Installed the XML configuration file for Mach3 from the PMDX website, added and extra output for the second x-motor, reversed the direction of the second x-motor and slaved its output to the first x motor.
Plugged in the parallel cable and tested the e-stop then jogged the motors from the computer.
Took about 1/2 hour total from loading the config file to getting the motors responding to a G-code program.

Table ends almost done. Have to weld on the flanges so I can bolt them to the legs.

I started cutting the 45 degree angles in the angle braces using a thin disc in my hand grinder. Soon gave that away. Went out and got a cheapish (but OK quality) cut-off saw. Having the piece fixed in the vice and using a 20" blade made cutting the angle braces quick(ish) and vastly more accurate. Well worth the $180!

I also bought a cheapish 140A welder. After agonising about work load, amps, etc., I decided that I could afford $120 to experiment. If it was all too hard then it would be sold on eBay and I'd seek professional help.

It's been fun learning to weld. I take it slow and get everything clamped tight before starting. Having some trouble blowing holes through one piece when there is a gap between the pieces to be welded. Getting better at laying down welds to fill gaps (a result of my hand-held cut-off attempts), but even my "very best welding" is ugly.

To give the machine a break between sticks (small machine will cut out if used continuously), I go drill a hole or cut a piece of steel.

I'm leaving spaces I can weld later when my technique improves, and not grinding back my welds until I'm sure I can get strong thin welds.

Photos of welds censored by the CAUW (citizens against ugly welding - not to be confused with crows that have similar worries!). Maybe later.

Red, my welding may never get pretty. The important piece is to keep trying. Good for you!

Shopping in China
 

This is a late report about a trip to Shanghai where I did some shopping. The scale of things is unbelievable, and the range of stuff available astounding. Tricky sometimes to verify quality. PS my wife is Shanghainese, so she really helped a lot describing things and clarifying what I needed - couldn't do it without a translater. But you can find students with passable english (and other languages!) who will guide you and translate for you if you want to try this route.

Some pics:
THE electronics parts superstore. If you can't get it here it probably does not exist. Outside and inside views. 6 floors of stallholders and stores - like a large department store, only with interesting things from bottons to proxy switches to motors chips, cable of every sort and even cable chains.
http://i119.photobucket.com/albums/o...oreoutside.jpg http://i119.photobucket.com/albums/o...toreinside.jpg http://i119.photobucket.com/albums/o...ronicsshop.jpg http://i119.photobucket.com/albums/o...torestalls.jpg

If you can't find what you want inside the store then the street has hundreds of little stores that specialise in different things (steel, fasteners, bearings, etc.) http://i119.photobucket.com/albums/o...dwarestall.jpg
Here's some of the goodies I bought. Skate bearings, 50m of shielded cable, proximity switches, connectors and some other odds and ends. I also bought some cable chain that was too good a deal to pass up. We'll have to see whether the quality holds up. Needless to say the prices were a fraction of what I'd pay in Australia.
http://i119.photobucket.com/albums/o...ingtrolley.jpg

Interestingly when I went to another computer superstore I found prices to be far less competitive and I could build a computer system in Australia for close enough dollars to not warrant the hassles and risk of having one built there.

Drool..... wipe.... Drool.....wipe. I am jealous. :)

Table ends
 

I got the table ends done.
Haven't ground down the terrible welding - I'm saving that for when my welding is better so I can do some good welds on the clean faces and then grind down the poor welds. Well, that's the theory, anyway!
The legs are bolted on temporarily - they will be part of the longitudinal ladder.
http://i119.photobucket.com/albums/o.../tableends.jpg

