Teaky's attic

[gordon s]

9 minutes ago, 73c said:

They come as a pair, listing is a bit confusing. Also in different length's

 

https://www.ebay.co.uk/itm/2set-SBR12UU-12mm-Slide-Block-Bearing-SBR12-410mm-Fully-Supported-Linear-Rail/282496146938?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

 

Thanks for that, they look terrific. The rigidity of the shaft could overcome numerous issues with a large table and the pricing seems reasonable compared to heavy duty slides. I'm guessing there are two diameters, 12mm and 16mm and various lengths. The really strange thing is that depending on the spec, some come from the UK, some from Bern in Switzerland and one combination I looked at was from from the US, but they said they wouldn't post to the UK. Certainly bears a lot more investigation.

 

Many thanks for that as they could be a possible solution to overhang on a large rectangular table.

[teaky]

10 minutes ago, 73c said:

They come as a pair, listing is a bit confusing. Also in different length's

 

https://www.ebay.co.uk/itm/2set-SBR12UU-12mm-Slide-Block-Bearing-SBR12-410mm-Fully-Supported-Linear-Rail/282496146938?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

Some of the links to similar items from US sellers are a little more helpful.  They look good.  I haven't explored yet but there didn't appear to be anything regarding the weight they are able to support.  I have been working on an assumed train weight of 2kg which adds up to quite a lot once there is a full traverser.

[gordon s]

One of the things I’ve been thinking about, Rob is that with three entry points with each covering five tracks, the total back and forth movement is just 200mm and I may make the bed wider than the table by 200mm, so the slides are fully supported all the way across and no overhang at all.

 

I’m still some way from building the traverser. It will follow after the full circuits are completed. We can compare construction notes....

[73c]

Did a bit of digging and found this, if I'm reading it right, the sbr12 will take 65kg and the sbr16 150kg. Need to scroll down for charts.

 

https://www.ebay.com/itm/SBR12-16-20-500mm-Linear-Rod-Rail-Support-SBR-Linear-Slide-Bearing-Block-/262916986977

 

 

[teaky]

9 minutes ago, gordon s said:

One of the things I’ve been thinking about, Rob is that with three entry points with each covering five tracks, the total back and forth movement is just 200mm and I may make the bed wider than the table by 200mm, so the slides are fully supported all the way across and no overhang at all.

 

I’m still some way from building the traverser. It will follow after the full circuits are completed. We can compare construction notes....

Not necessarily, Gordon.  The drawer runners have three sections that telescope out, so it is overhang of the runners you need to be concerned about.  However, you may have solved that with only 200mm of movement.

[gordon s]

I need to check the ones I have, but I was thinking of having runners at least 200mm wider than tbe table so that by they always ran within the confines of the slide.

 

To late to play around tonight, but I’ll dig them out in the morning and report back.

Edited February 6, 2020 by gordon s

[croydon junction]

2 hours ago, 73c said:

Would something like this be any good for a traverser?

There are other CNC fittings that will admittedly deflect more, but are much cheaper and will do a fairly good job. Deflections could be reduced by having a longer bar than required, and having an extra support at each end, pulling the bar down if loaded in the middle by the traverser.

 

Best of luck,

 

Matthew

Edited February 6, 2020 by croydon junction
too many uploads of the traverser

[teaky]

2 minutes ago, gordon s said:

I need to check the ones I have, but I was thinking of having runners at least 200mm wider than tbe table so that by they always ran within the confines of the slide.

 

To late to play around tonight, but I’ll dig them out in the morning and report back.

I don't think you need runners that long.  It's the total travel that is key.  It would be possible to alter the 450mm runners I have so that only the two larger slides are used and the third slide does not extend.  This would give more than 200mm of extension.

[teaky]

Whilst researching and pondering traversers I have also been fabricating a small unit for the joint between the elevator and the layout.

 

 

It is a little crude but I'm pleased with how it has turned out and was within a millimetre, needing only a light sanding of the end of the elevator to align satisfactorily.  At some point I will make a couple of bolts from brass bar and tube to align the rails and carry power.

 

With the end sitting on the plywood bolt all that is needed is a prop further along which is made from a softwood pole and a plywood foot.

 

 

The next baseboard will be bolted to the left hand end of the bolt box and continue on from there.

 

Edited August 11, 2022 by teaky
Re-adding photos.

[Stubby47]

Have you thought about one of those slidy-bolt units at each end, with the bolts driven by a servo, so you can hold the elevator and then engage/disengage both ends together?

