#61
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You can also mount the electronics on the wall above the machine. If you do re-orient a box, think carefully about the hinges.
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#62
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I want to make a quick comment on the prefabricated V-rails.
They do not save you time. To properly mount the V-rails you have to cut the support material - aluminum architectural angle - to height. Then drill A LOT of holes - precise holes. After assisting Nils during his build and watching the effort, it was clear that the amount of labor hours was equal, if not longer with the prefabricated V-rail. Just my view from doing both processes. Don't interpret this as a negative for the prefabricated rails - I love them. But from a purely time sensitive view, it's not a time saver. With the proper set up on the skate with an agressive 36 grit disk to do the major profiling, I bet I could do all of the rail fabrication in 2 days flat by myself. |
#63
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Fox,
orientation for your electrical components should not be an issue. if i see the picture of your available space I should also consider wall mounting. Do you see yourself laying on the floor clamped between the mechmate and the wall doing some trouble shouting? if mounting under the machine, check if you can open the door. place the machine that you can just walk between, and chose which side you mount the cable gutter ( I decided my one wall side) Working outside at this moment is not an option If I hear how the weather is in holland. I received snow pictures today |
#64
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@ Brad; I can't really do that: in my room it will: obstruct my walking, or has to be mounted too far away, or above the table. Hence this location ( good tip on the hinges, I already looked into the spec for some data on this, could not find it. Will now order big box first so I change size on vfd box if needed because of the hinges, leadtime is short luckily.
@ SM; noted. I might use linear rails, but go for grinding first. by pure luck I got offered lightly used second hand linear SKF rails the other day while talking to someone. And 2x3,5 meters of 25 mm linear rail for a few hundred euro total ! I thought SCORE, could not believe my luck. But then found out: the two rails are no longer produced by SKF, and they have only two carts with them. No newer carts will fit acccording to SKF, their advise was... buy new ones ( @4000 euro). Then I thought... hey... I buy one new rail of the same dimensions, it will still be a good deal. And then I calculated the X amount to buy the new rail and it is 3850 mm.... so that stings a bit ( I thought it would be around 3,50 meters or a bit less with my X of 3050, dunno why I had that number). Still contemplating on buying them just for the Y, but a bit hesitant, because of matching two different brand rails then ( friction?!)+ if I have to machine v rails anyway for the X the Y is relatively easy work. @ Ric Great ! Strip that off the list. Ordering all electronics etc. this weekend. Wall mounting is not really viable...see above. I was contemplating on mounting the box after all initial troubleshooting is done, just have it losse in the room on some trestles. I hope I do not have to lay under the table under daily basis once its up and running ??. And then maybe still mount with quick releases, and have some "loose" cabling so I could again put it on a stool, for more convenience if/when needed. I see a lot of commercial CNC have the boozes on the table, so I guess it'll work somewhat. Dutch: Sneeuwt en vriest idd lekker, dat zal wel tegenvallen straks bij terugkeer. De elfstedentocht waanzin "het-gaat-echt-wel/niet-gebeuren-dit-jaar" is al weer losgebarsten Last edited by Fox; Fri 18 January 2013 at 07:46.. |
#65
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Can any body point me towards the best compatible stepper from www.motionking.com
as an alternative for my current choice oriental PK299-F4.5A ? I am a bit lost, so may specs so many options, don't want to make the wrong decision. http://www.motionking.com/Products/H..._1.8degree.htm Would this be a good option: 34H2B9850 ? (I see they only make Bipolar on request) |
#66
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Those are like I use, my friend Milan and Pajka from Macedonia, they are Deitech 86HS9802 same spec. 5Amps and around 45V is ok for them, others used 9801 on Mechmate its a lower Amps but higher voltage motor but with same torque. Depends on your drives.
If you use DM856 from Leadshine or Gecko then you can use the 9801 one. |
#67
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I don't know if I understand the last sentence correctly.
I see your friend uses DM856 from Leadshine to drive his Deitech 86HS9802 motors. This turned out to be a wrong choice andhas been replaced ? Or do you mean if you use this driver or the Gecko 203V you can choose between the 9801 or 9802 bases on personal preference ? I do notice it saves a considerable amopunt of money to go with the leadshine vs gecko and motionking vs Oriental, so I might take that route and spend it on some otehr parts like linear drive. But then if I understand correctly you did not wire them Bipolar parallel ? Or did you order that custom, in short: how did you hook them up ? |
#68
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I believe he was referring to the fact that some drives are capable
of using higher rail voltages than others. Some motors cannot be used with some drives, as the require a rail voltage higher than some driver can support. The gecko 540 is limited to 50V rails for the motors, so you have to pick motors that work with up to 50V and no higher for example. |
#69
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Thats right Heath, I meant that with 80V capable drive you have more motor choices.
