Ian M's 7mm workbench - Back to the MACAW B.

[Ian Major]

Thank you for all the likes guys.

 

Well - the sheet hooks are made and fitted, only 20 on this one!

 

I have started on the trussing which I am making from 2 x 2mm brass angle. First were the 8 queenposts.

 

 

Then I fitted the outer horizontal parts and the cross bracing. Much checking of things being square etc. I also fitted the brake "V" hangers. I found out from the previous MACAWs that it was easier fit them at this stage rather than later. I used the kit supplied hangers that were displaced by my scratch built DC brakes on the first B.

 

 

Next on were the inner horizontal parts.

 

 

Then I started to measure up for the diagonal bracing. This revealed two issues - one predicted, one not.

 

The issue that I predicted was that the bogie mountings having to be attached fore and aft occupy the area where the inner diagonal bracing needs to be fixed. I should be able to secure them with some deep brackets.

 

The other issue is that the "V" hangers from the kit are a scale 4 inches too tall, about 2mm. My intention is to surreptitiously give additional support to the diagonal bracing by attaching it to the brake cross shafts. So the "V"s have to be the right height. This I should have spotted before fitting them. 

 

 

This is a detail of the MACAW B at Didcot showing how close the brake shaft is to the diagonal trussing.

 

 

I will take the "V"s back off and reduce their height and hopefully make progress from there.

 

Ian.
 

Edited July 14, 2021 by Ian Major

[Ian Major]

The next step was to fit the first of the diagonal truss parts. I removed the 'V's at that end and reduced them to the correct height. I used a piece of metric graph paper to make sure I was taking the legs down evenly. I didn't want a "leaning Tower of Pisa" effect.

 

When I was happy with its height I fitted it in front of the diagonal bracing. It looks much better now.

 

 

The next view shows the first diagonal on the right. I have fixed a packing piece between the brace and solebar. The join at the queen post was also a bit weak so I spanned it with a piece of 0.5mm wire - it acts as a sort of fishplate.

 

As can be seen the inner bracing would have fouled the bogie mounting.

 

 

To handle this problem I added an extra cross piece using the same brass channel as the solebars. After adding the second outer diagonal truss I wedged the new cross piece under the two diagonals, then when the inner diagonals were added they were simply fixed to the cross piece and cut short of the bogie mounting.

 

I made a boo boo with the cross pieces. I mounted them with their webbing facing the buffer beams. I should have mounted them with the flanges towards the buffer beams. If I need to cut recesses in the cross pieces to clear the wheel flanges it is a bigger job cutting the webbing rather than the flanges. Sadly I had already fitted all the diagonals before picking this up. My forward planning capability is obviously fading.

 

 

At this point I fitted the bogies and their mountings. I also added the bogie kit supplied spacers. This was to check nothing clashed, check the ride height plus seeing it on its wheels helps my motivation!

 

The next photo shows the new B next to the first B. The new B is standing about 1mm high. The kit supplied spacers are 1.5mm thick, so I will use my cutter to create some 10thou spacers from plastic - a quick job.

 

The photo also makes an interesting profile comparison between the old Connoisseur plate bogies (on the right) and the new ones. I think Jim's latest bogies look superb, and I haven't fitted the brakes yet. 

 

 

Whilst I was doing this I checked how far the bogies would swing before fouling any part of the body. It turned out to be 15 degrees. Now knowing the distance between the bogie centres and using my school Trigonometry I calculated my new B would be able to negotiate a curve of radius slightly less than 2ft. Though when I lower the body by one mm to correct the ride height this will reduce the wheel clearance so I will recalculate when the wagon is finished but before painting - in case I need to attack those cross pieces. 

 

 

I have a little more work on the trussing then it is adding the brake levers and making the ratchets for them. These will conclude the soldering work. The white metal detail will be glued on.

 

Ian.   
 

Edited July 17, 2021 by Ian Major
To get rid of my 'Alo, 'Alo spelling. "... would ave ..." I mean really.

[georgeT]

9 hours ago, Ian Major said:

The next step was to fit the first of the diagonal truss parts. I removed the 'V's at that end and reduced them to the correct height. I used a piece of metric graph paper to make sure I was taking the legs down evenly. I didn't want a "leaning Tower of Pisa" effect.

 

When I was happy with its height I fitted it in front of the diagonal bracing. It looks much better now.

 

 

The next view shows the first diagonal on the right. I have fixed a packing piece between the brace and solebar. The join at the queen post was also a bit weak so I spanned it with a piece of 0.5mm wire - it acts as a sort of fishplate.

