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Post by Deleted on Jan 28, 2011 21:34:33 GMT
Pic143 Bracket fixed to the hardened jig and held in the vice for filing. Attachments:
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Post by Deleted on Jan 28, 2011 21:36:39 GMT
Pic144 The final operation was to cut the shock absorber locating slot using the 3/16 ball nose slot drill as shown here. Attachments:
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Post by Deleted on Jan 28, 2011 21:42:42 GMT
Pic145 All 16 spring hanger brackets ready for riveting to the frames. The plan is to get these fixed tomorrow and then start the front brake hanger brackets, once those are finished I can give the chassis a base coat of satin black. Getting there ....  Pete Attachments:
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Post by Deleted on Jan 31, 2011 22:41:11 GMT
Just a couple of pictures today, Pic146 These are the brake hangers, they are laser cut items from Model Engineers Laser. There are 8 in total, 2 front which are the ones with the boot leg shape at one end, 4 intermediates and 2 for the rear. In the foreground is a jig made to ensure that they all have 2 3/4" centres between the hanger pin and control rods. There will be another hole about one third up from the control rod pin hole to fix the brake shoes too later. The 2 rear hangers are seen held on the jig awaiting the bossed ends to be brazed on once machined. The intermediates have to be bent a little as shown on the drawings, these should be longer to allow for the two bends as all have the same centres of 2 3/4". For some reason they are all supplied the same length, this is no big deal as I intend to machine the bosses as one piece and cut a slot to slip over the end of the hanger. To allow for this I'll need to cut off the end if each hanger half way through the hole, once the bosses are brazed on they will look complete and using the jig I can ensure that they all retain the 2 3/4 centres. Wow that was a mouthful , hope I explained myself well enough.. Attachments:
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Post by Deleted on Jan 31, 2011 22:46:29 GMT
Pic147 This shows progress to date, the spring hanger brackets are now finished and riveted to the frames. All brake hanger brackets have been fixed to the frames with 8BA small sized hex heads. The frames have been given a satin black base coat, final top coat will be given when loco is also ready. Pete Attachments:
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Post by Deleted on Feb 5, 2011 22:07:13 GMT
Hi all I don't think I'd realised until now just how much work is involved in building the tender, let alone the engine itself when I finally reach that stage. The brakes are very time consuming and each job completed involves the making of many small items , so far I've only scratched the surface of what lays ahead but I have to say I'm enjoying every second of it. I now understand most of what's involved in the brakes for the tender although it would have been helpful if Don had included a plan view of the tender brake layout as he has for the engine itself. I haven't taken pictures for every stage as most are straight forward and I don't want to bore you guys to much.. Previously I have shown you the brake hangers as cut by model engineers laser, I needed to add end bosses to these and decided to machine each as a single item, cut a slot and then file down each hanger to fit in the slot, using the jig to ensure each hanger retained it's correct distance between holes. Pic148 Their are two size diameters of end bosses, 1/4" and 5/32", these are centre drilled and then drilled No.22 and No.30 to match the hanger holes. They vary in length but the picture shows the 1/4" dia BMS being parted of at 1/4" length. A piece of 1/2 steel was held in the tailstock as a stop to measure each 1/4" section. Attachments:
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Post by Deleted on Feb 5, 2011 22:09:37 GMT
Pic149 Here the same 1/4" section is now having a 3mm slot cut for the hanger to fit into ready for brazing. Attachments:
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Post by Deleted on Feb 5, 2011 22:15:51 GMT
Pic150 The intermediate hangers have an offset angle as shown here, they have a small boss on one side at the top so no need to cut a slot for this one. The bottom does need a slot which is offset at 9/32 on the inboard side for wheel clearance. Here the parts are ready for brazing. Attachments:
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Post by Deleted on Feb 5, 2011 22:19:36 GMT
Pic151 Here are the completed hangers and pins for one side. The pins are 5/32 steel with 1/4x1/16 collars brazed on as suggested by Don, makes sense as it's quicker to make. The pins are also cross drilled to take a 1/16 split pin. Attachments:
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Post by Deleted on Feb 5, 2011 22:22:46 GMT
Pic152 Brake hangers fitted, the front hanger has two bottom holes, one (large) is for the front brake beam the second being for the first control rods. Attachments:
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Post by Deleted on Feb 5, 2011 22:23:47 GMT
Pic153 Close up of front hanger Attachments:
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Post by Deleted on Feb 5, 2011 22:27:53 GMT
Pic154 Close up of rear hanger, next job will be the brake shoes and pins, sounds simple but those damn pins take so long...  still I need the shoes done before I can do the control rods, oh and the brake beams to. Hopefully this won't take to long! Pete Attachments:
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Post by Deleted on Feb 5, 2011 22:40:16 GMT
Pete
I empathise over the brakes, as I found the same thing, and the Brit ones aren't as detailed as those you describe. I have yet to paint all the bits and to fit them to the frames - the holes are all drilled BTW!
JB
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Post by Deleted on Feb 5, 2011 23:03:31 GMT
Yes JB I think the painting stage will be very long..... I'm looking forward to finishing the brakes, will be nice to be able to turn the handbrake on... BTW, your cab is looking great... |
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Post by drumkilbo on Feb 6, 2011 10:06:56 GMT
All very interesting and informative Pete, you've given me a few ideas, many thanks.
Ian
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Post by Deleted on Feb 6, 2011 21:18:21 GMT
Thanks Ian
I too take on board a lot of the ideas given by others on this forum, it's one of the great things about belonging to a forum like this one.
Pete
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Post by Deleted on Feb 13, 2011 15:00:17 GMT
Pic155 On to the brake shoes, in the picture are the laser cut shoes from Model engineers laser , having now used these I think it may have been quicker to machine from solid. Being such thick material the laser had hardened the edges and cut at a slight angle in places plus the material is thicker than the drawing do had to be machined to size. They also need making symmetrical too. Still I persevered and battled on Attachments:
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Post by Deleted on Feb 13, 2011 15:04:15 GMT
Pic 156 Here is the jig I made for holding each shoe while it's inner face was machined to 2 7/32R. The pin hole has already been drilled to No.30 and used to help hold the shoe rigid between the two 5mm roller pins. Attachments:
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Post by Deleted on Feb 13, 2011 15:06:28 GMT
Pic157 Next stage was to mill the slot that slides over the brake hanger and then held via the pin. The pins were made the same way as the larger hanger pins. Attachments:
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Post by Deleted on Feb 13, 2011 15:08:39 GMT
Pic158 View showing the inside of the brake assembly for the front axle Attachments:
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still I need the shoes done before I can do the control rods, oh and the brake beams to.