Cross supports
 

After some good advice from much wiser and more experienced people on how to tackle my cross bearers, I got to drilling. I'd had some difficulty marking holes right, so Ross suggested I paint the beams with "Mark Out" (a purple paint) so I could score lines with a starp steel spike (scoring pencil?). He also suggested Drilling holes in a template and then using a punch through the holes to mark the hole centres. The pic shows these necessary tools.
The idea was to mark every cross beam accurately, drill the holes and then bolt to the beams. It turns out I had to do the calculations about four times. There are bits of tape on the template and one beam where I marked and drilled (the template) incorrectly. Eventually I got to where I could mark the beam from either end and get the same hole centres.
Then the drilling. Got better at drilling as I went along. Eventually got down from 400 to 250RPM on the 9mm bit and seemed to be getting nice spirals of steel moving from the drill bit. Lots of cutting oil!
Funny, not all the holes lined up when I aligned the beams. Still trying to figure how I missed centres by as much as 2mm!
http://i119.photobucket.com/albums/o...s_supports.jpg

Beams squared
 

After a day of moving these monster beams I figured I should take a break and push computer buttons instead.
The pic shows the setup I have devised. The beams are raised so that I can move the table drill under them and drill for the cross supports.
http://i119.photobucket.com/albums/o...blesquared.jpg
Getting the beams into position was a mission. I got the first raised and levelled and then got the second raise in more or less the right position. I clamped a cross support to them so they wouldn't topple and destroy something important (like my leg!).
Then I was tired of hefting the darn things alone so I got the car jack out. I struggled for a while to get the beams the right distance apart AND parallel at the same time. You may read this as several hours and a few thousand cuss words.

I already had wooden jigs made with flanges at outside beam width (1240 table + 430mm). My idea was to bang the beams into submission until they lined fitted the jigs at either end, and then clamp it all down.

Needless to say it didn't work that way. One beam was crooked and 20mm out of alignment. That's where the skateboard and broom handle came in (took a while to figure this out). I jacked one beam and put the skate under one end. Then I jacked the other end and put the broom handle under it. I loosened the clamps while supporting the beam from toppling with the table ends. Then it was a "simple" matter of turning the broom to move the beam forward and aft.

After a while it was lined up and could come off the wheels. A couple of short sharp blows with the 5lb hammer and I got it slid sideways to the correct width. Clamped down a couple of cross members and then got the jack out for some final levelling using end grain wedges.

Input, ideas and suggestions welcome. It might save the neighbour's ears for next time. For which I'm sure they will be eternally grateful.

Honey, I know I said it was only for 2 days, but I think It's staying there until I have the holes drilled and legs attached. A week at most, I promise!

Note: I had my fingers crossed.

A question about beam flanges not at 90 degrees
 

I notice that the flanges on the beams are not perfectly at 90 degrees - they tilt inwards a bit. Should I try to tilt the beams so that the flange is level (which may prove very difficult) or will I be able to shim the rails to get them level?

While I'm not advocating this, it seems upon reflection that the rails need to be parallel, but if they tilt in a touch it won't dramatically affect the way the vee bearings roll - as long as the tilt is even and not too dramatic? The 60kg y-car surely won't have sufficient leverage over the 28mm of the rails to cause them to fold if the forces transmitted through the vee bearings are not directly downwards?

Hi Red

You got some action going on there - well done.
When you find out how those little errors creep in be sure to let us all know! hehe

The rails can be packed level with shims - a few more or less on the inside or outside should correct for the error in the flange.
The rail will remain quite stable once the bolts are done up.
I corrected some twist due to welding shrinkage on the ends of my beams using this technique quite successfully.
The rails need to be 90 degrees to the x beam web so that the rack stuck on the bottom edge mates at 90 degrees to the shaft of the stepper motor and the pinion.
Failure to get this correct means the pinion teeth will not mesh along the full width of the rack.
This is an example of the need to get the relationship correct - http://www.mechmate.com/forums/showthread.php?t=2815

Regards
Ross

Two weeks and no action. Visiting relatives, work and other stuff getting in the way (finally got to repairing that surfboard with the snapped nose). Got the vee bearings and bushes from Rick at Superior Bearings. The entire process was painless (and more so because the AUS$ is creeping towards parity with the US$!

Picked up an essential item that came highly recommended by the guys at Total Tools. It's a drill sharpener made in Oregon. http://www.drilldoctor.com/. I see them offered for sale in the US on eBay.

Time to get drilling those beams!

Red,

You will not be dissapointed with the Drill Doctor, thats what we are using here too, they work a treat!! although I used to enjoy sharpening the drill bits on the old grinder by hand:p

Cheers
Tony.