[teaky]

I have thought about a whole heap of options.  The start point was an automated stack of tracks but I gradually dismissed various aspects due to space, access if anything derailed, unnecessary complexity etc. etc.  The design was gradually pared back to this very basic set up.  At the last minute I even decided to have only one prop.  I cut two plywood bases, tried it with one prop and found that the elevator is sufficiently supported and stays almost level# throughout its length.  There is a slight dip towards the right hand end but I don't see this as an issue at the moment since trains will have a locomotive holding them steady.  If the dipping increases too much with a locomotive at the far end, I'll just finish the second prop.

 

To operate the elevator I can stand near the centre and, by swapping hands reach the prop or the bolt with ease.  In fact, if I stretch I can reach the bolt and the prop at the same time but that leaves me holding the elevator in my teeth. 

 

# 'Almost level' in this context means the sprit level bubble might not be dead centre but always remains within the lines.

 

[teaky]

After further research on the web, the traverser thread and a helpful exchange of PMs with Taz I have changed some of my thinking on the traverser.

 

Rightly or wrongly (because I won't know until I try) the outline spec. for the traverser is as follows.

  - 2.8m x 0.6m x 9mm birch ply traverser bed with bracing underneath and raised sides and end.

  - Five drawer runners mounted flat - three one way and two the other.  (Already in stock so I'll see how this goes and I can change to the CNC style slides posted by 73c if more precision is needed.)

  - Open frame base for access to runners during construction.  (Although this may be of limited use with runners mounted flat so I might alter this.)

  - Overlap the ends of the base so that there is light contact between the underside of the base and the framing under the edge of the lead in and storage tracks plus similar framing at the far end.

  - Align tracks by eye then lock using home made brass bolts providing precise alignment and power transfer.

  - Copper clad strips at track ends to which the track and bolts will be soldered.

  - Dust covers.  (Probably softwood framing and polyethylene sheets.)

  - Single central handle to reduce tendency to twist.

 

I have a few more baseboards to construct first, so I'll have more time to think about the traverser whilst I do so just in case I change my mind again!

 

Edited February 13, 2020 by teaky
Added point about handle before I forget again.

[teaky]

Plus a further plug for our RMweb chum 2ManySpams via gwrrob's thread.

 

https://www.rmweb.co.uk/community/index.php?/topic/69664-a-nod-to-brent-fun-friendly-frivolity-and-happy-days-in-the-south-hams-1947/&do=findComment&comment=3836843

[73c]

Blimey! I've been allocated to Southall   

Edited February 12, 2020 by 73c
spelling

[teaky]

1 minute ago, 73c said:

Blimey! I've been allocated to Southall   

Oops, I knew I should have gone back and checked.  Now corrected.  Sorry.

 

I wasn't mixing you up, just mistyping, but there is actually another RMwebber called 81c.

 

[AdeMoore]

Hi Rob, on your traverser quest I wonder if you’ve seen Craster over on Western Thunder?.

Richard calls it a fiddle yard more super traverser in my opinion Link post #25 you need to be a member to see full size photos otherwise they are thumbnails.

Basically it moves in three plains back to front as normal, but drawer runners mounted on edge as they would in the drawer world. Then left and right to allow the above and the final action because of the last one a complete 360 deg turn! 
worth joining if your not a member to see it, and the baseboards come to that.

sorry if all that is spilt milk.

 Cheers 

[Barry O]

Beginning to think "KISS" principlal...the more complex something becomes the more chance of tears in operation..

 

Baz

[teaky]

9 hours ago, AdeMoore said:

Hi Rob, on your traverser quest I wonder if you’ve seen Craster over on Western Thunder?.

Richard calls it a fiddle yard more super traverser in my opinion Link post #25 you need to be a member to see full size photos otherwise they are thumbnails.

Basically it moves in three plains back to front as normal, but drawer runners mounted on edge as they would in the drawer world. Then left and right to allow the above and the final action because of the last one a complete 360 deg turn! 
worth joining if your not a member to see it, and the baseboards come to that.

sorry if all that is spilt milk.

 Cheers 

No I had not seen that thread, Ade.  I wonder why it didn't crop up in web search results?  Possibly just me not throwing enough alternative terms at the search engine.  I am not a member of Western Thunder (I expect brownie points for that Mr York ).  I already spend enough time on model railway forums so I chose not to add another one.

