Member postings for Joe Page

Just tested my 3D printed prototype, everything plastic apart from the drive shaft. Got it to around 50,000 rpm at 5psi, quite amazing when the impeller is 86mm in diameter, it is printed from polycarbonate however, just got to do a little rework on the design, then if it works I've got to completely re-print it from a higher temperature plastic (main housing is PETG) before I can give it a test in a car, hoping for around 8psi. I will scrap this design eventually and work on the gearing idea.

Hi, Duncan, I will be scavenging a compressor wheel from a turbo, spinning plastic at the speed I'm at now is scary enough, plus they're a lot less efficient compared to a turbo wheel.

Hi, Murry, should have probably read my post, I'm not making a simple 20W fan motor like those on ebay, it is actually the reason I started the project, to prove much more power is required and that the ebay units are complete junk, I'm using a 4kW system for now that will be modular for multiple units, I did state it takes about 10kW of power to boost a 140bhp car to 200bhp, that's assuming 100% efficiency. I don't understand why you don't see it's possible, the supercharger that Neil showed us from the H2R is exactly what I'm building, the difference is one is mechanical power and mine electric.

What I would agree is they're not practical since the electric system on a car is not designed for 4kW of power, let alone 10kW or more.

Thanks for all of the replies, some very useful information here.

Neil has just pointed out exactly what I'm trying to achieve, I did consider a planetary gear set at first but the ring gear was the thing bothering me with the high speeds, plus it's something I have never made before.

So my idea is to produce an electrical supercharger with a very small footprint, it's one of those proof of concept projects of whether it can be done. I'm trying to make it a compact modular system so that they can be paralleled up for more power, considering it takes about 10kW of power to boost a car from 140, to around 200bhp is probably a reason they're not produced, a project never the less.

So far I'm getting around 3 psi from a 70mm diameter impeller, it's 3D printed and spinning at 60,000rpm. I'm almost ready to test out a two stage compressor with 80mm impellers, just waiting for a power source. The whole thing is now 6" diameter which is far too big, so I want to upgrade the speed to 150,000 rpm so I can get the whole thing to around 3" diameter. I will probably knock something up of the 3D printer, if it works then I'll go to metal, of course I won't take it up to full speed in plastic. I imagine the Kawasaki super charger must have some kind of a lubrication system, this will be the difficult part.

Thanks, I will keep you updated of whether it works out, having fun with the 3D printer anyway. I'll post some pictures or a vid when I get it working properly, sounds like a jumbo jet at the moment, not sure I'm brave enough to put it in my car.

Edited By Joe Page on 18/10/2017 21:18:54

Hi,

I have a 4kW electric motor at 50,000 rpm but I need a final drive of 150,000rpm

Realistically what Is the possibility of using spur gears?

And if so what material would you recommend I make them from, and minimum footprint?

Do you think complete submersion in oil would cause too much friction?

The input speed will mostly hover around 20,000rpm, but in short bursts for maybe only 30 seconds it will spin up to 50,000rpm. This is all just the "idea" stage but my gut feeling is they wouldn't last two seconds.

Thanks

Hi Stuart,

your correct, something I overlooked.

I originally thought it was the filter and I was gonna modify it, turned out the filter was all integrated, some ferrites, one capacitor across the output, the rectifier and then the large inverter filter capacitors, nothing to ground apart from these inverter caps. just a common mode filter in my case which is why it could only be the large filters for me.

Hi John,

99% certain it is an earth leakage which is very common with inverters. I had the same issue on mine a while back, since I was not certified to play with the mains and change the breaker back to an mcb I chose to remove the earth to my inverter.

The supply was earthed, the motor earthed and the inverter plastic, so there was no reason why it needed an earth. After removal it never tripped again confirming it was earth leakage.

The reason it happens is because the filter capacitors negative terminal is grounded, electrolytics can leak current. If your inverter is metal then do not under any circumstances remove the earth, you would have to modify the inverters internals otherwise.

I wonder why Harrison chose the beige colour in the first place, makes them look so drab. Sorry about my last reply too, just read it back and I sounded a little brash.

