[peteeng]

Hi All - I have been thinking about the build and looking for alignment lasers or such. Also been looking for a big engineers square but hard to find these days. I came across PWL for those interested in alignment tools.

PWL | EDS Precision Systems

I also made a box for my squares and some stuff and came across the word "knolling" which seems to mean organising things parallel and orthogonal. Its become a "thing".

Back to reviewing the machine base and get the parts on order. Peter

[peteeng]

Hi All - Not much to tell. Commercial work came before YaG this week. Going to update the bench with better castors before I get serious with things on top. Now's the time to do it, once I have things on top I'll never do it. A friend sent me this link to Onsrud routers. A good tour of their factories.



So back to reviewing the YaG machine bench and I want to get it on order this week. Keep making and make safe. Peter

[machinedude]

interesting video but only had time to watch a little bit of it and will have to come back to it later. i just bought myself a 200 amp AC/DC TIG welder so i could get into doing things differently. noting high end but one of the better entry level machines. i wanted to learn the TIG welding process and get away from the MIG welding. should be fun and something new to me to play around with. hopeful life cuts me a break soon so i can get back to making stuff. looks like this video will give me some inspiration

if only i could do my thing and not get sucked into my kids problems new toys and no time to play around with them

[peteeng]

Hi MD - Many many moons ago I used to teach TIG so have lots of fun with it . Some pointers: a) cleanliness - can't be too clean including your torch, electrode and cup especially mill scale that will sparkle up on you or alum oxides floating around in your puddle laughing at you b) I found some students couldn't get various things right and after some time discovered that they could not see what I saw. So get your eyes checked and your glasses up to spec or get a set of close up ones just for welding. Plus its good to get a 2x or 3x lens in your helmet if you intend to do small SS or steel welds c) soft wrist - you learn by doing stringers on flat sheet. Unfortunately this teaches you to lock your wrist. When it comes time to do some pipework you need to be able to roll your wrist otherwise the electrode will soon get at the wrong angle. Some welders who never learn to roll the wrist do curves in short bits, stopping and starting to compensate for the locked wrist. I made a balanced gantry for the torch so it hung over the job nicely then I didn't have to carry the plumbing as much.

Just remember to relax and keep everything soft so you can control the electrode angle no matter what. This also reduces strain and fatigue on your body. d) Cup drag - used to be frowned upon but rocking the cup on some welds is now the norm. We had a large gas lens cup that was dropped and a large chip came out of it. The welder didn't throw it away and it turned out to be perfect for doing some titanium work we did. The welder dragged the cup and poked the wire thru the chip and the whole thing had excellent gas coverage... Cup drag is when you drag the cup on the surface to stop you from stubbing the electrode into the puddle. Which you will do lots of while you learn.... Peter

[peteeng]

Hi All - One of my commercial projects has been doing a dynamic analysis on a 17mx7.5mx3.5m Z 5 axis router. Its being recommissioned and they want to understand why the 3.5m Z wobbles (doh!). For instance I calculate it takes 2 secs for the Z axis to stop wobbling under acceleration loads. They are going to make a high modulus carbon fibre Z replacement for the steel Z axis once they get it running again. Unfortunately I can't show you that project stuff. But I have in parallel been running YaG dynamically as well. In contrast to that machine YaG takes <0.15 sec to calm down in the same mode this is called the decrement. This is using a machine and material damping factor of 3% or zeta=0.030. When I do manual calcs to predict what accerations will occur due to forces applied at the drive nuts for instance this is what occurs 1) the nut takes off and the immediate structure has that acceleration but the inertia of the Z axis means it lags behind and then shoots forward (called surging) and then springs back until it damps out. In YaGs case at the tool this is an acceleration of 26m/s/s or 2.6g. So wobbles can influence performance quite a bit. In this model of YaG I have placed a 10kgf load at the tool so not very big to get large accelerations at the tool due to mass inertia. Cheers Peter

One thing interesting with the acceleration is due to the uniform force of the cut being in one direction the surge is asymmetric. Classic "chatter" behavior. If I did this as a "free" structure it would be symmetric eg if we did a rapid from one place to another it could wobble freely in any direction. I also removed the drive screw from the gantry as it was vibrating in all sorts of modes. So need to go back to that and figure out if its significant.

Please pester the forum management to include MP4 videos in their allowable formats so I can put up videos of these things...

