Simon, Bill Et al, The thread started with a conversation between me and a member, as he was having trouble drilling some holes. The following day I was in a local tool stockists and mentioned said conversation to be shown a good quality drill bit that had been COMPLETELY wrongly ground - it had NO cutting edge at all. After grinding it had been coated, TiN. MY question was had anybody else come across new, wrongly or poorly ground drill bits ? Noel.
I thought that was the case, but did wonder if other folk might be latching onto the wrong thing re. BASS 666's problem.
Yes I've had some bits supplied with very odd profiled ends, mainly when purchasing cheap sets from Aldi/Lidl etc.
Most of the bits in the sets have been OK, but odd ones have been way off, to the extent of the cutting edge never meeting the workpiece. Might be OK in wood where the work will deform with more pressure, but certainly u/s in metal.
That said, I have still bought cheap sets from time to time, and re-sharpened where required.
The HSS itself seems reasonable, just the grinding geometry.
I use the Lidl sets for normal day to day use, and my better quality ones when I have a need for a specific hole size, such as a tapping job.
I'm with Simon here; I might be misunderstanding something due to insufficient coffee, but are Noel's first two paragraphs directly related to each other.
Are strange ones from the tool merchant the same as the Presto ones bought by BASS 666?
Presto's web site doesn't seem to show anything relevant; this link is on;y to one of the available boxed sets.
https://www.presto-tools.co.uk/Products/hsco-super-elite-jobber-drill-sets-din-338
Just coming back on this one for the sake of completeness.
I've just tried a length of NuTlink belt on my genuine Super-7, as opposed to the Warco 720 clone.
Like the Warco, I can't select the lowest speed belt drive in the S-7 headstock, as the deeper section of the belt doesn't easily allow the transfer of the belt onto the largest pulley; the little T nuts foul on the front of the headstock casting.
In the past I also tried a link belt where the "rivets" were actually thin headed hex nuts and bolts; this was also too deep and fouled on the casting.
When I originally bought the lathe 30+ years ago, it came fitted with a rather worn Brammer link belt; the type where the rivets are slightly domed/flat both ends, inside and outside the belt. That just fitted OK, but was eventually replaced as the links started to perish.
I'd be tempted to do a workshop trial using a 6mm centre drill to both start and complete the hole.
They work well on stainless, with a suitable lubricant, and are less likely to snatch and run up the spiral than a conventional drill geometry. (HSS, rather than carbide)
Have bought belts, Orings, seals and bearings from Simply Bearings. Very helpful. They stock Fenner Nutlink belts nutlink, but I've never used link belts. I do know that the generator on Tornado is driven off one of the tender axles by a link belt, otherwise they'd have to take an axle out to change the belt, which would be more than a bit inconvenient.
Nutlink belts, like T-Nut ones are deeper than the Fenner Powertwist, or the ones I linked to in my previous post.
I'm not sure if that would cause a clearance problem in the S7 headstock; It certainly did on my Warco 720, which is a close clone from the late '70s.
The extra depth fouled on the casting, so I struggled to obtain the lowest belt speed.
That isn't to say they are a bad option, I use one on the power hacksaw, and another on one of my drill presses.
Yes, I've tried both black and white plastic ones from RDG, and had little success with either.
I went with one of these green fibre reinforced ones off eBay, very similar to the red Fenner one, but the colour matches my lathe and, more importantly, it's cheaper; It also works well.
https://www.ebay.co.uk/itm/174456949982
The company does seem to have a web presence, but doesn't list this particular belt
https://industria.co.uk/brands/fenner-drives-2
See also, from the manufacturer
https://megadynegroup.com/files/resources/attachments/md_broc_acculink_web_am_en.pdf
Ketan, I'm on Plusnet & W10. All OK on Opera, Firefox, Avast, Chrome, Edge & Pale Moon browsers.
I'm also using a BT home hub, which has a fixed DNS of;
I think Plusnet's default DNS server address may be different.
I've had issues in the past, where, following a website's udpate, there was one or more DNS servers which failed to resolve the address, until at some point they were later updated..
This meant that some people on a particular ISP could access a website, but others could not without changing their default DNS server address.