 

As can be seen the inner bracing would have fouled the bogie mounting.

 

 

To handle this problem I added an extra cross piece using the same brass channel as the solebars. After adding the second outer diagonal truss I wedged the new cross piece under the two diagonals, then when the inner diagonals were added they were simply fixed to the cross piece and cut short of the bogie mounting.

 

I made a boo boo with the cross pieces. I mounted them with their webbing facing the buffer beams. I should have mounted them with the flanges towards the buffer beams. If I need to cut recesses in the cross pieces to clear the wheel flanges it is a bigger job cutting the webbing rather than the flanges. Sadly I had already fitted all the diagonals before picking this up. My forward planning capability is obviously fading.

 

 

At this point I fitted the bogies and their mountings. I also added the bogie kit supplied spacers. This was to check nothing clashed, check the ride height plus seeing it on its wheels helps my motivation!

 

The next photo shows the new B next to the first B. The new B is standing about 1mm high. The kit supplied spacers are 1.5mm thick, so I will use my cutter to create some 10thou spacers from plastic - a quick job.

 

The photo also makes an interesting profile comparison between the old Connoisseur plate bogies (on the right) and the new ones. I think Jim's latest bogies look superb, and I haven't fitted the brakes yet. 

 

 

Whilst I was doing this I checked how far the bogies would swing before fouling any part of the body. It turned out to be 15 degrees. Now knowing the distance between the bogie centres and using my school Trigonometry I calculated my new B would be able to negotiate a curve of radius slightly less than 2ft. Though when I lower the body by one mm to correct the ride height this will reduce the wheel clearance so I will recalculate when the wagon is finished but before painting - in case I need to attack those cross pieces. 

 

 

I have a little more work on the trussing then it is adding the brake levers and making the ratchets for them. These will conclude the soldering work. The white metal detail will be glued on.

 

Ian.   
 

 

Very nice young man...

[Ian Major]

Tempus Fugit! Well, like most people, I have been rather distracted by other things, including a spell in hospital (not COVID related). It was time to get a grip and do more work on the second "B".

 

The brake guard was made from a piece of 1.5 x 1.5mm brass angle and some 1.5mm N/S strip. 

 

The angle was filed to represent the teeth of the ratchet and (what would become) the upper end was bent over at 90 degrees. The resultant tab was later soldered to the underside of the solebar.

 

The strip I bent at 90 degrees 25mm from the end. The angle was then soldered to this using 202 degree solder.

 

 

The 25mm tail was adjusted so that it was at 45 degrees to the the ratchet and a 2mm length at the end was bent to form a tab. This was later soldered to the underside of the wagon floor.

The longer part of the strip was bent and cut to length to represent the guard. This end was later soldered to the upper surface of the solebar lower flange.

 

 

The assembly was soldered in place using 145 degree solder. The bracing is a bit wavy in the photo. i later sorted it. I then sorted it a second time after I managed to bend the guard whilst doing other work. Much use of Anglo Saxon language was involved.

 

Strictly, the bracing should be made from angle. I am hoping this wont to be too obvious an omission when it is finally painted black!  

 

 

The kit supplied lever that was displaced by the DC brake gear on the first Macaw was added ...

 

 

... and the vertical part of the brake guard was made from a short length of the 1.5mm strip with pressed rivet detail. This was soldered on to the face of the solebar. I originally tried to make this latter part by folding it as part of the main piece of strip but the result looked naff. It was much easier as separate parts. 

 

This was repeated on the other side. 

 

 

To finish off the soldering I ran 70 degree solder along the top edges of the sides to hide the join. This was dressed with files and emery paper to leave a smooth finish.

Having set the ride height using packing, I cut the excess length off the bolts that protruded through the floor. With the bolts permanently fitted I dressed their ends to be flush with the floor.

 

 

Most of the remaining construction work is to attach the castings. I am short of a couple of buffer rams/heads having run out of suitable steel stock in which to turn them. I will have to have a trip to MACC Models.

 

Ian.    

Edited February 19, 2022 by Ian Major

[Ian Major]

A quick update.

 

All the castings fitted. Construction is now complete except for the two buffer rams/heads.

 

 

When the weather improves the "B" will be moved to the paint shop.

 

In the meantime I will revisit some other projects.

 

Ian. 

 

 

[georgeT]

Nice to see you back at the bench lan, great stuff...