If you visit www.automationdirect.com and click on proximity sensors, you'll be able to download a data sheet that shows the internal workings of their sensors. The 12mm series (AM1-AN-2H model number) has a common data sheet. Compare the 3-wire sensors to a transistor and the two wire sensors to a diode.

I've used a nine-volt battery to test sensors, although a 12VDC to 24VDC power supply is better. All of the sensors that I've tested have worked fine with 9-volts (meaning that they've worked "fine" enough that I could check polarity and sensing distance - I would never use a 9-volt power supply to run an installed sensor.)

Hi Pablo

The term I have used -12V is not the correct one. I believe it is referred to as 0V.
Far better to propagate the correct term than my own homespun understanding.

Ross

Some More Parts Made
 

Made a few more bits up for the machine.

The Cable Chain Supports
Attachment 9950

The Car Stoppers
Attachment 9951

The Z Spider Welding- used a magnetic clamp to hold the motor bracket straight but it still needed trueing once the heat got to it.
Attachment 9952

Also bent it straight using this technique and cut and welded the small tab.
Attachment 9953

Finally got the Dust Collector Pipes - Just in Time now Bill Pentz is on the Mechmate forum
Attachment 9954

And a Ebay Bargain on Cable Glands from the UK
Attachment 9955

Regards
Ross

Nice going Ross

I fear your X cable chan support may be wrong (unless you are using a reverse installation) usually the two supports look the same with the main bracket on the right - only the size differs.

Bent the Wrong Way
 

Hi Alan

It seems your careful attention to detail has picked up something my sometimes random approach to things has missed, hehe.

What has happened (on closer inspection) is that the bending has been done the wrong way! Attached is a pic that sheds light on the issue.
Hmm, probably going to need another one of those X cable chain shelf bracket sets bent the "right" way now.
Thanks for your post giving me a chance to get going on the fix that bit quicker.

Attachment 9956

Regards
Ross

Proximity Sensors Source
 

Hi All

David has given us the details on how to wire up three PNP NO and one NPN NO proximity sensors without relays at http://www.mechmate.com/forums/showthread.php?t=2857

I have made an inquiry with the eBay seller "auspicious.e" and while they do not list the PNP sensors for sale on Ebay they were able to obtain them.
Four sensors where around $50 USD delivered to Australia.

My relay to test the proxy wiring as per Sergio's schematic is speeding from literally over the hill at the speed of an aging turtle with a bung leg.
In the coming week I hope to finally see the part and get on with that test.

Regards
Ross

Some Painting Done
 

It was a clear sunny day, so time to start some of the bigger pieces through the painting process.

I have to say I lingered in the back yard as it was so nice in the sun.
The photos actually make the paint job look far better than it is in the flesh.
Attachment 9983

Attachment 9984

The missing/ not ordered / reordered/ forgot to ring you/ we are stocktaking, relay finally appeared after doggedly following up the supplier.
A photo for those who might be inclined to copy the part number or style of relay.
Attachment 9985

This is the pic that Sergio sent me of his relay he used for his proximity sensor wiring.
The only real difference is that in Italy they have the good sense to put the printing on the relay the right way up or maybe I got the down under version.
All a matter of perspective I suppose !!

Attachment 9986



I forgot to take a photo of some of the other parts I was painting black and hanging on the very Aussie Hills Hoist (rotary clothes line).
If I remember tomorrow I will include a photo of this alternative use for a domestic appliance.
All the parts are spending a day or so in the sun to set up as the paint is so easily damaged when not properly dried.

Regards
Ross

Ross, be careful of setting the parts out in the sun. I cant remember it was here or on another forum but I do remember reading that the steel heats up to much in the sun and will boil/bubble the paint off the steel before it can cure.

Wait until you have to read that relay when its mounted on a din rail. You will be happy for that down under version:D

Thanks Russell

KenC offer this advice on the MM forum but I have not found this to be an issue.
As a check though, the current temp in full sun of the metal is 28 deg C, this temp is not high enough to boil the paint.
On a summer day 60+ degrees C would be possible and that may indeed damage the paint film.

The printing on the relay as you rightly point out is for the "peering in to the enclousure from the top" sceanerio.
That is exactly what I will be doing but hopefully not for toooo long, hehe.

Regards
Ross

Parts on the Clothes Line
 

As promised the parts out to dry ... and a sheet too.

Attachment 9994

regards
Ross

Ross!!

