Member postings for JasonB

My thinking is that I use the mill with minimal quill extension when cutting so that is the best way to check the tram, as Graham says it may well be different when extended so why test it in that position.

Even having the quill free or locked is likely to affect readings, so test it as you are likely to use it would be my way of doing things.

Even then you can get smaller hex metric fixings which I use all the time or just make your own if commercial is not to your liking

You then start to get into the realms of which do you tram, usually the spindle axis is trammed to th emill table but there is also colum to table and quill movement to table to be considered which may show*

* however it still comes down to showing tiny deviations over a short distance that you would be hard pushed to see.

As Pete says even with perfect tram you may get slight back cutting as the front pass may deflect the spindle slightly upwards and also cause minute flex in the machine particularly if your facemill has the blunter inserts which means that as the deflection and movement is removed once the front edge has cleared the work the tool drops down and takes a skim on the trailing edge

Looking at the Chart Michael links to there is really very little difference between what it shows for the thread sizes you are likely to find on a clock say M1.6 to M6 all pitches if you pro rata them to what is shown they are within 0.1mm mostly 0.05mm

Add to that as Foggy say you can get several pitches if you need something finer than the standard coarse pitch and I see little point in using BA, only real reason may be that 2, 5 and 7 work well on fractional imperial stock but as metric is easy to find these days not an issue.

Tooling is also more plentful in metric with choices in types of tap etc

The 290 machines come with 150mm chucks so no problem, not sure what the smaller 7x machines with big bore spindles have

As Bazyle says Warco tend to include 3 & 4 Jaw chucks, fixed and travelling steadies, faceplate etc. Others including Amadeal only supply the 3-jaw so that can make several £100 difference. Then there can be differences that are not so easily seem such a scontrol boards, some make smay use American ones, other far eastern which may have lower grade components

As for screwcutting it really depends on how much you need it. I may only use it once a year so it was not a deciding factor when I bought my Warco 280 but if you feel you are going to do a lot then it may be higher up your list of wants

My prevous Emco was a geared head machine but I'm mor ethan happy with the variable speed I have now and would not want to back to having to keep stopping to change to one of th elimited range of speeds

Edited By JasonB on 01/10/2023 06:53:33

Better still embed it

Chris, try putting a 0.1mm or 4 thou feeler gauge under one side of your jig and see just bt moving the X and Y you can get the coax to show zero, I think iy will still show zero as the difference between flat and shimmed is 0.000032mm which is 1/3rd of a micron you you will never see with the naked eye

I've built a couple of engines for a guy in near Skibbereen and he also says it is hard to get anything for when he builds the smaller engines

The cylinder pivots in two trunion bearings, I made a start by skimming the top, bottom and two side to get rid of the draft angle and was then able to close up the chuck jaws on these now flat faces, the sides needed a packer as the foot would have got in the way of the jaws otherwise. The 3/4" dia x 1/4" long outer spigot was turned, a 1/4" hole reamed right through and then counterbored 3/8" for the packing gland. Just like the milling I'm using CCGT polished and ground inserts for non ferrous metal here and did for just about everything lathe operation on this engine.



I made up an expanding mandrel so that the casting could be held the other way around, brought to width and a shorter 3/4" dia spigot formed and faced on the inner side.



Over to the mill a piece of 1/4" Silver steel (drill rod) was used to support the work so the bottom could be milled to the correct distance relative to the bore. Face mill gives a good finish and minimal burrs which can be an ussue with gun metal unless the tools are good and sharp.



After bringing the castings down to finished height they were again slipped onto the piece of silver steel to mill the sides and finish the feet to thickness and overall length.



The crankshaft bearing supports are similar shaped castings, after some initial cleanup i decided to use the CNC to tidy the cast tops and at the same time incorporated a small raised boss to take the oil pot rather than just filing the top and having the pot screw into a convex surface. After bringing them down to final size the foot holes were drilled 2.5mm and the stud holes drilled and tapped M2.5 before opening up the ends of the holes to 2.5mm. Red and blue Sharpie marks ensured I knew my right from left before sawing off the caps with a slitting saw.



After cleaning up the sawn surfaces the caps were screwed into place so that the hole could be drilled and then reamed 1/4"

I find I tend to make more or less equal use of both maybe 60/40 in favour of the facing one. So maybe think about getting that first and see how you get on. I find I can more or less keep up with using all my inserts on all four corners having the two options, if it were just for facing then I'd probably start to build up a backlog.

I also find the fact that the other two "unused) corners being over 90deg are a bit more durable so ideal for castings or other irregular work

Plenty of other suppliers other than Glanze, Mine were JB Cutting tools, look for SCBCR and SCBCL such as the ones from APT

Not sure why Clive's one can't easily be used for facing, could be as his are pin location rather than the screw location I have and why my codes start with S for screw .this is mine in action

Edited By JasonB on 29/09/2023 14:15:13

Any reason you can't use a slice of round bar?

Someoen like M-machine may well be happy to cut you a thin slice from square or round brass but you may have to pay a small premium over the typical 1" length increments they generally sell by, drop them an e-mail.

If you can use something other than brass then a Stuart Progress flywheel casting can be bought from them, look under spare parts.

With the right holders all 4 corners of a CCMT can be used

Looking at the mods you have done the magnetic tapes could simply be stuck over the engraved scales you already have. You then only need to make provision for the mini encoders. The X encoder could be mounted to the left of your stop and the Y take the place of the pointer and it's rod that you have. The stop clamps could just be modified to clear the tape if you still wanted to be able to us ethem.

Edited By JasonB on 29/09/2023 10:57:34

Guildford is now a lot smaller than it used to be and is more just an open day for the track. Insurance and marquee hire became too great for the club to risk it as poor weather would reduce the gate and they would make a loss.

That is another issue for the likes of Ally Pally, being in January could put it at risk of snowy weather which would again keep numbers through the gate down and with higer costs for the organisers the risk of a loss is far more than one this time of year in a venue they own.

Having Model engineer and teh London show around the same time of year was never going to help as people either visited one and not the other or if they visite dboth only had the same amount to spend over the two shows so half the possible sales for the traders who still have to pay to attend both shows.

As Benedict has shown in his other DRO thread with people taking the chance to buy direct from the far eastern selling sites that too has reduced sales for the UK suppliers so even less income likely from attending an ever more costly show. Can't really complain about a lack of shows if you don't support those attending.

Just sketched it out in CAD

If we assume the widest point of your cone would be 65mm dia then applied the equivelent change in shape corresponding to 0.1mm over 100 of tram error you would be looking for 0.000032mm on the coax. One is easy to read the other you won't read. Given that most would want something like 0-.01mm or better over 100mm then you will never see th eneedle move on the coax

I drew it as a cylinder, sliced the top off a 0.1:100 (0.06deg) and then measured the major axis of the elliptical end.

You can also see from the Y delta that by measuring over 65mm dia even if done the traditional way your reading will be smaller, half of less of what can usually be swung across a mill table.

If you were to work out the effective major and minor axis of the elliptical shape that teh Coax may follow iff the tram were off by say 0.1mm/100mm it would be such a small difference that you would not be able to measure it with the usual dti scales on these coax indicators

You would also need to ensure your piece of bar had the end facing the chuck completely true to the cone, I did not see mention of even facing it.

Have a look at this particularly last post

It's a closed group so I'll resist joining to avoid spending too much time there.

I just had a look and F360 will produce code for Proto TRAK conversational which sounds like what he has so could go either way.