FreeRiders V-Bearing Modified Momus


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Thread: FreeRiders V-Bearing Modified Momus

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    Default FreeRiders V-Bearing Modified Momus

    Well after many hours of reworking and design I have successfully completed my modified Momus build!

    There are many facets of this build that I would have done differently the 2nd time around but its what to be expected when you start deviating from the plans. With that said the stock Momus is a very well designed machine, I just chose to use what I had on hand to see how cheaply I could make it.

    On Ward!

    First I am lucky enough to have access to a large format 5x10 CNC with vacuum hold down so naturally I took the printed plans and moved them all over into DXF files so I would be able to cut them automagically.



    The part layout is very tight and I would have liked to slice it up with a 1/4" endmill but the greatest sheet usage was designed around a 1/8" kerf so I had to slowly cut it out with a 1/8" endmill...I guess slow is a relative term, still faster then hand cutting.



    After cleaning off the onion skin I cleared my little assembly table at home to get ready to assemble the base. I wanted to finish the bulk of the metal work first but seeing as I would be making up lots as I went I needed a base to start bolting things to. With that considered I figure I best finish the woodworking first.



    Printing off and getting the plans coiled bound was a great idea, I very much like to work in digital media but sometimes paper plans are still the clearest and most efficient way to go. With everything ready I layed out the stack of cut parts.



    I ended up using 2 beautiful sheets of "2 side finished" maple plywood. I figure for the amount of time and effort I am putting into this creation, saving money on plywood is the last concern. In the end it turned out that buying the nicer wood probably saved me hours in spot filling and sanding...plus maple smells nice. The nice part about having everything CNC cut is the parts fit together nearly perfect. I had resized all the mating cutouts and dog-boned the edges to make for less hand work. I accounted for a bit more wood/glue expansion then required but all in all it made for quick easy assembly.



    Now we crack out the drill and begin to piece this beast together!

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    Excellent practice and very fine work - of course it is much easier with a big-brother CNC taking the hand work out of the problem!

    It looks like the quality of your material is much better than mine. As you said, the second time around, you get better and the methods improve.

    I am looking forward to seeing your progress.

    Build on!

    -=Doug

    "IT ≠ IQ " Starwalt 1999


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    Quote Originally Posted by vtxstar View Post
    Excellent practice and very fine work - of course it is much easier with a big-brother CNC taking the hand work out of the problem!

    It looks like the quality of your material is much better than mine. As you said, the second time around, you get better and the methods improve.

    I am looking forward to seeing your progress.

    Build on!

    -=Doug

    Thanks for the kind words Doug! In actuality the machine has already been built and is currently cutting...I always rush a build when I run a build log at the same time so for a change I built the entire machine and decided to start posting once finished.

    Should have another update tonight...



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    Default Base Assembly

    With all the layout lines marked I was able to quickly screw and glue the base torsion box together. A nail set and a copious amount of glue are good to have on hand for the next bit. I went with slightly heavier finishing nails to help pin the parts together while the glue dried.



    In hindsight I should have altered the lengths of some of the bed parts as the slight difference in material thickness from exactly 0.750" made for a little hand planing here and there...I guess this is still wood working tho and is to be expected . Screws glue and a good counter sink are your friends.



    I know that my work bench is quite level but I kept double checking for bow's or twists while gluing panel after panel onto the massive base. I dont plan on pouring epoxy into the bed for squaring the axis's so it will make for less work later to ensure the bed is as flat as possible. I took a round over bit to a few sections on the electronics bay side to make it easier on the hands when working inside.



    Its quite amazing how heavy this little assembly can get, but then I guess it has nearly 1.5 sheets of 3/4" plywood in a very condensed space! With the bulk of the wood assembly done (the upper cover was built a few days later) I turned my focus towards assembling the aluminum parts that I knew I would require (even with my modifications)...