Incidentally the lathe is from the 80's, I wonder what the colour choice was,

I spent the whole day cleaning the lathe, the paint isn't too bad, it's around the base where the paint has peeled, shame because when I got it five years ago it had been in storage from a year after it's manufacture and it literally didn't have any paint chips.

Hi Jon,

I'm not sure where you got your information from but all of the M280's are in fact green from new. It has never been painted either as it still has the original Harrison inspection sticker.

Hi, thanks all

That is one thing I feared but didn't expect everyone to say,

I have to admit seeing some peoples machines on here I would expect them to have Rolls Royce emblem let alone Ducati, haha

I think I will leave the paint then, its clearly had light use.

Cheers

Edited By Joe Page on 12/03/2016 13:47:29

Hi,

I'm sure lathe paints been done to death but I will soon be selling my Harrison M250 / M280 CNC lathe. All of the bed ways are in perfect condition and the paint is mostly there but there are some bad spots and I need to get the most money out of the sale.

My questions are;

The original paint is green, now do I keep it original or is there a preferred colour people go for, such as white or grey. (or is that a silly question)

I'm pretty sure colour won't match perfectly, and the electrical cabinet has perfect paintwork, so would it put you off if the lathe was in two slightly different tones of green, or should I paint the lot.

What is the best paint supplier? I can spray or brush it, brushing would be easier but I want something that won't leave brush marks.

Would you paint the coolant sump with the same paint or go for something specialised?

Much appreciated,

Thanks,

Joe

Neil - I think these would be far too small but I certainly wish myself knew about these long ago.

Les Jones - It's definitely a 6 diode bridge, second picture shows five wires going into a rectifier. Like you say it will need a bigger capacitor or a bank of them, only problem is a bigger capacitor, the more surge current, I noticed a NTC thermistor to limit surge current so without doing any calculations I would probably just double the capacitance at most.

Tony Ray - I think this sounds a really good option, they are unbelievably cheap. With the size of the auto transformer just to power the control and servo I would assume he would be needing quite a few transformers, it looks around a 5KVA size transformer, although just speculation. I couldn't imagine the servo's needing more than 500W each though.

I was hoping the control boards would have stated their make or ratings so we would know what power we're dealing with. Chirs, would you be able to tell us the ratings of each of the servo motors?

Rotary or static converters are just about ok for running motors with pretty constant loads like compressors or conveyors. I have heard a lot of people drive lathes and millers and found their motors are noisy or run quite hot. I wouldn't want to try it on a cnc, I may be wrong, some may be doing it but I would advise against it.

Either way your going to need three phase whether it's 220v or 415V. Motor's can usually be wired in either star (415v) or delta (220V).

If you go down the 220V three phase then you will need inverter for the spindle motor, a 24v transformer for the control, a 110V transformer for the switch gear, and an 85V transformer for the servo drive which I imagine could be quite difficult to source cheaply. Your probably talking £300-400 for the inverter, £100 for the 24v and 110V transformer and ??? for the 85V transformer. Then it depends how confident you are doing all this? You could also use a variac to get the 85V but probably talking £200 upwards.

You could get a 220 to 415V inverter and leave the insides, you would probably need at least 5hp, personally I would go 7.5hp to be safe but your talking £1500. Don't go with static or rotary converters.

Hi Chris,

We are all probably going to speculate and without a wiring diagram or seeing it in the flesh we probably can't give you an exact answer. I've worked on a few machines and some transformers step the voltage down to 200/220V three phase which are normally the big machines. With you saying the motor is wired in delta then it must be 240V three phase, so the big transformer sounds like it's stepping the 415 supply down to 240V three phase.

So you could cut out the transformer and stick an inverter in there but you will have to check the power of the control circuits, normally they are powered by single phase, tapped off one of the phases to make 240V. I did also notice 24V on the transformer too which probably is what powers the servos and control circuitry, so if you did remove the transformer you would need an extra supply for the control circuit.

Include some photo's of wires going to and from the transformer, some pictures of the controllers too. Maybe someone close by on here would have a look at it for you,

Regards,

Joe

I bought some graphite rod from these;

**LINK**

Seems to be good quality and machines nicely, I have about 6" of it left, if your in the Sheffield area you can have half of it for free.

