prepman
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Will you need financial backing? I could start a crowdfund appeal.
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Screwdriver
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Will you need financial backing? I could start a crowdfund appeal.
All I'd really need is a laser and sufficient motivation. I can make the parts and then it's just consumables like film (glass plates) and some chems. A quick Google tells me a digital version is entirely possible now. Don't get the impressive cosmetic details but the interference pattern is where the accuracy lives. Dunno how much a sensor like that might cost. Wouldn't surprise me if they too were dead cheap.
Only issue being, what the real world results would be with the size of the target (being an entire lathe bed I assume) so there would be some development costs. I would imagine it would end up being something you could rent out, rather than a tool you'd want to buy.
A super quick thought experiment suggests I'd also need to dial down the accuracy (i assume trivially easy) because otherwise you'd be counting 100's of lines to measure one thou".
Be interesting for you though because you could literally watch the stress lines being created on a part in real time as it moves by a couple of hundred nm (10's of millionths"). Apologies if I may be an order of magnitude one way or the other, am in the middle of something else currently.
You'd definitely be able to see where a dirty big English wheel casting was moving though. Real time. I'll see if I can dig out my old paper on the subject.
prepman
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Returning to project that created this thread i.e. the milling arbors. I decided to set up a larger toolpost grinder.
Looked at all the designs and priced up motors etc. Then I thought 'why not mount a small bench grinder directly on the toolpost?' My old Clarke one has large diameter motor which would be a hinderance. However this hasn't....
The motor is a small 150W with small diameter. At £34 including 2 x 6" wheels 3yr warranty. Doesn't appear to have any end float.If it had it wouldn't be an issue, as long as radial is repeatable. Taking extremely fine cuts if stable enough should do exactly what I want...? Not after micron accuracy 1/10th thou' will be fine.
Once the wheel is dressed in situ and the clamping bracket, should be fine. Certainly feels solidly built.
Looked at all the designs and priced up motors etc. Then I thought 'why not mount a small bench grinder directly on the toolpost?' My old Clarke one has large diameter motor which would be a hinderance. However this hasn't....
The motor is a small 150W with small diameter. At £34 including 2 x 6" wheels 3yr warranty. Doesn't appear to have any end float.If it had it wouldn't be an issue, as long as radial is repeatable. Taking extremely fine cuts if stable enough should do exactly what I want...? Not after micron accuracy 1/10th thou' will be fine.
Once the wheel is dressed in situ and the clamping bracket, should be fine. Certainly feels solidly built.
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prepman
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I'll give it a go....and report back. At £34 nothing to lose. If not good, then I can mount pulleys instead of wheels and produce a shaft for the wheels. But I'd only use roller skate bearings in that as well.
prepman
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Well....... my motto is 'hope for the best and plan for the worst'.....
prepman
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Well it did work. It doesn't obviously have much power and only light cuts are possible, As the lathe is running in opposition to the wheel, a too heavy a cut ends up with the lathe turning the wheel
Couldn't keep the guard on because of a missing mounting hole. To be resolved. The grind wheel supplied is pretty naff.
But it works. 5 thou cuts, which is all I required. Get some measurements tomorrow.
Short video..
do
Couldn't keep the guard on because of a missing mounting hole. To be resolved. The grind wheel supplied is pretty naff.
But it works. 5 thou cuts, which is all I required. Get some measurements tomorrow.
Short video..
do
prepman
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I think I'll be just using the motor and my ready built (motorless, uses powerdrill) toolpost drill/grinder or make another and use a smaller wheel 3-4"
The 2nd grindstone will be removed whatever I do as it isn't possible to use the tailstock centre. Also can't use topslide for
morse taper
.
The 2nd grindstone will be removed whatever I do as it isn't possible to use the tailstock centre. Also can't use topslide for
morse taper
.
prepman
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One thing I'm going to check today is for distortion in the chuck backplate after the parting off incident. If that is skewed then it'll never be correct. Would account for change in parallel when work piece is rotated in jaws. Means it is not due to surface runouut. Made a new jaw grinding jig.
prepman
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I made the backplate out of EN8 (unhardened) years back....just clocked it and it's out 0.1mm runout on face. Pretty substantial chuck, can't imagine it would distort. Could be wrong, have been before. In the process of skimming backplate.
Taking a break/
Had to make 100% sure the L0 nose was perfectly engaged, no microscopic bits of swarf etec. The other possibility is the spindle/bearings are distorted
Which doesn't bear thinking about....as that's how they'll stay. Timken bearing + shaft = ££££s! I will never part off with the offcut unsupported again. Never, never, never. The thud, as the chuck slammed it into the bed was horrendous,
prepman
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Tomorrow will...(which is now today 6am). I'm also going to check for ovality in the chuck body. Could not get it to clock true on diameter by reducing backplate register diameter and opening out bolt holes. Hopefully nose is still true as I'd had a morse taper drill 18" long running true and the tip wasn't scribing an arc. Might be getting a new chuck 6 jaw maybe, although changing 6 from internal to external and back would be a pain.
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prepman
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I'm just a windy-poo...belt & braces and some. When I made the backplate I had a struggle getting the 3 socket screw holes aligned equi-distant....not having CNC or DRO like some of the more affluent forum members
So the holes had to be slightly corrected and are now well oversized.....butchered...naw! It'd make a terrific bouncing bomb. Barnes Wallis.... eat your heart out
As soon as I get out of the drug dependency clinic I''ll be right back at it. Very relieved I haven't SNAFU'd my lathe.
prepman
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Need to get a move on today...
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