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    Default Bolting on the metal

    Going with the standard momus build I used plate aluminum ontop of the gantry walls. Unlike the standard build I did not like the idea of using lag bolts (primarily because I only had a few on hand) so I decided to thread hurricane nuts into the gantry supports. With this I was able to run standard 1/4" hardware to bolt the y rail supports to the machine. I had neglected to take a photo of this step but you will see further on in the build what I am talking about.

    One problem with deviating from known good plans is the likelyhood you will run into small time vampire issues. Heres a photo of my 1/4" angle aluminum supports, they required me to mill a small relief so I could clear the hex head on a 1/4" bolt. Would it have been faster to just use socket cap bolts for this step, probably, but I had literally hundreds of 1/4" bolts so I did what I did.



    I had to increase the square stock size from .750" to 1" in order to keep my offsets correct for my v-bearings while still allowing for enough "meat" to tap set screws into. All cuts were marked out with a scribe, the lines brought around with a good machinist square, then chopped to rough size with a hacksaw.



    You can get quite close to a perfect cut with the hacksaw alone if you follow your lines close.



    Not liking the imprecise nature of a file (or of my filing skills I should say), I then took all the square stock to my lathe and cleaned the end up with a slitting saw. Anyone who does not own a taig lathe needs one! I cannot believe how many times I use this machine, next to the drill press its probably the most used tool in my shop!



    Since my slitting saw does not have the depth for a cut this deep I had to attack the material from 2 sides...not ideal but it made for a neat finish on the ends of the stock.



    Once all the stock was cut to size I punched all the hole locations (that I assumed I would need) and started drilling. I have a somewhat heavy cross slide table on my drill press alone with a precision vice which made this process wayyyyyy easier. If I was a little careless with the center punch I was able to chuck in a starting bit and force the hole to go where I needed. For the most part a quick pilot with a ~1/8" followed by the final size was all that was needed.



    Another good tip is to buy a cheap bench grinder and learn to sharpen bits. Nearly all my bits are throw away's from my old place of work as its not economical to sharpen small sized bits. However its very economical for me to sharpen old free bits . Now when a bit starts cutting funny I can spend 30 seconds on the grinder and bring it right back up to full health.



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    Very nice build documentation!
    I am assembling my base on the cast iron area of my table saw. The base is only slightly larger than the saw surface. Even with measuring twice and cutting once, there are still slight misalignments.
    It is wood working - as you said. I find it interesting that even with cutting on a CNC, the misalignements/cut errors still stack up.

    I have the right inside skin pockets to mill away and both inside skins to install. At that point, the base is mostly done.
    Even with triple efforts to ensure the wall top plates were level, yet when bolted to the main base top skin, some deviation is clearly seen from 'flat'. I am considering some bondo type composite, lightly applied to both walls, layered. Then take a (cheap) 4 foot level with sand paper applied to the flat section and gradually true the top wall plates. After this, the final top plate can go on and be 'flat'.

    Without the effort, the Y assembly will vary significantly in the X direction while traveling.

    I like machine metal work far better than the wood working as far as precision in fabrication.

    Build on!

    -=Doug

    "IT ≠ IQ " Starwalt 1999


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    Quote Originally Posted by vtxstar View Post
    Very nice build documentation!
    I am assembling my base on the cast iron area of my table saw. The base is only slightly larger than the saw surface. Even with measuring twice and cutting once, there are still slight misalignments.
    It is wood working - as you said. I find it interesting that even with cutting on a CNC, the misalignements/cut errors still stack up.

    I have the right inside skin pockets to mill away and both inside skins to install. At that point, the base is mostly done.
    Even with triple efforts to ensure the wall top plates were level, yet when bolted to the main base top skin, some deviation is clearly seen from 'flat'. I am considering some bondo type composite, lightly applied to both walls, layered. Then take a (cheap) 4 foot level with sand paper applied to the flat section and gradually true the top wall plates. After this, the final top plate can go on and be 'flat'.

    Without the effort, the Y assembly will vary significantly in the X direction while traveling.

    I like machine metal work far better than the wood working as far as precision in fabrication.

    Build on!

    -=Doug

    I like the level idea!

