Flexi Chassis an Appreciation

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proto87stores

Re: Flexi Chassis an Appreciation

Postby proto87stores » Sat May 20, 2017 5:16 pm

billbedford wrote:
proto87stores wrote:
But you continue to propose Hornblocks. They fall into all your criticism categories. And several others.



Please feel free to enumerate that way you think this would be true.


1 Coach bogie : Image

2 thru 16, various locomotive frames: e.g. sample Image

Andy

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Horsetan
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Re: Flexi Chassis an Appreciation

Postby Horsetan » Sat May 20, 2017 6:27 pm

The hills are alive.....with the sound of sneering..... :roll:
That would be an ecumenical matter.

billbedford
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Re: Flexi Chassis an Appreciation

Postby billbedford » Sat May 20, 2017 6:47 pm

proto87stores wrote:
billbedford wrote:
proto87stores wrote:
But you continue to propose Hornblocks. They fall into all your criticism categories. And several others.



Please feel free to enumerate that way you think this would be true.


1 Coach bogie : Image

2 thru 16, various locomotive frames: e.g. sample Image



Your point?
Bill Bedford
Mousa Models
http://www.mousa.biz

proto87stores

Re: Flexi Chassis an Appreciation

Postby proto87stores » Sat May 20, 2017 6:55 pm

Horsetan wrote:The hills are alive.....with the sound of sneering..... :roll:


Sorry, I thought Bill was denying that he proposes Hornblocks normally and challenging me to show that he does. There are several CLAG examples where he supplies/uses equalizing beams, so I had to then look up Bill's loco kits site to be sure that he was consistent on locomotives. I don't live here, so I'm not particularly familiar with all UK suppliers current activities.

I'm pretty sure I already listed several relevant disadvantages of hornblocks in earlier postings, including at least one back to Bill. So I already previously answered the other aspect of his post.

Andy

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grovenor-2685
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Re: Flexi Chassis an Appreciation

Postby grovenor-2685 » Sat May 20, 2017 7:55 pm

Sorry, I thought Bill was denying that he proposes Hornblocks normally and challenging me to show that he does.

Bill, and I earlier were asking to see your alternative, hornblock free version, so we might understand you better.
Regards

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Will L
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Re: Flexi Chassis an Appreciation

Postby Will L » Sat May 20, 2017 7:59 pm

For what its worth, I had the chance today to put my head into the guts of a nice japanse built, american style, bar framed, fully equalised narrow gauge Pacific which is currently residing on the Hejaz railway in Jordan. I have to tell you that as a form of loco suspension, simple it is not.
DSCF1388.JPG

There's were a lot less bits under the the UK classic Doncaster built plate frame individualy sprung version.
P1100125.JPG

Philip Hall
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Re: Flexi Chassis an Appreciation

Postby Philip Hall » Sat May 20, 2017 8:14 pm

Will, nice to see the engine is still there. Looks in the same condition as when I was there a few years ago. I guess the desert must be good for it...

Philip

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Will L
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Re: Flexi Chassis an Appreciation

Postby Will L » Sat May 20, 2017 8:43 pm

proto87stores wrote:
billbedford wrote:Speaking as a kit designer, I think there is a difference between things being simple because people are used to the methods of construction and simple because as much of the design work as possible has been separated from the construction. i.e. anything that increases the component count is going in the wrong direction.


But you continue to propose Hornblocks. They fall into all your criticism categories. And several others.

Whats wrong with using hornblocks? The only person criticising them seems to be you . Beams with bearings in are fine for a 4 wheeled truck but for anything bigger I'm not sure you have made any case as yet. As to component count and good design keeping it simple, as the horn guides in Bill's chassis are included in the main frame etches, the suspension component count for his kits is kept to a minimum, (two axle blocks per axle plus two spring wire for the driving wheels, and two more if there is a bogie). How many composts would your need to equalised for the same loco have do you think?

In any event as full optimised designed chassis, CSB or equalised, are never going you exist for most UK loco types. So most of us will be making our own from individual generalised components not custom designed items, and that inevitably means more components than a customer designed job would need. So again, how is your equalising system going to address something like my O4 2-8-0?

Crepello
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Re: Flexi Chassis an Appreciation

Postby Crepello » Sat May 20, 2017 9:51 pm

Will L wrote:So again, how is your equalising system going to address something like my O4 2-8-0?

Or indeed anyone's 9F. A good head start for Andy might be to acquire one of the Dave Bradwell chassis kits, and show us a photo of what he has to leave out, and what he needs to put in to obtain his improvements.