Got to drilling beams this weekend. I'm drilling so I can bolt the cross members in place and can bolt the side ladders on.
The beams are 3m x 300 x 95 PFC, and each flange is about 15mm thick, so I have been concerned about how to drill them.
I raised the beams off the ground and levelled them as in the post above, then I put the drill onto a trolley and moved it under the beam to drill each hole. I found I had to chock the trolley and also brace between the drill base and underside of the beam, otherwise the drill would just ride up when I lowered the drill bit.
http://i119.photobucket.com/albums/o...ling_setup.jpg
I worked down one side, bolting (on the drilled side) and clamping (the unddrilled side) each cross member, then worked down the other side, moving one cross member aside at a time to allow the drill access to the next hole to be drilled, and then bolting both sides of the cross members as the drill passed by.

Looking Good!!

Thread should be moved to Construction Started but not cutting!!:D

Cheers
Tony.

Tony,
I don't mind. The build progresses regardless.

2 questions: Locater tabs and Protection for MDF support board
 

Fixed the support board under the cross members.
Laid the board on the floor, skateboard under one end. Rolled it under the inverted table.
Lifted the board, squared it and clamped it in place.
Having holes drilled through both flanges of the cross members (thanks, Ross) made it really easy to use a hand drill to pop holes down through the board.
Slide around underneath and countersink. Lots of sawdust in my hair.
Bolt up and it's secured. Long arms help to hold the centre bolts under the board and get the nut on at the top!

Bugger! The beams are 0.5mm out of alignment at one end.

Now on to building the longitudinal leg assembly (seemed easier to have the cross supports in place so I could be sure of missing them with the legs and flanges for bolting legs on).

Two questions:
1. Since I have to dissamble in order to paint, what about welding tabs onto the cross members at the beam to locate the beams at correct width for accurate reassembly? Or will the 9mm bolt holes with 8mm bolts do this accurately enough?

2. What do I coat the MDF in to protect it?

Hi Red

For an undercoat try - Blitz Total, it is a very tough exterior water based acrylic.
Good for virtually anything (including MDF) and is the best primer sealer undercoat I have come across.
Impact resistance, film strength and bond to the substrate is excellent.

It is distributed through Amazing Paint Discounts here in Australia.
They are solver paints stockists so Solver may make an equivalent.
Topcoat I would use an enamel paint of your choice and it is ok to mix the acrylic base with the enamel top coat in case you were wondering.
Clean all dust from the raw MDF board before painting with a damp rag and work the paint in with a roller to get the best bond.

The board will warp when it is painted on the sides and one face but will pull flat once mounted to the cross bearers.
I would not paint the other side as a further sacrificial spoil board will be glued to that remaining clean face later.

I used some Kinetix Surfboard Epoxy to fill over the cuphead bolts.
An ever so slight overfill will relax back down to level once the MDF takes a bit up.
Also used a bit of white pigment as a depth warning in case the cutter ever got that deep.

Regards
Ross

Thanks for the heads up on Blitz Total. And the smart idea for pigment. I'll file that one for when I get to the painting and filling stage. (Started grinding some welds to neaten them up. The bits might be welded together, but all that extra welding sure takes some grinding down! Time to consider a "big" grinder). A few weeks before I get to that stage, though.

Leg sub assemblies done
 

Well the bits that keep the beams off the ground and roughly parallel are almost done. I built the leg sub-assembly on top of the beams (i.e. upside down). This worked because I could not move the beams around and I did not want to work under them suspended 3' from the ground. Once I had the beams level and parallel they formed a nice base for getting the leg sub assemblies done.

