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23-03-2017, 01:56 PM | #91 |
No turn left unstoned
Join Date: Jun 2010
Location: leicester
Bike: M750
Posts: 4,559
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I've done a bit of turning ... shout up if you need any advice.
I wouldn't have thought you'd need a fixed centre ("pointed taper") at all on 25mm bar if the part you're making is only 25mm long .. as long as you do them one at a time. It should be rigid enough without, particularly as its only soft ally you're cutting. Also, paraffin is the best lubricant/cutting fluid for ally, and will stop swarf welding itself to the tool point. (and incidentally, is also useful to stop files clogging if you're doing any of that on ally). Apply it with a kids paintbrush, during the cut. Try to cultivate the habit of turning the chuck one revolution by hand before starting up, to check for clearance. I assume you know all about eliminating the effect of backlash in the slide threads by always winding out and then back to your chosen mark. And finally for now, NEVER leave the chuck key in the chuck ... std workshop safety practice to avoid it being slug at your teeth when you switch on. Oh, and also beware of "parting off" operations. Shouldn't be a problem on soft ally but on tougher materials the tool can easily drag itself into the workpiece and cause a foul-up, particularly if the tool height is set a tad low. For parting off, the tool should be set dead on centre height or even slightly above, to reduce thus tendency. Or do as I do and get out the hacksaw ... its often quicker than setting a tool to part off just one or two pieces. Hope some of that is helpful, without being patronising. Oh, and a useful way to check your tool height setting is to trap your thin, 6 inch rule between the tool point and workpiece and then view it from the tailstock end. It will be dead vertical if the tool is spot on centre height, but slanting if not. Slightly below centre height, or spot on, is what you want .. never above or obviously the tool will rub rather than cut (unless for parting off, as mentioned above). |
23-03-2017, 03:11 PM | #92 |
Too much time on my hands member
Join Date: Jan 2013
Location: Shipbourne
Bike: M900
Posts: 1,422
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Advice gratefully received, The chuck key issue I have already learned the hard way, it is surprising how far it goes on a quarter turn start up, fortunately without hitting me or anything valuable in the garage.
I plan to turn 25mm bar down to 22mm for both plugs first so approximately 50 mm then reduce to 18mm for the middle 42mm then drill right through 5mm (to later tap a 6mm thread) then part off in the middle. Then part off the chuck jaw end. I will obviously have to allow for the thickness of the parting off tool in the total length reduced to 18mm. So would the use of a fixed centre be advisable with this method? |
23-03-2017, 03:28 PM | #93 |
Too much time on my hands member
Join Date: Jan 2013
Location: Shipbourne
Bike: M900
Posts: 1,422
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Another job tackled today, I bent up some 2mm steel for subsequent brazing to the frame. This is to hold the hanger bracket for the exhaust can.
screenshot on pc Then using some of the 4mm aluminium from the road sign I made the hanger bracket itself [img]httpimage hosting over 5mbs://s12.postimg.org/o1y34r0ql/Exhaust_hanger_bracket_1.jpg[/img]free image uploading I think the finished product looks too wide so I shall probably reduce it in width by about 10 - 12 mm although now it is bent I will not be able to use a jigsaw easily and I do not fancy filing 12mm. One day when it is raining outside and I am feeling energetic??? |
23-03-2017, 03:31 PM | #94 |
Too much time on my hands member
Join Date: Jan 2013
Location: Shipbourne
Bike: M900
Posts: 1,422
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23-03-2017, 03:34 PM | #95 |
Too much time on my hands member
Join Date: Jan 2013
Location: Shipbourne
Bike: M900
Posts: 1,422
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23-03-2017, 04:09 PM | #96 | |
Transmaniacon MOC
Join Date: Sep 2013
Location: Sutton In Ashfield
Bike: Multiple Monsters
Posts: 6,091
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Quote:
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Roast Beef Monster! Termignoni and Bucci - Italian for pipe and slippers! S4 Fogarty, S4R 07T, 748, Series 1 Mirage |
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23-03-2017, 04:37 PM | #97 |
Too much time on my hands member
Join Date: Jan 2013
Location: Shipbourne
Bike: M900
Posts: 1,422
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Darren69 you are absolutely right. I will see what it looks like thinner first. The other concern I have is that as it is it is not a "fail safe" bracket; if the vibration mount breaks (not unknown) then the exhaust can is only held on by two springs.
Mounting off the rear set is possible, there are two holes to hold the rear brake master cylinder but it will be difficult to get the alignment for the brake master cylinder push rod. I would not want the exhaust hanger bracket to be outboard of the visible machined face of rear set. This is precisely why I want to dry build it before brazing lugs onto the frame and before painting it. |
23-03-2017, 05:24 PM | #98 |
Transmaniacon MOC
Join Date: Sep 2013
Location: Sutton In Ashfield
Bike: Multiple Monsters
Posts: 6,091
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The ones I was thinking of must have used the main rear set mounting and must have been fitted between the rearset and frame, and maybe dog legged somehow to line up.
You should be be able space out the rearsets from the frame quite a bit if necessary and should not have any issues in doing so. The original monster hangers were angled down and away about an inch or maybe more so hoses, wiring and stuff should still be long enough.