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LesGros
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Re: Flexi Chassis an Appreciation

Postby LesGros » Sun May 21, 2017 7:34 am

Crepello wrote:[... A good head start for Andy might be to acquire one of the Dave Bradwell chassis kits, and show us a photo of what he has to leave out, and what he needs to put in to obtain his improvements.

Possibly.

Whilst that may provide an interesting exercise for Andy, at the end of it we would still be left with the conclusion that the main function of modelling is to replicate, in miniature, what we see; at an appropriate level of detail resolution for the scale adopted.

I think it is also safe to say that: an exercise in making design changes to Dave Bradwell's carefully worked out chassis' is highly unlikely to make any worthwhile improvement to their quality as working models of British steam locomotion.
LesG

The man who never made a mistake
never made anything useful

billbedford
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Re: Flexi Chassis an Appreciation

Postby billbedford » Sun May 21, 2017 2:28 pm

proto87stores wrote:
billbedford wrote:
proto87stores wrote:
But you continue to propose Hornblocks. They fall into all your criticism categories. And several others.



Please feel free to enumerate that way you think this would be true.


1 Coach bogie :

2 thru 16, various locomotive frames: e.g. sample



That's all old stuff. The new production has neither springs nor equalisation.

Gresley Standard Bogie.jpg
Bill Bedford
Mousa Models
http://www.mousa.biz

proto87stores

Re: Flexi Chassis an Appreciation

Postby proto87stores » Sun May 21, 2017 2:32 pm

LesGros wrote:
Crepello wrote:[... A good head start for Andy might be to acquire one of the Dave Bradwell chassis kits, and show us a photo of what he has to leave out, and what he needs to put in to obtain his improvements.

Possibly.

Whilst that may provide an interesting exercise for Andy, at the end of it we would still be left with the conclusion that the main function of modelling is to replicate, in miniature, what we see; at an appropriate level of detail resolution for the scale adopted.

I think it is also safe to say that: an exercise in making design changes to Dave Bradwell's carefully worked out chassis' is highly unlikely to make any worthwhile improvement to their quality as working models of British steam locomotion.


I agree. My intention is not to have parts to modify existing chassis kits. Nor would I consider myself at all qualified to match the prototype knowledge and dedication to accurate detail of those who make their UK model chassis extremely cosmetically realistic. So I'm not trying to.

Instead I'm suggesting designing the functional working model suspension aspects of loco chassis, (for kits) from scratch in a fundamentally different way. And focusing that as a "problem solved" solution to those who would consider any current aspect of P4 (or Proto87) working suspension loco methods beyond their basic necessary 00 or HO modelling skill level.

Andy

proto87stores

Re: Flexi Chassis an Appreciation

Postby proto87stores » Sun May 21, 2017 2:48 pm

billbedford wrote:
proto87stores wrote:
billbedford wrote:
proto87stores wrote:
But you continue to propose Hornblocks. They fall into all your criticism categories. And several others.



Please feel free to enumerate that way you think this would be true.


1 Coach bogie :

2 thru 16, various locomotive frames: e.g. sample



That's all old stuff. The new production has neither springs nor equalisation.

Gresley Standard Bogie.jpg


Well, provided it does have some form of working suspension, that can handle a practical range of different model weights, that's clearly a good thing. However, it's not clear to me from your picture if the hornblocks move separately. If not, and the the suspension method is just some form of plastic flexing, I'm unsure how that would apply to the previously suggested 9F chassis problem though.

Andy

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Jol Wilkinson
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Re: Flexi Chassis an Appreciation

Postby Jol Wilkinson » Sun May 21, 2017 3:41 pm

billbedford wrote:
That's all old stuff. The new production has neither springs nor equalisation.

Gresley Standard Bogie.jpg


So it "compensates" by distorting? Which is what Peter Chatham's etched PC bogies did, but which were rather more complicated to assemble. While it has the beauty of simplicity, it goes away from the claimed benefits of using springs for a better "ride", no?

billbedford
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Re: Flexi Chassis an Appreciation

Postby billbedford » Sun May 21, 2017 4:51 pm

Jol Wilkinson wrote:
So it "compensates" by distorting? Which is what Peter Chatham's etched PC bogies did, but which were rather more complicated to assemble. While it has the beauty of simplicity, it goes away from the claimed benefits of using springs for a better "ride", no?


