robertspark Posted August 10, 2015 Author Share Posted August 10, 2015 Anyone interested in torch height control, this is a good read.... http://www.cnczone.com/forums/plasma-edm-other-similar-machine-project-log/256240-anyone-tried-thc3t-03-stand-alone-plasma.html?s=3d031bde09034a52b135631f15bcaaaa Quote Link to comment Share on other sites More sharing options...
simonr Posted August 11, 2015 Share Posted August 11, 2015 Well that was a long read! I didn't learn much about THC, other than to avoid CandCNC products! I'm sure they are OK, but Torchhead comes across very negatively and I would not give him my money! Si Quote Link to comment Share on other sites More sharing options...
robertspark Posted August 11, 2015 Author Share Posted August 11, 2015 Sorry, I thought it was probably more useful as a comparison with some of the under the skin functionality, given there was a manufacturer in the discussion who appeared not to be able to deal with the points raised and provide some straight answers like no it doesn't do that and here's why Candcnc have had a long proven track record in THC, and when I first started with a plasma cutter (2001ish), and was struggling to hand cut clean straight cuts and complex shapes and was dreaming of a machine interface controller, candcnc (and the fella who designed the original ... Campbell designs??) Were one of the few available. I thought it was interesting from the neuron review and pid comments too. I'm going to try to put my calcs and thoughts in a PDF document as typing stuff on here in bitesize chuncks is a PIA Couple of questions though.... What acceleration and velocity settings, and stepper motor ustep settings are you running (only for the z axis?) And what pitch is your z axis leadscrew? Thanks Rob Quote Link to comment Share on other sites More sharing options...
fraser1 Posted January 20, 2017 Share Posted January 20, 2017 On 13/05/2015 at 10:29 PM, simonr said: A couple of things worth mentioning.... I couldn't get the Proma THC to work on material thinner than 6mm. Less than that and the torch just rises & rises! I don't think much of the user interface either. I've actually ended up just using the touch-down torch height control (winding z down until the micro-switch opens and using that to reset the Z=0 position). That works well for all thicknesses. I have also been thinking about building / writing an Arduino THC but using one of these http://www.adafruit.com/products/1085 in differential mode and using a variable resistor to set the reference for the differential. It has a 16x amplifier for differential - so your resolution can increase by 256x compared to a standard Arduino. You only need to measure under / over the target voltage with any precision. My USB / Parallel adaptor is THC compatible: UC100 USB Motion Controller and not withstanding the shortcomings of the Proma, it works fine! I'm surprised you need Backlash Compensation! I have so close to zero backlash that it's not worth worrying about. Anyone worried about the wiring / software / setup - have a look here: http://www.instructables.com/id/CNC-Plasma-Table/ where I've written it up. There are still two of the kits available - just in case! Si Dear Si, Are there still any kits available? I contacted SSC with the job number you quoted in instructables but they no longer have the folding detail, just the dxf profiling. I was also wondering if the info they hold is the latest revision? I want to build an 8 x 4 table in my barn. I would happily buy the kit or work from drawings, whatever suits you? I am new to forums and tried to post yesterday but the post has disappeared without trace, but I apologise in advance if it turns out I am repeating myself. This will be my 1st CNC project, and it looks a cracking idea, Fraser Quote Link to comment Share on other sites More sharing options...
landroversforever Posted January 20, 2017 Share Posted January 20, 2017 1 hour ago, fraser1 said: Dear Si, Are there still any kits available? I contacted SSC with the job number you quoted in instructables but they no longer have the folding detail, just the dxf profiling. I was also wondering if the info they hold is the latest revision? I want to build an 8 x 4 table in my barn. I would happily buy the kit or work from drawings, whatever suits you? I am new to forums and tried to post yesterday but the post has disappeared without trace, but I apologise in advance if it turns out I am repeating myself. This will be my 1st CNC project, and it looks a cracking idea, Fraser FYI, new posts on the forum from new members need admin approval before they appear on the site. Quote Link to comment Share on other sites More sharing options...
