Alternative to PC based Cnc controllers

[Anonymous]

We expect to see real metal swarf by the end of the Easter break.

Andrew

[Martin ConnellyParticipant @martinconnelly55370]

The problem with all this is – it makes me want to spend some money and play with one myself. I look forward to reading the complete tale when it is written up.

Martin C

PS Is play the correct word for this?

Edited By Martin Connelly on 11/04/2017 14:18:15

[John Stevenson 1Participant @johnstevenson1]

I have a Beaver CNC mill here, old but in very good condition and fully working, no faults, that I need to get rid of cheap but it requires dismantling to get it out and move it.

A job I don’t have time for unless it gets ripped to pieces and scrapped.

If interested then message me but ABSOLUTELY NO TYRE KICKERS

[Ex contributorParticipant @mgnbuk]

found that the mythical "suitcase compressor" was finally in stock at Lidl as of yesterday. Clouds and silver linings etc. So now I have a means of operating the power drawbar and gear selection solenoids. The CNC gods smiled on me again.

Not with that compressor they havn't. Have you read the specs ? – 1.5 minutes operation, then 8.5 minutes rest to cool down ! No receiver. "Hearing protection required" This maybe OK for the occasional tyre top up, or football inflation, but it won't run a machine tool & survive very long.

The vee twin compressors on a 50 litre receiver that Aldi did recently would be more like it – you would still be deaf when it ran, but at least the receiver would keep the machine operating between deafening bursts to top it up. And, being a wet sump compressor, it is continuously rated. Unfortunately it also cost £100 more !

Retrofit looking good.

Nigel B

[Anonymous]

Power drawbars, and presumably the gear selectors, tend to be transitory. They don't need continuous air flow at pressure to work. Provided there's enough capacity to operate once it comes down to how often you're going to be tool or speed range changing. Probably not that frequently.

Andrew

[Ex contributorParticipant @mgnbuk]

Power drawbars, and presumably the gear selectors, tend to be transitory. They don't need continuous air flow at pressure to work. Provided there's enough capacity to operate once it comes down to how often you're going to be tool or speed range changing. Probably not that frequently.

Indeed. But oil-free compressors don't take kindly to this application – been there & killed a Wolf unit with a 25 l receiver in a very short period doing just this. Killed two of them, actually – the first one was replaced when it died, as it was presumed faulty. I was working part time for the company at this point & the first one came & went while I wasn't there. I read the booklet that came with the second unit & found it had a 15 minutes in an hour duty cycle. Unfortunately this enlightenmant came just as the second unit turned it's toes up. OIl-free compressors are OK for very light use, infequently, or they die young.

Nigel B

[MuzzerParticipant @muzzer]

Yes, it's f noisy – the box claims 97dBA(!!) and sure enough it would wake the dead. As you say, no receiver and there doesn't seem to be a pressure switch. I thought that I could mount it inside the machine main casting / body to keep the noise down but probably not this one. I'll probably end up taking it back.

The previous plan (before the trains were late yesterday) was to use one of the argon bottles. I would have to check the regulators but typically the outlet pressure is between 2 and 8 bar for welding. That may be enough to operate the gear and drawbar actuators. Alternatively, Makita do a neat compressor that is reasonably quiet and compact but costs about £140. Seems a big investment for such a minimal usage….

Murray

Edited By Muzzer on 11/04/2017 21:40:27

[Clive FosterParticipant @clivefoster55965]

That Makita compressor looks good value. About half the output volume of the Compact 106 suitcase compressor I have with similar pressure capability and reservoir size for something around 1/4 the price. Checking the manual its another intermittent use DIY device. Maximum of 20 minutes use per hour advised. However, according to the wiring diagram, at least its got a proper motor start – stop regulator so it should be possible to keep within the 33% duty cycle.

I'd set it up with a bigger external tank so it has a decent run. 5 minutes or so sounds good. Then a decently long wait before it comes on again. You will need to be anal about leaks tho'. Takes very little to stop these low output compressors from getting up to their rated pressure.

Clive

[John Stevenson 1Participant @johnstevenson1]

What about the small Bambi type compressors with a supplementary tank ?

I have one in my shop that I use all the while for the odd times I need air to blow off etc. The Bambi is quiet and for what Muzzer wants should be able to keep up. Not sure what the duty cycle in on these things but mine is switched on all day but isn't used continually.

I have two large Hydrovanes which hardly ever run given the size of the tanks on them.

**LINK**

[Ex contributorParticipant @mgnbuk]

I thought that I could mount it inside the machine main casting / body to keep the noise down

Not a good plan to put an air cooled compressor in a small enclosed space, or to introduce a heat source within the carcass of a machine tool.

Nigel B

[MuzzerParticipant @muzzer]

I saw the Bambi things before but they are a few hundred quid ie several times what I want to cough up. They appear to be fully enclosed ie rather like a fridge compressor – presumably this is how they manage to be so quiet. I can't be arsed to change the actuators to electric, yet buying a compressor just to shift gears and change tools is verging on the extravagant. And there's The Internal Controller to consider. If she found out….