The most important thing in the quest for good running is keeping the wheels on the rails. The one thing, more than anything else, that stops wheels running on rails is the inability of people to finish kits.
Bill Bedford
Mousa Models
http://www.mousa.biz

proto87stores

Re: Flexi Chassis an Appreciation

Postby proto87stores » Sun May 21, 2017 5:02 pm

billbedford wrote:
Jol Wilkinson wrote:
So it "compensates" by distorting? Which is what Peter Chatham's etched PC bogies did, but which were rather more complicated to assemble. While it has the beauty of simplicity, it goes away from the claimed benefits of using springs for a better "ride", no?


The most important thing in the quest for good running is keeping the wheels on the rails. The one thing, more than anything else, that stops wheels running on rails is the inability of people to finish kits.


Well, I was going to ask what was the specification (limit numbers) for handling track twist and track height bumps. And of course how those differ (more/less, better/worse) from the numbers for your "old" versions.

Andy

billbedford
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Re: Flexi Chassis an Appreciation

Postby billbedford » Sun May 21, 2017 6:17 pm

proto87stores wrote:Well, I was going to ask what was the specification (limit numbers) for handling track twist and track height bumps. And of course how those differ (more/less, better/worse) from the numbers for your "old" versions.


Why do you need to know that? It's for a toy train for goodness sake.
Bill Bedford
Mousa Models
http://www.mousa.biz

garethashenden
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Re: Flexi Chassis an Appreciation

Postby garethashenden » Sun May 21, 2017 6:46 pm

Will L wrote:For what its worth, I had the chance today to put my head into the guts of a nice japanse built, american style, bar framed, fully equalised narrow gauge Pacific which is currently residing on the Hejaz railway in Jordan. I have to tell you that as a form of loco suspension, simple it is not.
DSCF1388.JPG
There's were a lot less bits under the the UK classic Doncaster built plate frame individualy sprung version.
P1100125.JPG


I've always thought of CSBs as spring-compensated or spring-equalised as they use the spring to compensate multiple axles for a given deflection. This is actually fairly close to the method used on bar-framed locomotives where the springs are often connected to the frame on one side, the axle in the middle and some sort of compensation beam on the other side. This beam is then connected to the neighboring axle's spring linking the two axles. Depending on the specific locomotive all the axles can be linked this way or just a pair with a single axle sprung separately.
There is a Boston & Maine 2-6-0 I'm working on that has the front axle sprung above the frames and the second and third axles sprung-compensated bellow the frames. Luckily for me the model is in N and can be built rigid.

Here is a drawing of a B&M 2-8-4 showing the springs above the wheels and the compensation beams between the axles. From Mainline Modeller November 1984.
Image

proto87stores

Re: Flexi Chassis an Appreciation

Postby proto87stores » Sun May 21, 2017 7:23 pm

billbedford wrote:
proto87stores wrote:Well, I was going to ask what was the specification (limit numbers) for handling track twist and track height bumps. And of course how those differ (more/less, better/worse) from the numbers for your "old" versions.


Why do you need to know that? It's for a toy train for goodness sake.


It rather depends on whether you are, as a designer, guaranteeing (money back) that it will therefore always run flawlessly on all your customers popular notions of what is all "toy train track", and it does, then you are right. No-one needs to.

Andy

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Jol Wilkinson
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Re: Flexi Chassis an Appreciation

Postby Jol Wilkinson » Sun May 21, 2017 9:26 pm

billbedford wrote:
Jol Wilkinson wrote:
So it "compensates" by distorting? Which is what Peter Chatham's etched PC bogies did, but which were rather more complicated to assemble. While it has the beauty of simplicity, it goes away from the claimed benefits of using springs for a better "ride", no?


The most important thing in the quest for good running is keeping the wheels on the rails. The one thing, more than anything else, that stops wheels running on rails is the inability of people to finish kits.


Bill,

I quote an previous comment from you "With the exception of traction engines, just about all full sized vehicles rode on springs, why would anyone want to model anything else?"

So I wonder if you see any irony in this and other posts posts from advocates of CSB's extolling the advantages of springing - and then presenting a product which is literally a "Flexichass".

Further, unless you finish a kit, how do you know the wheels won't stay on the rails?

Joking aside, will you have LNWR 8' and 9' bogies available in that new concept?

Jol

proto87stores

Re: Flexi Chassis an Appreciation

Postby proto87stores » Tue May 23, 2017 12:22 am

Jol Wilkinson wrote:
billbedford wrote:
Jol Wilkinson wrote:
So it "compensates" by distorting? Which is what Peter Chatham's etched PC bogies did, but which were rather more complicated to assemble. While it has the beauty of simplicity, it goes away from the claimed benefits of using springs for a better "ride", no?


