1.7*0.74*0.4m Mill / Router building...

[blackburn mark]

Splendid!!!! im surprised how fast its cutting

0.06mm

thats a lot better than i would have thought :)
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

Yes one X motor is much stiffer than the other. It's limiting my feedrate...

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 bizzar
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

[Jonathan]

Well done Jonathan and good to see you up and running :-)

congratulations lad

Thanks, I'm glad it's working at last!

Splendid!!!! im surprised how fast its cutting

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.

thats a lot better than i would have thought :)
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

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.

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

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.

[Swarfing]

Well done Jonathan and good to see you up and running :-)

[blackburn mark]

What feedrates do you/other people normally use with MDF?

cant help you there, im not into wood... im just going off what iv seen on the net

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

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 sure

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 tedious

Z still works at 10000

your definitely 18 :)

[Jonathan]

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 sure

Yes I did exactly that. I think I'll try it again.

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.

[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 winner
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 :)

[Jonathan]

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

[Jonathan]

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.

[blackburn mark]

One of the videos hasn't finished uploading.

just watched them both :) splendid!! it is nice and quick
wind turbine blades!! can i order three for my paramotor :)

[h4ppy-chris]

fanatic jonathan i read all your post and watched all your vids love it keep um coming :)