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	18-12-2010 #71shank=5mmWhat's the diameter of the shank of those 5mm cutters you pointed me to? Also flute length?
 the blade is about 10mm with about 5mm clearance above that (15mm cut depth)
 theres aprox 20mm of clean shank to grip onto
 13mm of coarse (1.3mm pitch) thread 5.7mm diameter
 
 check your er16 5mm collet to see how much shaft you need
 
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	19-12-2010 #72Christ if i could keep my workshop as clean as yours is dirty i would be heaven................Where do you keep the tesla coil? If the nagging gets really bad......Get a bigger shed:naughty:
 
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	20-12-2010 #73It works!!! 
 
 I'll add photos/vid shortly.
 
 I did a relief thing, 200x200mm ... 1mm stepover with a 6mm cutter. Varied the feedrate and seemed ok at 3000mm/min. One of the X motors stalled, twice, so that needs looking into. The result doesn't look very good, but that's due to using a flat not rounded cutter since I didn't have one.
 
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	20-12-2010 #74
 
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	20-12-2010 #75looking good jonathan (the router that is, you need a hair cut :) 
 hows it getting on with thet much Z ?
 have you made a provision to drop the whole gantry down for your smaller /finer jobs ?
 it is a good feeling when the thing springs into life :)
 
 iv was having trouble with one of my X motors stalling, i had to back off on the speed, i swapped channels and the same motor stalled, im thinking there is slightly more drag on that side
 i might swap the bearings for double row A/C bearings to make sure the drag is identicalLast edited by blackburn mark; 20-12-2010 at 01:32 PM. 
 
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	21-12-2010 #76:rofl: thanks 
 
 It seems fine. There's a bit of wobble visible on the latest part (see below), but I think other factors are contributing such as the whole router wobbling madly due to the floor not being strong enough...
 
 I have measured the Z deflection parallel to X. I can bend the Z axis by about 0.06mm if I push as hard as I can with little finger, so a reasonable force but not huge. It takes a lot of force to bend it more than that which makes me think it's the linear bearings that are a bit sloppy. Not much I can do about that.
 
 I've not made it so I can lower the gantry, it's far to heavy to be doing that sort of thing. I think I'll make a raised bed and machine aluminium stuff on that. It's a compromise, but the gantry sides are very strong.
 
 Yes one X motor is much stiffer than the other. It's limiting my feedrate...
 
 Anyway, at last here's a video of it running:
 
 
 
 (I'll post the first test video tomorrow when I've edited it)Last edited by Jonathan; 21-12-2010 at 01:09 PM. 
 
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	21-12-2010 #77Well done Jonathan and good to see you up and running :-) If the nagging gets really bad......Get a bigger shed:naughty:
 
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	21-12-2010 #78Splendid!!!! im surprised how fast its cutting 
 thats a lot better than i would have thought :)0.06mm
 i had to try your scientific test, im getting about 0.03mm but i only have 120mm cutting space so your gantry sides were a good choice over plate
 i removed the drive from one side (in order to find the one that was stalling/binding) and it ran better on a single stepper than it did on both which i found pretty bizzarYes one X motor is much stiffer than the other. It's limiting my feedrate...
 i could only think that there was some kind of sympathetic (machanical) interference between the two with there being more drag on one side and because i was lazy when i fitted the the standard brearings (the fit is to tight) i cant back the pre-load off... the diffrence in drag between each side isnt massive but im hoping that its that causing the problems
 
 my double row A/C bearings have turned up so ill give them a try at some point but for now ill stick with 1500mm/min
 
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	21-12-2010 #79Thanks, I'm glad it's working at last! 
 
 What feedrates do you/other people normally use with MDF? I looked it up and found the chipload should be about 0.3mm. That would mean with my router at 11500rpm (lowest) it needs to be fed at roughly 6.9m/min ... which is huge! I wanted to get it fast enough to make chips, not dust, and in doing so reduce wear on the cutter.
 I accidently cut all the way through 18mm ply with 6mm cutter at 2m/min last night. The cutter survived but the finish was poor/wobbly.
 
 Er, I wasn't testing the deflection of the gantry sides - the DTI was stuck to the side and touching on the back of the Z axis. I'll see how much the gantry bends today.
 
 My problem with the X motors is one of the nuts is stiffer than the other, and the screws are a bit bent. I put them under tension to remove the bend, however that doesn't help when the gantry gets to the end of the bed since there's no give in it and as a result it often stalls.
 
 
 Hmm, I thought 3600mm/min was tedious 
 Y is happy at 5000, maybe more - not tried. The backlash seems to have increased slightly on Y. It's now 1/2 a step - 0.012mm.
 Z still works at 10000, and X seems reliable at 3600mm/min...but not at the end of travel.
 I think my toroidial transformer is too small now I've got an extra motor.Last edited by Jonathan; 21-12-2010 at 01:33 PM. 
 
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	21-12-2010 #80cant help you there, im not into wood... im just going off what iv seen on the netWhat feedrates do you/other people normally use with MDF?
 
 
 im assuming you slackened everything off at one end (nut housing and bearing housing) and ran the gantry to that end and nipped it up, then did the same at the outher end... back and forth a couple of times to make sureMy problem with the X motors is one of the nuts is stiffer than the other, and the screws are a bit bent. I put them under tension to remove the bend, however that doesn't help when the gantry gets to the end of the bed since there's no give in it and as a result it often stalls
 
 i read somewhere that i might need to staighten my screws when they arrived, mine are only 750mm so i got away with it
 i was thinking i would need a reasonably flat surface to find the curve and use my knee to ease it out
 as long as its a nice lazy curve you should be able to get the worst of it out...... bit more of a problem if its a short bend, it would be pretty easy to make it worse
 
 Hmm, I thought 3600mm/min was tediousyour definitely 18 :)Z still works at 10000
 
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