Member postings for Russ B

+1 Andy, great idea!

I've just got my ER40 Sq.+Hex set!

I've bought things in the past that I thought was going to be handy..... and it really just didn't fulfil that expectation.

The more I do and see people doing with the these blocks, the more I like it!

I've added a pair of 20-40-80 + 10-20-40 Stevenson’s blocks to my Xmas list as I've always fancied a set and they'll prove invaluable for a couple of checks I want to make on my lathe next year.

Edited By Russ B on 07/11/2017 05:25:14

I got a mini lathe for this reason, I removed the back guard and drip tray, and slide off tailstock and then it's not too much trouble to slide it away under my bench when not in use. I've not stripped and checked it, but it turns acceptable/good parts out of the box - I can't complain.

This reminds me....... my main powder extinguisher's lost pressure.

Where (assuming you do) do you take these extinguishers to get checked and filled. It's a modern, good quality extinguisher with refill port etc, not a cheap jobbie

Exactly my point. The white metal bearings are no longer available, so I'd crunch a few numbers to get a feel for what's sensible, but all dependant on the oil feed, and I would consider the oil cups on the ML7 to be extremely effective. Also oils theses days have some very advanced additives so I'd expect them to outperform the kinds of oils available 70+ years ago when these were designed - by 25% maybe? I'm a long way from home so cant pull out any figures from texts but I'm sure it's in many of the old school engineering encyclopedias.

All this talk of speeds and motors is near irrelevant if you ask me. The answer is, however fast you like - change your pulleys and shoot for 10,000rpm!!

Or not....... because you'll melt your spindle to your bearings, and this is really the limiting factor, nothing to do with which motor you've gone for, you can always change a motor, you'll probably be able to pick one up from a junk sale for a fiver as a spare just in case.

You need to identify if you're running the original white metal bearings and soft spindle, or the newer bronze type bearings with a hardened spindle, then look up the maximum surface speed for your bearing material, and measure the size of your bearing and take it from there, if you think you think you can hit 2000rpm I'd say gear for it with your VFD at 100%, and I'm sure an occasional blast to 120% won't hurt anything, adjust your driver or driven pulley size to suit and make sure you're oil cups are working well (although I think these run significantly more oil than is required anyway, it was slightly comforting to see it pooling on the drip tray... oil cooled bearings would be a more accurate description of my old setup!

If you're near or passing Doncaster, let me know.

I have used "Durafix" to great effect and would recommend it for dissimilar metal too (copper to aluminium, no flux needed, no problem)

You need a lot of heat, anything sub 0.7mm, and you'd probably melt it unless you've got excessive amounts of "the knack"

Edited By Russ B on 01/11/2017 03:57:59

Well bloody hell..... I think Michael Gilligan has just flashed up half of what I was rambling about while I was typing!!!!

Good stuff there in 1.23 and it will easily fit with many other standard calcs surrounding belts

(and just look how much simpler rads make the equation!)

Edited By Russ B on 29/10/2017 01:03:05

sadly I'm 7000 miles from my notes at the minute but I don't do it like this....

I calculate the contact angle overlap on each pulley first (in radians if I recal correct) (if the pulleys are equal the formula should equal zero) - so if one pulley is larger, it's contact will be 1(pi)r+overlap arc, and the small pulley will be 1(pi)r-overlap arc.

As far as I know, this is the normal/standard way to calculate belt length (or pitch length at least) because it also gives you everything you need to calculate the torque that can be transmitted with a known tension (not totally applicable for toothed, but still needs to be done) and simple manipulation can tell you how tight the belt would need to be to transmit "x" amount of torque - it also tells you what the tension in the taut side will be, which will be a limiting factor (since you don't want to stretch or snap your belt! - hence the calc still needs to be done for a toothed belt, although it can be shortcut, but the next point would alter the tension because....

you can also easily apply inertial forces to the equasion as the belt tries to throw itself off the pulley.

you can then start manipulating the figures to see how much pulley overlap is required to transmit the torque you desire (for a flat or vee belt etc) which gives you an idea of where your idler needs to be to create the desired overlap.

for a toothed pulley, you'd just drop the friction factor our of the maxiumum torque calcs and assume it's 1:1 with no slip, and just concern yourself with the tension in the taut side to make sure you're not going to snap it. Since you don't have any slippage, adding an idler won't change the results, but common sense tells you need a certain minimum number of teeth engaged and the manufacturer or standard texts will probably dictate a minimum radius anyway.

has it been considered that many common toothed pulleys have inherent backlash - and there are a few which specifically dont - hence ideal of automation/cnc

- Sorry I can't give you proper formula - I've googled but didn't find what I need, I've seen other ways but they make it look complex...... see here for the closest but note, because he's using degree's and not radians, i think.... his calcs are significantly more complex/long hand with some slightly more exotic trig functions that im not entirely sure are necessary!

I should add, it’s nothing that can’t be worked/engineered to a satisfying solution - but I don’t think the extra agility or Z height is really worth the hassle!

Speaking from experience, Delta printers throw up more challenges for the mind and wallet - for little benefit.