I had the short (y-axis) subassemblies done, so could clamp them in place on the beams and use the lower longitudinal support to get the spacing right and the two vertical bearers to get the longitudinal support at the right distance from the beam. The pic below shows all these bits clamped together ready for tack welding. TIP: you can never have too many clamps! I always seemed shy one or two..
http://i119.photobucket.com/albums/o...C/PIC_0320.jpg

Once the longitudinal ladders were tack welded I unbolted the legs from the Y-axis ladders and took the frame to ground level where I could do some horizontal welding (which is about where my "skill" level stops!
http://i119.photobucket.com/albums/o...C/PIC_0341.jpg

Once the "easy" 90 degree bits were done I could cut the angle braces and weld them in place. Cutting the angles proved tricky because thher were greater than the clamps on my cut-off saw allowed. A lot of messing with G-clamps and one broken blade (darn!) when the piece wasn't clamped tight enough and shifted.

Eventually I got the angles fitted and welded and could bolt the longitudinal sub assemblies back to the y-axis ones. Observant people will see that the legs are off centre in the picture. This is because I have them clamped to a cross support so the entire leg sub assembly does not slip off the beam and hurt someone important (mainly me!).
http://i119.photobucket.com/albums/o...C/PIC_0340.jpg

I could now square up the leg sub assembly and weld it in place and be done, but I'm going to weld plates to it and drill them and the beam so that I can bolt the legs to the table. So the table will break down into 6 parts - two y-sub assemblies for legs (light), two longitudinal sub assemblies (heavier), two beams (heavy).

Wow !!

The size of those beams make the rest of the table look so small :D
Good work and keep the photos coming.

Cheers
Tony.

I hope a forklift is handily by the frame! Great work.

Watch out for toes with that guy!

Thanks for the encouragement, guys. I need it to keep the motivation going as I move to grinding rails and the trickier welding of Y-car. Wife wants it out of keitchen window and into the "garage" (actually a dirt floor corrugated shed), so it's a weekend of levelling floors and laying forcing mesh and then concreting.

Feet arrived
With the Au$ almost at parity with the US$ it makes sense to get stuff from the US at the moment. Mike figured that he could ship 3 sets of feet at similar price to 1 set. I am duly proud owner of 3 sets of feet that arrived well packaged in wrap, foam beads and two boxes with lots of tape!
http://i119.photobucket.com/albums/o...ingoffeet2.jpg

Andrew has already snagged one of the extra sets, so there is another set available to a local builder.

Question on Racks and pinions
 

I know I need to order module 1 racks and I'm better ordering 3m lengths for x-axisif I can. I see that some people have not welded rack segments together, but have simply double taped them in place. How has that worked out?

My main question is on the pinions.
The shafts on the motors are 14mm according to my trusty calipers.
I can't find a pinion with this size hole (without going to 60 teeth or something).
Should I be able to find a ~24 tooth pinion with a 14mm hole or will I have to machine the hole bigger (with all the attendant problems that is likely to bring?)

Input much appreciated.
Regards, Red

It has worked well on 4 machines MM's. The "joints" are invisible to the running of the machine and silent to the ear.

Thanks Gerald.

After extensive search I have found that standard 24 teeth pinions have a 8 or 10mm hold, so I will have to be boring. I see from another thread that Sean has a way of turning a drill press into a lathe for boring out pinions. I also remember surfcnc explained how he did it. Looks as though I might need a few sacrificial pinions.

Hi Red

My experiments with the drill press failed.
Unfortunately the holes were not concentric.

My eventual 'solution" was to be done over by a local engineer to the tune of $160 AUD to put six pinions on his lathe and then tap two M6 holes for the grub screws. After returning them to him to have the tapped holes put in the RIGHT place the second time, he had managed to turn a two day turn around $80 rough estimate job, into a $160, three week long job with errors.

If you can find a way of doing them without a lathe can you let me know. Really not ready to subject myself to any more client service like that experience if I can help it !!

Regards
Ross

Ross, your went to a slaugter house???? My friendly neighbourhood machine shop charged me less then a beer for boring, drill & tapping the scrub holes in less then 2 hours... Even after I told him I'm in no hurry to collect them...

I had trouble boring concentric holes so I asked my supplier to supply the pinions pre bored to 14mm.

the pinions were 5 pounds sterling each, same bored to 14mm are 17.50 pounds sterling.

so basically it'll cost me 62.50 pounds sterling for 5 pinions supplied bored to 14mm.

Expensive for 20 minutes work on a lathe but I may pay it for the ease.

