Printable View
well not done any think today as I fell out the attic and done my back in plus I think I've broken my little finger
ladders slipped on the garage floor, I will need new ladders now
James:thumbdown::thumbdown::redface::redface:
and I feel a right twat
oops bought the wrong power supply (only 50w) and I need 70w
so this is up for sale £10.00 but it's not come yet so you will have to wait, just like me
http://www.ebay.co.uk/itm/1505921946...84.m1439.l2649
James
You want 70 volts, not watts! About 500 watts... it's going to cost more than £12.99 I'm afraid. I'm using a 500VA toroidal transformer with two 25V outputs in series - that gets just under (25+25)*2^0.5 = 70.7V
Jonathan It was a genuine mistake where can I get the right power supply from
PS
Luke loves his badge big big thank you mate
James,
I know how that feels. When I was building my new workshop earlier this year I was using ladders for some work on the edge of the roof. I had sat them on top of some of the roof sheets I was fitting. Everything was fine until one of the sheets slipped and the ladder went with it. Felt like right t**t as well. Hope you get better soon.
Ian
http://www.rapidonline.com/sku/Elect.../82719/88-3840Quote:
Originally Posted by luke11cnc
That one plus a couple of capacitors and a bridge rectifier, which I will already have. I can't find any on eBay at the moment ... that one is a bit expensive.
No worries :)Quote:
Originally Posted by luke11cnc
Try Farnell as well . You don't pay for delivery. Recently I received Item which wasn't working. Then I contacted them and with no problem they replaced faulty item and arranged and paid for collection of the damaged one. Good customer service.
Yes Farnell is good, however in this case I had already checked and they're more expensive than Rapid.Quote:
Originally Posted by wiatroda
They do have suitable capacitors at a very good price, but I've already got some so that's no problem.
Last time I bought from Rapid ( ages ago) I paid few £ for delivery. Some items are cheaper some not. The same IGBT I needed were cheaper in Farnell and wider selection of them. For me personally not always price matters but service you receive, but this is individual. Small items Farnell posts with Royal Mail , bigger -courier. I was pleasantly surprised when I placed order 2pm and had my components next day in the morning with everyday post. Return: nearly instant reply, next day replaced part and collection. With e-bay shops - they exist today, next week they've gone (maybe exaggerated but true).
I just order from either Rapid or Farnell, whichever is cheapest taking into account postage. Lately I've used Farnell more because, as you say, their product range is better.
is this the right power supply ?
please look at link
http://www.ebay.co.uk/itm/500-Watt-A...#ht_1856wt_905
James and Luke
No, an ATX power supply is a computer power supply so although the power is fine you only get 12V (and 5V, 3.3V and some others) which is not sufficient. You will get a much higher feed-rate if the motors are run on a higher voltage. You ideally want 70 volts.
I can't find the right power supply on farnell
I found a power supply 500w but only 48v ??
Help
rapid web site is down so I can't look on there
James
Would be OK, but since your drivers can accept up to 80V it's best to do that. I can't find any on eBay that are above 50V, so I think the best option is the transformer I linked to on Rapid in post #46:Quote:
Originally Posted by luke11cnc
Annoying that the site is down, but it's easy to get round - just use google cache:Quote:
Originally Posted by Jonathan
http://webcache.googleusercontent.co...w.google.co.uk
Jonathan I will order the one from rapid on Tuesday
Will I need to order anything else for it (box) or will it fit in a old computer case along with my drivers and break out board
James
Computer case will be fine. Wire is cheapest from Rapid:
http://www.rapidonline.com/sku/Cable...119346/02-1066
(I'll buy the spare from you)
I emailed them and they said 2 weeks to deliver it.
Also for the power supply I'd get a bridge rectifier and terminal strip. I'll find them tomorrow when the site is working. They will also have suitable switches for limit switches.
cool thank you Jonathan
well Luke has been in the garage/work shop for most of the day drilling the legs ready for the stepper mounts
to say he loved it is a understatement at the end of it I received the biggest hug,smile and kiss ever and as he was walking out the door he turned around as said dad " it's been the best day ever dad I love you"
I've taped the motor mounts with just a couple of mm to go but that's for Monday and Luke to do
Jonathan that jig worked really well
I think I've had the best day of my life as well
James and Luke
I have a spare torodal transformer and some 4700-100v caps and probably Br-rec that will get you 70+volts if you haven't bought them yet.
The torod is almost new I think it's 1000va but will have to dig it out to get full specs to be sure then i'll be able to work for you the exact volts + amps.
I think i've got 4x caps which can be wired parallel and If memory serves me I think this transformer and 4 caps was giving me around 76 ish volts and 14A ish.
PM me If this is any use to you and I'll give you my contact details.