 

I followed your link and it is an interesting idea but for me there are flaws:

 1. I don't think my carpentry is up to the precision required.  I don't have a workshop with the necessary tools to cut precise straight lines, so my construction tends to allow for some inaccuracy.

 2. I would need a lot of space to move and rotate a 2.8m traverser which I could squeeze in but it would mean a substantial area being kept free of furniture of any kind.  If you have a layout at table height or higher then you could arrange for the traverser to swing out above furniture.  I have compromised on a lower datum in order to be able to maximise the width beneath the sloping ceiling.  This puts the storage tracks much closer to the floor, leaving no space for furniture underneath.

 3. I'm not convinced that two drawer runners are sufficient for larger tables.  Not because they won't take the weight but because of a greater tendency to move around.  I have been using a working assumption of 2kg per train so if the weight of the timber is included the total is well on the way to 50kg.  This is bound to introduce some wobble and would have momentum too.

 

For a layout with shorter trains it is an appealing idea.  I might be tempted to opt for an off-the-shelf solution though from one of the laser cut baseboard manufacturers.

 

[teaky]

2 hours ago, Barry O said:

Beginning to think "KISS" principlal...the more complex something becomes the more chance of tears in operation..

 

Baz

I agree, oh rain god Baz.

 

[Barry O]

Next place needing rain..north island new zealand...

 

Baz

[teaky]

It might be worth commenting here that the simplest solution to storing long trains is a traditional fiddle yard and this is especially true for large exhibition layouts and for people wanting to recreate working time tables.  The arrangement I have gone for means there is a slightly long-winded route to and from storage but what I gain is a greatly increased length of scenic layout.  I am aiming for four trains at a time at layout level which will have two storage loops and a double track main line.

 

Although this is the first layout I have built, I know that I like watching the trains go by and the construction of models.  I wanted to avoid the station along one side of the room with fiddle yard along the other approach.  Nothing wrong with this, just not for me.  In fact, there are plenty of exhibition layouts where this works brilliantly.  Of course, when I come to ballast all the track I may change my mind!

 

Edited February 13, 2020 by teaky

[AdeMoore]

11 hours ago, teaky said:

No I had not seen that thread, Ade.  I wonder why it didn't crop up in web search results?  Possibly just me not throwing enough alternative terms at the search engine.  I am not a member of Western Thunder (I expect brownie points for that Mr York ).  I already spend enough time on model railway forums so I chose not to add another one.

 

I followed your link and it is an interesting idea but for me there are flaws:

 1. I don't think my carpentry is up to the precision required.  I don't have a workshop with the necessary tools to cut precise straight lines, so my construction tends to allow for some inaccuracy.

 2. I would need a lot of space to move and rotate a 2.8m traverser which I could squeeze in but it would mean a substantial area being kept free of furniture of any kind.  If you have a layout at table height or higher then you could arrange for the traverser to swing out above furniture.  I have compromised on a lower datum in order to be able to maximise the width beneath the sloping ceiling.  This puts the storage tracks much closer to the floor, leaving no space for furniture underneath.

 3. I'm not convinced that two drawer runners are sufficient for larger tables.  Not because they won't take the weight but because of a greater tendency to move around.  I have been using a working assumption of 2kg per train so if the weight of the timber is included the total is well on the way to 50kg.  This is bound to introduce some wobble and would have momentum too.

 

For a layout with shorter trains it is an appealing idea.  I might be tempted to opt for an off-the-shelf solution though from one of the laser cut baseboard manufacturers.

 

I have to say although impressed by Crasters woodwork, I actually entirely agree with all your points above. I do need to take a wider view. Impressed first realistic 2nd!

 Cheers 

[teaky]

A mini milestone.  The final baseboards are now in place.  These boards will act as a kind of spine to which to attach the scenic supports.  The legs are just temporary pending completion of the storage area below.

Edited August 11, 2022 by teaky
Re-adding photos.

[gordon s]

That's far too good for a model railway. I daren't show that to my wife as she'd have me painting everything to that standard.......

[teaky]

11 minutes ago, gordon s said:

That's far too good for a model railway. I daren't show that to my wife as she'd have me painting everything to that standard.......

I read your comments elsewhere in relation to spectacles.  You definitely need some new ones! 

 

Don't be fooled by the green emulsion.  It is an effective way of hiding the dodgy carpentry but only from a distance.  Close up it's rubbish.  I think it should be strong enough though, which is the main thing.

 

Edited March 6, 2020 by teaky