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Yes I did exactly that. I think I'll try it again.Quote:
Originally Posted by blackburn mark
I saw on you-tube a video about making ballscrews and they straightened it by putting the screw between two blocks, and pushing down in the middle with a lever to bend it.
sounds like a winnerQuote:
I saw on you-tube a video about making ballscrews and they straightened it by putting the screw between two blocks, and pushing down in the middle with a lever to bend it.
just take your time untill you know how much pressure it takes to get it to move or youll end up going passed the sweet spot and youll be chasing muliple curves up and down it till new year :)
I relieved most of the tension on the X screws and now it's much better. Seems happy at 3600mm/min over the whole bed. I'm using a 42T pulley on motor, and the 28T pulley I posted about earlier on the 2.5mm pitch screw.
Bed surfacing, not terribly exciting but it demonstrates the vacuum working reasonably well:
http://www.youtube.com/watch?v=Jb1TL..._order&list=UL
Attachment 3500
Been doing a bit more testing, latest videos:
This is the video of the first ever test...
http://www.youtube.com/watch?v=ZrhZL..._order&list=UL
And here I tried machining some aluminum:
http://www.youtube.com/watch?v=b4NrS..._order&list=UL
Bit of a faliure! I think I'll try that again but with it mounted higher on the bed. I could see/hear the Z wobbling.
Owch !!!
a bit uggly on the aluminium :( im a bit gutted
i was over the moon with mine, 3mm single flute 3000rpm, cant remember the feed i also had a go with the engaving spindle at about 10000rpm cutting small fonts (low feed) and they both were lovely and crisp
if mounting the work higher doesnt work out to well id be really tempted to stick a block n tackle above your gantry and make provisions to drop it down by 3/4 for alli and any fine work
im confident you would be amazed at the diffrence it would make
i guess it depends on what you are going to do with the machine generally
That's a lot less aggressive than 3 flute 8mm ballnose with 1mm DOC and 2m/min I tried! Anyway I've since noticed the plywood router mount I made isn't as tight as I thought which should make a huge difference.Quote:
Originally Posted by blackburn mark
I think I will look into making it easy to lower the gantry.
Having said that it's working nicely with woods:
(Wind turbine blade mould section)
http://www.youtube.com/watch?v=93SSlH0ldC4
We got chickens recently, so I made an egg holding device for my Mum for Christmas, hopefully it will go down well:
http://www.youtube.com/watch?v=GZC_0PWQc3g
I'm certainly pleased with the finish on that.
i wouldnt dare!! :)Quote:
3 flute 8mm ballnose with 1mm DOC and 2m/min
the vid you posted isnt working
i could do with getting some vids up (might have to speed them up a bit to make it look like its actualy doing something)
One of the videos hasn't finished uploading. It'll be done in 5 mins...you were too quick!!Quote:
Originally Posted by blackburn mark
I often sped up the videos on my milling machine.
Better go, cat is drinking my tea again, sigh...
just watched them both :) splendid!! it is nice and quickQuote:
One of the videos hasn't finished uploading.
wind turbine blades!! can i order three for my paramotor :)
fanatic jonathan i read all your post and watched all your vids love it keep um coming :)
Thanks for the kind words. I'm intending to get the 5th driver wired up for the 4th axis today so I'll take a video of that...Quote:
Originally Posted by h4ppy-chris
:lol: yes she was. I just used CAMbam free edition for the relief. It's limited but should work if I use the right cutter next time...Quote:
Originally Posted by chip
Well...I got the 5th driver wired up, switched it on and just get a red LED. It's dead on arrival :cry: Tried connectors from other drivers which hold motor/power wires with it (and vice versa), and it still doesn't work. I've emailed Zapp, sadly it looks like I've got to test their customer support...:cry:Quote:
Originally Posted by Jonathan
Good news, I sent the driver back and they replaced it a few days ago.Quote:
Originally Posted by Jonathan
Currently I'm designing a stepper driver and thinking about how to make the machine more rigid.
I made a 1.6x0.25m wind turbine blade mould with it a few weeks ago out of MDF. It went well, leaving a nice finish. I will post a video of it at some point, though not all of it since it took a few hours!
I've bought a 2.2Kw spindle from eBay along with inverter. It was £247 including postage - I saved a bit via best offer. Having said that customs also charged £19 (well, customs charged less but DHL STOLE some)... so 7.7% added which isn't bad I guess. The spindle will arrive home tomorrow, but I'm at University so can't see it yet :(
ER20 collets have arrived for the spindle, and I've won some 4" extractor tube to sort out the dust issues. Hopefully.
Not much has happened since with the rest of the router. I've made and mounted the brushless motor as spindle, as detailed in another thread.
On a related topic I'm currently designing and prototyping a 120v, 10A ish stepper driver. It's going ok so far. I started prototyping with a H-bridge IC (to prove the principle) and got microstepping working with that. Now I've made a PCB with two N-channel H bridges on with power MOSFETs and a good heatsink.
When it's done I'll replace my PM752s with it.
I've come home for the weekend - lots of post, including spindle.
