Luke11CNC Build Log ,I'm so naïve

[Jonathan]

Your almost right Jonathan? The screw is very hard and can easily crack (only the centre is soft). If this is added to the floating end then no need to knurl it, just go for a nice tight slide fit and let the loctite do it's job.

The reason I knurled it is because that's what John S does. Well, says he does at least. Could anneal the very end of the screw to stop the risk of cracking, but that's probably taking it too far.

Putting the extension on the 'floating' end sounds good to me as all it's doing is stopping the screw whipping, not transmitting torque. The other end is probably easier though as the tolerances to fit the pulley are not tight as for a bearing. It depends how much we need to add?

[Swarfing]

Jonathan the problem wih extending the belt end is as you have pointed out to is torque on the jointed section. As WG said that end can always be machined to allow for the pulley. An even easier solution is to just extend out the floating bearing housing with some ali round bar and mount the bearing in the end?

At the end of the day the KISS approach is always best, less to go wrong

[luke11cnc]

I haven't got a clue what your all taking about but I think I've solved the problem.

If I take the retaining nut off and have the pulley machined to slide over the threaded part and have 2mm machined of the pulley shoulder and fit a grub screw plus slide the other bearing right to the end and cut off the excess ballscrew material It will fit



what do you think is this a solution or am I making more problems for my self

James

[luke11cnc]

No one with any advice on my solution ??

James

[i2i]

I take it you're going to replace the bearing clamp nut with a thread in the pulley. If so you'll need a more positive location for the pulley, one grub screw just won't be enough. Possibly a pin right through the pulley and shaft when it's clamped up tight.

[luke11cnc]

Well after a lot of soul searching I've decided to take it down to my local engineering shop and have it rematched if it doesn't work I will have to buy a new one but I'm not going to cut corners to make it work now

and if it works they can do the other one (z-axis) as that is the same

James

[Jonathan]

take it down to my local engineering shop and have it rematched

Rematched? Wont they charge a lot :(

if it doesn't work I will have to buy a new one but I'm not going to cut corners to make it work now

I'll buy the old one if it is spare, then you don't loose out. Just need to get ball-nuts for it and that's my milling machine X and Y sorted. I need to do the end machining myself for that anyway.

and if it works they can do the other one (z-axis) as that is the same

What is the overall length of the Z-axis screw?

[luke11cnc]

Jonathan the length of the z axis is 400mm

and yes if a new y-axis is required then you are welcome to it


James

[luke11cnc]

Just to let you all know the build is back on


Luke is walking now with shoes on so I'm getting him in the garage at the weekend to work on his CNC machine.

we have so much to do and I am hoping to get the machine up and running by the end of November

James and Luke

[luke11cnc]

well we did do some work on the CNC Machine at the week end and have now mounted the gantry support extrusion to rear beam and gantry sides



poor poor Luke "Dad how many more time do we have to take it apart just to build it back up again"




at the week end we also started the mounting of drivers in the old computer




Now I must admit I did most of this and Luke just did the last one and as you can see he finished mounting the transformer



In this image Luke is drilling out the y-axis supported rails as they came blank



I'm hoping to receive the y-axis supports from Jonathan on Saturday

so we can fit them on Sunday as Mum is out for the day

any way I just thought I would post a quick update

James and Luke

Ps

it's Luke's bday next month any suggestions for a CNC related present ??