    I probably had some slight height differences in the gantry tops. Initially I was concerned about it but once fully assembled I use the machine to mill its bed level and most inaccuracies cancel out...this is assuming your relatively square to start with (within ~50 thou). I've been as much as an eighth out on older machines but as long as its along only one axis milling the bed will make it negligible. If your + and - out of tolerance on one axis thats when problems creep up. Milling the bed then leaves you with a "tent" in the surface making it impossible to get square stock to lay flat.

    I with you in regards to metal work tho. I quite enjoy woodworking but its nowhere near as precise of an art as metal working...as someone once told me there is no "metal filler" to correct mistakes .



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    Default More Metal Madness

    Carrying on with the metal work...

    Even with my enlarged aluminum stock and my highly modified y gantry rails I still had very very little clearance between the lower bearing bolts and the wood side walls of the base. Just as is required in the plans I took 4 bolts to the lathe and faced the heads down.



    As my modifications to this build are being carried out on the fly I encounted all sorts of troubles working set screws into the bottom of the z-axis assembly. As you will see later in the build I have bolts cross drilled thru the stock where I also require a set screw. The only way around this issue was to use proper set screws, not the socket cap screws I am using. Since I had a bushel of socket cap screws I set to work with the lathe and a hacksaw to make everything work.



    With the blind hole tapped in a spare chuck of stock I was able to thread in the socket cap screw and use the slitting saw to cut a slot...this was done off the cuff with no measuring so ignore the off center cut :/ .



    This is where I spend most of my weekend mornings. A hot cup of coffee, tinkering with the lathe, and the sun shining in...my happy place.



    Here you can see the breakdown of the y axis bearing assembly. I stayed as true to the plans as I could but modified where I saw fit. I upped the thickness of the L braces as I wanted to use aluminum over A38. I also required clearance in front of and behind the y axis rails so I used thin 1/8" flat stock and offset it to the rail. I was worried that the decrease from 1/4 to 1/8 would result in too much flex so I went a little crazy with the supporting bolts. With both sides in place the y rails work together to "hide" the others weak point...in other words the cutting force from the bit is always acting in the strong axis to these rails. The benefit to v-bearings is the double race nature and the fact they can take axial and radial loads. I had posted a thread a while ago about the over-constained nature of my build but it turned out to be a non issue. With this design modification I have better rail constraint as well as a much reduced tendency for racking.





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    Default Ready for Paint

    At this stage I had fully built the machine. I completely assembled everything, double checked that everything would work then broke everything back down for paint. Below you can see what I was talking about when I spoke (wrote?) about the hurricane nuts in the gantry tops. The hurricane nut insets allow me to remove the y rails or reinstall them as many times as I like without relying on wood threads like a lag bolt. Please note I am not slagging the original design, in fact I think the Momus is probably the best designed DIY machine out there. I've bought many sets of plans and so far the Momus is the only set of plans I have read thru that justifies material choice with numbers and data...not just "do this because I did and it works".

    Anyways,

    I wanted to paint the base of the machine bright white, I also like the way oil based paints flow. Sadly oil base paints will yellow under UV. To correct for this I sprayed the base with 2-3 coats of oil based "cover stain" but zinnser (AMAZING PRIMER). With a quick sand between coats I layed down 2 final coats of water based white. This let the oil base seal the wood properly (no tannin bleed thru) and then gave the water base a smooth surface to adhere to and keep the UV monster at bay.



    With everything dry and ready for assembly I finally put the unit together. All in all the machine is close to the book plans...the z axis however is totally different. I had a horrible oversight with the z-axis and made it far far to tall, forgetting that there is a top to this machine! Needless to say the cover does not yet fit. I planned to finish the machine to the point that it could start cutting a new z axis for me from aluminum.



    Both the x and z rails are 3/4" A38 steel from my old machine. From the picture you can see the z rail is wood (oak to be precise). Not my first choice, and it will be changed for a 3/4" slab of aluminum. Left and right flex on the z axis is minimal as the bolted angle will resist this flex direction but forward and backward flex is relying solely on the friction between the bolts and the oak center spacer...not ideal but more then strong enough to mill itself a replacement.