Setting up the VFD was no problem. I've got a little 8L/m submersible pump for the water cooling. I've just tried it with a bucket of water and an odd assortment of tubing, about a couple of meters in total, and I got 1.3L/m flowing. I think that's fine.
With 5l of water in a plastic bucket the temperature rose by about 0.25°C/min. The spindle was only drawing 0.6A from the mains.
Going to make the mount later today and hopefully try cutting with it tomorrow :smile:
At 24,000 rpm is quiet enough to listen to radio and I can't hear it over the dust extractor...Also I can barely feel any vibration at that speed on the spindle body.
No I didn't get it cutting. Went to my grandmas on Sunday so didn't get as much done as I'd hoped.Quote:
Originally Posted by chip
I got one mount done and started the top one. I've not got a photo of the finished mount, but you can get the general idea from here:
Attachment 3807
Attachment 3808
Attachment 3809
The extra aluminum on the side will let me fit dust extraction.
Quick video:
http://www.youtube.com/watch?v=xciLC...=youtube_gdata
Spindle is mounted and working!
Runout isn't great - 0.05mm ish.
But it seems good in all other ways. I just cut some carbon fiber with it, about 2mm thick at 450mm/min with a cheap diamond burr at 24,000rpm. It's cut well and left a decent finish.
I'll post some photos soon.
Spindle mounted + VFD:
Attachment 3818
Water cooling... crude but it works. My mum is wondering where her bucket has gone!
Attachment 3816
Closeup:
Attachment 3817
Trimming carbon fiber sheet. Having the spindle going off the end of the bed is dead useful:
Attachment 3819
I intended mounting the VFD there to be temporary, but now I'm thinking I might leave it since it saves on cable. The extra mass on the Z axis isn't much compared to what's already there. If I switch the steppers off the Z axis now drops due to gravity. Before the detent torque of the motor was sufficient to stop this.
I've finally got round to uploading the video of cutting a wind turbine blade mould, with my router, to youtube:
http://www.youtube.com/watch?v=Puge7MSYoZU
It's, quite a long video but I've tried to use only short clips of each stage so it's not too tedious.
I will edit this post and add some more tomorrow.
I'd be more worried about the effect of vibration on the VFD.Quote:
Originally Posted by Jonathan
Yes I thought that too. I mounted it using those foam sticky pad things which, thinking about it, should damp the vibrations a little. Another issue is dust getting into the VFD which would reduce the efficiency of the heatsink.Quote:
Originally Posted by FatFreddie
Carbon fibre dust is conductive...
What were they quoting for runout? I was looking at some that were quoting ten times better than that - just wondering how reliable the claims are.Quote:
Originally Posted by Jonathan
True, and texalium which I'll machine at some point is going to be even worse. Apparently carbon fiber dust is worse than asbestos, so I will allways use the dust extraction with it anyway.Quote:
Originally Posted by FatFreddie
Yes mine was indeed quoted at ten times better than than.Quote:
Originally Posted by FatFreddie
I've decided to make a welded steel frame for my router. This is my initial design:
Attachment 3915
I will probably add a few more triangles to that, however I'd like to keep the front of the machine open.
In that drawing I've discarded the tall gantry sides and replaced it with a bit of 100x60x3.6mm steel box section, so now the 'gantry' is only 100mm tall, not several hundered mm. This should help with the stiffness.
Also I am intending to have the existing bed fit inside the frame and attach it to the 6 vertical pieces with a series of holes which will allow the bed to be raised and lowered depending on the size of the job. Most of the time I will have it as close as it will go to the gantry, giving only 100mm (ish) z-travel. I've not yet needed more than this so I think it's a good way of stiffening up the machine without compromising on working volume. It'll also gain a good bit of travel on the Y axis.
That one does look good, except for the position of the X-axis ballnuts which will cause uneven loading on the X linear bearings.Quote:
Originally Posted by chip
I'm not sure that the 100x60x3.6mm steel box section I've used on the sides is going to be sufficient. That cross section is weak with forces parallel to the Y axis. I may get some aluminium profile to fit there. Chip, can you remind me where you got yours please? What you used for your gantry sides looks about the right size.
Quick update. I've ordered the steel for the frame and it should be ready Thursday or Friday. I've now started dismantling the machine ready for the conversion. I'll post more here with pictures as it happens...
Thanks for the link. I'm tempted to use it for the sides, but if I did I can't weld it. I think I will weld some steel sheet on to the ends of the box section to strengthen it.Quote:
Originally Posted by chip
I got the steel on Wednesday. Adey Steel were very organised and helpful. They cut the steel to the lengths I specified. They did accidently not give the offcuts from cutting my steel that I requested, so I went back and got it plus they gave me some box section free of charge along with some 6mm plate to practice welding with!! I'll use some of the extra box section to make the frame stronger if required..
Since then I have used my metal bandsaw to cut the box section - it's cutting very close to square now. I'm currently drilling lots of holes in it which will be used to support the bed at different heights. I intend to motorise the bed, effectively making it an F axis, to minimise the overhang of the Z-axis for each job.
