love this sort of things.
Title: Re: Isetta counter weight
Post by: Jean on October 02, 2010, 06:08:08 PM
Quote
I have never heard of Heinkels using counter weight, with a central engine what would be the point? Its certainly not from an Isetta. Someone has been leading this guy up the garden path! Unless someone know different?
When Edwin bought our German Heinkel way back in the late 70's it was driven up from Brighton to Sidcup by its student owner and he had a weight, which we still have,on the floor on the passenger side .  As you are all well aware I no nothing about technicalities so I will have ask Andrew what he remembers out it.  Jean
Title: Re: Isetta counter weight
Post by: marcus on October 02, 2010, 06:14:36 PM
I never heard of Heinkel, Trojan or any supplier fitting or selling counterweights for H/T cars, but some people probably improvised their own. I rarely drive mine alone, but when I do, I store tools, spares, shopping etc on the left side, but really the balance is pretty good anyway. Mind you, I am not exactly the heaviest person around!
Title: Re: Isetta counter weight
Post by: steven mandell on October 02, 2010, 06:22:35 PM
Jean Thankyou for tipping over Bob's assertion of gobblygook.  In consideration of your disclaimer, I only address the latter two questions to yourself.
Does that mean that if you picked up a passenger you were supposed to slide the weight  closer to the centerline of the car a distance proportionate to the difference between the weight of the driver and that of the passenger biased in the direction of the lighter of the two?
Did the weight just sit there, or was it affixed by some means?
Did it look like the gold brick being auctioned on E bay?
Title: Re: Isetta counter weight
Post by: marcus on October 02, 2010, 07:20:53 PM
In about the late 1970s I heard that Bonds (or some of them) had a rod running across the car (under the dashboard?) with a slidable weight. Seems like quite a good idea for a light side-by-side 3 wheeler, as long as you can remove it easily when fully loaded. Tandem seating avoids this issue, but given the choice of being balanced but separate from your partner, or sharing a bench seat is a no-brainer for me!
Title: Re: Isetta counter weight
Post by: steven mandell on October 02, 2010, 08:13:16 PM
Sounds good for establishing equal tippability right and left.
However if one wishes to limit tendency to tip over as effectively as possible-  under dashboard mounting would be considerably higher than the ideal. 
I didn't catch which way you were leaning towards with the tandem vs. bench seat options. 
Don't forget that the extra rearward displacement of a tandem seated passenger places the center of gravity considerably more rearward, and hence away from the only significant source of resistance to roll over- the front springs.
Title: Re: Isetta counter weight
Post by: marcus on October 02, 2010, 08:19:26 PM
Bench seat any day of the week! I love 'smitts but nothing beats a bench seat! True about rear tandem passenger: the more weight at the single wheel end the worse the cornering.
Title: Re: Isetta counter weight
Post by: Bob Purton on October 02, 2010, 08:42:17 PM
Sliding weight under the dashboard? More gobbledigook!! I would stake my overdraft on it!!  Some individuals may have come up with these things independantly, when I drove a Hillman Imp I carried a sand bag under the bonnet to improve grip but Huillman did not supply there cars with a sand bag as an optional extra!
Title: Re: Isetta counter weight
Post by: marcus on October 02, 2010, 08:56:02 PM
 Reckon so, another urban myth!
A fellow Fabulous Fezhead used to drive his Bond around Maidstone.


Balanced on 2 wheels.
Title: Re: Isetta counter weight
Post by: g-o-g-g-o on October 02, 2010, 10:00:29 PM
Hi All
         Let me solve this puzzle for you - the advert for the gold covered brick - is a FOOT WARMER - I have a similar brick and on the base it has cast into the brick "NAWELL'S PATENT FOOT WARMER" it is painted yellow/gold also - you warmed it up in the oven and then you took it out to your car to keep the passengers feet warm. I can only suppose that the current owner found it under the seat!!!
   The Isetta block of steel was much heavier and placed as far to the left of the car as possible ( The Isetta works at Brighton used to repair Railway Steam trains ) to counter the weight of the driver - you have to remember that people were a lot lighter in the 50's being just after the war - and no Big Mac's to feed them up - that is why the RHD Isetta's were slower than the LHD cars - if you put a weight in the Heinkel/Trojan or bond it would slow the car down - I think it took 3 MPH of the RHD Isetta's top speed.
                                                                                                                                                                                   Mike
Title: Re: Isetta counter weight
Post by: marcus on October 02, 2010, 10:06:22 PM
A foot warmer, that makes sense!
Title: Re: Isetta counter weight
Post by: Big Al on October 03, 2010, 09:51:31 AM
A foot warmer, that makes sense!

In an historical context way yes. I used to be sent to pre-school with a baked potato in my pocket to keep warm and which I ate with my free milk. None of this school closed because its cold nonsense. That ages me into a very rural type. From a modern perspective the 'warmer' sound bonkers but in the bubble era we used to have winters. I am not sure it is an improvement on the hot water bottle though. Great marketing of a brick really.

Tandem verses bench. If you are sociable in a car then there is no contest but the Tandem is the purer arrangement of a trike for drivability. Of the products that attempted it I think the Messerschmitt was really the only successfull one in terms of sales. That suggest the driving public prefer the bench. It will come as no suprise that I prefer the tandem. If I want to be sociable I will take out something a bit more sophisticated so my special friend does need a hot brick as it has an efficient heater. Are females reptilian as they always feel the cold and want to sunbath on holiday instead of doing something interesting? That said I have a Messerschmitt rear heater assembly which feeds hot air to both rear and front seat areas with shut of valves on it. It works better than the standard arrangement and can be quite toastie in winter.
Title: Re: Isetta counter weight
Post by: marcus on October 03, 2010, 11:08:55 AM
Going back to units of measurement: I use Imperial and metric depending on what I am measuring, but I have just been ordering some drum heads and parts from a huge German company. Interesting to note that around the world drums and drum heads, drum hoops, tuning bolts, drum sticks, cymbals etc. are mostly measured in inches.
Title: Re: Isetta counter weight
Post by: Big Al on October 03, 2010, 12:13:12 PM
Wheels seem to be imperial, except France who, of course, do there own thing meaning there are really nice cars like CX Gti for which tyres are a real problem. So are round things imperial?
Title: Re: Isetta counter weight
Post by: marcus on October 03, 2010, 12:18:08 PM
Round Toits are immeasurable!