Denford Software & Machines

What about setting machine selection to triac atc and changing limits etc to suit novamill? Then a triac style carousel should work

Hi

Has anybody made progress with retrofitting a power drawbar? I'm in the process of getting all of the parts together and in need of some pointers...

- what is the correct hole pattern for the mounting bracket? An presumably no longer needed bolt can be seen in assembly drawings, but is missing from part drawings.
- what are the specs or make/model of pneumatic cylinder used?
- when setting the cylinder and the preload nut, what force/tension is ideal?
- what is the best way of drilling/tapping the 3x holes in the head casting? I'm loathed to remove the head, but gather I will have to.

Does anybody have pictures of the ATC power drawbar with the cover removed? Maybe pictures of the assembly in detail?

I hope to have the parts in the next week, and will install during downtime over the holiday - any tips or advice is much appreciated!

Thanks
Jon

Hi Jon.
I haven't really done much since turning the drawbar. Still have to index and drill for the ball bearings but I'm sure ill get round to it any year now.
Most of the information you seek is in this thread but to answer your questions.....

- what is the correct hole pattern for the mounting bracket? An presumably no longer needed bolt can be seen in assembly drawings, but is missing from part drawings
The correct hole pattern will be dependant on that cylinder you can get your hands on. Make it to suit using the drawings as a guide.

- what are the specs or make/model of pneumatic cylinder used
Iirc its 63mm dia, 10mm stroke although it says in the assembly drawing. I got one off eBay for less than £10 straight from china

- when setting the cylinder and the preload nut, what force/tension is ideal
Good question, I imagine some trial and error would find the optimum preload. The more important issue is in what order are the Belleville's to be stacked. series? Parallel? Both?

- what is the best way of drilling/tapping the 3x holes in the head casting? I'm loathed to remove the head, but gather I will have to.
Well if your confident you could do it with a hand drill but I wouldn't personally. I would take the head off and drill and rigid tap on a haas vmc in work, or if you don't have access then a pillar

drill should suffice (use the drill chuck to hold the tap and get it started by rotating by hand then finish with a tap handle. Being care full not to drill into the spindle

There is a video on YouTube of a novamill atc changing tools with the cover off
Good luck with the conversion and don't be afraid of posting pics of it once it comes together

Thanks!

I've bought most of the parts, and will turn the draw bar this week or next. I'll use a pillar drill for the casting then...

Any idea how long the cylinder shaft is? Plus, how far should the cylinder engage the arm - it obviously sits 5mm or so above the drawbar. Want to avoid over-compressing, or mounting too far, so will try for an adjustable mounting.

With the bellevill springs, I'm basing it on the design/layout shown in the drawings - both the hand drawn and the CAD drawings show them to be parallel.

There'll be some trial and error, but looking forward to it.

One thought, wondering why the arm isn't attached to the cylinder with a pivot point to ensure it's pulled away from the drawbar?

Jon

Hi

Does anybody know if the Novamill head/z-carriage was redesigned at any point? The artwork for the plate that fits onto the head was altered at some point (shown in the revision notes) and in my case, this revised artwork appears too small. I've had a plate laser cut, but doesn't appear to be big enough - not sure if it'll fit someone else's Novamill? Getting the front lined up (so the cylinder centre is aligned with the spindle) means the rear doesn't overlap the back of the head casting, and the clearance hole for the oil nipple is in mid-air. When pushed back to align at the rear, the 3rd mounting hole is in mid-air and the alignment is off. It would seem the original measurements where correct for this machine.

Not a major glitch - but if anybody is in need of the mounting plate as per the drawings on the forum, let me know. Will cut another with some improvements!

Can anyone shed light on the cylinder - it seems to have a longer rod, but I'm struggling to find one. Is it a single rod, or is it a threaded rod extension? Also, as the brackets are not listed with part numbers, I gather they're supplied by the cylinder manufacturer (or standard ISO dimensions).

Thanks
Jom

madebymccoy wrote:Hi

Does anybody know if the Novamill head/z-carriage was redesigned at any point? The artwork for the plate that fits onto the head was altered at some point (shown in the revision notes) and in my case, this revised artwork appears too small. I've had a plate laser cut, but doesn't appear to be big enough - not sure if it'll fit someone else's Novamill? Getting the front lined up (so the cylinder centre is aligned with the spindle) means the rear doesn't overlap the back of the head casting, and the clearance hole for the oil nipple is in mid-air. When pushed back to align at the rear, the 3rd mounting hole is in mid-air and the alignment is off. It would seem the original measurements where correct for this machine.

Not a major glitch - but if anybody is in need of the mounting plate as per the drawings on the forum, let me know. Will cut another with some improvements!

Can anyone shed light on the cylinder - it seems to have a longer rod, but I'm struggling to find one. Is it a single rod, or is it a threaded rod extension? Also, as the brackets are not listed with part numbers, I gather they're supplied by the cylinder manufacturer (or standard ISO dimensions).

Thanks
Jom

Hi madebymccoy,

Thanks for the heads up, I've also been sorting out all of my components for a power draw-bar (Denford sourced parts and those from china are on the way) and was about to order a mounting plate from my local fabricator. Having double checked my 1999 Novamill by measuring, it appears to have a deeper carriage as per yours.

I've attached a drawing of what I think the correct dimensions are, I'd appreciate it if you'd compare it to what you came up with.