James,
what about something like this: http://www.antekinc.com/details.php?p=317
Ian
That would be ideal - it's just a lot more expensive than the one from Rapid, especially when you include postage.Quote:
Originally Posted by Web Goblin
Sounds good...but where are the pictures?Quote:
Originally Posted by luke11cnc
As requested more images of the weekends work
Attachment 4392Attachment 4402Attachment 4401Attachment 4400Attachment 4399Attachment 4398Attachment 4397Attachment 4396Attachment 4395Attachment 4394Attachment 4393Attachment 4403
James & Luke:heehee::heehee:
Check your PM's.
The aluminium angle you appear to be using to attach the gantry sides looks a bit flimsy. It can bend quite a lot with forces parallel to the Y-axis. Are you intending to reinforce it? Or perhaps you are mounting the gantry some other way...
Your workshop is looking almost as tidy as mine!
What's in the background of the 7th photo looks ideal for a wind turbine lattice tower :naughty:
Edit: Forgot to say, almost done the ballnut mount.
Yes Jonathan Image 7 has my display gantry and It's just been sold to help pay for the cnc machine But I may have a length spare would you like one ??
what would you suggest for the bearing support as I was just going to mount the gantry sides to it ??
James
That's a generous offer... how long is one length and what diameter/wall thickness/material are the main 3 tubes?Quote:
Originally Posted by luke11cnc
Difficult to say really. I used 100x60x5mm steel RHS which would be better but still not ideal. Aluminium extrusion is almost certainly the best option. You could just use solid blocks, but that's a bit crude and probably more expensive than two small lengths of extrusion. You just need to think of some construction that is strong in that direction.Quote:
Originally Posted by luke11cnc
Hi james,Quote:
Originally Posted by luke11cnc
Please excuse if you have posted this info in earlier because i've not read every post just flipped thru. What are you using for a gantry.? Do you have a general drawing or sketch of the overall machine as you would like it complete.?
I've been looking at the pics and think this the layout your going for please correct me if i'm wrong.
The bed will be down where the MDF is layed in pic 7, gantry it will be driven with twin slaved steppers which I presume will be attached at each side directly to the end of the gantry, by this I mean NO lower gantry cross piece. Presume ballscrew on Y axis.
I'm also presuming the bed and frame are not yet complete thou if yes then I see some areas that would concern me and will definaitly cause problems when machining.
What do you intend to mainly cut with this machine.?
Cheers
From the pics I'm thinking you plan to use the
Cheers.
Jazz I don't mind recapping:heehee::heehee:
This is the second recap I've done but lost the first one I typed 10 minuets ago:redface::redface:
You are Correct the bed is not finish yet three more length of extrusion to add 45x45 profile. the gantry is moved by two ball screws, two stepper motors and two drivers.
ball screw are to be mounted to the under side of CNC rail show in this photo
Attachment 4406
Material I would like to cut is Aluminium, oak, maple, MDF and Acrylic
I am building this with the idea of adding a 4th axis for turning wood
Ok the drawings well most of it is in my head and as I'm new to most of the drawing software I'm finding it hard to articulate my self but here is a drawing of the Y-axis
Attachment 4407
the Gantry sides and supported rails are shown in blue
profiles are as follows
gantry side 45x180 extrusion
gantry rail supports are 45x45 extrusion with a bolted brace in 12 mm Aluminium shown in yellow witch will also be bolted to the gantry side rails to stop twisting and vibration movement
shown in green is the Z-Axis support made in 20x 200mm I have gone for a box configuration as it is a lot stronger than a lot of the open three sided I have seen
the rails are 20mm supported and I may even change the drawing to include a third rail at the back in line with the ball screw attached to the bracing aluminium
the gantry sides will be attached to the angle bolted to the support bearings by no less than six bolts
I do hope this makes sense to you :whistling::whistling:
James
Drivers and Break out board arrived just ordered my spindle 2.2k and just waiting for a invoice for the rest of my ballscrews and supported rails
end of the week I will be ordering the aluminium for the Y-axis from aluminium warehouse I will be picking up the bed extrusion and some of the gantry extrusion as I have a two week waiting time for the big 180x45 extrusion profile
It's all coming together just water pump,nut and bolts and cable to order now and some bits from Jonathan
Luke is getting excited O'and me as well:naughty::naughty::heehee::lol:
James and Luke
Oh if your excited now you better get the adult nappies ready for the big fire up day. :)
replyed to your PM by the way.
Hi James, Luke.
Regards the gantry and the way you intend to use the angle, like jonathan I feel this is not enough and will be weak area.
From your rough drawing and the fact you mention using Ali 20mm plate have you thought about using 20mm for the gantry sides and bearing plate.
Doing it this way would let you bolt the bottom extrusion to the bearing plate which the ends would be bolted into the gantry side also the 12mm front plate will be bolted to the gantry side plate all could be located into shallow machined groves for easy setup.
It would save buying the 180x45 which really wont had any extra strength and would be very strong.
