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Have any of the Aussie members of this forum successfully used self-levelling-epoxy such as the West-Systems resin type 105 with type 209 (very slow) hardener, or used another similar product locally available in Australia?
If so, please let me know how and where you obtained it, etc..
I'm thinking of starting a DIY CNC Router build this year, but want to clarify this availability, before I start a build relying on Self-Levelling-Epoxy.
Thanks,
Andy
I used West system with the 209 super slow hardener.
I got disappointing results. Better than raw steel tubing perhaps but nothing as good as some people report / claim.
It seems you need quite a thick pour (5mm plus) to overcome surface tension.
Epoxy is not a stiff material, so now you have 5mm of relatively soft stuff between your rails and the underlying metal.
I got indents from my rails in the epoxy despite waiting weeks for it to harden before mounting rails.
Overall I would not go for epoxy again.
There is no good cheap solution.
Send out for machining - $$$$$$$
Making the frame very adjustable is probably the best option. You can then do a lot with a machinists level and a good straight edge.
Andy,
Aluminium profile is very popular and based on the pictures we see on the forum is straight enough for directly mounting the rails. Problem is it costs an arm and a leg in Australia. My own machine has the rails mounted directly onto the steel section and relies on the straightness of the steel. It works OK for fully suported round rails but that may well not be good enough for Hi-Win or similar. The alignment of the rails to each other is done as pippin88 describes. Whether that's straight enough for you depends on what you want to make with it.
I'm not sure if anyone has tried a hybrid design with a steel frame and aluminium for supporting the rails. We're then into possible problems with differential expansion!
Kit
Many thanks guys for your responses!
@pippin88Quote:
Originally Posted by pippin88
Yep, I intend making the frame (top rails) very adjustable, and take your point about not wanting to go for self-levelling-epoxy again, and I am actually undecided about using self-levelling-epoxy.
But can you perhaps recall where you bought the West Systems 105(209) epoxy and the rough cost?
There was another forum guy from Melbourne who also used West Systems 105(209) epoxy, but he stopped using this forum back in 2014, in his build:
http://www.mycncuk.com/threads/6626-...0662#post50662
@KitQuote:
Originally Posted by Kitwn
My thoughts have been tempted from time to time to consider fully supported round rails, due to my understanding that they're more forgiving than Hiwins, but although I might not need the extra precision provided by Hiwin-type-profile-rail, I've been led to believe that they make sense in a cost-benefit and future-proofing kind of way, so will go with Hiwin-type-profile-rail.
Luckily enough, over the past few years I've bought some "bulk" lots of used aluminium off eBay, so fingers crossed may even have enough aluminium profile (90x45 -ish) for both the top rails and the gantry. I wouldn't have enough for a full frame of aluminium, and I really like the rigidity that a steel frame provides, so I may just go for a hybrid design with aluminium supporting top rails bolted to a steel frame. It looks to me like Jazz is doing something similar on his newest 600x900 machines?
As part of the process of aligning the rails, I'm now also thinking of using Milliput-epoxy-putty, that is readily available in Oz, similar to what Jazz explains in the following two posts:
http://www.mycncuk.com/threads/6382-...7754#post47754
http://www.mycncuk.com/threads/6382-...7815#post47815
Btw, some Milliput-epoxy-putty links are:
https://www.hobbytools.com.au/millip...low-grey-putty
https://www.milliput.com/howto.html
Andy
Those links to Dean's posts were very interesting, I'd not seen those pictures before.
I have never sugested that anyone copy my own machine, but if you have a look at some of the pictures on the build log you will see that my facilities for aligning the frame parts for welding was not exactly of the 'professional' standard. This frame was only my second attempt at welding, the first having been the gantry of the same machine. Despite all the limitations I managed to get the four corners on the same plane to within 3mm. If I can do it then anybody can! The basic technique was to get everything stuck together in the right places with small tack welds and then go round adding short welds at a time to prevent excessive heating in one location.
The beams holding the rails were then made accurately co-planar using shims on one corner. You only ever have to adjust one out of four corners! I sat the other 3 up on fixed,12mm shims to give me wriggle room in both directions. Making the end result more rigid with epoxy putty makes sense. Thanks for the links to Milliput, I would have tried to use Knead-It which is on the shelf of every Bunnings but sets in only 10 minutes.
Regarding buying Hi-Win rails immediately: There is a great deal to be said in favour of buying components for your first machine with an eye to upgrading in the future. Those rails are more unforgiving though and your flatness and general alignment will need to be much better than you will get away with for round rails. I doubt you will ever see Hi-Wins on a plywood and MDF router :glee:
http://www.mycncuk.com/threads/13904...-Machine/page2 Posts 15 & 16
Kit
Thanks Kit,Quote:
Originally Posted by Kitwn
In your posts 15 & 16 you have raised a number of welding and alignment techniques that a novice like me can use to great effect.
I particularly like your explanation that you only ever have to adjust ONE out of four corners to get the rails co-planar.
Btw, looking at the scenic background in one of your images, it looks like you guys have moved down to a patch of heaven in Van Diemen's Land. . . . . .
Andy
Andy,Quote:
Originally Posted by AndyGuid
As you will no doubt have learned in school, the three corners of a triangle MUST be in the same plane. Therefore when you add a fourth corner to make a rectangle, only the fourth corner needs adjusting to bring it into the same plane. I was so glad I realised that before I started the adjustment. I knew that going to school would come in useful one day!
When I made the gantry I covered the crappy welding with body filler and paint. This time round I decided not to bother. I'm not ashamed of it! It works!
Yes we have indeed forsaken the baked iddyl of Exmouth, WA for the cooler, greener climes accross the Bass Strait. It's a bit of a slope but being on 2 acres means there's nobody going to complain if I run the router, complete with dust extraction, late into the night. Or do my occasional and very poor Jimmy Page impersonation.
Kit