#11 Has died a fiery death– Cape Town (S. Africa)

[Gerald D]

Alan, I found the "missing" dimension ...... racks needs to be 300 long and not 280. (Well, you did get 250 stroke, so you can't really complain ). I see that Kobus sommer stuck all his leftover rack behind the slide - that's not a bad idea either!
http://www.mechmate.com/forums/showt...&postcount=159

[Kobus_Joubert]

I had the extra rack, so just used it...Boer maak 'n Plan...

[Alan_c]

Rack and upper strut mount modified:

a) made rack longer - 315mm
b) placed first mounting hole 45mm from top end of rack
c) moved upper strut bracket down by 15mm

mod pinion up.jpg mod pinion down.jpg

full travel with equal amount of rack to spare

mod slide up.jpg mod slide down.jpg

slide almost in centre of middle pair of wheels 67mm above spider, slide at lowest point 187mm below spider = 254mm of travel (10")

That looks better

[Gerald D]

If it wasn't for the limitation imposed by the gas spring, there would be a lot more travel offered by the rack.

Can't stop admiring the photography!

[Kobus_Joubert]

Me too..time I bought myself a proper camera

[Alan_c]

Advice needed on the bolt together option.

I will need to bolt my main table together as moving it (which I will have to do) will be problematic if I can't take it apart. I will be using 180 x 70 PFC (parallel flange channel) for the main beams and 100 x 50 PFC for the cross bearers. I will also be bolting the legs and braces to the main beams using bolt on flanges. (much like Mickey did)

I have two proposals below, should I use 12mm bolts (only one at each end of the cross bearers) or 10mm bolts (two at each end)

bolted connection.jpg

[hennie]

Alan I am also doing it bolt together.

On the legs I am using example no 1 -12 MM bolts ( no bolt in the centre )
On the cross bearer I am using example no. 2 - 10 mm bolts.
I will also be using pratley on the joints of the legs.
I have also added some req tubing as cross bearers to bolt some brackets onto later.

[Gerald D]

Alan, if you have the diagonal braces/gussets, you only need one bolt between the leg and the main beam. Yes, only one.

If you want to leave out the diagonals, then go for at least 5 bolts (as per your right hand view)

[Alan_c]

Gerald, if one bolt is good enough for the legs, can I safely assume that only one would be needed for each end of the cross bearer as the MDF sheet will keep the table square?

Hennie, what brackets do you have in mind, for a vacuum plenum maybe?

As some more finance has become available, it looks like I am on the home stretch now, Steel has been orded and delivered to my Fathers factory where I will do the rest of the construction, taken the plunge and ordered cable chain from RS (Thanks Gerald), even with having to buy full meter lengths, it still worked out about R600 cheaper than buying the exact same items from the local agents (note, it has to come from the UK and will be delivered to my door at no extra cost)

Having worked on big iron machines and been involved with factory moves, I have never cherised the idea of the cables to the control box being hard wired into the box as when moving the machine and the box there is a good opportunity for cables to be pulled loose so I have been trying to source multipole industrial connectors as used by the big boys. My first enquiries left me with severe chest pains and a racing pulse, but I have found what I am looking for and at a reasonable price (a third of what I was quoted by IGUS and the like) from one of the elctrical supply warehouses here in Cape Town. These are made by GEWISS (I suspect in China) and seem pretty good quality, they are not going to be plugged and unplugged very often so I dont think I need the Rolls Royce quality. These will be used for all the cables running the the MM, 16 pin for the motor cables, 6 pin for the spindle fan and HV E-stop, 10 pin for the control circuit, 10 pin for the VFD control circuit.

multipole connectors 1.jpg

If you look carefully, you will also see that I have used braided cable sleeving on the stepper motor wires, this is more flexible than heatshrink and gives a neater appearance. Those connectors on the stepper are also from GEWISS and are good for 10Amp at 240/400V and latch very well. Price R47.50 per motor (cheaper than 4 pin Neutrek XLR connectors).

The only items still outstanding now are the screened cables, computer and Mach licence. The spindle will have to wait until I have started making back some of the green stuff .

[Gerald D]

Nice connectors . . . the HSD spindles also have them fitted.

Yes, the table top makes one huge "gusset" in the flat plane. I am currently drilling all the beams for single bolt connections.

[smreish]

Alan,
You have more $$$ in connectors than I do in my entire building! Jealous I am.

[Greg J]

Alan,

Very nice !!!

[hennie]

I have those on the vacume press they work well, good seal against dust.

[sailfl]

Those are industrial grade connectors. Nice!

