[peteeng]

Arg - Wiring, my favorite part of the build (NOT) - I've been waiting for 2 cable chains to arrive and they did today. So down to the shed and start figuring out how they will work. I'm generally not happy with cable chains as I can't get them to do what I want... like go around two corners... and I hit a bit of trouble with the shielded spindle cable as its tight in the cable chain and I don't like how the cables bunch and turn the corner at the gantry. So I go back to my umbilical tube and it gets around the 2 corners. After a bit of boiling down I got the umbilical to do what I want from the electrics to the gantry. Now I want to continue and turn it up to the top of the Z axis. What would the world look like without octopus straps and fast action clamps? So once I get it roughed to the Z I can start making brackets and clamps for the umbilical... and fine tune the loom. Peter

[rodw]

Pete, i think you are missing something with the drag chain. It not designed to go round corners. Wires can do that cos they do not move at that point. you need 2 chains. one for x and one for Y. It needs to be attached to the opposite side of the machine from where the cables are coming from.
Ideally, you need a tray or some kind of rack for it to rest on.

Actually the chains can start in the middle of the axis cos only half the length flexes but sometimes its easier to run the chain full length. I do it bith ways on my table.

Pics of my plasma table for reference.

[peteeng]

Hi Rod - Thanks for the images, I understand how they work and I made provision for a "tray" on the wall top. But the gantry chain would have to run quite a bit away from where I envisaged it so would need long bracketry plus I didn't like how the wires would loop from the wall cable chain to the gantry cable chain (the second corner I spoke of). I didn't bother showing the 76 versions before I got close...

The umbilical starts approx halfway along the axis as you suggest. The umbilical allows me to do two 90deg bends vs one... On Scoot 3 I had an umbilical that went from the electrical corner to the top of the Z in one go it used a soft fibreglass batten whip on the umbilical to maintain a nice shape. . I liked that.... But I don't have any of that left, it was one of the last sail battens I had from my dingy sailing days. I'm trying to use up stuff vs buying new stuff at the moment... The cable chains I bought for Frankie I'll move onto Brevis-No2 the 3D printer I'm building... Peter

[rodw]

Seems like you did not think about the drag chain when you designed your machine.
I had allowed for it from the ground up. Even a standoff at the plasma torch was in the cad design and there is a folded up tray welded to the frame.
But the number of cables I needed needed a decent sized chain so your solution would not work.
I think If I were going to do it with conduit, I'd add an elbow pipe fitting where it goes up onto the gantry.

[peteeng]

Hi Rod - In prior machines I have modelled the wiring but when it comes to the actual wiring I see things on the real machine that I can't in the model so I end up doing it different. So I have not modelled the wiring for some time and figure it out on the machine when built. Seems that's the way my head works. Still playing with the first run today. Found some neat umbilical ends that fit some clamps I made 30 years ago for aluminium tubes on wheelchairs, so I'm going to use them. Wiring version 103A... Peter

[peteeng]

Evening all and Sundry - Todays job was making a top umbilical clamp and another and another. Four tries later was good. So I made a clamp but decided to make 2. The first one snapped as soon as I screwed it in place. So I thought I made 2, that's OK. The second one snapped too. So I made it thicker and made another. It snapped, not instantly but close to. So I investigated, even ran an FE model which showed it broke at the expected place... So I glued the first too together but rather then wait till tomorrow I made one in plastic, problem solved. So I looked again and the clamps broke with the grain and the grain was in the wrong direction. The first batch of clamps I made had the grain in the correct dirn and didn't look or feel like breaking. Anyhow onward to sorting the hardware. The umbilical works great... & I'll need to paint all the clamps....Peter

[peteeng]

Evening everybody - Today I continued with the wiring. I ran out of real estate on the LHS for the power supply so had to rethink some things. So the RHS is now the power side and the LHS is the control side. So I wired up the power side and got the green lamp & 30V YEH. I'll make a little cover for the PS terminals. I usually have a lead tail as the power in but I have been wanting to use an inlet GPO for some time. Locally they are expensive and they only stock the 15A ones for caravans. On the net I found a cheap one and its 10A but I ordered black and now I think it should have been white. But it works. I think I'll go back to the tail from the GPO... So now to pull down the trial LHS and wire it properly. BST have started to make the ballscrews so Frankie is getting close to sawdust day! Peter

