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| raynerd:
Hi guys, I`m in need of some advice..... After seeing my mate Steve’s router out of the corner of my eye one visit back during the Christmas period I`ve been frequently going on cnczone to eye these machines up. As is usually the case with the internet, and that is part of its brilliance, there are countless ways to make these and every time I`ve been close to getting started something has put me off. When my brother-in-law started to build one back a few weeks ago that just tipped me over the edge with determination and I had to make a start!! My plan is to build a fixed gantry machine so the table with move on bearing draw slides (kindly donated by Steve - cheers mate!!) These are heavy duty draw slides and are like nothing I`ve seen before, certainly nothing at B&Q! For the other two axis I`m going to use ground 1/2″ drill rod running over home machined phos. bronze bearings. It certainly sounds good, I just hope it works! The router will be made almost entirely out of 3/4″ MDF. MDF Cut: Draw Slides: Setting up the moving table - Trapizodal lead screw - 12mm with 3mm pitch. Lead screw running on bearings at either end of the bed supports: |
| raynerd:
...and this is where I need some advice if anyone could lend any? Since the trapizodal lead screw nuts are round, I need some fixing to hold them to the table but as you can see in the picture below I don`t have much room between the bed and table. There are a few solutions I can think of, 1. Lift the bed even further but this will now only give me extra space above, between the nut and moving table but between the bed will still have no extra space. 2. Route a small - 5mm groove into the 3/4" mdf bed to give more space between bed and nut. I know this would weaken the bed but since it is 3/4" and supported in the centre under the table (I could even support it more) I can`t see it being such an issue. My initial plan was to machine some small split blocks that would clamp down on the round nut but my question. Before I get to work on one of the above methods to give me more room and get on with my machined ally nut clamping blocks, can anyone think of a more simple solution even possibly using the current 4mm above and below the nut, that I could use to lock the nut the under side centre of the table? I just think with it being made of MDF, it seems a little OTT making ally blocks to support the nut... any advice appreciated! Chris |
| Jasonb:
Machine a 2mm flat on the nut and solder it to a bit of 6mm brass flat. You can then put a couple of csk holes in the brass flat and screw to the MDF. BTW if you do find the draw slides sag a bit at the end of their stroke you can add extra balls and cages from another pair of runners, used that method on this extending table that I made. Jason |
| raynerd:
Excellent! I did consider machining a flat on the nut but tried coming up with some contraption to clamp the nut the bed - didn`t think of that! Cheers |
| DICKEYBIRD:
The drive nuts on mine are round and made from a low friction composite plastic. They are threaded on one end so I just made some mount brackets from aluminum angle and drilled & tapped them to match the thread on the nuts. It worked great. Maybe you could turn one end down a bit and cut the threads in a lathe? |
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