[kaartman]

More Alan
Could you please post a close-up picture of a Gecko drive that wil show the wrighting clearly, just curious to know why there is so many connection pins.
Thank you

[Gerald D]

Surely you have already seen this thread?

[kaartman]

Yes i did thank you, so the labeling stayed the same on the 203V.
Regards

[Gerald D]

Yes, the pin labelling (and locations) and the resistor values are the same for G201/2/3

[kaartman]

Baie dankie, thank you

[hennie]

Hi Alan

got my cables prices after 4 weeks

40 meters of lapp olflex 115 4 core shielded .75 R 856.00 excl vat.
other lapp cable cost me R 490.00 ( cable will hopefully be in town on Monday )

I dont know if R 856 .00 is reasonable as I don`t know what these things realy cost.

also got proxy`s R 398.00 excl. each ( ouch!!!!) also don`t know if it is reasonable.

[Alan_c]

Hi Hennie

That price on the cable seems to tie up with my quotes here in CT, its not reasonable but that is the going price. The price on the proxy seems high, Electromechanca has them for about R270 ea (12mm) but their prices are going up 25% end of this month

Spent the day at my Dad's factory doing some of the steel work. When I arrived there today I saw the steel that was delivered last week, for the first time...I had ordered parallel flange channel and paid a litle bit more for it, guess what... it was all taper flange needless to say the words that followed would have made an old sailor blush. Phone calls to the supplier were fruitless so decided to carry on anyway, too much time has been lost already, I will just have to get taper washers for the assembly, not what I wanted to do but it wont affect the strength.

Managed to drill the two main beams with all holes for assembly (not the track mounting holes) and cut the ends to shape, I am not suprised Greg built a gantry, these beams are HEAVY. I also did the holes in two cross supports before running out of time. I have brought the cross supports back home with me so I will be able to work on them in the week (its about 60 Km's to the factory, not a trip I want to do every night with the current petrol prices). Sore hands and back tonight so its bath and off to bed...pics to follow

[hennie]

I think my supplier got the proxy`s from acdc in CT.I also have to pay delivey charges to Plet on every thing so that also pushes the price up.Did notice that there are four wires on the proxy`s and not three as per wiring in another thread.

I do know that when this machine is complete and the chance is good that I will build another one ( 4 meters long for my wooden tops ) I would make a road trip to one of our big city`s and do the shopping myself.Cape Town would be first as I have never explored your area.I did flew in once to get a client to sign a contract and also did the one good thing and drove to Houtbay and had fish and flew straight back to Jozi so it is more raeson to do my shopping there.

[Gerald D]

RS Components has 12mm proxies at R251. They are next door to ElectroMechanica, but only hold a tiny range in Cape Town. This is true of a lot of companies in Cape Town - best to pre-order everything by phone first, and then just do a trip to collect.

[Alan_c]

Considering your location, and if their price is good or better, it will pay you to order the goodies from RS, if the invoice value is high enough (4 proxies will be) they will deliver to your door, free of charge. Dont let that stop you from coming to CT though, Grabouw is on your road in and Gerald is right next to the airport, visits will have to paid...

[hennie]

Would like to come that way soon and a visit is one of the reasons .Probably for a long weekend.As you know when one lives where we live there is a lot of up country visitors..Next visitors will be Caroline`s parents and they will bring my motors down with them so you can imagine this will be one visit from the mother in law that I can`t wait for.Pitty they can`t bring my racks with but I will have to make a trip to Jozi still have a lot of stuff up there.

Alan I have a question to ask?
On your machines at work you do framed doors for mirrors.
Does the vacume cups hold the frame doors or do they sometimes come lose? I do know that the material is raised from the surface.I need to brainwave a hold down sistem for my machine as I would like to nest my glass framed doors as the frame of the doors are 65 mm wide.I can do tabs for the outer side of the door but then I need to manually trim it off with an edge trimmer.

[Alan_c]

Hennie

Racks are also available here in CT if you want to avoid going up to the big smoke (who wouldn't )

I assume you are talking about the MDF doors for the bathroom cabinets? (all other fames and doors are done by mitering and underpinning) I have never used the machine cups to hold small items like doors as they dont have sufficient holding power. On the Biesse I make intermediate jigs (using 20mm HDPE) that I clamp onto the cups. In the top of the jig I have two grooves, 6mm wide x 5mm deep, 3mm in from the outside and inside perimeter. In these grooves I place 7mm rubber cord that act as gaskets. Between the two gasket grooves, I rout a third groove for vacuum. I drill and tap from the bottom of the jig into this groove and insert a 8mm push fit air hose coupler. (making sure it will not fall in the area where the jig is held to the machine cups) The vacuum on the Biesse is split so that I can hold the jigs down with constant vacuum and the vacuum that holds the job is switchable. I also make the centre portion of the jig into a clamping area by putting in a gasket groove and vacuum port (this is to ensure that the centre portion of the door cannot move when cut loose).

