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Member postings for Adam Harris

Here is a list of all the postings Adam Harris has made in our forums. Click on a thread name to jump to the thread.

Thread: Burnerd Multisize collets vs Crawford Multibore collets
18/04/2020 23:54:38

Thanks Clive

18/04/2020 22:03:22

Thanks everyone and thanks for the specifics on short parts Andrew. Andrew, why did you choose the Multisize system over the Multibore system?

Edited By Adam Harris on 18/04/2020 22:12:27

18/04/2020 20:14:52

But I don't see how the fingers can cant because the finger is trapped hard between the workpiece and the conical bore of the collet chuck - there is logically no way for it to cant in my opinion. Perhaps one could imagine the finger could slide in its slot if not tightened up enough, but even then the finger is a continuous piece of metal and it would have to deform/squash around the workpiece in order for the workpiece to come loose.  I think the ER "fingers" that don't run in a slot but are all spring together could twist out of position and in doing so release the bar .

Edited By Adam Harris on 18/04/2020 20:23:29

Edited By Adam Harris on 18/04/2020 20:27:12

18/04/2020 19:49:09

Thanks Clive - so no runout spec for Multisize to usefully compare with the Multibore. If the Multibore is using rubber inserts presumably they are perishable in which case it sounds to me that the Multisize could be better especially as I am always thinking buy used. Yes I was viewing the Multisize EC collets as a type of 6 jaw chuck (and MC as a type of 8 jaw chuck) but am disappointed to read that not recommended for holding short ends of bar which I though might be a particularly useful extra benefit over a 3 jaw chuck...is this so and if so why?

18/04/2020 18:05:26

There are detailed specifications in the official Crawford Multibore brochure (eg for a 16mm diameter bar, measured at 38mm from end of collet, runout up to 0.03mm) but I have not managed to find any such detail for Burnerd Multisize, despite being part of the same "600 Group". This makes me wonder if perhaps Burnerd Multisize are not so accurate and so 600 Group are not falling over themselves to provide such data, which should be normally of interest to buyers of any expensive collet system. Regarding resistance to rust and corrosion, obviously everyone knows what are the best methods and conditions to keep tooling rust free, but nevertheless some manufacturers do seem to produce tooling that is remarkably resistant to rust (eg in my experience particularly swiss makers like Schaublin and Aciera) whereas others rust remarkably easily (eg in my experience Myford collets, some chinese ER collets).

Edited By Adam Harris on 18/04/2020 18:27:40

18/04/2020 15:19:41

I wonder which type is preferred, particularly in terms of better results for runout and which is manufactured with better materials resistant to rust. Any views much appreciated

Edited By Adam Harris on 18/04/2020 15:20:27

Edited By Adam Harris on 18/04/2020 15:22:12

Thread: Holding block for ISO 30 shank
04/03/2020 23:18:00

Michael thanks - I think that's a fair idea but really I am better off just buying a short bit of hex bar 2.76" AF and boring an ISO30 female taper into it on the lathe, and then machine the face on the mill to leave a pair of permanent dogs.

04/03/2020 16:02:48

I agree not too difficult to make, but I was wondering if there is something already out there at a reasonable price

Edited By Adam Harris on 04/03/2020 16:03:05

04/03/2020 15:39:47

Kennametal have a TF30 which looks like it would do the job, but not found one used in the UK, and would like something sub-£100 otherwise I'd rather make one myself. The TF30 is £202 +VAT new in the UK!

Edited By Adam Harris on 04/03/2020 15:51:14

04/03/2020 15:35:07

I agree it would be possible (though less easy) to do the profiling, drilling , tapping while in the milling spindle but the off-centre indents would need to be milled when mounted in a vice. 

Edited By Adam Harris on 04/03/2020 15:35:29

Edited By Adam Harris on 04/03/2020 15:36:11

04/03/2020 15:33:07

Thanks Andrew - no it is a machining process that requires profiling, drilling, tapping and finally milling indents off-centre. Ideally I would like a hexagonal block that holds it in a lathe chuck and then can be moved to a milling machine vice for off-centre indents.

04/03/2020 15:06:49

Having seen the hexagonal holding blocks for Straight shanks (using ER collets) that then allow clamping in a vice or a 3-jaw chuck for machining the face, I am wondering if there are similar holding blocks for an ISO 30 shank so one can machine the face of an ISO 30 arbor in a lathe. I have been searching without success....any directions much appreciated.

Edited By Adam Harris on 04/03/2020 15:09:07

Thread: Alternative to PC based Cnc controllers
06/01/2020 14:44:33

Two and a half years later, is there now any better sub-£400 simple stand-alone lathe controller than the aforementioned NEW990TD-b where you simply connect encoders & motor driver boards & stepper motors and enter the thread cutting pitch required to get going (no pc or keyboard required)? Have come across the Rocketronics ELS4 Basic at about 250 euro that does thread cutting and taper turning etc - does anyone have experience of it, or recommend any similar products now out there?