I'm impressed mate, you are starting to get close :D we might be painting our parts this coming weekend too if the weather is good to us ;)

Keep up the good work!!
Cheers
Tony.

Spindle Mount Haircut and the Painting Continues
 

Trimmed up the spindle mount today. The "standard issue" 80mm mount is a little too wide for the Z slide and needs some clearance for the V rollers.
The mount is marked with permanent marker then scratched with a scribe to give a high visibility cut line for the saw.
I actually cut away a little more than the roughed in marks on the spindle mount, those marks were just to show how to clear the rollers.

Original Mount
Attachment 10020

Trimmed Mount - An 80 tooth timber drop saw blade cuts it like butter, but produces a shower of swarf, so wear eye protection if you use this method.
Attachment 10021

Still Painting Bits - The bottoms of the rails this time.
Three of them have been masked off where the racks will go.
This time I have tried a no undercoat enamel and a paint additive to see if it adheres any better than some of my other parts have.
To prep the rails I sanded all the factory scale off back to shiny metal with a 80 grit then 120 grit flap disk (Metal Head recommended these earlier in my build history).
Attachment 10022

Last night I also repainted the x beams of the table base to cover up the fire marks (yes the fire, from welding my gantry in place on the beams on some paper spacers, haha), the impact marks and other assorted damage.
I used a tiny foam roller to apply the hammertone paint and it did a great job.
It worked so well if I had my time again I would use the roller for all the metal top coat.

Regards
Ross

I am a believer in the foam roller method.

I have used it to paint my Dynatorch Plasma machine and it works great. I used it and little plastic mixing cups on the painting isle at BigBox Hardware (orange or blue you choose :D ) and a pack of the plastic drop cloth to go under the items being painted.

Once finished I toss sponge part and save the cup and handle until I finish with that color. Then I toss the cup. I also recycle the plastic drop sheets. They wad up read small.

No over spray and the finish is fine (really !!!) give it a try. Setup and tear down is quick and you wont catch grief for overspray on everything in the garage/shop :D

A Few More Things Done
 

The painting continues - every time I look at something I give it another coat !!

First up - Thanks Alan C, I got my replacement part from Lasercentral, they were very good about the replacement part, even although it had been some time since they made it.
Attachment 10026

Put my spider together again after painting and mounted the short piece of rack on the Z slide.
Attachment 10027
Attachment 10028
Attachment 10029

Finally got the rails painted and put them up on the machine to dry for a while before I start to straighten and level them.
I was quite pleased with the colours once I saw them in place.
Attachment 10030

Regards
Ross

Pumps and Pipes
 

Aus Maddog and Skippy are pump and pipe experts due to their salt water fish tank hobby. Tony gave me a look at his reef tank and it was quite spectacular.
Both the boys recommended the Aquabee pumps but I had some time today and just started experimenting to get one more thing off the list.
I found a tube to fit the spindle inlet and before I knew it I was in a pet shop buying a pump to do some further tests !
Seems that pumps for the water cooled spindles have been a stumbling point for many.
Given this I oversized the pump on some of the other wattage ratings I had seen on the forum and threw thoughts of low power consumption out the window.

First was the pipe to distribute the water - in the end a 5mm internal diameter clear plastic tube was the correct size to fit the 2.2 kw Chinese spindle inlet and outlet ports.

Second was to adapt the pump 19mm outlet to the 5mm tube. This was achieved by sleeving over the outside of the pipe with larger diameter pipes until it fitted.

Third test if it leaked, thankfully it was a dry as a bone, otherwise I was going to set it all in an epoxy mold.

Fourth was to test the flow rate. The pump used as a 45 watt 2200 l/hr with a maximum head of 2.5 m.

The end result was a flow rate of exactly 500ml per min at 1.0m head through 7 meters of the 5mm internal diameter tubing.
Passed the 375ml per min "beer glass" standard the forum members are using as an adequate flow rate for cooling.
The pump easily cleared any bubbles in the line and quickly settled down to an uninterrupted flow.

Attachment 10035
Attachment 10036
Attachment 10037
Attachment 10038

Regards
Ross

Ross, This can work but you must be careful with a few things.
Are you going to install your pipes in your cable chain? 7m might be a bit too short to go into the cable chain. Is your return pipe 7m too? so a total of 14m pipe is involved? AND the viscosity of the liquid/water will change when you add coolant to it & that will further reduce the flow rate as well...
Industrial pneumatic PU pipes are great for this job, OD6mm tubes will fit the chinese spindle snuggly & I use OD8mm for the supply & return pipe, use 2 8 to 6mm push on reducer just before & after the spindle. They aren't any more expensive than aquarium pipes & they have suitable push on reducer, elbows, swivel elbows... & other fitting that are affordable too.

