Learning
That's really interesting. I'd kept baseline settings on the FCR41's and only had trouble starting on seriously cold mornings... but it'd run like a pig until it warmed up. Gutless, too.Originally Posted by Voltaire
An idea I'm toying with is installing A/F metering, just to see what's actually going on with the carbs at various throttle openings.
Learning
Had a chance for a go with something a bit different in the weekend: a field-portable X-ray set. Don't have any piccies of the setup, sorry, but it's basically a battery-powered X-ray source on a tripod, a light-tight box with a fluorescing reusable X-ray plate and a DSLR, and a laptop.
This isn't needed for the home garage worker. Clean your bike, take a good close look at it, if you don't see any cracks then you're fine.
It is useful if you're trying to see something behind something else, like say what's going on inside an engine without taking it apart. That's about it, really. Definition isn't great - resolution is about 0.3mm or so, depending on the X-ray source - and it's a pig to align on something as narrow as a hairline crack. The only way you image a crack is if you're shooting straight down the crevice. X-ray images only show how thick / absorbent a material is, so a narrow air gap gets lost to low contrast if shooting across it. Even a degree or two to one side or the other and the crack doesn't show up.
The 2 pdf images below are of the crack in the frame, the crack itself shows up as a brighter squiggle line. This is the only usable image from nearly four hours of trying, we did a lot of playing with angles and got this pretty much by chance. The other two images are my practice pieces, one of the T-joints and the straight pipe that I tried beads on. Darker areas are thicker / more material, lighter spots match up with visible pocks or pits.
Learning
The latest practice in welding, a couple of T-joints and a first go at 45's.
Comments while I remember (to help me remember) and for first timers out there... no particular order.
The moment your tungsten contacts the weld, stop working, pull the thing and regrind it. Grind the pool or broken-off tungsten tip out too. If you keep welding regardless, you'll get porosity and it'll never weld out. The porosity will set in virgin areas of metal as well as the contact area, bits of metal stuck on the tungsten will mess up new areas you're working on. The tungsten itself will also immediately run hot, oxidise and deform, this won't help either.
Hot tungstens will oxidise even if they haven't contacted. All it takes is running too hard for too long. After this, they have a habit of melting, balling and oxidising, then the arc becomes a pig to control. Avoid by keeping tabs on how hot the torch is getting and letting it cool again. Don't give in to the temptation to get into it and go hard.
Sharp, clean tungstens = well directed and controllable arc.
Gas post flow keeps your tungsten clean as well as the weld.
If you have to get into a corner, extend the tungsten from the gas lens, use a narrower (smaller number) gas lens as well.
Walking the cup works. In fact it works so well that it's worth spending an hour or two with the mask off and the welder shut down, just practising the motion and getting it into muscle memory.
Welding into tight corners is possible if you extend the tungsten, just be careful about contacts. You will have to make a radius of filler metal, but with practise this radius can be minimised.
If a weld pool appears sunken below the original surface, the amps are too high.
Hot things will roll or fall off your welding table. I've managed to avoid anything personal or too much on the workbench getting melted, but trust me on this, it's going to happen.
Check the back face of your weld, if possible. The pool should only just break through.
The sizzling bacon thing is real, when you're doing it right it will sound just like a rasher in butter. Mmm.
Cheap regulators (like the BOC kit) have a modified pressure indicator to try to indicate volume used per minute. The good ones have a transparent vertical column with a bead. Gas flow lifts the bead, then the scale on the side tells you what volume of gas you're using per minute.
TIG is pricey, expect bucks on setup and then more bucks on gas. It's also s-l-o-w. Especially if you let the damn torch and the tungsten cool down again, like I should have been doing. Watercooled would be nice. Watercooled would be really nice. The duty cycle so far is the torch, not the welder itself.
The couple of test pieces below have nearly finished off my first D-bottle of argon. Not much to say here except that I tried extending the tungsten on the second tight 45 joint, with a much tighter radius and less fill material used. It can be done, it just takes practise.
Que?
You do have the torch connected to the negative terminal, yes?
It's unusual to overheat a torch running low-amp DC. I suspect you have reversed polarity, which in DC has the effect of putting 70% of the heat generated into the Tungsten, rather than the work.
Very few single-phase TIG machines in this country run water-cooling. Only about 1 in 10 AC/DC machines will have a water-cooler added, from my own experience.
You'd be better off going to a 26-Series torch before buying a water-cooler & torch but I doubt you really need that either.
What are your settings used in the above welds?
Are you using the pulse function?
What diameter and type Tungsten are you using? (Thoriated, Lanthanated, Ceriated?)
What's your filler wire diameter?
What's your flow rate?
Are you referring to the pink cups used on the end of the torch when you say Gas Lens? A Gas Lens is actually a different style of collet body and uses a different series of pink cup, or nozzle.
It's good fun, eh?