[peteeng]

Hi All - Today we had a power outage while line maintenance was done. So no computer or cnc work done today till late. So was yardwork all day....But I managed to get the cover for the power side done. Now to move to the LHS and get it wired. These little parts will get painted when sorted... Peter

[peteeng]

Hi all and sundry - Todays little job amongst all the things I have to do was to get the Y motor cable terminals on. I have been thinking about these and was going to machine some ply covers to keep with the aesthetic. But the ply was a bit thin and the options became poor. So off to the hardware and bought some std 70mm terminal boxs. Its white but done. Now to start getting cable to the spindle and Z axis... Peter

[peteeng]

Hi you All - Today I finished painting the small bits and reassembled the umbilical. Now to cable up the Z axis. On track for motion next week. Tracker says delivery in 2 days but that won't happen. Somewhere between Shanghai and Oz in a 6th dimension...Peter

[peteeng]

Hi you lot - Today I got a bit more wiring done. Coming along nicely. Some of it didn't go the way I thought if should but that's the way of wire I have found. There's still quite a bit to do. The motion parts are still in cyber space CN-AU hurry up!! Peter

[peteeng]

Hi All - This morning I did some earth checking and started thinking through the machines earth system. I added an earth to the RHS. Sparkies don't like the idea of earths through bearings..... Yesterday a branch fell from a tree onto one of our beehives and we had to re-stand it. I got stung on my hand twice and its a bit oversize today... Ouch. Peter

[peteeng]

Hi All - Yesterday I picked up the spindle. I wanted the ballscrews but they are separate and slow. But now I can make the spindle plate as I have the clamp... I got excited because the spindle had a manual this time! But it was in Chinese Peter

[mactec54]

Hi All - This morning I did some earth checking and started thinking through the machines earth system. I added an earth to the RHS. Sparkies don't like the idea of earths through bearings..... Yesterday a branch fell from a tree onto one of our beehives and we had to re-stand it. I got stung on my hand twice and its a bit oversize today... Ouch. Peter

Bee stings can be nasty for some, do you smoke them they would have been mad that their house was messed up.

That is correct, you should not have any Ground / Earth connections going through Bearings, your spindle does this though, that is why the Bearings fail. you should always have a Ground / Earth Bus Bar or a single Star Point Ground / Earth Point, where all Grounds Earth wires connect. having multiple Ground / Earth Paths you will have formed a Ground loop.

A snip of an Ac motor driven by a VFD Drive shows how important Grounding is as the Rotor is charged it's only path is to Ground / Earth

[peteeng]

Hi M54 - Yes the Bees were riled up as it was over at a 45deg angle and well off the stand. Smoke takes a while to calm them and its just easier to step in and pick up the hive (2 people a full hive is heavy) and lift and replace. Luckily it had a tight band on the hive and it was fairly intact. Can be really messy if the hive splits open. Back to sorting earths and cabling. I think I'll make a carbon fibre spindle plate. I've got some commercial work on at the moment which is getting in the way of Frankie...On another note I was approached to design a spray painting robot and that seemed to get really close but its gone quiet. Shame was a good project.... Peter.

