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Post by David on Apr 10, 2020 12:17:54 GMT
Thanks Jim. I put a 6BA thread on the end of a piece of brass hex. As I wrote above this bit is pretty heavy and I didn't want to risk it dropping off the stick after I'd dropped it myself a few times in the last week! Doing that with wet paint on it would be a disheartening experience.
Something was bugging me about the front left splasher and when I put a rule along the tops of the rectangular bits I saw the one on that splasher was tilted towards the rear of the loco. So that was unsoldered and moved back a few mm to get it sitting level. That was enough for today, didn't want to over-do it :)
I'm sure the boiler will go back on tomorrow. If nothing else I want all the bits off my bench and back on the loco!
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Post by David on Apr 11, 2020 11:17:20 GMT
While looking at putting the boiler back in I noticed a few things that needed doing. First up the little strips along the bottom of the smokebox sides had to be riveted on. I couldn't rivet them over at the ends due to lack of room for a hammer (or anything else) but a small tack hammer did for the rest of them. A couple of holes were blind too - these are the holes that blunted or broke about 6 drills - not sure why. No photo of this, the strips can be seen earlier in the thread. I also had to replace 3 rivets that had fallen out on the smokebox wrapper. I used JB Weld to glue all these things in. Then I decided to put a new strip around the front of the smokebox wrapper. It's not sitting flat because (a) corners, and (b) I guessed the location of the second screw down on each side so close to where I'd drilled them in the original strip that the drill just found the original hole when I was spotting through so has moved the strip a little bit. This wasn't apparent until all the masking tape holding things in position was removed so I didn't work around it by just making those holes bigger. All the holes would have to be enlarged to sort it out. I'll just live with it.
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Post by David on May 2, 2020 1:23:22 GMT
I'm guessing these parts are inspection covers. If not, let me know what they are. I tried to make a few in 0.7mm steel, but they were too short, too long, not easy enough to bend. It eventually occurred to me that CAD and paper was the way to experiment with length and make them easier to sand to shape on the linisher. In the end I used 0.5mm brass and annealed it before bending around the same 25mm brass bar I used to do the corners of the firebox wrapper. The annealed brass was obviously a great deal easier to work with. Pretty happy with the final parts. Here they are in place, with the trial parts resting on top.
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Post by David on May 7, 2020 5:39:42 GMT
Started work on the handrails. There's a couple of dummy steam chest lubricators sitting on the running board.
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Post by Roger on May 7, 2020 9:15:22 GMT
This is really looking good, it's been well worth the time and trouble to get a result like this.
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Post by Jim on May 7, 2020 11:11:23 GMT
I agree, You have a very fine model emerging there David and it's a great credit to you and your persistence. I must say the chimney looks fantastic. Well done.
Jim
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Post by David on May 7, 2020 11:45:08 GMT
Thanks guys. I can't take any credit for the chimney. It was done by CNC, by someone else. The model wasn't quite right but I wasn't willing to try and fix it in case I ruined it. Barry didn't like the look of it and offered to fix it in exchange for some cab angles. You'll note I still don't have the 8 bolts in the flare either.
It is good to see it looking more like a loco again.
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Post by David on May 18, 2020 5:37:42 GMT
I think the handrails are done now. One of the handrail holes in the front of the cab was out of place so I blanked off the dud one with a 1/8 plug of brass riveted over. I also had to move one of the stanchions in the boiler cladding because I put it in the wrong place by about 3mm. Just enough to make it obvious because the front ones are near a boiler band which acts as an excellent visual reference. So why didn't I use it when placing them? I don't know either. The stanchions were silver soldered together and then soft soldered in place into the wrapper. I really wish I'd used brass for the wrapper. I washed and scrubbed it after soldering so I hope the flux has gone away. I tried filling the misplaced slot with solder by putting a thin brass shim behind it but the solder wouldn't go into the slot and wet to the brass despite the area being flooded with flux, and I didn't want to muck about in case the stanchion solder melted. So I used JB Weld over a thin shim backing. I had to remake the front left handrail because I'd filed a bit too much off the curved section of the original so it didn't quite go into the handrail knob on the smokebox. The second one isn't as good a shape but it does sit firmly. I had to silver solder a couple of mm extension to the straight bit that goes into the dummy blower valve because I cut that too short too! The joint is hidden in the dummy valve.
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Post by Jim on May 18, 2020 7:40:39 GMT
We all have these annoyances David so take heart you're not alone we've all 'been there and done that and have the tee shirt to prove it' I think you should be very pleased with the way the loco is coming along, there are many who would love a model as well mades ad yours.
Jim.
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Post by David on May 18, 2020 8:06:49 GMT
Thanks Jim. I'm glad it's together again! Between the two posts all the bands and cladding was on and off many times. I might bite the first bullet and do the dummy backhead next. The second bullet is the dome, which is still looking a long way off :)
I'm expecting to have to remake the handbrake handle because the boiler is so big that cladding will cause it to foul. That's not too bad, but the air will turn blue if the reversing wheel is also fouled. I'll have to extend the cab end of the screw in that case.