I'm using the existing non concentric pinions for the moment as I finalise my build and will change to the correct ones once completed.

John

Hey Ross,
It sounds as though the pinions were not the only thing that got reamed!

Ken,
I'm jealous of you living in the land of cheap services. Here we have OSHA, GST, high rents, minimum wage and all sorts of other costs that get rolled into such services. If I was going to Shanghai again I know I could get it done "round the corner" there for cheap.

John,
Thanks for the input and benefit of your unfortunate experience. I'm now sure about not spending time with pinions on the drill press.

It sounds as though I'm looking for someone who takes beer in exchange for lathe work.

Springs
 

I got a quote for springs today.
4@$15 each
16@$11 each.
Contact me if you're local and want to go in on some springs.
PS I see Bunnings now has a range of springs, but I couldn't find one close enough to the spec.

After a few weeks of doing other things I got to working on the table again. If you recall pictures above I have the leg support substructure resting on top of the upside-down beams. If I were to weld them in place then I could finish the table chop chop. Actually if I had gone for a welded table I could have finished in half the time. Something for bolt togethers to bear in mind.

I've welded tabs onto both ends of the cross supports so that I can locate them in place easier when reassembling the beams i.e. I can get the beams the right distance apart using a mallet so i can locate the bolts (because the beams are resistant to being moved by hand).

I've cut and drilled plates and welded them to the table legs and vertical supports. Now to drill the beams so I can bolt the sub structure to them.
The Drill Doctor is worth its weight in gold for bit sharpening. So good to see those long curls of steel oozing out of the drilled holes!

Anyone have a good tip for locating the centre of a 13mm hole so I can get the holes drilled in the right spot?

Red,
Are you referring to the 13mm holes in the rails?
If so, you can use a transfer punch (or the 13mm drill bit) to transfer the center and then bore the smaller dia needed.

Putting a layer of masking tape on the main beams before you do this step will great aid in seeing the mark you make accurately.

We normally use a center punch & make a healthy indent for locating the position & help the drill to stay put at the begining of the drilling exercise.

Start by drilling with a bit that is 1/8" or smaller. Using the small bit helps in two ways. A small bit will be easier to keep located on the center punch and having a small hole will help the larger bit stay centered. Always start the bit spinning with little or no pressure when starting to drill. This will keep the bit from biting suddenly and moving off center. After a second or two increase drilling pressure to normal levels.

Some pics for you Red

An example of a punch ground down to give a center.
Attachment 10677

An example of the hole drilled after the center has been marked.
Note rotate the punch and hit it several times to even out any inaccuracy in the conical grind.
Attachment 10678

Regards
Ross

Thanks for all the tips. Here's one in return. Remember these are close to 1/2" holes, so 1/4" punches tend to float around a bit.
I found this epoxy marker pen (with a rattler inside, so it's good quality paint). You push on the felt tip to get the ink to flow. I got a bright yellow one and ran it around the hole followed by a pointed scribe once the ink had dried. This gave a nice outline of the hole. If I did it right the centre of the hole would not be painted. I could then centre punch and use the depression for centering the drill press. Nice thing about using the press is that I didn't have to worry about the drill wandering.

Anyway, I'm declaring the table bit done. Now I can hold the beams off the floor and somewhat parallel it's on to thinking about things like rails.

The rail grinding plan is to clamp the rails together to give a 190mm wide work surface. Give them a sand to smooth the surface. Clamp the rails to one beam and then attach the grinder and skate top to a 300mm (1ft) wide board and slide this over the beams to cut the rails to height. Probably 1m passes, moving the rail so I'm always cutting using the same piece of beam. Thin blades etc. Comments?

You shoul be ok.
As long as you secure the angle rigidly & no large free play between the guide bearing & the work piece. Any inaccuracy can be dealt with during your shimming process.
Nice progress. The tough part is almost over.

Question on plan M1 20 2220T part
 

Can the bearing support bases (bushes) on plan M1 20 2220T that are used to space the vee bearings from the spider be replaced with washers as done on M1 20 100?

Much appreciated, Red