Hi Ken

I purposely ran the whole run through a small pipe to see what the effect of the maximum restriction would be.
Indeed the return is also 7 or so meters and I have not modeled this as that was all the pipe I had on hand.
The 7 meters estimate came from Doug Ford's comments at http://www.mechmate.com/forums/archi...php/t-505.html, 7 meters has to be pretty close I'd say especially for a test situation.
My objective is to get the required flow rate of 375ml /min into the spindle for cooling, so as long as a solution provides this I will be happy.

There is a buffer of 125 ml/minute or 33% remaining in the system.
While it is pretty unscientific, my gut feel is that it will readily meet the criterion.
Once I get some more pipe and mix in some Ethylene Glycol will give you a new flow rate.

Regards
Ross

Regards
Ross

Nice Work Ross!!

Check out these fittings http://www.johnguest.com/range_spec....FIT&rs=1&id=17 these are the push together "John Guest" fittings we use, and the plastic flexible tubing that is used with these, fits straight onto the spindle coolant fittings. There is a guy on Beaudesert Road just of Grannard Rd that stocks a full range of fittings and tubing.
Pneumatic/Hydraulic shop think it might be Tony Powers.

Cheers
Tony.

This looks like it - Hose and fittings !!

Attachment 10040

Ross

Yep!!

Thats them!! your on too it!!

Cheers
Tony.

Yes, that's the right way to find out if the pump really works.
My machine is a tat longer then normal, but it is not far off. I used up ~25m of tubing in total. so I hope you will source enough tube for your installation.
375cc is good enough, but 300cc/min can still keep my spindle cool (35C). I recon the long tubing does radiate some heat while the coolant travels in the whole journey.Mine is running about 350cc/min
For my aquarium pump experience, the flow rate will deteriorate over time, a short 3 months & mine is down to a trickle. & 50cc/min could still keep my spindle alive... barely... 500cc will give a longer service life for you assuming that it's performance deteriorate like mine did...
Be careful with pure glycol, it is more viscous than just neat water.

Ken

Been checking up on your concerns re viscosity and found these engineering tables http://www.engineeringtoolbox.com/et...col-d_146.html

According to this source
1. the hotter it gets the more it flows
2. a reasonable maximum estimate of combined pressure and flow reduction at 40 deg C for a 50% mix of Ethylene Glycol and water is 114%.

Your comment regarding the decrease in pump performance over time is certainly something to factor into the design side of the cooling system - thanks.

Regards
Ross

We all paid a handsome amount for the spindle even though it is a steal in comparison to non-chinese equivalent.... but it is money after all, it breaks my heart to see equipment damaged in any circumstances...

Ken, the serious aquarium guys pay more for their fish than the price of a spindle - they use decent pumps to keep those fish alive.

I'm not a serious aquarium guy, but I do keep Arowana in captivity... yes, a 6" little fish fry cost more than 2 spindles...

I purchased a slightly larger pump probably made by the same manufacturer but branded differently for the local market.

When I was testing the spindle I left a 24L paint bucket full of water running the whole afternoon at 8K RPM it got warm, I would say 30~35C after at least 5 hours continuous. I'm sure if I use a larger tank this wont happen.

Mine is rated 2700L/hour and with 2 meter long flexible pipes for the test it was too much pressure and you could hear the impeller rattling even underwater. My guess was that when I build the MM with way more meters of flexible pipe the pump will need the pressure.

Hi Pablo

I agree probably not an industrial grade pump but it seemed to give a very good result anyway.

Also put a 12m pipe on the outlet - no difference in flow.
Think I know why but the result speaks for itself.

Regards
Ross

Leveling Rails
 

In another post I asked everyone how they straightened and leveled their rails.
The best suggestion in my eyes was Gerald's method of using an aluminium extrusion and a gauge.
I have some well used aluminium screeds but did not trust these to be straight after much work both in the cement and out of it.
In the end a 6.5m 75x25x2.5mm length of aluminium extrusion was the option I took to get a good straight edge (two actually after it was docked in half).