Learning
Addictive
Torch is on Negative, ground lead Positive.
DC, no pulse (not yet anyway).
2.4mm and then 3.2mm (for both the above), rare earth tungsten. Have Thoriated but haven't ground and tried yet.
Filler wire is 1mm.
Gas flow rate approx 10 l / min.
Pink cups, yeah. My mistake.
Que?
You're using too big a Tungsten. I don't know what "Rare Earth" is, but a 2.4mm Thoriated Tugsten is no good below 150 amps DC. You should be using roughly 30 amps for every 1mm of work thickness, looks like no more than 1.5mm? So swap the 2.4mm Tungsten for a 1.6mm. ALWAYS use the smallest diameter electrode able to do the job, irrespective of process.
Use the pulse, it helps with round things so the hot stuff doesn't fall onto the floor.
Turn your flow rate down to around 8lt/min and don't have your tungsten sticking out any more than 5mm beyond the edge of the cup. If you need more stick-out buy a 1.6mm Gas Lens Kit.
I'd be using 1.6mm filler wire, if not 2.0mm. Your beads are very wide and using 1mm you'll be having to stay put for too long to lay that much filler wire down.
Just trying to help
Bogeyman
Perfect.You're using too big a Tungsten. I don't know what "Rare Earth" is, but a 2.4mm Thoriated Tugsten is no good below 150 amps DC. You should be using roughly 30 amps for every 1mm of work thickness, looks like no more than 1.5mm? So swap the 2.4mm Tungsten for a 1.6mm. ALWAYS use the smallest diameter electrode able to do the job, irrespective of process.
Use the pulse, it helps with round things so the hot stuff doesn't fall onto the floor.
Turn your flow rate down to around 8lt/min and don't have your tungsten sticking out any more than 5mm beyond the edge of the cup. If you need more stick-out buy a 1.6mm Gas Lens Kit.
I'd be using 1.6mm filler wire, if not 2.0mm. Your beads are very wide and using 1mm you'll be having to stay put for too long to lay that much filler wire down.
Just trying to help
And the electrode should be sharpened to a length of 2 1/2 times it's diameter. So a 1.6mm electrode should taper about 4mm from the tip. And move the tip across the grinding wheel, or you'll wear a groove in it and it'll be good for bugger all else.
Go soothingly on the grease mud, as there lurks the skid demon
Que?
Thanks, I've had good teachers.
Learning
Thanks guys, will do. Looks like it's shopping time, need some 1.6mm ceriated tungstens and thicker filler rod.
Forum whore
From the dept i think i know your answer already .
I hoping to measusre my Cbr 900 rr gears and thrust bearings for service limits i brought a veriner caliper from super cheap auto.
Budget one example in the book says 5th 6th gears standred 28.000 to 28.021 mm service limit 28.04
But on the packet for the one i brought says Accuracy of + - 0.02 in other words might messure 28.021 but be 28.041
and be knacked ;-) might take them back get money back just take gear sets to bike shop say can u measure them say nah or ya
Went onto tool shed and there one cost double and it says +- 0.05 know really cofussed
Learning
OK, I think I can help you here.
Tool Shed - no. Super Cheap Auto - no. About the only place I know of selling decent gear OTC is Blackwood Protector. Online, try Trade Tools.
Look for Mitutoyo or Insize gear for preference. That said, I have had good performance from a relatively cheap Kingchrome micrometer.
Mitutoyo: the best
Insize: nearly as good, usually excellent value
Kingchrome: cheapest, the digital calipers are widely available and look alright but they're crap. The manual gear is OK though.
+/- 0.02: vernier or dial calipers.
+/- 0.005: a micrometer with graduations of 0.01 on its barrel. Micrometers come in spans, the usual story is 0-25mm, then 25-50, 50-75 and so on... it'll be difficult to find a 25-50 at the shops, you'll probably have to buy online if you want to go that way.
For a one off the easiest answer is go to an engine reconditioners and ask - chances are very high that they've got this kind of kit.
Forum whore
you mean get them to messure for me one just down the street he un did a main bolt for me for free nice guy.
Mitutoyo
thanks man watched guy on you tube said this brand was good to iGaging ABSOLUTE ORIGIN said what you said on Mitutoyo
Insize half the cost as good and said the 3rd best iGaging ABSOLUTE ORIGIN looked a ebay 55 nz
What worrys me about my gearbox got blacking on some gears as well few chips on square gear dogs . shift drum is mint
But i may be completly wrong but 2 gears on the counter shaft have quite bit side to side rocking movement . but of course
When there driven there connected to splined gear beside . is the blacking old oil deposit or heat i have no idea.
also 6th gear on main shaft seems be quite dull as in the harding . i was getting gear box whine .this is reason striped the motor.
Learning
Been doing a bit more over the last few days. I've had to leave more welding for a few days, money's tight and I want to get some more electrodes and filler rod before continuing. I've switched tack to engine reassembly.