Murray

[Clive FosterParticipant @clivefoster55965]

Bambi, Jun-Air and the other lab / dental compressors are excellent and very long lived if you don't exceed the duty cycle (40%?). Bambi is quietest. Tanks are a more useful size too. But even on the little doughnut tank its a bigger lump than it looks in the picture. Market seems to have decided that £100 – £150 is the used price range so you'd be doing well to get one significantly cheaper than that Makita. Similar units to the Makita with other badges but Lawsons price seems to be biggest bang for buck at the moment. Obviously a "made for our badge" device but I'd trust Makita more than some of the other folk offering what is almost certainly essentially same design unit under the skin. Lawsons are decent to deal with too. My first stop for mail order power tools and similar.

Autojack are about the only breed that commonly comes up at a significantly lower price for similar oil-less low output compressors. But their idea of quiet is fantasy land "at only 96 dB this is easily one of the quietest compressors on the market". Ahem. You really need under 60 dB to be unobtrusive, mine claims 57 dB and is.

Clive

[MuzzerParticipant @muzzer]

Clive – according to the manual, the Makita claims to be 72dBA (at 4m) which is quite a bit louder than 57 but a lot less than 97. Most of the Machine Mart / Halfords / Aldi etc compressors seem to be around the 95-100 mark. It also has a pressure switch and a modest reservoir.

Might be tempted by a dental one if I can see something sensible. There are also the airbrush-type micro compressors. But first I must dig out my argon regulators and see what their delivery pressure is….

Murray

[MuzzerParticipant @muzzer]

Update on the CNC retrofit – first successful metal cutting. Nothing broken (yet) and a reasonable result. However, a lot of learning, setting up and wiring up still to be done….

Fairly urgent job on the task list – fit swarf guards and chip tray. The floor's a bloody mess now.

 

Murray

Edited By Muzzer on 25/04/2017 22:39:48

[Anonymous]

Posted by Muzzer on 25/04/2017 22:38:08:

Update on the CNC retrofit – first successful metal cutting.

Excellent result! Nice stream of swarf flying off. That's how it should be, especially with aluminium. If the swarf isn't streaming off all over the place then you're not running hard enough. Swarf guards are a bit soft; buy a broom and dustpan and brush. Swarf on the floor will keep the ducking fogs out of the workshop; they don't like it in their paws. The only caveat is that guards are essential if using flood coolant; you want the coolant back in the tank, not all over the floor.

It might be possible to talk ones way out of the odd bit of swarf in the house, but not out of a coolant soaked carpet.

Andrew

[MuzzerParticipant @muzzer]

Haha don't believe it. Our dogs will eat pretty much anything and that would probably include swarf. Recently they have eaten an entire slipper (plastic and fabric – in its entirety over a couple of weeks), a plastic "hippo" bucket (small, work in progress, including the sand it was filled with), multiple garden snails (down in one), pieces of rope (all gone now), bird seed (comes straight through) etc etc. As you can tell, we never feed them.

Their favourite of a weekend is ice cubes. They will eat as many as we can give them, as quickly as caninely possible. That is surely the original negative calorie diet – no calorific content, takes energy to eat them and more energy to melt them internally. If I could get humans to take it up I'd be a billionaire in no time.

I have some nice guards that came with the machine, as well as the optional (giant) chip tray. Must fit them now. The Screwfix "shop vac" actually sucked them up very effectively.

Murray

Edited By Muzzer on 26/04/2017 22:33:49

[David RileyParticipant @davidriley61024]

Update on the CNC retrofit – first successful metal cutting.

Muzzer,

Can I ask you to provide some details of the toolholder and inserts on your CNC mill please.

Thanks

[MuzzerParticipant @muzzer]

I'm not involved in machining professionally at a personal level, so my understanding of tooling systems is rather limited but I believe that the BAP series of indexable milling cutters was possibly created by Mitsubishi. They use the APKT / APMT (sintered) and APGT (polished) type inserts that are quite widely applied in milling cutters and readily available from most manufacturers.

Other manufacturers also sell AP*T tooling, eg Korloy "Alpha Mill", Sandvik "Coromill R390" etc – and loads of Chinese suppliers whose products of differing qualities are freely availably through Aliexpress, ebay, Banggood and UK hobby suppliers.

There seem to be 2 main insert sizes – AP*T1135 and AP*T1604. The 1135 is the smaller insert, with 11mm long edge and the 1604 has a 16.5mm long edge. There seems to be a 6mm version too but I've not seen much of them. They have a fairly high positive rake angle (12-20 degrees depending on the application) and many of the inserts have a flat "wiper" edge to eliminate the ridge you would get from using a simple radius edge. The high rake angles make for low cutting forces and are good for light duty machines like ours, although the intermittent spindle load makes them noisy!