Here is the basic setup, soft drink cans trimmed into shims, the extrusion and a set of metric automotive feeler gauges.
Attachment 10088
Attachment 10087

Using the feeler gauge I was able to EASILY measure any gap between the rail and the 25mm face of the extrusion down to ridiculous increments.
The resolution I choose to work to was 0.1mm as that was the thickness of the shims I was using.
The difference between a .15 and a .10 low spot in the rail was night and day when checked (literally done by feeling) with the gauge.
Now that I have the method and the tests done, I feel very confident of getting a great result with the rails.

For those inquiring minds that may suggest the extrusion may not be straight, Gerald also suggested setting up with opposing sides of the extrusion to check if the result is reproducible.
I checked using this method and got very good reproducible measurements, the two sections docked from the 6.5m length also checked well against each other.
For the even more inquiring minds, this is an inferred measurement of straightness not a direct measurement of straightness but for my purposes it is more than sufficient.

Thanks to everyone who gave their opinions and techniques on my question about the rails.

Regards
Ross

Aluminium RHS
 

Ross thanks for the photo's and how you and Gerald did it now just need to get started.

You should keep the RHS and rent it out.
See your machine can earn you money before you start.

Thanks
Peter

Greetings Pete

I see you are from Brisbane, must be something in the water here that makes people inclined build CNC machines.

Regards
Ross

Rails Packed and Gantry Rolling
 

Have been working on getting the rails level then straight with the alloy extrusion. Very pleased to say it all went really well.

The coke cans slivers proved to a very effective shim.
First I packed them up and secondly I counted them and then cut new ones at 25 x 30 mm to fit exactly under the rail.
The photos below show how it was done and how tidy the end result was (the small silvery line under the rail are the shims in place).

Attachment 10174
Attachment 10175

Next I put the gantry up on the rails and rolled it up and down to check how it sat.
After that it was more a process of listening to the noise of the gantry as it rolled to check if it was true.
I heard a few bumps as it rolled along and these turned out to be some tiny bits of paint on the rail.
Given this I hand sanded the V on the rails with some 320grit sandpaper (quite a bit) and ended up with a finish that showed no scratches at all.

Attachment 10176

Regards
Ross

Cable Chains and Y Car Are On
 

Mounted my cable chain brackets and then the cable chains themselves.
The bracket that holds the X cable chain to the gantry was made out of some 6mm aluminium plate I had lying around and it turned out very nicely.
I had to shorten up by X cable chain by about 300mm so I have a few spares or something to use on a later project.
Starting to look like the part !

Attachment 10221
Attachment 10222

Trashed a few pinions as I learnt how these things are done.
The photo attached is the first victim on the block.
"He" was followed by two more before I figured out the way to get the bore concentric was to use a metal lathe.
All part of the learning experience and learning I am.

Attachment 10223

Small Wood Lathe Purchase - 4th Axis Maybe?

I have purchased a small wood lathe that gives me a very sedate 254 mm maximum swing but it has a meter between centers.
My reasoning is that a table leg is around 900mm max so as a starting point for a minimum price it fits the bill.
Found some floor stock in Adelaide for a good price - thats around 2,000 klm from my door so no one can say I did not look hard enough, haha.

The lathe itself is a Chinese model that is re branded around the globe (the same as the small machine in the videos but with an extension bed).
The inspiration for the conversion I might undertake later when the machine is finished came from these two videos.

http://www.youtube.com/user/mikescnc.../3/Wj1BN7JGvek

http://www.youtube.com/user/mikescnc.../2/f1wP4vbkJwQ

It does not look like he has finished his 4th axis project but the basic concept looks sound.

Regards
Ross

Z Slide Setup
 

Greetings

Tonight I mounted the spindle mount to the Z slide.
It took about 30 minutes to drill the Z slide the tap the 4 M6 socket head screws holding the bracket to the Z slide... and plenty of time of measuring and thinking !!

Here are some pics of the end result.
Attachment 10234
Attachment 10235
Attachment 10236
Attachment 10237

One of the Z slide limit stops is done but I need my pinions before the other can be put into place.

The measuring and thinking all centered around how far the spindle could retract up into the gantry.
Initially I thought that if the collet of the router was level with the bottom of the gantry all would be fine.
Upon a bit more thought I realised that where the collet was was also dependent upon where the spindle was in the bracket, so just lining the collet up was not enough detail to use alone.

The pics show the spindle mounted in the bracket, set like this it will retract to level with the underside of the gantry, however the spindle can be further adjusted away from the base board by another 42 mm.
This gives the ability to have a cutter mounted and still get the full height of the machines envelope to cut with.
Specifically I am thinking of cutting foam surfboards "up there" at the top of the stroke. For this to work of course any dust shoe would need to be removed or modified in some way.