[peteeng]

Hi Mactec - The return path via rotor is a stray current? The spindle works if the body is not grounded so the rotor path is stray? Peter

[mactec54]

Hi Mactec - The return path via rotor is a stray current? The spindle works if the body is not grounded so the rotor path is stray? Peter

I'm not sure what you mean by stray current, it is introduced to all VFD Drive driven 3 Phase motors, the Spindle must be Grounded it is dangerous to use a 3 Phase motor like this without the correct Grounding, this is not a stray current, it is a constant current produced in the Rotor which only path is to Ground, this means out through the bearings or protection that some motor have built in like a Brush that is in contact with the Rotor

Because of the unbalanced Single-Phase power being used it gets quite bad because of the unbalanced supply, here is a small snippet

Influence of VFD on motor shaft voltage and bearing currents
The advent of variable frequency drives (VFD) aggravated the phenomenon of induced shaft voltage/current, due to the unbalanced waveform and the high frequency components of the voltage supplied to the motor. The causes of shaft induced voltage owing to the PWM supply is thus added to those intrinsic to the motor (for instance, electromagnetic unbalance caused by asymmetries), which as well provoke current circulation through the bearings. The basic reason for bearing currents to occur within a variable frequency drive fed motor is the so called common mode voltage. The motor capacitive impedances become low in face of the high frequencies produced within the inverter stage of the variable frequency drive, causing current circulation through the path formed by rotor, shaft and bearings back to earth.

You should never buy one of these Spindles unless it has a 4Pin plug, the 4th pin is for Ground this needs to be connected to the spindle body inside the spindle.

[peteeng]

Hi Mactec - All of BST's spindles have 4 pin plugs.

This mornings job was to complete the main loom. I picked up the spindle and associated plumbing so can run the water pipes etc. I started running the water tubes thru the unbilical but they were really sticky so I used some furniture wax on them and they shot thru! A good lub always makes it easier. The motor cables are rubber sheathed so they can be really sticky. I did a brake test with the 24V all good. Now two wires to connect and the major loom is done. Very pleased with the umbilical (the zone spell check wants to change this to unbiblical haha ) so now to decide on the spindle mount , carbon fibre, Tetrium-S or aluminium. CF & T-S are mainly plastic so are not good conductors so a good earth on the spindle is a priority. Also the ballscrews are at the freight deport so next week could be sawdust time!! Are we having fun yet? Peter

brake test - can't live without forceps
spindle inverter - Its the 1.5kW one and we have an 800W spindle so very good
wiring - only a couple of wires left to terminate
spindle terminal - being 230V I put it into a metal earthed box
unbilical - nice run from electronics to spindle

On another note the next build (called Lanky; brother of Frankie) is to be 2.8 or 3m long so I will need a rack and pinion supplier. I'd like to do it with a belt but if the R&P is good price I think that's the go. BST don't deal with R&P. Anyone recommend an R&P supplier? Peter

[peteeng]

Hi You Lot - Rounded out the day finishing the wiring. Pump works, inverter works, wiring is pretty tidy. Will add an earth the LHS rail and I think its good to go. Next is to design and make the spindle plate. I think I'll do a combo carbon fibre glass fibre block. Stay tuned. Peter

[mactec54]

Hi Mactec - All of BST's spindles have 4 pin plugs.

This mornings job was to complete the main loom. I picked up the spindle and associated plumbing so can run the water pipes etc. I started running the water tubes thru the unbilical but they were really sticky so I used some furniture wax on them and they shot thru! A good lub always makes it easier. The motor cables are rubber sheathed so they can be really sticky. I did a brake test with the 24V all good. Now two wires to connect and the major loom is done. Very pleased with the umbilical (the zone spell check wants to change this to unbiblical haha ) so now to decide on the spindle mount , carbon fibre, Tetrium-S or aluminium. CF & T-S are mainly plastic so are not good conductors so a good earth on the spindle is a priority. Also the ballscrews are at the freight deport so next week could be sawdust time!! Are we having fun yet? Peter

brake test - can't live without forceps
spindle inverter - Its the 1.5kW one and we have an 800W spindle so very good
wiring - only a couple of wires left to terminate
spindle terminal - being 230V I put it into a metal earthed box
unbilical - nice run from electronics to spindle

On another note the next build (called Lanky; brother of Frankie) is to be 2.8 or 3m long so I will need a rack and pinion supplier. I'd like to do it with a belt but if the R&P is good price I think that's the go. BST don't deal with R&P. Anyone recommend an R&P supplier? Peter

I think with what I have seen BST Spindles are made by G-Penny which make one of the better Spindles.