[machinedude]

i did get a new hood with the true color high definition filter optics and the large viewing area to help me see things better. i knew being able to see well was going to be a big factor so i upgraded to give me some extra help i'm sure the glasses will be needed as well since age is catching up with me i should have the basics covered as far as needs i already had the argon bottle since i was set up to do light aluminium on the MIG welder i have. i should have just bought a TIG 10 years ago or better but they were not affordable back then and the welders were starting around $2500 back then. i happened to stumble across the AHP alpha 201 XD unit i got for a special price so shipped to my door was $670 which is pretty cheap and this particular welder seems to be one of the few cheaper ones people seem to be impressed with. granted i spent another $500 on odds and ends but should have a nice little TIG set up to start out with.

[peteeng]

Hi MD - Don't use a MIG gas regulator - it won't come down to a low enough gas flow for TIG. If the flow is too fast it will be turbulent and suck in atmosphere. Need a ball bearing gas flow meter....but they may have improved I moved from metals to composites some 25 years ago....Cheers Peter

[machinedude]

actually the welder came with a regulator so that was covered with the unit. the only thing the welder was missing was the tungsten for the torch. so i picked up some 3/32 blue to start with and once i get some practice i can play around with different size tungsten and filler rod. right now i just wanted to keep things simple until i get the hang of it. got some ER70S-6 3/32 rod of steel and some 3/32 4043 for aluminum to practice with. i figured that was about middle of the road and a good starting point.

[peteeng]

Hi All - Had to take a couple of steps back with the bench. Where it is, it needs to be moved for another project. And since I used upstands under the castors to correct its height these sort of defeat the purpose of having castors. So I started building a sub frame to correct the height and allow the castors to be at ground level. Tomorrow I finish the sub frame and instal it in its new spot. Then I pull apart the current bench and reassemble it on the frame. Then in the future it can be rolled around easily. Phewww. Also in the rebuild I'm going to replace many of the timber screws with M6 thread inserts so breaking down and rebuilding in the future is easier. Better off to do it now then when I get a machine on top of it!! Peter

https://www.boltandnut.com.au/m6-x-1...0aAu5PEALw_wcB

[peteeng]

Hi All -Today I completed the subframe. Next week I'll place the subframe where it will go, level it and break down the bench and rebuild on the sub- frame. I used expanding PU adhesive for the joints. I have a love hate relationship with this stuff. Its super sticky and strong but ozzes out of the joint and is hard to clean up. Plus the joint bondline is left with bubbles and flaky bits. I think I'll stay with Titebond, PVA or epoxy in the future... Peter

[peteeng]

Hi All - Been away for a few days visiting the folks. Back at it today. While away I decided that the castors on the bench were a bit small so bought some 80mm braked units in my travels. I'll make some levellers/jacks if needed. Using the combo of small levellers and small castors didn't sit right. I'll use the smaller castors on small tables needed in the new workshop. Its workshop month!! The shed kit has been confirmed to be delivered on the 17th and the builder starts on the 23rd excellent!! Peter

[peteeng]

Hi All - This morning I pulled apart the bench, fitted the new castors and reassembled it. All looks good. Now I have a solid bench for YaG. I have learnt a little about the PU adhesive today. I have contemplated building a router out of formply for a couple of reasons. 1) It has well spec'ed mechanical properties so structural design is easier 2) It has the phenolic coating on it which means I don't have to paint it just edge seal & 3) It has an industrial look which I like. Prior to today my hesitation was about laminating the plys together. The phenolic is used as a release for casting concrete and I have used it to make moulds for composite parts as well. So the coating is sort of non stick. But when I built the leveller pads I screwed and glued them with PU adhesive. Today I expected to pop them off with my hammer but NO. They put up an admirable fight. I had to chisel the remainder off after a hefty thump to break them off. So now my mind is back to a structural ply router Hmmmm... Peter

[peteeng]

Hi All - I was reading up on some history of CNC amazing stuff: https://en.wikipedia.org/wiki/Histor...erical_control
and we definitely stand on the shoulders of Giants : https://en.wikipedia.org/wiki/Standi...ders_of_giants cnc is so easy these days.... Peter

[peteeng]

Hi All - A couple of things happening in the background for YaG. 1) I finished the bench today and it's really interesting how in about 5 secs of new horizontal space it gets covered in stuff!! So now to get YaGs machine base reviewed and on order 2) YaGs Z axis assembly will be soft soldered together (or silver soldered not at crunch time yet) . The laser will cut tabs and holes and I'll propane torch solder it together. Brevis my small tabletop machine has a slightly wobbly Z so I added a small web this way. I soaked the parts in hydrochloric acid which removed the mill scale really well. But some of the laser glaze had to be filed off. I was hoping the acid would do the entire job. Then I soldered the webs on. Next time I'll tin the sides I think then join them. Anyhow the FE says its 21% stiffer. A Brevis machine is unlikely to be built again. I use B1 for small jobs and this webbed bracket will go on that with an updated anti backlash nut. B2 I have been trialling some drivers and geared motors. I'm going to rebuild B2 into a bigger machine. Brevis was never intended as a router but was built as a plotter. It does a surprising job as a small router/carver. So I think it's worth upgrading it slightly. I have a B3 mechanical parts set if anyone is interested... Keep making Peter