No point in having it retract way up high and not bottom out well below the spoil board top, so using this setup the collet will bottom out at the top of the base board.
The third and fourth photos show the detail of where the top of the 2.2kw watercooled spindle extends to on the z slide for those who might be interested.

Thanks to Matty Zee for the photo he sent me many months ago explaining how the collet on his machine retracted relative to the bottom of the gantry.
These things certainly help.

Regards
Ross

Joining Up The Racks
 

Sanded the ends to a bevel.
Attachment 10238

Clamped them up with the splint rack and a few G clamps, then welded the bottom and each side of the racks.
Attachment 10239
Attachment 10240

Ground the welds flat.
Attachment 10241

The joins ended up good and strong.
As I did them I also made sure the pinion rolled smoothly over the join.
One join required a redo and I have just one more X rack to do.

Hope you enjoy the photos of the process.

Regards
Ross

Good photos, good welding

Manual Forth Axis
 

Hi All

The lathe I purchased arrived today. For the moment it is a "manual forth axis" that is, you stick a sharp chisel into it and do it yourself.
No fancy CNC electronics anywhere near this little fella just yet but some time in the future, it might end up as an indexer (if that is the correct term).

The lathe came with a live center, headstock spur, faceplate, various Allen keys and an extension bed not shown in the pics.
Buying a 4 jaw selfcentering chuck, lathe chisels and a No2 MT jacobs drill chuck - well that cost what the lathe did in the first place !!

Parts of the wooden packing case ended up as a handle for an old garden trowel and a tool holder.
Already earning it keep - not exactly.
Attachment 10253
Attachment 10254

Kind regards
Ross

Looks nice and sturdy Ross. You should be able to fit a 120 tooth gear on the left there for the stepper motor.
Good luck with the conversion

Hi All

My progress has been slow especially by comparison to the Aus Maddog / Skippy dual table build.

I had a clearance issue with the Nyloc nut that holds the Z axis motors and the rail itself. After completely removing the perfectly leveled and straight rails, I realised that all I needed to do was to reduce the 10mm nut to 8.5mm by sanding it down on the linisher. It just took me a month or so to get back to doing the rails again !

The joins in my rack have been a mixed bag, some perfect, some acceptable and one needed a redo. So still trying to get that right before doing any wiring. If I had to say what was causing the problems was that I had not let the pinion drop fully to the bottom of the tooth in the rack, this causes a bump as the pinion rolls over it. I can confirm the double sided tape sticks like crazy after removing one Z rack to fix a join up. It was NOT going to fall off, haha.

I see Aus Maddog has the Vectric Aspire software rolling, so good to see you have even the next phase of development firmly in your sights.

Also see that Red Boards has a substantial table base underway. Don't worry about the grinding Red, mine took me ages to "massage" into an acceptable state. All part of the learning curve.

Still really enjoying the whole project and have really got into the engineering aspect of the build.

Regards
Ross

Hey Ross!!

I was wondering when you were going to give us all an update:p thought you might have been busy with work.
we have been having similar fit issues with the racks, roll the pinions over them and they appeart to be fine but once fitted in place with the pinions locked on its a whole different scenario with little bumps being felt whilst the gantry or the car are moving. I have decided to wait it out and see what they are like when the motors are moving them under there own steam.
Seriously thinking of replacing our rack to the 3m lengths that are available to avoid any joints:) so if you are interested let us know.

Anyway on with the work and I look forward to more regular updates from you again :D

Cheers
Tony.

Gidday Tony

After a further go at one rack today, the worst join was better but not perfect.
Called TEA and they had one 3m length of module 1 rack in stock.
When I first looked many months ago, nobody had 3m lengths available, so at that stage one join in a 3m length was unavoidable.

I have ordered 1 x 3m rack for one side of the X axis and have left the other side with the 3 x 1m lengths joined.
Did some rack dentistry on the joins and made some improvement by reshaping the intersection with a file and a diamond hone for the valleys.
The most infuriating part is the perfect join is between two pieces of stock with the biggest dimensional variation.

TEA do not have any more 3m lengths, so buying one as I have is probably setting myself up for more grief as the racks are not a matched set - but no guts no glory.

Between doing the rails twice and playing with the racks, I certainly have wasted some time, but it all still qualifies as good experience !!

Regards
Ross