Because doors are generally a square or rectangle shape, we dont worry trying to optimise the sheet by nesting the doors on the CNC, but bring the blanks cut on a panel saw (5mm oversize) to the CNC for cutting out and trimming to size. Depending on the face profiles (complex or simple) I use two different approaches when it comes to actual machining. If it is a simple radius profile around the perimeter of the door and a square profile where the mirror is, I do all the machining from the back of the door - First cut is made using a custom made cutter which is an inverted radius cutter (widest part of cutter is at the bottom with the radius facing up - note jig must be correspondingly smaller to allow wide part of cutter to fit in under the door) this does the outside of the door, second cut is made with a 12mm cutter to cut the rebate and then the through cut to make the mirror opening.

If the door has complex profiles on the outside and around the mirror I use a 2 stage machining process - Machine the front first - outside perimeter, inside perimeter and through cut (usually two cutters) then turn the door over to machine the rebate. This can be done two ways - either on a second vacuum jig or a simple frame jig as you will not be machining the outside perimeter, the most important thing to remember though is that this second jig must be accurately positioned and referenced so that the rebate is in the correct position.

On the SCM which does not have vacuum pods I use a similar process as above but the jigs dont have seperate vacuum pipes coming to them, the table on the SCM has grooves for placing gasket material in whatever arrangement is required and has referencing pins on the perimeter. The jig and material is placed on the table against these pins and sucked down together. If I want to follow the first method as outlined above, the jig has to be double thickness to allow the cutter to get in underneath without cutting into the table (very expensive aluminium extrusion).

On the MechMate I would use a system similar the SCM one, but clamp the jig to the table and use external vacuum to hold the part (vacuum can be generated by vacuum pump of compressed air vacuum generator) With a sufficiently sized jig and vacuum source almost anything can be held as long as it is not too small, big thing to remember when deisgning the jig is to make sure that the vacuum area is not breached when cutting the part, if that could happen you must place gasket either side of the cut area to maintain that integrity.

We used to make a type of mirror that was joined with butt joints or half laps at the corners and had strange shapes , obviously you cant run the rebate before assembly so we used to do the rebate on the SCM with the same sort of vacuum jigs which used to work very well. We seldom had any work coming loose and when it did it was because of warped or knotty timber.

Hope that helps, if unclear just ask.

[Greg J]

Alan,

Would you mind posting a picture of the jig/setup?

[Alan_c]

Not at work today, off with the flu, will snap some shots and post when I am back.

[hennie]

Hi Alan

Thanks for the explination.What is the 7 mm rubber cord and where can one get some can it be obtained in long lengths?

I can take vacume from the press so that is not a problem ,I would like to do the doors by nesting them ( cutting out human operation on the pannel saw).I supply a lot of framed doors for kitchens and mainly vanity`s doing them the old way some 22 mm mdf doors I do on the multiborer with dowels in the joints even shaker doors.(mostly one size).

Maybe one option is to do a full size board with all the groves cut in for vacume and seals and split the board up in zones.that is for this specific size doors. On completion of the nesting one remove the board and put it in storage.Would use mdf but have to seal the board with a sealer as the vacume would be lost through the mdf.

All the other guys that already built their machines did you seal the bottom side of your spoil board?

Something that I did notice from working with s/f white mdf is that whith the one side covered with melamine it tends to warp/bow/bend but once it is covered on the other side with sealer,paint , pvc foil it tends to go flat.It might be something for thought when fitting the spoil board is to coat it with acrilic sealer on bottom side and edges and top with automotive body putty 3-4 mm thick it would stop moist from being absorbed and would give me a spoil board that I would not mind cutting into and is easy to fix and resurface.

[Alan_c]

Austro stocks "expensive" Biesse cup rubber (actually a D shape) and "cheap" round rubber that comes in long lengths, but I have found that 7mm rubber cord (on a roll) from Rubber Products & Mouldings in Maitland CT is about 1/3 the price of their "cheap" option and works just as well.

I used to use MDF for jigs and found that spraying them with lacquer both sides after cutting the rubber grooves and vacuum grooves worked well to seal it, but somehow the MDF still managed to take up moisture and the thin areas started to break up, thats why I changed to HDPE, much more durable and impervious to moisture, only snag is its not available in MDF sheet sizes (1mx2m).

I dont know about sealing the bottom of the spoilboard as it may hinder the gluing down to the base board, lets see what the others say who have more actual experience with this.