[peteeng]

Hi All - I have been tuning up YaGs machine base. I have been looking at plywood and mdf solutions for it. I've decided to use a highly engineered composite sandwich prefinished in white high pressure laminate and the cabinet maker will edge finish it for me. Don't have to paint! Bonus. Tried to get grey but cost jumped from $48/sheet to $163/sheet AUD. In the tune up I found a 2mm discrepancy from LHS to RHS? Quite a mystery as it was mirrored. Tracking that little delta down, what a mission. Ended up deleting the mirror and building a LHS and RHS drive module. Speaking of machine bases and composites I was looking at the Hermle machines and they have built a new mineral composite factory to cast their bases. I like Hermle they do everything in house. Once I get YaG running I'll be able to cut my own panels and these will be aluminium laminates for future machines. Want to get the base on order tomorrow. Peter

[peteeng]

Hi All - I have checked the machine base and have quotes for cutting the parts and shall order these on Monday. That means I can start building the base next saturday, Yeh. I have been trolling through the model checking various parts and adding manufacturing details. I sent a note to Fred at BST and they are back to normal lead times so about 3 weeks to get parts to Oz. Next step is to get all the parts for BST completed. Then once they are on order finalise the sheet metal parts and get them on order and everything will arrive at once!! I got out some sheet metal parts made by a local company and measured them up carefully. I was hoping to use them but they can't seem to get 90degs right. So I shall go with the original company. Luckily they are in a zone that I can drive to. Here we have what's called the Qld/NSW border "bubble" If your in the bubble you can cross the border but can't go past the bubble. Creating havoc with various things....Hopefully the YaG build will accelerate now, so many decisions are now under the bridge.... The shed steel has been delivered and the builder set up his caravan here today so the workshop build starts Monday in earnest as well. Excellent...Peter

[peteeng]

Hi All - I have been checking thru the assemblies looking for glitches. Especially for holes that don't line up. I have one here that's a mystery. In the sub assm they line up and are constrained correctly yet in the GA they are out by 1mm??? I've mucked about with it enough to sat "enough!". Only thing left to do is to delete the parts in the sub and re build to see what happens. The hole pattern is correct so no big deal (yet) its best to have a model with no mysteries... Peter

I bit the bullet deleted the parts and rebuilt and the glitch disappeared. But the assembly did go a little awol so there are some gremlins in there hiding (don't add water). I want to close out the end of the gantry but have not decided how yet.... Next is the part by part hole check and dwg slog....Peter

[peteeng]

Hi All- I've been wanting to put in some shear supports at the gantry ends. Options are use a cast aluminium bracket that the construction extrusion people supply or make a shear web. The shear web could be tricky once bending radii and other bolt heads are considered. The cast bracket by a fluke actually fits! This would mean the spacer needs reprofiling but that's not a biggy. Perhaps a quick model will help decide... Peter

[koenbro]

This is one top-notch thread. Love reading along your thought process — thank you Peter!


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[peteeng]

Hi Koenbro -Ta - The machine base parts are on order and are in the production stream. Soon we'll have real bits to look at. Now I'm detailing/checking the motion bits to get them on order. Peter

I have committed to brazing or soldering YaGs saddle together. This is to minimise the part size as bends & bolts take up so much space! and to maximise stiffness. Brazing or soldering is preferred to welding as the parent is not melted and therefore there is no parent shrinkage only the process temp differential to deal with. Technically if you heat something up it grows and when it cools it goes back to its original size. Over the years I have soft and hard soldered and brazed many things. I want to soft solder this saddle (process temp 200-280C so not even red) but then I need to clean the mild steel really well. Being lazy I want an easy cleaning method. I've tried acid which works nearly to what I want. But I still have to put it on a belt for the laser glaze. Then I have to paint which is an expensive process and adds issues to the fit.
So I've come back to stainless steel silver soldered. If I'm neat I won't have to paint... The silver solder flux cleans really well and a quick scotchbrite on a belt cleans SS very well for prep. Silver brazing alloys (SBA) melt at 600-650C which is just red. My plan is to get the sheetmetal shop to tig tack it together then I'll finish braze it. I use oxy acetylene for this sort of thing, a nice soft big flame gets it just right quickly... But there is a flaw in the plan I have to get around, if anyone is clever to point it out...