    The belting is kevlar weave and seems very nice (not cheap but worth it in my opinion). I went a little large on the pulleys as they are 14 tooth instead of the recommended 10 tooth...in the future I will mill myself a new smaller set as I have far more speed then I require (750-1000IMP rapids).



    I had no fancy acme rod on hand so the z is currently running on 18 turn all thread. While slow its working more then well enough to mill itself new components. I tend to do quite a bit of 3D machining so upgrading the Z is a requirement. The spacer behind the z beam is made from HDPE. Once again its a part I intend to replace with 3/4" plate aluminum but considering its a part that only under compression HDPE is working fine. The rails of the z axis cause quite a bit of twisting force once fully tensioned so I ran 5/16" rods thru the y carriage. With this I am able to use nuts to squeeze the carriage together very firmly (you can just see the tensioning nuts of the left side of the carriage along the 1" stock).

    Nothing to fancy in the electronics bay. I have a cover that sits over this part milled from white dibond. My drivers are somewhat overkill for the current requirements of my steppers so they run quite cool even without active cooling. I will probably still cut some ventilation holes in the cover to allow for air exchange but don't think I will require a fan...time will tell. The breakout board has also been properly secured at this point (picture was taken before the rear mounting screws were installed). I use shielded cables for all the stepper motors but its always a good idea to keep AC supply lines clear of signal lines, keep your crossing points at 90* as well. While I have never had troubles with my home machines I have noticed all sorts of interference problems with our larger machines at work.



    Next up cutting tests!



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    Very nice build so far, thanks for all the pictures and the write up - lots of new ideas for the one I'm building right now in there. :-)

    One thing that would worry me a little is the way you mounted the z-axis motor. Just from looking at that, do you think that there is a possibility that the motor could twist on those studs by tiny amounts in either direction, thus creating something like a backlash effect depending on the direction it moved last? It probably won't be much, just wondering...

    Thanks again,
    Mac



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    I 've got to get one of those cut-off saws for either my lathe, mill, or both.
    My stock roughing was with a hand hacksaw and then final size/square was on the mill.

    It looks to me as though another accomplished hobby of yours is photography. Very nice lighting and compostition. Thank you for taking the time to post good photos.

    My practice is the same as many folk in this hobby: use what you have if you can cut/mill/turn it. Most of the hardware was purchased but, there were still items that were made at home. It is part of the hobby and instructive.

    Regarding the 'hurricane nuts' I too have considered another fastner that would allow removal, adjustment, and service better than using lags. Lags will do the job no doubt but if the material fatigues and the lag is torqued too much, material is lost and tension is lost.

    What size did you employ? I would think a minimum of 1/4-20 (as the lags were spec'd at 1/4).

    Again, thank you sir for your post.

    Document on! (you've already built it)

    -=Doug

    "IT ≠ IQ " Starwalt 1999


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    Quote Originally Posted by Mac.CNC View Post
    Very nice build so far, thanks for all the pictures and the write up - lots of new ideas for the one I'm building right now in there. :-)

    One thing that would worry me a little is the way you mounted the z-axis motor. Just from looking at that, do you think that there is a possibility that the motor could twist on those studs by tiny amounts in either direction, thus creating something like a backlash effect depending on the direction it moved last? It probably won't be much, just wondering...

    Thanks again,
    Mac
    Many thanks Mac,

    Being as the rod is already 18 turn the amount the stepper motor would have to slip would be large before I would notice an accuracy change. Honestly the bigger worry to me is the cobbled together thrust bearing and the lack luster HDPE drive nut. I do intend on upgrading this part but its worked for the last 3 years on my first machines so I have less pressure to immediately change it.

    Post some pics of your build! I think I combed thru every build 4 times before starting mine .



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    Quote Originally Posted by vtxstar View Post
    I 've got to get one of those cut-off saws for either my lathe, mill, or both.
    My stock roughing was with a hand hacksaw and then final size/square was on the mill.