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Roast Beef Monster! Termignoni and Bucci - Italian for pipe and slippers! S4 Fogarty, S4R 07T, 748, Series 1 Mirage |
23-03-2017, 06:14 PM | #99 |
No turn left unstoned
Join Date: Jun 2010
Location: leicester
Bike: M750
Posts: 4,559
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Parting off with a centre fitted is never a good idea because it can cause the part to jam between tool and barstock as it falls away.
The best method to use will depend somewhat on the lathe in question and the tools available, but ... I'd make them one at a time. Either way around really, but if you do them "flange outwards, there will be a smaller diameter at the part-off position. I would only have just enough barstock sticking out of the chuck to make one part, plus clearance for the parting/turning tool/s, and I wouldn't use a centre at all. Face and turn both diameters, then drill for tapping, and countersink for a lead on the thread. Then, with the headstock drive disconnected, fit the tap in the tailstock chuck and enter it into the bore, then tap a short distance by pushing on the (unclamped) tailstock while turning the headstock chuck by hand (using the chuck key as a lever). When it becomes too hard to cut any more by hand, undo the tailstock chuck and withdraw the tailstock leaving the tap in place. You can then finish tapping by hand with the part still in the chuck if you like, or remove the tap, part it off and finish tapping in the vice. The swarf falls away better if the hole is vertical in the vice, but its easier to hold in the chuck, so you takes your choice. If you made them "flange inwards", you could perhaps hacksaw them off leaving a bit extra, then replace them in the chuck and face the end afterwards ... BUT realise that a 3-jaw chuck is somewhat self-centring but the part will not run dead true when replaced (it may be true enough though .. depends on the part and its function. Doing them the other way round eases the parting-off process and leaves both ends true (though you will need to remove some residual metal by hand with a file as it wont break away entirely cleanly). Doing them one at a time reduces the length of hole to be drilled too, which is also very much better. Centre drill first. I sometimes drill undersize then set a tiny boring tool to clean up the hole to finish size .. and this helps the hole and the resulting thread to run dead true, as the drill on its own will probably run off somewhat. Again, it depends on the requirements of the particular part in question. Use paraffin for everything .. turning, drilling, tapping and in particular for parting-off. |
23-03-2017, 06:23 PM | #100 |
No turn left unstoned
Join Date: Jun 2010
Location: leicester
Bike: M750
Posts: 4,559
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ps. a man of your talent and ingenuity may want to consider setting up an anodising tank ....?
Its not difficult, as far as I know. The main prob is getting good dyes which wont fade, but doing them silver avoids the problem. I've been meaning to get around to it myself for ages. Oh dear ... what have I said ? |
24-03-2017, 11:08 AM | #101 |
Too much time on my hands member
Join Date: Jan 2013
Location: Shipbourne
Bike: M900
Posts: 1,422
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Utopia: point taken re parting off with the centre fitted I will make them one at a time and good advice re tapping the thread with a countersunk hole to start with and using a lathe to start the thread and ensure concentric threading. I will have to investigate boring tools as all I have is drills (none of which are the correct size for tapping holes perfectly).
I will also investigate home brewed anodising, I would only ever consider silver so no need to worry about dyes and colour matching. I want the finished product to look classy not like a tart's handbag. |
24-03-2017, 11:51 AM | #102 |
No turn left unstoned
Join Date: Jun 2010
Location: leicester
Bike: M750
Posts: 4,559
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I was being a little fussy about the boring tool, and speaking generally.
It wouldn't be necessary for frame plugs. It would be hard to find such a small boring tool anyway. I guess it must have been on my mind because coincidentally, the other week I snapped my prized micro-boring tool that I've had since I ground it up myself in the 1970s. Yup, I did exactly the same as you ... clouted it with a jaw of the 3-jaw chuck ... first time I've ever done that .. there must be something in the air. |
24-03-2017, 11:57 AM | #103 |
Transmaniacon MOC
Join Date: Sep 2013
Location: Sutton In Ashfield
Bike: Multiple Monsters
Posts: 6,091
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Roast Beef Monster! Termignoni and Bucci - Italian for pipe and slippers! S4 Fogarty, S4R 07T, 748, Series 1 Mirage |
24-03-2017, 12:10 PM | #104 |
No turn left unstoned
Join Date: Jun 2010
Location: leicester
Bike: M750
Posts: 4,559
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Yep, and operating machine tools when you're on your own is potentially dangerous as there is nobody to come to the rescue in the event of an accident.
When I do so I am constantly running a little mantra in my head which says "take your time and double-think everything before switching on". Solo machining simply wouldn't be allowed in a regular engineering shop. Its easy to let familiarity breed complacency, as was the case with my boring tool. |
24-03-2017, 06:13 PM | #105 |
Lord of the Rings
Join Date: May 2013
Location: Norwich
Bike: M900sie
Posts: 5,963
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I designed up some frame plugs and a friend of mine with a lathe, turned them up for me.
They were two part items with a polished stainless screw pulling the two halves together expanding an O-ring, to grip the inside of the tube. They grip very well indeed, but ultimately were over engineered, as all it needed to be was a single part with a correctly sized O-ring groove. I discovered that if mine are adjusted just right, they will push in tight and prize out again easily enough. Dookbob made some really natty ones for his 600.
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