I started by assembling and then measuring the blue conrod big end bearing half shells, in preparation for crankshaft reassembly. Guess what, they're almost exactly the same size as the reds... both are (in theory) outside the workshop manual's tolerance bands as brand new components. Not good, Ducati.
It's possible that they were mis-measured while writing the manual up and thus are actually OK. The manual shows a two-point internal micrometer with dial being used. A relatively small error in locating centrally could reduce the measurement by 15 or 20 microns. It's got to be exactly across the diameter, it's got to be square and straight, and it takes several goes to be sure. The bearing surface material is also extremely soft, it's very easy to dig the transfer gauge ball ends in, and this could expand the measurement as well. Plasti-guage on the crankshaft and an external micrometer would be the way to go here if I was to do this again.
In the end I got pissed off and just reassembled with reds and new conrod split cap bolts. The photo shows a feeler gauge being substituted for the offical Ducati assembly tool - a 0.014" feeler on each side took up the slack and prevented the conrods twisting against the bearings while torquing the cap bolts up. I presume that the factory has some kind of rack mount for the assembly. I found that bracing one end of the crankshaft against a hip and working by hand got it done.
Next - reaseemble the cases. Got bearings back into one engine case half but found that I'd somehow missed a bearing off the shopping list, have had to leave the other for now. I only want to heat and drive once if I can help it.
Replacement of bearings: heat case half to 100 C in oven, use bearing driver kit, square up and tap in. A couple of them dropped straight in, not too suprising with the bearings left overnight in a 5 C garage. Swingarm bearings and seals reinserted with M6 mudguard washer and socket set extension bar for a driver. Rough but it worked.
Switch again, cylinder head reconditioning and reassembly. I tried the valve seat cutters.
They're simple to use. Insert the guide rod, twist and push to lock the very fine taper into the valve guide. The cutter slides on, check the extension of the cutter teeth to make sure it covers the seat but doesn't cut into the head, fit the handle, then it's press down and turn. I had to secure the cylinder heads, this couldn't be done with the heads resting on the bench.
They're reasonably fast, they re-center the seats very well too. Unfortunately they have a nasty habit of biting in and then releasing instead of cutting steadily. It introduces low spots, shown by looking down the port, turning the lights off and using a torch to see if light got through anywhere. This might be down to operator skill (or lack of) of course... I'll have to lap as the final step. Doing a multi-angle valve seat cut with this tooling would be patient and slow work, but it could be done relatively easily in a home garage.
Learning
Valve lapping with coarse and fine compounds didn't take too long. Not much to say here - a dab of paste, suction cup stick and 2 forward, 1 back, or as much random back and forth as possible. Pressure doesn't have to be high. I used grease, not oil, on the valve stem - I wanted as strong a self-centering action within the guide as possible.
I used the inspection technique mentioned before - clean everything, refit the valve and close it on the seat, shine a torch at it and look for the light breaking through on the other side. There's been a definite improvement over the valve cut.
This done, I cleaned up the outboard bearing plate's gasket surfaces with a flat metal block and wet-n-dry, then dunked the complete head in a bucket of water and degreaser. Every trace of lapping paste and valve seat shavings or dust should be gone before rebuilding.
The biggest roller bearing is a light interference fit on both the camshaft and the head. The way to assemble it is to heat the bearing, slide it onto the camshaft, then allow to cool. While that's happening, heat the head to 100 C. The camshaft, plus bearing, will slide into place in the head. Then fit the spacer and the belt-side outboard bearing (push this home with the lip seal sleeve). Do everything by hand, there's no need for hammer and drift tube.
The cap-mounted outboard bearings are slide fits over the camshaft ends but interference fits in the cylinder head caps. Heat the caps and the bearings drop straight in, just like the heads.
Valve rockers, spacer washers and rocker arm shafts are next. The spring-loaded closing arms went almost straight in - the cable ties I'd used to remove them were still tight. A bit of jiggery-pokery with a screwdriver and some pushing and it assembled. The opening arms were easy. That done, I could fit a new gasket and the camshaft end cap, then tighten up.
Note that I've removed the shields from all bearings, both sides. Previously this hadn't been done, the outboard bearings both had their outer face shields kept in place, and I think this would have interfered with the lubrication circuit. There are ports for coolant flow on the outer sides of both these bearings.
Learning
Check all load bearings for play, if in any doubt whatever then replace them. Photo everything, better, get the Sharpie out and label everything so you can rebuild it even if it's down loose bits all over the bench.
The 2 countershaft gears are probably loose on their freewheel bearings. Not a worry here unless it's massive free play permitting a mechanical collision of some kind.
Chipped gear dogs are a worry, your call on these but if there's a chance it'll pop out of gear under load then it'd be a good idea to replace these too.
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