    It looks to me as though another accomplished hobby of yours is photography. Very nice lighting and compostition. Thank you for taking the time to post good photos.

    My practice is the same as many folk in this hobby: use what you have if you can cut/mill/turn it. Most of the hardware was purchased but, there were still items that were made at home. It is part of the hobby and instructive.

    Regarding the 'hurricane nuts' I too have considered another fastner that would allow removal, adjustment, and service better than using lags. Lags will do the job no doubt but if the material fatigues and the lag is torqued too much, material is lost and tension is lost.

    What size did you employ? I would think a minimum of 1/4-20 (as the lags were spec'd at 1/4).

    Again, thank you sir for your post.

    Document on! (you've already built it)

    -=Doug
    Doug,
    Wow thanks once again for the kind words. Photography is also another huge hobby of mine but I dont much like hauling the SLR into the garage so its just "cheap" iphone pics for this build .

    I agree with you on lags, I ended up using 1/4" sized inserts as its what I had on hand. When I start torquing them down I can hear the wood fibers straining. Ideally using 1/4" T nuts on the backside of the gantry tops would make for insanely strong bolting points, but T nuts lack the easy of installation after the fact.



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    Default Router Mounting

    With the axis all sorted out it was time to start working on squaring everything and getting rid of backlash.

    Tension along the X axis belt is an area I wish to redesign. Currently I use spacer washers to adjust the tension along the belt which actually works surprisingly well but its somewhat of a hassle to adjust. The next iteration will have either custom milled bolts with small spreader nuts inside the little adjustment space I have, or use long 10-32 setscrews to apply tension and then large 5/18 bolts to lock everything down. None the less I have managed to get the backlash down to about 4 thou on this axis...far from ideal but this is half due to the belt tension and half due to my larger drive pulleys. Running 1/64th micro stepping can get me pretty consistent 1 thou steps (real world testing with dial indicator)...not quite as nice of a step as my slow Z axis can get but more then enough for now.



    You can see the top v-bearings here for the x-rail are at a fixed height. The holes where tolerance fit to the bolts and I had to make damn sure everything was square for assembly. I was counting on my x-axis rails to be level and square and thankfully everything worked out. The bottom v-bearings are an absolute cluster f&(k! I had to bore a hole down the end of the stock to allow for a set screw to apply tension. The path to that setscrew is blocked buy not one but 2 cross drilled bolts. The adjustment works perfectly, but its not exactly user friendly to adjust. Once again thankfully these X rails have been used prior and are already work hardened from the bearings, I dont foresee needing to adjust them to much more.



    Here you can see the z-axis all tucked away behind the router mount (milled on the machine at work). I kept the z axis as low profile as I could to avoid any cantilever effects. The double nuts on the x carriage dont help the issue but I have a few idea's I will implement down the line to correct for this. The 1/4" bolts running thru the fronts of the router mounts thread into steel cross dowels. This is a part I will use the machine to remake as well. I'll probably change the 1.500" wood clamps to either 3/4" aluminum plate or 1" delrin.

    Here you can see the "anti backlash nut". I once again have an idea about using the mill to machine a proper anti-backlash nut while still keeping a nice low profile. The little burrow in the aluminum bar on the left is due to a 1/8" bit deciding to snap off inside the material. I spent about 1/2 hr. trying to remove that little creature and finally had to admit defeat...so I'll just call my machine an aluminum/carbide hybrid.



    With everything adjusted and tensioned I had to tram the spindle over quite a bit. I actually milled the bed level before tramming and only noticed I was out due to the surface finish on the table. Even with my larger full sized router I still have 14.5" x 16" of cutting area. The 3 layered MFD bed is this size and I can easily cut to all edges. Once again I put some hurricane nuts into the base of the CNC to bolt down sacrificial table tops. The very top layer just just held on with screws as I can remove it to gain extra Z height if needed.



    I designed the machine to be able to mill 2-3" tall foam blanks for 3D castings. This is for the most part the thickest stock I work with. If I need to mount my precision vice inside the machine I could remove the spoil boards and gain an extra ~2". I also designed the Z to sit as high as possible during normal machining. My old machine had a huge amount of Z travel but milling at the very bottom of your Z travel only leads to excessive flex, milling much closer to the bearing mounts makes for happy cuts .