Thread: DRO magnetic encoders - generic?
17/10/2019 18:55:11

What I am looking for first is a cheap source for a 3rd generic chinese magnetic tape encoder 5 micron (5v TTL quadrature) - the magnetic scales are super thin and impervious to coolant so great for small machines

17/10/2019 17:45:58

Well I have learnt that there are consoles from the far east like Shumatec DRO-550 that run DRO-open source software which allows them to receive a variety of Chinese signals (24 Bit, BCD7, BIN6, 21 BIT) and also 5v TTL quadrature, but the big names of Newall and Heidenhain each run their own completely closed system whereby proprietary encoder signal technology must be used (and does not work on any other consoles). However popular generic consoles that take 5v TTL quadrature signals from magnetic tape encoders will take that format signal from any encoder producer and indeed from any glass slide product that gives a 5v TTL quadrature signal.

17/10/2019 00:50:00

All sounds good. Thanks. Will check out the M-DRO/Allendale stand at Warwick ME show and see to what extent most consoles have the flexibility to receive a variety of different types of signal from 5v TTL quadrature to others such as Spherosyn and glass scales.

16/10/2019 17:10:59

I have cannibalised a pair of 10 year old M-DRO 5 micron magnetic tape encoder heads (with 10 feet of cable and 9-way  D-type connectors) from an M-DRO "Budget Console" lathe kit that back in 2010 did not garner good reviews on MEW. I assume today consoles are better and cheaper, so I am thinking I would not mind having a 3-axis milling DRO and wonder if these magnetic encoder heads are generic and will work fine with any magnetic tape DRO system and in doing so save me some money, or are some 5 micron encoder heads significantly better than others. These have an output signal of 5 volt TTL quadrature with 90 deg phase difference - is that the generic signal that most magnetic tape consoles use today?

Also any recommended budget Milling DRO consoles that take magnetic encoder input?

Edited By Adam Harris on 16/10/2019 17:14:29

Edited By Adam Harris on 16/10/2019 17:43:38

Thread: Bright EN24T steel vs Black EN24T for cutting gears
14/10/2019 22:06:38

"But as they like it rough, very often the answer to a disappointing cut is to push carbide harder, the exact opposite of HSS where slowing down usually helps" - thanks Dave, that is useful to know. And I will try carbide Inserts at 4x "Coated" speeds and experiment increasing from there. 

Edited By Adam Harris on 14/10/2019 22:21:33

14/10/2019 21:29:58

Thanks Andrew, so are you saying that my chart of speeds is acceptable for HSS and Coated tools but if using carbide inserts I should go at as much as 4 x those speeds? Ie Stainless I should be looking at 240-360 ft/min with inserts, and aluminium I should be looking at 1600 - 4000 ft/min with inserts?

14/10/2019 20:31:21

Well my chart does give for 400 ft/min material in 1" diameter exactly 1528rpm using HSS tools (actually it gives 1986 rpm for Coated tools). My chart (and I cannot remember where on earth I found it on the internet) offers that a general category of material has a wide "range" of speed in ft/min, depending presumably on its alloy variations. It gives Aluminium at 400-1000 ft/min, but I see that L.H. Sparey gives Aluminium a rate of 300 ft/min. My chart gives Stainless 60-90 ft/min and I see that Sparey gives it 50 ft/min and David Clark's Teach In article in MEW 216 (corrected by Neil Wyatt) gives "Carbon Steels, Stainless Steel and Alloy Steels" all at 50 ft/min . My chart gives High Carbon steel a range of 40-70 and Low Carbon steel a range of 80-140 and Stainless a range of 60-90. Perhaps, embarassingly, my chart is all nonsense, or fit only for large industrial machines, but until now it is fairly academic because I use it as a broad indication, since the best speed (and feed) for me has been one found by trial and error that produces nice chip formation and partly because I am rarely sure of the spec of material I am cutting! I do try to follow the principle that one should start erring on the slow side. However I have always believed that harder material should be turned much slower than softer material, hence my surprise that this hard EN24T stuff should be turned as fast as Aluminium. Have I been doing it all wrong, or is the major discrepancy the difference between Coated tools and Carbide Inserts (for which I have no data and actually hardly any experience)? I know inserts can be used faster than Coated cutters, but how much faster, and is the faster speed an option or a necessity? And if my chart's  ft/min ranges for materials are no good, can you point me to a chart that you recommend as giving better results?

Edited By Adam Harris on 14/10/2019 20:34:01

Edited By Adam Harris on 14/10/2019 20:47:35

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