Bill
I can still remember Bar 1 in the Sheffield University students union back in the '70s
Three doors in a row, the outer two being "Ladies" and "Gents"; the centre one was "Switch Room"
I've not made one with the round toolholder at the bottom yet, but I do have several of the Jones and Shipman American style lathe toolholders, which accept a length of HSS bar set an angle.
I've left and right hand ones as well as a couple which take parting blades.
Also have a straight one by DST Ltd of Brighouse, under a brand of Andycraft Series.
I used the angled ones when I was roughing out the dovetails on some QD toolholders I made for the Warco GH 1330, though I did the final finishing with a conventional dovetail milling cutter in the Centec.
For anyone curious, Robrenz has a quite a good video on the subject.
As mentioned above, Don Bailey also covers them very well. Stefan Gotteswinter, has a video, and also supplies them, but no longer to the UK post Brexit ( It looks like he's struggling to get the base stones at the moment anyway).
https://gtwr.de/precision-benchstones/
here you go, I hope this reproduces/prints OK
I don't have a CAD package, so this was a quick sketch in Visio and reproduced as a jpg
N.B. it is not to scale.
The 30° angle is as close as I could measure it, but obviously to suit the collet. I came up with 15° per side.
If you need any more measurements, just shout up.
Bill
Babiels, the link on Tony's site suggests that the mill originally came with an MT3 or an as yet unidentified taper.
It's quite possible that the latter is actually a Clarkson fitting, or a variation on it.
If you have a look in my album, of which this is one photo, there is a variety of different chucks on show there.
When I got my Centec, it came with a Clarkson C type and a set of imperial collets; I successfully made a full set of metric ones myself to suit, so it's quite possible to make your own from scratch.
I've since picked up a full set of genuine ones over the years.
I don't think it will be practical to convert S type to C type, though I will happily supply any measurements you need.
On the C type, there should certainly be a closing sleeve.
Find a bit of steel/alloy/wood/plastic etc and produce a slightly tighter radius on one corner.
Wrap an old fashioned double edged razor blade around that radius, with a couple of mm protruding, and you have a punch. Other sources are available
https://www.sweynforkbeard.co.uk/product/double-edge-blades-derby
It's certainly possible to get a single to single phase VFD, and as I understand it some models can have a scaling factor added to the display, though I'm not sure which ones.
A friend of mine has a 2"x72" belt grinder running off one as an experiment, though I don't know if that model has a programmable display.
It's also possible to run a single phase motor off some single to three phase VFDs, though not all will allow the correct programming. I don't know personally if any of those allow a display to be scaled.
This video is worth a look on how to run single phase motor off a specific ATO three phase output so it might be worth contacting ATO directly.
I guess you could try a single phase motor on it, and swap later to a three phase one, but it looks like they advise an inverter of double the normal rated capacity, so a higher initial expense.
You would have to check the prices yourself, as it may be more cost effective to get a smaller inverter and a new/second hand three phase motor.
,
Personally I'd use a separate tacho running off the main spindle, as the cheap LED ones off ebay work well enough. If you were to make a separate housing for the VFD, then adding one to the box cover would be easy enough.
They do a similar video for their single to single phase converter.
If you have access to a vacuum pump, one possibility would be to stabilise the wood before machining; it's a method often used by knife makers.
Essentially evacuate a vessel containing your wood and a resin; as the air is re-admitted, the resin is drawn into the pores of the wood.
I did mention it on a different thread, but "Cactus Juice" is one such resin, but I'm not sure if it is readily available in the UK in small quantities.
Maybe have a look around the pen makers forums, whilst you're researching Corian.
........... they also supplied square centres and fluted centres. Does anyone know what these were used for? I can't even picture a 'fluted centre'. The square centre had a steep square taper on the front; in fact there is one on eBay at the moment.
Many thanks,
Mike
Edited By Mike Donnerstag on 20/02/2022 14:52:19
The square centre is good for cleaning up damaged centre drillings on work which you want to re-mount, say the damaged end of a motor armature that's been hammered or dinged.
Also handy for re-centring an off centre centre drilling.
The fluted centre looks a bit like a centre drill, but without the starting pip at the end.
I've never seen one in real life, so I'm not sure if it's intended to cut, or to provide a sharp edge to bite into the work, a bit like a self driving centre.
There's diagrams of both in one or more of the older Myford catalogues, but I'll not reproduce here for copyright reasons; I got them off the old Yahoo Myford groups files before ithe groups were removed.
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