    Here you can see the stripes in the bed due to an out of tram router. Bed was milled at 200IPM. The 3 open holes on the router mount were used to help with clamping during glue up, and will be used to bolt the dust collection system on to. The main reason I have gone with the larger 3.25Hp router over a trim router like the colt is due to the fact that I mill quite a bit of aluminum. While I know the colt can do it just fine the hitachi has a bit more lower end grunt and is a HELL of a lot quieter.




    For the cable arms I used some 0.750" HDPE off cuts from work and used the skate bearing trick to allow for smooth motion. HDPE is so slippery I didn't even use a bearing between the arms. The bearing isolates the bolt from grabbing to much but otherwise it moves as smooth as silk. Might need to be replaced overtime as its not nearly as ridged as an aluminum bar would be.





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    More nice pictures and a better view of how the V-bearings come into play.

    Many thanks again!

    -=Doug

    "IT ≠ IQ " Starwalt 1999


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    Default Aluminum Results

    Without fully correcting for my slight backlash (I believe at the time of this cut it was close to 0.010...now its around 0.003"), I gave milling aluminum a shot. This particular cut was using a Vortex Tools 0-Flute aluminum endmill (1/4") running a 0.03" DOC at 20-30 IMP. The 0 flutes really let you get your chiploading to the correct specs even if your router cannot maintain low end speeds.



    Face milling a part is an easy way to see how ridged your machine is as any bumps or jumps will show up in the finish. Overall I am happy with the cutting ability at this level but I have already started modifying the machine to allow for a mist coolant system when cutting aluminum. Dry cutting aluminum is easy if you keep your feeds reasonable and don't cheap out on your tooling, I actually find aluminum far more forgiving then acrylic, cheap tools and acrylic are most defiantly not friends.

    Here you can see the edge finish. I was climb cutting with no finishing pass to see how much stair stepping I would get. Besides the chatter from my stock being poorly secured the cut came out quite nice. There is pretty much no evidence of stair stepping which is odd since I know there is a measurable amount of backlash in this beast.



    In this light you can see a bunch of tooling marks from recutting chips, the spindle speed was a little low as I was constantly adjusting it during the cut to see how well my hitachi could hold speed at slower RPMs. Dimensionally the part is within 0.001" on the x axis but quite far out on the y axis (0.008 - 0.01). This has since been corrected for but its a good test to see that even a poorly tuned momus is capable of some very nice work in aluminum.



    The machine has already worked 2 or 3 paid jobs (1 of which was cuts in some less then ideal 30 series aluminum) and I'm very happy with its outcome. The entire inside of the machine is going to be lined with water resistant material to allow for me to use small amounts of cutting fluid, I'm quite sure the paint would take the abuse for a while but seeing as the final coat of paint is water based I decided not to push my luck . Once that has been finished I'll be able to start cutting the thick stuff, 1/2" and 3/4", to replace the remaining wood parts with aluminum.

    Back out to the garage with me now...



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    Default Containment Bay Finished

    Once again I slightly cheated with this modification and used the large CNC at work to do my bidding. We use quite a bit of an aluminum polyethylene composite material (known as signboard, dibond, etc.) so I scavenged a few off cuts to sheet my machine with. I was going to fasten it to the inside with contact cement but decided to use double sided carpet tape in the end. I used a 90* v groove bit to throw a matching edge chamfer on the top of the sides to keep with the lines of the machine. All exposed edges and holes were then sealed with a little bit of silicone to help keep any moisture from working in between the signboard and wood frame.



    While I had the wire disconnected I also applied the sheeting to the back door of the machine even tho that part is not yet painted. Seeing as this is an easy to replace part I used carpet tape as well as glue to hold this section to the wood. Some closed cell black foam was layed out around the perimeter of the rear panel to keep chips and whatnot away from the computer held behind the machine.