simonr Posted January 20, 2017 Share Posted January 20, 2017 2 hours ago, fraser1 said: Dear Si, Are there still any kits available? Nope - and not for a couple of years now. If you have a look at: http://www.instructables.com/id/CNC-Plasma-Table/ I've published the whole thing Open Source including the DXF's and drawings for the folding. If you give these to SSC or any of the other (potentially cheaper) laser cutters, they should be able to sort you out. SSC are great for bulk orders, but I've found them expensive for one (or a few) off. If you do find someone, get them to keep the job details on file & post it here or on Instructables (or even mail me) so other people can use it too. Feel free to PM me if you have any questions. Si Quote Link to comment Share on other sites More sharing options...
lo-fi Posted January 20, 2017 Share Posted January 20, 2017 Try LaserMaster.co.uk I've just ordered a bunch of parts in 316 stainless for my jet engine project from them. Very helpful, the price is very reasonable (I thought so, anyway), and they're happy to do one off orders with no tooling or set up cost. Will do folding too. Love your work Simon - thanks for open sourcing this. The 3D printer looks brilliant too. Cheers Ian Quote Link to comment Share on other sites More sharing options...
fraser1 Posted January 21, 2017 Share Posted January 21, 2017 On 20/01/2017 at 11:27 AM, simonr said: Nope - and not for a couple of years now. If you have a look at: http://www.instructables.com/id/CNC-Plasma-Table/ I've published the whole thing Open Source including the DXF's and drawings for the folding. If you give these to SSC or any of the other (potentially cheaper) laser cutters, they should be able to sort you out. SSC are great for bulk orders, but I've found them expensive for one (or a few) off. If you do find someone, get them to keep the job details on file & post it here or on Instructables (or even mail me) so other people can use it too. Feel free to PM me if you have any questions. Si To download dxf files do I need a premier account with instructables and is this the latest incarnation? Quote Link to comment Share on other sites More sharing options...
simonr Posted January 21, 2017 Share Posted January 21, 2017 It is the latest - in fact it incorporates a couple of improvements over what I'm running. I don't believe you need a premier account - I don't think you need an account at all come to think of it. Si Quote Link to comment Share on other sites More sharing options...
elbekko Posted January 22, 2017 Share Posted January 22, 2017 The link at the bottom of the page contains a RAR file with all the DXFs in it. Works fine for me, without being logged in. You may need something like 7-Zip to open the RAR file though. Quote Link to comment Share on other sites More sharing options...
fraser1 Posted January 23, 2017 Share Posted January 23, 2017 Aha on windows it's a snap, I should get off the sofa and stop trying to do everything from my phone! Quote Link to comment Share on other sites More sharing options...
Cynic-al Posted January 24, 2017 Share Posted January 24, 2017 I have always found ESP laser to be good. Quote Link to comment Share on other sites More sharing options...
simonr Posted January 25, 2017 Share Posted January 25, 2017 On 1/20/2017 at 11:52 AM, lo-fi said: 316 stainless for my jet engine project That sounds interesting! Quote Link to comment Share on other sites More sharing options...
lo-fi Posted January 25, 2017 Share Posted January 25, 2017 (edited) 8 hours ago, simonr said: That sounds interesting! Thanks , it's a fun project! Apologies for the subject being off topic, but the construction is definitely relevant. Laser cut 316 stainless steel: Drawings made in OnShape.com (free online parametric CAD) Build thread here if anyone is interested. And because it's relevant, here's my (highly questionable) manual circle cutting jig for the plasma. No pilot arc on my machine, and torch height control with a screw in the bottom of the wooden torch holder, If it didn't strike, a little tap enough to bring the torch into contact with the sheet did the trick Crude, but very, very effective and had some lovely cuts out of it. The wild invention: Edited January 25, 2017 by lo-fi 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.