The most important thing in the quest for good running is keeping the wheels on the rails. The one thing, more than anything else, that stops wheels running on rails is the inability of people to finish kits.


Bill,

I quote an previous comment from you "With the exception of traction engines, just about all full sized vehicles rode on springs, why would anyone want to model anything else?"

So I wonder if you see any irony in this and other posts posts from advocates of CSB's extolling the advantages of springing - and then presenting a product which is literally a "Flexichass".

Further, unless you finish a kit, how do you know the wheels won't stay on the rails?

Joking aside, will you have LNWR 8' and 9' bogies available in that new concept?

Jol


I'm not seeing any statement from Bill about any flexibility incorporated the frame. So I'd rather wait for Bill to tell us how it is better suspension-wise from the Hornby and other common plastic bogies.

Andy

billbedford
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Re: Flexi Chassis an Appreciation

Postby billbedford » Tue May 23, 2017 8:13 am

The bolster is fixed in place with two torsion pins. This gives it plenty pitch and a little roll freedom.
Bill Bedford
Mousa Models
http://www.mousa.biz

proto87stores

Re: Flexi Chassis an Appreciation

Postby proto87stores » Tue May 23, 2017 2:39 pm

billbedford wrote:The bolster is fixed in place with two torsion pins. This gives it plenty pitch and a little roll freedom.


But the side frame ends are solidly linked, so no twist freedom to handle even small bumps on one side of the track only? I can tell you from lots (really lots) of experience, with many similar plastic designs over here, that none of them stay on the track with P:87 wheels. My Bachmann MK1 ones didn't either, until I added equalization to handle it. Even ones with open ends like below didn't have enough twist flexing freedom.

Image

and ones designed to be even more flexible:

Image

Symmetrical pitch is really only needed for vertical curves. But regardless, the really simple way to provide bogie pitch on plastic trucks is to have a slight crosswise ridge on top of the bolster. That way there is no stiff resistance to pitch movement. If you want a little roll freedom as well, make it a tad crescent shaped vertically. On this RTR, the ridge is on the king pin, but of course they have the option of molding their own floor.

Image

Either way, with roll freedom, you have to make sure (or adjust) the coach body c of g is perfectly central sideways. Otherwise the coach will have a permanent static sideways tilt.

Andy

proto87stores

Re: Flexi Chassis an Appreciation

Postby proto87stores » Wed May 24, 2017 3:14 pm

The etch for the Airfix Mineral Wagon fully equalized Flexichas experiment arrived yesterday.

Here's a quick preview:

Image

The longitudinal and (fold up) transverse equalizing beams containing the w iron end shapes are designed to fit up against a flat wagon floor. The existing kit floor upside down may a simple solution .

The duplicated W iron shapes are thin and are presently intended to be hidden situated behind the plastic Airfix W Irons and solebars, for the purpose of a functional rather than perfectly cosmetic test. The wheel bearings are ball bearings which conveniently act as the pivots for the beam ends as well as connecting them all together.

The fold up beams have holes for twin guide pins mounted in the (optionally pre-drilled) floor, for holding them in the correct position, together with a hole for a mounting screw to keep the whole assembly loosely together when the wagon is off the track.

The 4 washers are to make sure the inner and outer sides of the wheel bearings don't cause any friction with the wrong parts.

Providing there are no fatal goofs, I'll post construction progress as I go along.

Andy

Proto87Stores

Re: Flexi Chassis an Appreciation

Postby Proto87Stores » Wed Jun 28, 2017 3:42 am

Sorry for the long pause in continuing. The town where my workshop is situated has just passed an ordinance that makes industrial growing, preparation and distribution of Marijuana locally legal. Sadly the owners of the suite of buildings used by the Stores has sold out at a huge profit to some LA investors who will convert our building to that use, making it necessary for me to pack all the equipment and relocate at short notice. Similar relocations are taking place for many of the small businesses in the area. Such are the joys of unrestrained capitalism.

Image

Never the less, I did find time to knock up a chassis test floor for the 16 T Mineral wagon. I don't want to destroy any of the the Airfix ones, as I rather like the thought of having a bunch on the nostalgia section of my layout. So above is a picture of the original and the experimental one side by side, plus a similar very small test floor for the London Transport E1 tram. The latter has a mounting aperture for what may be a suitable motor along side and mounting holes for the new power trucks.

Andy


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