I've done a few quick drawings see what you think.! . . . It's could use a bit more bracing etc and could be fancyed up a bit but it should give you the idea of what I mean.
Cheers
This should keep us out of trouble for a while :heehee:
Attachment 4487
Edit: Just dropped one bit on the lawn and made a hole ... will be in trouble if I do that again!
Yes Jonathan I can wait
I'm going to install Micro switches on my machine are this the right ones
http://www.ebay.co.uk/itm/AC-125V-1A...ht_2168wt_1139
Thank you for looking
James
Well I've received my spindle today and
nobody warned me how heavy they are??
I may even put the spindle in between Y axis for support or is this over kill. I must admit I've never seen this done but how hard will it be
spindle weight is like trying to control a brick on the end of my little finger but that is just my own view
with all that weight at the end of a CNC machine no wonder there is issues with twist
James
They're heavy as there's lots of copper/steel in there. Be glad it's 3-phase as otherwise it would be heavier.Quote:
Originally Posted by luke11cnc
Switches:
http://www.rapidonline.com/Electroni.../Microswitches
The best switches (I think) are these, but they're a bit more expensive than the rest:
http://www.rapidonline.com/Electroni...switches-73549
You don't need the roller.
Don't buy cheap micro switch's for home switch's they wear to fast and not accurate enough. You only need 1 for each axis (2 on slaved axis) so buy decent switch's like honeywell or Telmanique they will pay for them self's in the long run and give hassle free service.Quote:
Originally Posted by luke11cnc
Another thing to beware of with cheap micro switch's for limit switch's (not so much home switch's) is the potential for switch bounce or noise, esp with low voltage, low current setup's that most folks use IE: 5v straight from the BOB. . . This will show it's self as false E-stops.
It's a common ocurrence with cheap switch's due to poor quality contacts and the fact the limit's don't get used very often.
What happens is over time the contacts degrade and become pitted and dirty, this cause's noise on the signal line which can fool the controller(Mach3) into thinking a limit as been tripped or an E-stop occured. This often happens when taking heavy cutt's or on machines that vibrate a lot which make the switch's trembel slightly, when really worn/dirty or very crappy switch's used it can even happen when the machine is stood still or just with spindle running.
Also Another thing regards spindles and really crappy switch's used on low voltage setup's. If using a VFD then it's very likely you'll come across some noise issue at some point making it another good reason to buy decent switch's. (And use sheilded cable)
There are various ways to help stop this, using 24v or 12v for limits is the better way and the way it's often done on industrial machines. Thou for DIY just using decent switch's and tripping the limit switch's every so often helps greatly. . . . Also the use of a small 0.1uF capacitor across each switch helps keep the switch contacts clean by charging up to around 5v when the switch is opened then sending a short high current burst through the switch when it close's shorting the capaictor so cleaning the contacts. If you do this and trip the switch's every so often then the contacts are kept clean and noise free.
Please don't think I'm scare mongering because I'm not and noise on the signal lines is one of the most common cause's of electrical trouble folks have, often they don't even know it and blame somehing else like BOB, drivers or motors. When often it's down to cheap switch's and poor control box setup IE: Unshielded cable or bad earthing practices.
Personally I dont use limit's just good quality Home switch's and Mach's soft limit's.
Excited going to watch my parts being cut on Jonathan's CNC today taking my Camera so lots and lots of Photo's to bore you with later
James & Luke
poor Luke he's at school until 4.30 so he will just have to watch a video and photo's of it
Quote:
Originally Posted by luke11cnc
Hi James
Microswitches bounce when they close, not when they open.
If you want to avoid bounce, without extra circuitry, set your position when the switch opens.
Do you "do" electronics?
If you want maintenence free precision consider an opto-slot with Schmitt trigger.
If you want zero hysteresis consider a standard, photo-transistor opto-slot and feed it into an op-amp wired as a comparator.
best
Robin
Quote:
Originally Posted by Robin Hewitt
Hi Robin,
Great advice robin, thou you might as well be talking Marshen if folks are not into electronics:rofl:
Don't belive James/Luke are into electronics to that level, did consider suggesting opto switch's but didn't want to cause info overload.! . . . simpler to just say use good switch's and warn of the dangers of cheap bad switch's I thought.:question:
I've considered using opto switch's on my machine when the existing switch's start playing up. . . Thou I'm a bit unsure if they'll be ok due to flying debrie passing the opto falsely triggering switch.? . . How do they handle flying Ali chips.?
My machine must hold the world record for slinging chip's.! . . . They even make it into the house 20yards away.! . . . Thou my boots may play a part.:naughty:
Well, in Martian...Quote:
Originally Posted by JAZZCNC
Probably need photo-diodes to pick them up if they have any speed, here's the circuit :heehee:
He he spelling ain't my thing.:whistling:Quote:
Originally Posted by Robin Hewitt