    The black edges of the dibond stand out very nicely against my less then stellar painting job . Clear silicone was used to seal the joints but keep the edges looking clean.



    Since I wanted to allow ample time for all the glues to set (its still a little chilly up here in the great white north) I decided to play around with some DIY machinable wax. I have a very small CNC that I keep inside (details on my blog here : http://www.confoundedmachine.com/3/p...completed.html), and I want to try some complicated carvings. Through work I have a non-stop supply of HDPE chips from the big CNC (mills lots of HDPE sheets), mix that with a little wax and you have some nice DIY machinable wax.



    First time making this stuff I nearly burnt my house down so do use caution when following the guides online. My first few batches were terrible but this last one turned out nearly perfect. You can see here after machining all faces I have a nice void free material to work with. Should be a nice material to run some 3D molds with as it should be totally stress relieved and have no tendency to move after cutting.



    I plan to make a few larger blocks of this stuff as its stupidly cheap (I buy candles from ikea by the boat load as its the cheapest source of wax I have found), and it cuts wonderfully while being nice and easy on cutters...even if you accidently rapid thru your stock .



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    Very nice posts!
    I enjoyed looking over your website also (and referred a friend on another forum to your site, he is in Canada also and is looking for a small CNC machine to build).

    You didn't 'cheat' by using another machine. You exploited a resource available to you.

    There are those that think if we don't mine our ore, refine it, forge it, then pour castings and cut/machine it all out with antique methods we are just wusses.
    Pffft! Use the tools at your disposal.

    Now you've let the genie out of the bottle by teasing us with this recipie for machine wax... fess up to how you do it and we won't turn you into the 'machine man' police for using other machines to build other machines. <grin> Did you use this article?? How to make Machinable Wax at home!

    Interesting 'tub liner' method. I put the best finish side of the wood inside the tub area and plan to use a polyurethane for the inside sides finish, maybe a light stain, to show off the wood grain. The bottom will be protected with the epoxy 'bed'. The outsides will be primer/paint as normal. There is much bondo filler on those areas so a clear finish would not be attractive.

    I used just polyurethane on my wood constucts for my mini-mill and lathe and have had no problems with all sorts of lubrications spilling and dropping on it. Then again I put about 4 coats of the stuff knowing it would get beat up.

    -=Doug

    "IT ≠ IQ " Starwalt 1999


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    Many thanks Doug!

    I totally understand the mine, refine, forge mentality (had me laughing)! Not sure if I can talk tho as I am just waiting for the snow to disappear so I can fire up my forge again . Also thanks for the website traffic, let your friend know if he's ever in my neck of the woods I'm sure I could outfit him with a CNC kit or 2, I think I now have 2 MDF frames sitting out in my storage shed from my earlier machines.

    Onto the machinable wax, yes that was the exact guide I followed...well actually I initially read about it on a site from the UK but basically the same information. The guide is excellent and the only thing I can add if you try this on your own (or whomever is reading this) is to keep the temp at 300-320C. If you see smoke your too hot, preheat your mold pan and cool it as slowly as possible.

    I would have liked to stain my machine as you said your doing on the inside of yours. Wood grain is quite nice but sadly I used far to much wood filler to have that become a reality. Do you have any pictures of your mini-mill? I have an odd fascination with mini milling machines and even more so if the item in question has been hybridized with wood!



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    Beautiful craftsmanship, and great build log!

    In hindsight I should have altered the lengths of some of the bed parts as the slight difference in material thickness from exactly 0.750" made for a little hand planing here and there..
    Yeah, the plans are dimensioned assuming an exact .750" thickness, which it obviously never is. This isn't much of a problem when cutting with a table saw or circular saw, as the tolerance most people can hold with those tools is greater than the thickness deviation from the ideal 3/4". But when using CNC equipment, it would be best to adjust dimensions based on exact material thickness, so you get the very best part fit. The best situation would be for me to create a parametric model of the base one of these days, so that all you need to do is input the true material thickness, and all of the other dimensions would automatically adjust based on that.

    -Bob



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