I've ordered the ballscrews for X and Y (RM2510 and RM1610) - the tracking says they should arrive in one week, so my aim is to have the frame done by then.
The basic shape of the frame is going to be the same as in post #113, with a few extra pieces to strengthen it. The front is 'missing' to allow the Z axis to protrude past it at the end of the travel. I've used 50mm and 60mm, 3mm thick box section and 120x60mm, 3.6mm rectangular in places where I wanted a bit more strength.
Here's a couple of photos:
Attachment 4155
Slow progress with the frame, I've been getting distracted making other bits - such as spindle mounts:
Attachment 4173
I've drilled most of the holes required in the frame, just got a few more to work out. I think it's best to drill them all using the milling machine ... except I can't really do that with the holes for the linear rails as I'm not confident I will be able to weld the frame parallel enough. I'm using the bed support rails to clamp the three upright pieces of the frame in place to weld, not sure about the rest...maybe some sash cramps:
Attachment 4174
Excellent ... I'm hoping I'll be able to mill them on the router when it's done as that should be quicker, or at least easier, than milling them. I would still bore the 80mm hole on the lathe. I will also round off the two corners that look a bit thin.Quote:
Originally Posted by chip
Attachment 4175
Attachment 4176
I've just drilled fixing holes in the 100x60 box section for the bed jacking screw mounts. I just need to drill some more holes for the X axis ballscrew mounts and chamfer quite a few of the ends then the main frame is ready to weld.
I've started welding it at last!
I clamped everything together with M12 studs and G clamps:
Attachment 4177
First weld was fine:
Attachment 4178
Didn't need the hammer to get the slag off...the wind did that for me!
Attachment 4181
Some tacking:
Attachment 4179
Then I got worse...
Attachment 4180
I've finished one side of the frame... took all day! It's nice and flat/square :)
Attachment 4186
Got some tidying up to do now! ...
Attachment 4185
I'm going to get the other side of the frame clamped up now, and weld it tomorrow. I think I'll clamp the other side to the side I've just welded.
I have now welded the second side of the frame. I clamped it to the other side to get it flat etc:
Attachment 4192
I then tacked it together and welded the horizontal joins ... then rotated it and did the same etc:
Attachment 4193
My welding is getting much more consistent. Still probably should have chosen something simpler for my first welding project!
Attachment 4189
Now I have positioned the remaining pieces to work out how to proceed:
Attachment 4191
I decided to use some spacers from steel tube. I'll put a few more in and use them to clamp the in between pieces. Cats were interested...
Attachment 4190
Any comments / ideas welcome.
Thank you..... as soon as possible! I've just moved the frame up into the workshop since I decided it's best to weld it in there. I'm going to get it clamped together now (just stopped for a tea break!) and weld tonight.Quote:
Originally Posted by chip
I think realistically another two weeks to get it running, and some more for it to actually be finished. When the frame is done I still have quite a few parts to make to mount the X and Y-axis ballscrews and rotating ballnuts.
Frame clamped together then tack welded:
Attachment 4196
Some welding, then rotate it...
Attachment 4197
A weld:
Attachment 4194
Done!
Attachment 4195
Finally got the gantry mounted. Started making the aluminium plates to mount the X-axis bearings on 50mm wide, then realised it needed to be 60mm so that was a waste :sad: ... anyway, picture:
Attachment 4203
The important point is I now don't have very high gantry sides, so the machine should be much more rigid.
I spent all of today working out where to put these holes for the Y-axis ballscrew bearing mount:
Attachment 4204
Got it all together ... and it works!
Attachment 4243
Attachment 4242
Attachment 4241
Attachment 4244
The last photo was after cutting 3mm off the edge of a sheet of 18mm MDF in one pass at 6000mm/min.
Y-axis rapid speed is 16000mm/min, X-axis is 10500mm/min and Z is 8000mm/min. The Y-axis will do much more, but I've left it at that as I don't see much point having it twice as fast as the X-axis. I prefer to keep the resolution good...
I think I'll try cutting some aluminium now.
(More to follow shortly, + video)
I tried cutting a sign ... the test one with V-carve:
http://www.youtube.com/watch?v=ThVYR...=youtube_gdata
I need to get a cutter which has a sharper point ... that one has a 3mm or so flat on the end which spoilt things somewhat.
Just tried cutting aluminium ... no problem! I put a bit of cutting fluid in the slot as it went round at 800mm/min, 0.85mm depth of cut with 6mm 2 flute HSS cutter @ 9000rpm. A lot faster than I could have used on my milling machine.
The edges are reasonably nice, still room for improvement but not bad I reckon for a first attempt. Next time I will add a climb milled finishing pass. Better than the milling machine...
Attachment 4246
Attachment 4245
Attachment 4247
Video:
http://www.youtube.com/watch?v=ossjj...=youtube_gdata
I'm happy now that the conversion was worth it ... I always wanted the machine to be able to cut aluminium at a decent feedrate. I might try a relief with aluminium and ball nose cutter next.
nice cnc you have there Jonathan are you going to paint it at some point ??