Mainly freeplay/backlash in the Delta arms

Machines that make use of universal joints aren’t very clever.

It’s much harder to accurately calibrate your z axis - since you basically have 3.

Trickyness all round - agile, but tricky...

Yes.... they're quite a few quid, but better than an Ultimaker or the likes (which are £3k upwards!)

If you just want to 3D print very accurate models, without needing any skill or knowledge of 3D printing or computers, it's basically ideal, quick, reliable, easy - and if you want to tweak it, go for it, it's completely configurable via "expert" tick box in settings which opens up a wealth of menus and settings if you feel like killing a few hours.

I still have an i3

disagree strongly ^ see above....... 3 years old, pre-production unit.

There is one catch however, I do own 2 print heads (it came with one, I bought a spare) - the early models had issues with their needle valve system, which has now been resolved with a completely new head (both of mine have been replaced for the brand new version, free of charge when they eventually failed)

I still keep 2, just in case I need to send one back for servicing (all free under warranty, I just pay postage to them, although they do offer to refund it!)

I've not had the version 2 fail yet, they're about a year old now and my spare is still brand new in the box.

To summarise, zero time needed tweaking settings, installing or software, writing or messing with firmware, zero bed cleaning or levelling routines etc etc.... its basically, just like a paper printer, install the software, install the "ink" and press print, it will lock the door... sit and wait

Edited By Russ B on 24/10/2017 20:55:13

I have a CEL Robox - the reviews just don't do it justice.

It comes with proprietary software "Automaker" which is ultra ultra polished - smooth as a babies bum and super easy and intuitive to use. The interface is so simple its basically fool proof but behind it, it is just as configurable as any 3D printer and uses standard slicers to write the machine instruction which are a modified form of gcode (Cura is the default slicer). This software is just a simple installation, no setup required - take the printer out ofthe box, install the software (before you....) plug in the printer, load the fillament (poke it in a hole, and it detects it, and takes it off you, and feeds itself) - and then find a 3D model, and press print - wait, enjoy.

It also uses proprietary fillament spools, which come with the material data written on it (print speed, temps, bed temps, layer cooldown, everything - absolutely everything) - HOWEVER it's totally open, you can use whatever material you like, and Automaker even includes a module that lets you write and re-write the spools EEPROM and they give you their complete library of material print properties which they've researched and fine tuned.

The bed doesn't require any sort of preparation, you don't even have to clean it (although I give it a wipe with alcohol between ABS prints as it leaves a residue), parts stick first time, every time, I've only ever had 1 or 2 parts come unstuck. This applies to PLA, ABS, Polycabonate, all sorts.

The print heads are quick release, dual nozzle units with needle valves to control flow. The heads are either "quick fill" or "Dual Material" the quick fill has a fine 0.3 nozzle, and a wide 0.8mm, it does the outer detail in 0.3, and then quickly fills out the inner with the big 0.8 - saving time, which is the biggest enemy - a single large part can take a day or more, easily!!!

The hot end can hit 240c in just 1 minute from cold, and the heated bed will hit 130 in 4 minutes - this is roughly 1/3rd of the time of anything else ive seen. Further more, the nozzle will reach 280c max, and the bed will hit 150c which would actually melt most parts back down - however, its future proof!

Print quality exceeds that of the £30,000 professional solutions.

It's a very, very, very neat piece of kit - and the customer support is unbelievable, UK born machine, UK based customer support - I have a pre-production beta 3+ years old and it's just about to go back for a standard £100 full service, which will include any and all updates - even though it doesn't need anything it will get an new updated extruder and other tweaks and enhancements, plus anything it needs.

I could keep going on, if it exploded into a thousand pieces tomorrow - I'd go straight out, and buy another!

Edited By Russ B on 24/10/2017 20:52:34

Very sad to hear this, he was one of those great guys who was an encyclopedia of engineering knowledge. I remember when I first started model engineering, and training to be an engineer, there seemed like a vast array of knowledgeable and experienced people to look up to. The older and wiser I got, the more idols became equals and team mates, but there are a select few who are still way up at there, and John was certainly one of them in my eyes.

A great loss to the community, and to his friends and family. My thoughts go out to all.

I thought exactly the same as soon as I saw it

I've just read every post here to see if it had been suggested....... and then you pipped me to it Neil.

If these bespoke nozzles are $30 a pop - I'd do exactly as Neil said and just make a new hot end! To be more precise, I'd remachine the existing one to accept the standard M6 male nozzles.

I would also move the NTC thermister to the opposite side of the block to the ceramic heater, it's practically sitting on it at the moment, you're hot end could be colder than you think.

I have a Chester Craftsman going spare, I keep saying I'm going to sell it, and I never get round to it

- Tool Hoarder!

I assumed both Excel and Baileigh Industrial were mostly just selling the same sort of far eastern machines as everyone else.

I've seen equipment from them and Warco identical to my own Axminster kit, just with their own stickers and colours, everything else seemed identical.

Neil, thanks!!

I'm on the mailing last I checked! I did a search on here looking for any discounts but only found this thread!