The generic toolholders for the smaller 1135 are generally labelled as BAP300*** and the larger 1604 equivalents are BAP400***. If you look on the likes of ebay, Aliexpress, Banggood etc, you will see many tools identified using this BAP nomenclature. The numbers that follow typically indicate the size of the body and the number of inserts, so on ebay etc, a BAP300R-12-130-C12 would have a 12mm effective dia with a 12mm / 130mm long shank. For face mills, a BAP 400R-50-22-4F would have a 50mm effective diameter, 22m bore and 4 of the 1604 inserts etc. Be aware that a RAP300*** has the inserts at 75 degrees(?), which you probably don't want.

I bought the Mitsubishi cutter used in the video and 5 inserts from ebay new and unused for £40. It's BAP300R121S16 ie 12mm effective diameter, 16mm shank and uses one 1135 insert. I have also just acquired a brand new Korloy 50mm Alpha Mill face mill AMCM-3050HS for £70 (no Torx tool or box) – this requires 5 of the 1604 inserts. I also got 50 various genuine Mitsubishi 1135 and 1604 inserts for steel (APMT) and aluminium (APGT) from ebay at under £2 an insert. I'm not convinced these inserts are all fully compatible and interchangeable, so I plan to stick to named brand inserts.

If you follow a few of these links you may get a flavour of what's available.

Murray

Edited By Muzzer on 28/04/2017 13:42:02

[MuzzerParticipant @muzzer]

Quick update on recenet progress – a major woohoo milestone was achieved yesterday. I managed to complete a moderately complex part using 6 operations and 5 tools, making use of the prepopulated tool table to set the tool lengths:

1. 3D adaptive clearing with 20mm YG-1 rougher (done)
2. 3D adaptive to clear up with 9.5mm carbide (actually 3/8&quot end mill
3. Bore out the counterbores for the cap head fixings with the 3/8" end mill
4. Drill out the clearance holes for the cap head fixings (4mm drill)
5. 3D contour to clean up the taper bore with Mitsubishi BP300 indexable tool (0.8mm radius) using fine stepdown
6. 2D chamfer to clean up the top edges (1/2" carbide tool) – where the tool can get in.

The CAD model and CAM toolpaths etc were made in Fusion 360. Tool lengths were previously set up semi-automatically using the in-built macro and the electronic tool setter I made a couple of weeks back.

I ended up loading and running each operation one at a time, to allow blood to drain back into my knuckles and buttocks after each success.

I've ended up with the part looking pretty much like the CAD model, no tool breakages, no mud made(!) and a feeling of great relief and satisfaction. It's the blue bit in this assembly:

It's a fixture that holds a ISO40 toolholder while the collet etc is tightened. It could also be used to set and measure tool stickout etc but with the tool table macro feature combined with the electronic tool setter, the latter function doesn't look necessary. To finish it off I need to make up the extension piece and foot. These allow me to secure the toolholder with an M16 finger screw while tightening the collet.

After I'd completely finished designing all the parts, I rotated the main component to do the CAM work and noticed it looks like a Startled Man. So that's how I now refer to it! Completely unintentional.

Trial fit:

There's an on-going, rambling blog at http://www.murraye.com

Murray

[Anonymous]

Posted by Muzzer on 24/06/2017 14:55:12:

Quick update on recenet progress – a major woohoo milestone was achieved yesterday. I managed to complete a moderately complex part using 6 operations and 5 tools, making use of the prepopulated tool table to set the tool lengths

Bl00dy hell; got to be worth at least a triple woohoo, plus beer! I'm mighty impressed; nice finish too. Is it hot rolled steel?

Andrew

[MuzzerParticipant @muzzer]

Yes, they (Jenkins Steel) only had hot rolled steel in this size (25×100). Funny how the finish looks a lot better in the flesh than in the photos. Pretty pleased with it as a starter.

The bummer is that I'm off to China for 3 weeks (flying tomorrow), so that's it for the moment. Back to the armchair / hotel workshop….

Murray

[Adam HarrisParticipant @adamharris13683]

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?

[RctintinParticipant @rctintin]

I’ve just come across this thread while researching for a CNC controller for a planned project to convert a small lathe into a CNC lathe.

Was there any developments in a stand alone all in one unit, rather than Mach or Linux ?

Has anyone done a side my side comparison on different controllers?

Finally, does anyone know of a useful YT series to follow where a successful lathe conversion has been done?

[sam sokolikParticipant @samsokolik60334]

I enjoyed this one.. (but he is using linuxcnc..) He is up to 25 episodes

[Phill SpowartParticipant @phillspowart84010]

If it is of any use to anyone, I've rebuilt a boxford TCL with PlanetCNC stuff. It's not bad for the price. The cost of all the electronics, including two steppers and two power supplies, was £655. You still need to plug it into a PC through the USB port to set up, but I think you can get it running off a flash drive of some kind. Support is excellent. Only drawbacks so far are that it doesn't support constant surface speed or feed per rev for turning, which is a shame. I'm also struggling to get the spindle speed feedback loop to work.

[Author]

Posts