Member postings for pgk pgk

I dug out a 12mm 2-flute new endmill.. yes it avoids the side forces on breakout (thanks) but a much slower feed and more vibration. Perhaps on a wider slot a starting cut with a thinner 2 flute at higher rpm then take the sides...

APT have heaps of cutters.. any more specific recommendation and sizes? At the moment while I develop my feel for all this I'm a tad happier destroying the more economical cutters direct from china (I'm on the wrong PC to look up specifics but the site got a recommendationfrom from a member here).

I've got the hand feed feel for the way I've been doing it so on this bulk lot I'm half way through I'll probably carry on and then experiment later

I had a go with 6mm... certainly ploughs OK full depth but I wasn't gentle enough towards the end of the slot and the cutter was destroyed on exit. It may be a way to go with a little more finesse but I only have one spare 5mm which needs reserving. I'll probbaly try in the future when i have some more.

I'll give it a go with a 2-flute. Of course it's not just the side pull there's a back drag as well. The rougher is 4 flute. I'm still getting a feel for chopping through a mini production run efficiently and cooking the tools and a balance between heavy cuts and machine vibration. The chester stand has too much flex too... with the mill on top you can manually twist the combo - I think it needs some reinforcing.

I'm milling a series of 16mm wide 13mm deep slots across 70mm BMS with my chester superlux. I take 4 lots of 3mm deep cuts along the middle of the slot with a 12mm HSS rough cutter at 500rpm and finish the last 1mm. Then 1.5mm each side full depth then tidy up the last 0.5mm with a finishing cutter each side conventional milling.

I'm driving the cutter through with lots of hand sprayed coolant and keeping the chips just a shade towards golden. (I'm collecting bits to build a flood coolant system).

Driving the cutter like this on the first section of the slot and the differential forces each side of the slot/cutter and drag on the cutter mean that one has to slow the feed down markedly as one breaks out of the end of the slot. Of coures once the cenral section is cut out that stops being an issue.

Toms techniques recommends slotting with a series of overlapping plunges to almost full depth and then tidying up- claims that's easier on cutters.

I'm just wondering if there's other alternative ways that may be better...such as a thinner initial slot for chip clearance with a faster rpm/ feed speed and deeper cuts the full depth sides with 'medium cutters? Or whether blowing compressed air to clear chips is better than spraying coolant - not enough hands to do both until i build a system.

Carpet tape??

Indeed it is for the challenge..or rather the pleasure and stress of figuring it all out and having it fit and work. I'm guessing a cheap far east table wouldn't cost much more than a kit and supplies and cutter wear...?

pgk

I'm not knocking the efficiency or ability to use a program for that purpose, But to be clear my immediate thought re light sensing was an array of 4 tubes with photocells radiating out from a point and if (say) left tube reads more than right then motor left until they match .. the same for up and down tubes. The failing in such a system is when the sun sneaks round the back at night and no tubes face it... so it'd have to be set to travel back at the end of it's arc and wait.

Many blooms manage that without lookup tables

..and I thought the idea was just to point the panels at the best light source; not plan the next druid festival

I'm too stupid to have thought of doing it that way. My first thought seeing the title was a simple array of photocells centre and slightly offset from centre and move into the direction of best response...

In my model heli blade grips the thrust bearings have washers each side of the race to cope with the centripedal forces on the grips/blades. In that application the outer facing washer has a fine tolerance to the shaft whereas the inner washer is a looser fit

Thanks for that and the fascinating link!

I was thinking of having a go at:

**LINK**

Which for me would be a big undertaking.

The drawing calls for a Mod1 worm and 72T gear and it looks fun to try and cut my own but I don't see ay simple way of getting my Crusader lathe to cut a mod1 worm without hunting up two new gears. It can cut a 3mm pitch.

Is it reasonable/will it work to just reduce the circumference for the 72T gear by 3/Pi and otherwise hob by the drawing? Also in the interests of economy (and likely mistakes) making that 72T out of cast rather then bronze?

...spectrum of available light, sensitivity and spectral range of the observers optical receptors, spectral reflectance/absorption of the object..

I have a vague recollection of a desert flower that reflects ultraviolet from moonlight such that a sensitive moth can see it nearly a mile away..

..is the grass green you see the same as the grass green I see?

Chinese and modern but hey still make more for the US market so some parts may still be imperial.

As to the shape of the tool (never having cut one of these threads myself).. then from the top It's going to be a 29 r 30 degree point truncated at the tip either as a very shallow radius or as a flat with two tiny corner radii. From the front it's gong to look thinner at the bottom than the top but the front edge will 'lean' by the lead angle. You need to dig out a chart for that angle to add and subtract from the side rakes of your 29/30 deg tool for the material you cut and to find the width of the tip 'flat'. You'll be feedng it in at roughy half that 29/30 deg angle for most of the cut then going in square with the cross slide for the las pass or two as a straight form tool (so the half angle doesn't have to be perfect)

I'm fairly new at al this too. 'Tom's techniques' (youtube) describes shaping thread tools a lot better than I do and after following his tutorials I happily single point any i don't have a die for (lazy when possible)

...or ypu buy a length of acme/trapezoidal allthread <g>

A quick search suggests that metric trapezoidal type threads at 12mm diameter are usually 3mm pitch but 1/2in imperial and us threads are 1/10th inch pitch whichwould be closer to your 2.5mm...With the trapezoidal at 30deg and the acme at 29degs. My brain;s not in gear enough to hunt up the lead angle for modifying the tool side rakes and my machinery's handbook is down in the shed.

This?

**LINK**

Yeah, but that puts you 6 hrs out. What you need is a rotating bezel and turn the numbers a full turn forwards

I'm intrigued as to why? If the current box is too long then trimming it and redrilling for a crossbar is easiest..or a longer crossbar.

If able to adapt the box you have then making a round bar to fit and milling/filing flats on it for your 10mm spanner should be easy enough and you don't need to insert into the tube and cross pin until it's right..

That's what i understood and I'll take a crack at the answer (although as a beginner I could be way off)...

Eyeball with a bar in .. take a dti reading with each jaw in line with the dti... add the three figs and divide by 3.. back off the tightest jaw(s) in turn to that number (tghtening the loosest towards that number).. remeasure and adjust/repeat...???

Does it have to be brass?

If you paint the edges white can you judge the rpm from the red shift?