DM856 is THE most silent and smoother drive I have seen, we accomplished feedrates of 42000 mm/min Wire bipolar parallel and have no worries. It works best for me. |
#70
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Cool.. I save almost a 500 euro on that combo; no-brainer, ordering from Deitech !
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#71
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Ok, working things out with Deitech at the moment, want within teh next two days... for engines, controllers, e-chain etc.
QUESTION: Should I also order some milling bits from them while I am at it ? Or should better stay away from 'Chinese' cutters ? My experiences with drill bits on this topic. If so; anybody got some tips on what an absolute beginner should order for starters ( some basic cutting mdf, doing the spoilboard leveling, some bits for testing alu, and cutting polycarbonate acrylates ? ) THNX ! |
#72
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For basic cutting with carbide spiral up-cut bits look for carbidechiu on ebay, I use bits from him all the time more than a year. Even some dia 10mm hrc55 labeled I use for hardwood cutting, guitars and stuff, it cuts like hot knife trough butter and stays sharp for ages.
For spoil board there are large diameter bits for leveling. For aluminium look for single flute bits but not all work nice, it depends on the geometry of the tool. Same thing for polycarbonate or acrylic plexiglass cutting, single flute 4-6mm carbide. Best thing is to find one from a well known manufacturer and try it, if it works ok but the price is a bit high look for a Chinese equivalent, for important jobs use real quality and Chinese for every day cutting. In the end everything depends from proper feeds and rpm. |
#73
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Again asking for urgent help:
86HS9801 engine Leadshine DM856 engine spec: mH 4.1, 4A I want to wire it Bipolar parallel. I do not see different specs on the Deitech site, but it does state 8 wires. Do I need to multiply the amp value ? If not 32 x √4.1 = 64,79 Volt 5x4=20x0.67=13,4x64,79=868.18 VA/Watt ( taking one extra engine into account for future 4th axis here). Watt can be around 300-500, and still be fine everybody says ( engines not asking full power all at once ). Then I wanted to built my own powersupply, cause Antek will be to much delay, and no local alternative: DYI powersupply toroid, check: use a 64 volts, 400 va rectifier: Quote:
I continue the math for the capacitor just in case... Capacitor=mF=(8000*I)/V= (80000*20)/64=25000mH= 24000uF (only one available), 100V ( this also needs to be able to take the 1.41 higher voltage, I've read ) or I could/should I just hook up 3 x 10000 uF x 100 volts ? Last edited by Fox; Tue 22 January 2013 at 15:48.. |
#74
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no you divide by 1.41 , that is the voltage output of the transformer, after the capacitors do their work it will be 64V
you can parallel 3x10.000uF bipolar parallel current for 9801 is 4Amps , 8 wires gives you 4 separate winding which you can parallel to get bipolar PARALLEL connection. This and other information given here are very valuable and should not be taken for granted, what you need if you get into building this machine is to understand all this and its done with reading build logs and discussions about these information to get a better insight into it. Regards |
#75
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Danilom, believe me I have read/still am reading a lot on this forum. Metalhead can probably see that by my user statistics over the past few weeks. And I've read a lot over the past years ( I am member since 2008) I am not being lazy. I thought I understood it, but electronics are not my strong point. The information is often so splintered, often a thread starts out with a conclusion which at the end has 10 other conclusions/suggestions. I am not moaning about that, just asking for help and explaining why, casue I want to understand every bit on this machine.
I thank you VERY much for your quick reply, but I am very sorry to say I do not completely understand the answer: Quote:
Last edited by Fox; Tue 22 January 2013 at 16:12.. |
#76
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If you need 64 Volts to power a stepper drive, then a pure transformer output should be 45V AC !
After bridge rectifier and capacitors you get 64V DC |
#77
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Your 64 volts you calculated is DCV. Therefore you divide the 64 by 1.414 to get the ACV of the transformer you need. In this case it would be a 45V AC transformer secondary. When rectified and filtered it would give you the 64 VDC you calculated.
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#78
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Sorry Danilo, guess we were typing at the same time.
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#79
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THANK YOU ! for putting up with me-helping me out. Appreciated.