Otherwise I used to machine carbon or graphite impregnated PTFE, should be quite easy to get hold of. Seal manufacturers may give you some, or fluorocarbon uk make it, or GAPI uk will stock it. It's not hydroscopic, very easy to get a good finish and has little thermal expansion.

As Circlip says, do not use any nylon it will expand when the moisture hits it, normally about 1-2%.

Hi Steve,

Someone may have to correct me, but I think the taper is a little over 7deg so a MT reamer would not work.

I bought the same collets from RDG and not a single one of them has a runout of more than 0.01, some don't even register on the clock. My chuck however is a Bison one, it came with the back plate fitted, stuck it on the lathe and literally no run out. My collets are pretty much flush with the end of the chuck too.

I would clock everything in sequence. DTI the lathe spindle nose, if ok, Remove the chuck from the backplate, DTI the backplate, if ok, install the chuck, DTI the ground part on inside of chuck, if ok, then it's your collets.

Hi Dave,

Forgot to mention, if you work in imperial, the "original" taper is 0.624" per foot. (or a taper ratio of 1:19.2308, not 2307, not that it makes much difference. I recorded the process on **LINK**

Regards,

Joe

Muzzer - stood with a thick Perspex sheet in front of me with one hand and the other hand on the emergency stop, It did scare me so I haven't run it that fast since.

Dave - The taper is 1:19.2307. I started the big end a mill above the nose bore and tapered down a mill below the bore. So the big end was 39.2mm tapering down to 34mm at a length of 100mm (39.2 - (100/19.2307). I admit I'm not happy with how little contact area there is in the nose, not sure what the Colchester is like, but the Harrison M250 is only 15mm long, about a 30mm gap and then a little more of a taper.

Turns out I had a MT3 arbor for a drill chuck, has a M12 thread in back .

Anyway as for the adapter, made a nut for the draw bar from a top end timing pulley, magnesium alloy so it seems to have worked out ok because the threads aren't sticky, saved some time instead turning and milling a nut. Drilled out the adapter nose to 20mm as the smaller end of MT3 is 20mm, just to allow tung types to fit down it. Then bored it out using aluminium inserts and the final pass was 240rpm, 0.5mm at 20mm/min. The boring bar was only turning 90mm inside but had to stick it out 120mm due to the carriage hitting it's limit.

Overall I'm really happy the way it turned out, taper came out perfect and no mistakes, yeay. Piccy's:-

Same thing happened to me when I were about 13, I got my first drill press, exactly same vice too and it was on brass, luckily the belt was loose. At the time I never knew about this problem with brass as schools used to give you a hand vice and give you a hole to drill, I always assumed it was ok as it's what I were taught at school, probably why they don't teach metal work in schools anymore.

Andrew- I used to machine plastic seals which couldn't be clamped most of the time and had to be held by hand, I used to use only slot drills as even the slow spiral drills were unusable. I admit I had many accidents on the miller at work, no emergency stop on machines either, it was a case of deal with it, this was the kind of place where you given an interlock key to over-ride CNC machine doors so you could catch the parts as they come off, one of the reasons I left.

Maybe someone should start a near miss thread,

Decided to start making an adapter today, I instead have gone for two draw bars. A tube like one for the MT4.5 adapter and then a rod drawbar to run down the middle for the MT3 adapters. I wanted to machine the MT3 bore with the adapter inserted into the headstock, hence the reason for two drawbars. Used the CNC to get the angle right and it turned out perfect, 2000rpm, 12mm hold, 110mm over hang, 0.6mm cut really didn't feel all that safe :s.

Just got to make a nut and machine the other side, piccys:-

Thanks John, I assume it's M12 x 1.75.

Hi,

I've never had any experience with the threaded type of morse taper sleeves, only the tung type.

My question is, what size thread drawbar would you use for a mt2 and mt3. Are they normally metric or the same thread as an R8 type.

Decided that I'm going to make a mt4.5 to mt3 sleeve for my lathe as the Harrison m250 has the annoying mt4.5 headstock, so I need to know what kind of clearance hole to drill through the sleeve so that a draw bar for the larger mt3 can pass through.

Thanks,

Joe