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Post by David on Jul 3, 2020 7:10:49 GMT
I was holding off posting a picture of the dummy backhead until it was finished but it's taking a very long time so here's a work in progress. I even made a steel former for it, but it didn't help. I think it would have been better if (someone else) had formed it in 1mm brass, but I didn't think I'd manage a tidy job with that so tried 0.7mm instead. I can't do corners. It is so thin it deforms in every direction and buckles as soon as you waft a flame near it for soldering, and you can't tap a thread in it so you need to solder backing plates on, making everything worse. I'm hoping enough cleaning, some black paint and shadows will hide it sufficiently. It was looking a bit better a few days ago, before I tried putting the knee guards on which required a lot of soldering, caused the wrapper to come off and the fire door ring to come out - that's still not soldered back in place, it's just sitting there. I may use JB Weld for that as the solder just isn't working for me. Who would have thought soft soldering brass would be in any way difficult?!? The knee guards were done on the CNC machine because it was so much easier than any alternative I could think of. I ran the spindle into a clamp, but I do that almost every time so nothing new there. God knows what I'm doing to the spindle and head alignment! In more encouraging news I got these castings for the dummy injector steam valves. I made a couple of mistakes in the 3D model but they're recoverable so that's not too bad. The nuts on the flanges should have had dummy studs in them, so I've just run a tap through and will put them in. There should have been a 5BA tapping size hole in the leg connected to the flange, where the sprue is at the moment. But having looked at it I'm not sure where the sprue could go if I had included that. At the same time I received a pair of dummy clacks from a tweaked model. The angle to the inlet leg is a bit greater to try and allow it to screw down closer to the boiler, and the leg has been made a bit shorter to try and help that too.
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Post by David on Jul 8, 2020 9:35:37 GMT
The dummy backhead continued to get worse so I decided to bin it and try pressing it from 1mm copper with the steel former I'd already made and a matching 'outside' former with a 1.1mm gap all around for the material. This is what happens when I leave the CNC machine unattended. You can't really see it in the photo but the tool pulled out of the collet and kept cutting deeper, right into the table. I don't know much damage it's done yet but it's pretty deep between at least two T slots. I may as well finish the job before I take it off the table. It's too hot to touch now, the whole table/spindle is hot and you can really feel the heat coming off it. The 6mm wood backing is pretty charred and there was some smoke in the room, so I'm probably lucky it didn't catch fire. I'll let it cool down overnight and have another go tomorrow, taking less depth of cut. I did the other former with 1mm depth of cut, so I tried 2mm this time with a roughing endmill at 30mm/min and the first couple of passes went ok before I went inside for dinner. I have no idea if it was cutting forces, heat, or a combination. There goes the resale value!
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Post by steamer5 on Jul 8, 2020 9:44:09 GMT
Well BUGGER!!
At least 2 soothing ales are required.....medicinal purpose of course!
Cheers Kerrin
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stevep
Elder Statesman
Posts: 1,070
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Post by stevep on Jul 8, 2020 11:37:58 GMT
David, that is indeed bad news.
What sort of collet were you using?
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Post by David on Jul 8, 2020 21:41:34 GMT
The machines tooling system uses ER collets. I've had a cutter pull out of an ER collet on my manual mill too, and cut into the table on that while the auto X travel was going... never let me near your own machine tools!
Two years ago I would have been beside myself, one year ago I would have been extremely upset, now I'm finally getting to the point where after a couple of hours I can shrug my shoulders and carry on to the next stuff up.
I would certainly have had a couple of soothing ales if I'd had any around!
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uuu
Elder Statesman
your message here...
Posts: 2,808
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Post by uuu on Jul 9, 2020 6:15:57 GMT
If you can source a closing nut with a bearing in it, you may find it easier to get the collet really tight. I have one from ArcEuroTrade. Wilf
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stevep
Elder Statesman
Posts: 1,070
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Post by stevep on Jul 9, 2020 8:22:02 GMT
Or, as discussed in the thread on holding milling cutters in collets, use threaded cutters in an auto-lock chuck. I don't think they will come out.
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Post by David on Jul 9, 2020 11:27:53 GMT
That's not really an option with the Tormach. It uses special toolholders on 3/4" shanks with a land to sit against the spindle nose. I changed cutters this morning, went back to a 1mm depth of cut, and slowed the feed to 25mm/min and after about 4 hours when the cutter got to the depth the old one gave away at sparks started showing. So I stopped it and put a brand new cutter in and reduced the depth of cut to 0.5mm and a few hours later finally got through. So by trying to save some time yesterday I ruined my mill table and had to take all of today! Something about never having time to do it right, but having time to redo it comes to mind. The damage was more extensive than I thought, but it's done now so no point worrying about how long the gouge is. The discolouration must have been caused by the smouldering wood backing, it wasn't there when I started the job. The question now is how do I smooth down the huge burrs either side of it - they're way too big to start with stoning. Can't say I'm feeling terribly chirpy right now having just caused such damage to the most expensive thing I've ever bought other than my house. I was even trying to be careful - I moved the tool to each extent of the toolpath to check clearance so I didn't crash the head again, I cleaned all the chips off the table and the clamp stands so I wouldn't mark the table (HAH!) It seemed to do exactly the same job a couple of weeks ago with no trouble at 1mm doc :( Still, work again tomorrow and I won't be listening to the damned machine droning on all day behind me and the compressor kicking in and breaking my train of thought, and then back to uni next week, so that's all a bit of a relief!
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kipford
Statesman
Building a Don Young 5" Gauge Aspinall Class 27
Posts: 566
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Post by kipford on Jul 9, 2020 21:41:39 GMT
David I sympathise with you, although nowhere near as bad, I accidentally drilled a hole in the table of my mill today! With your table although it looks bad the damage to your table is essentially cosmetic and won't affect it functionality. Can you dress the burrs with a dremel? You need to keep a good supply of beer at home to deal with these occasional set backs. I have just laid down 36 pints of amber ale for such eventualities . Keep up the good work. Dave
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timb
Statesman
Posts: 512
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Post by timb on Jul 10, 2020 14:20:02 GMT
Not much consolation David but it is done now, nothing you can do about it and you dont have to be overly concerned in the future. Its a bit like buying a new car and seeing that first scratch, something was going to happen eventually and now you dont have to worry about it.
Tim
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