Ps. So, my hunch/back reasoning after reading this figure in the rectifier thread and getting all puzzled was correct, and I do understand this stuff a tiny little bit, or at least now I do. But.... how ever did you guys figure that out when you were first building and knowing nothing ?! Same way ? Or am I really the first one ever to be so stupid ? Imo it woudl be a good idea to put a small tip "for DYI powersupply toroids divide this number by 1.41" on this in post 1 here: Calculate the Voltage and VA size of the DC power supply for stepper motors/geckos. Or at least fix the link in that post; part of my confusion was fueled by the fact that the link Or consider to design & build your own. in post 1 links to the same thread/calculation, instead of this as i think it should ? |
#80
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No offence, conversion from AC to DC is really a very elementary, I'm very sure its been mentioned many times. If you had googled, you will find enough information to fill a library.
I remembered I have a few very comprehensive calculation in one of my building threads. The forum is a treasure of info on CNC building. but sometimes, you gotta look else where suit your learning level. |
#81
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No offense taken, everybody asks questions on different subjects/is skilled in different subjects. I am sure you have asked a "stupid" questions in your life to someone else (maybe even on this forum). Google and the search on this forum can be very helpful, but you've got to know how to ask the "right" questions, to get the right answer. Human interactions prevails imo when really stuck.
At least we got it sorted in a very quick manner, thanks to all the help here on the forum. In 2 years time, I might also think it's "easy", right now it was darn difficult So I will try to remember that when in two years time I need to answer a newbie here. Anyway, let's agree I am totally stupid and all that, let's move onto more important stuff. Electrics orderlist now sorted. Ordering today. Hope to have steel for table arriving tomorrow, and the lasercut steel will be done by the end of this week if things work out. So we are moving onto actually building stuff; looking forward to that. Brace yourself for some questions here and there along the way |
#82
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While you are waiting for your electronics parts, I strongly suggest you focus on reading up on "Kitchen Table Project" & start asking questions on the subject.
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#83
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Will do ( was already reading it to see what elektro/mechanical parts were needed, beside the big ones)
but I just hit a big issue. Deitech can't supply the engines 901 or 902 untill after Chinese new year= two weeks from now:-( Last edited by Fox; Wed 23 January 2013 at 05:53.. |
#84
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If in a hurry ... sorotec in germany has some nice motors which I also had used
http://www.sorotec.de/shop/product_i...-5-5nm-ds.html |
#85
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Thnx Danilo,
mailed them ! Also talking to stappenmotor.nl for alternatives. |
#86
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That's motors Fox - are you sure your reading ?
regards Ross |
#87
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Huh ?
Motors are pretty essential for a Mechmate I would reckon, I don't want to build the Fred Flintstone version... :-) So when I received a message from Claudia I can't have them in time, I need to look for alternatives immediately, right ? Or what are you aiming at ? Btw. I e-mailed you with a question if your beltdrives .dxf files are Inches or Metric based ? I thought AU was metric, but I noticed the Flange bearing you suggest is an Inch based model ?? Last edited by Fox; Thu 24 January 2013 at 01:06.. |
#88
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Hi Fox
It was just a hint that "stepper motors" are not called "engines". The use of the correct terms really helps as servos motors, stepper motors and even hybrid steppers with encoders all power CNC machines. Never seen anyone use the term engines so thought I would pull you back on track. I saw that post but could not find it once I had the time to go back and think about it. Not ignoring you on that one, just disorganised, so my apologies. The files are metric in MM. The flange bearing may be a mistake as I ordered some and noticed the inner shaft diameter was larger than what I had intended to use. To make it work check that the outer diameter fits the hole size in the plate and that the center bearing hole suits your chosen shaft size. VXB bearing on the web are a great source for cheap flange bearings. Regards Ross Last edited by Surfcnc; Thu 24 January 2013 at 02:08.. Reason: Spelling ...again |
#89
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Hi Ross,
ahaaaaa I see, "Engines" is of course Dunglish because I work too many hour days lately, type in a rush on the forum, and English is not my native language. I thought you were after me because of what Ken said and felt a little offended... "Motor" is used for "engine", "motor" and even "motorbike" in Dutch. Hence my mix-up. Thnx on the metric, I can source the flange bearing you mentioned but have also found a metric alternative. Was just wondering if I woudl be doing it all wrong again, ending up with metric stuff on inch based designs, making everything not fit as it should. Your bearing had 12,7 inside, no problem if you axle is 12,7 mm. |
#90
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Hi Fox you are spot on with the design there.
It is hard to read what the intent of some posts are at times so don't sweat the little things. Everyone helps here but sometimes that help might extend to a little tough love ! Even the most negative of comments will often have benefit after the initial ouch wears off a little |
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