I also noticed that to get the Piston Rod Clevis BI01127F bracket centred on the top of the draw-bar it needs to be centred 45mm back from the front of the carriage, rather than the 49.5mm on the current drawing.

Finally w.r.t the drawing I've centred the mounting holes within the available footprint on the side of the carriage, and raised the centre hole by 5mm to site it 15mm down from the top face of the carriage floor thus giving the bolting arrangement a little more stiffness.

What Dia bolts are you using to attach the plate, its been suggested to me that given the tolerances on the drawing the 11mm holes are to allow clearance to fit M10 bolts. Do you have any thoughts?

If you've got any thoughts it'd be much appreciated.

Also, if the folks at Denford have a copy of issue 1 of the drawing (the current one went to issue 2 Dec 2001) that'd be much appreciated. I assume the 4 holes removed at issue 3 were for the Air Cylinder mounts?

Anyway, glad I got sidetracked at the weekend and didn't order this on Monday as intended.

Hope this helps, any constructive feedback would be great.

Cheers
Barry M

Steve wrote:Yes the sensor to count the toolchanger is a prox switch on the Genova Cam. However it has to read two pulses to know the thing has gone a full station. Two reves of the cam are required for a toolchanger.

Hi Steve,
Just to be clear I think what you are saying is;

The Carousel sensor (NVM-D4C) / ATC Datum Sensor (NVM-D7A) needs to register two pulses to confirm a single station tool change move. Is that correct?

Also does the CCR relay cycle twice to rotate the ATC motor one station, or does the two step carousel move (I saw on youtube) come from one cycle of the CCR?

As I'm running Denford V2 control software, do I just need to activate the ATC check box in the machine setup to enable this functionality? I only ask as I have a spare set of control hardware (Box + looms + steppers, from another NVM someone converted to Mach3 I bought as spares) that I'd like to do some prototyping on.

The longer term plan is to build equivalent ATC hardware that satisfies the control interface, albeit with 3D printed parts and controled by its own electronics so I can use obtainable hardware.

As usual, any help would be much appreciated.

Cheers
BPM

Hi Barry

I'm remeasuring the plate and the cylinder positions to correct myself as well.

I scaled the original drawings and measured the bolts for the plate-to-head and the clevis, and the cylinder brackets from memory they're all M10, but I'll draw up a BOM when I have the sizes to hand. I've not sourced the cylinder yet, so when I do, I'll redesign the plate to incorporate the cylinder mounting too. I want to ensure the stroke matches up with the original design - its a guess as to how far the drawbar needs to be pushed and the tension of the springs, so I'll try to align up as many variables with the original drawings, so I only need to worry about tension.

The cylinder also appears to have a shaft extension...

I'm not sure about raising the middle bolt hole... Worth a think through on that front.

I'm also wondering if the holes are already there, but just filled/plugged. I noticed a few holes in the main casting that have been filled and painted outside - so wonder if that's the case with the head too. After all, the ATC clearance hole is there along with other unused holes...

Jon

Hi Barry

The bolt sizes I measured:

M10 x 35mm
M10 x 25mm
M8 x 40mm

Think the M8 is for the cylinder brackets, so 4pcs
The 25mm for the plate, so 3pcs
The 35mm for the clevis, so 1pcs, plus washers as spacers (hence the length)

And washers all round!

Jon

Hi Jon,
Doesn't look like the holes are there in the head stock casting. I wafted a magnet over the casting and it was magnetic all over the mating surface.

I'm picking up my bracket in the morning (I don't have a welder). I tweaked the drawing that I uploaded previously, adding a recess to the front edge to allow a cover to pass in front of it.

The only thing I am missing now is the draw bar, which I am going to attempt to turn on my Novaturn, courtesy of Autodesk 360's integrated CAD/CAM solution.

The price of getting a draw bar professionally made was a little steep for my liking, but it will always be the fallback if I don't like the quality of my own efforts.

I will post how I get on with the draw bar and final assembly next week.

Cheers
Barry M

I realise I'm a little late to the table and I haven't read the whole way through this thread, but i thought I'd throw a little compromise idea into the ring for those who might want a (slightly) simpler solution.
The last Haas I bought had a 24-tool carousel mounted vertically, between this and the spindle was a simple double ended (hooked) arm with a pivot in the middle. The carousel rotates/indexes to the desired tool, the arm engages with the tool in the the spindle with one end while simultaneously engaging the chosen tool in the carousel the with the other end. Arm drops down (removing both tools) spins 180 degrees and lifts up again (locating tools into the spindle and carousel). When finished, the arm rotates to a parked position perpendicular to the spindle.
It may sound complicated but is actually very simple and effective. The idea lends itself to a few options;

a) Simply have the double ended arm on its own, after each tool change manually load another tool into the 'open' end, ready for the tool to change when the time comes.

b) Have the arm and a six pocket carousel, rotate the carousel manually after each tool change, ready for the next.

c) Have the arm and a powered carousel BUT the carousel only rotates/indexes and doesn't move toward or away from the machine, the rotating arm makes that part redundant.

The final option is basically the same as the Haas and may or may not be simpler than the carousel indexing and then moving into position of the spindle

For those who are interested, the retrofit works!

For the record some fine tuning is still required... will be uploading a video of drilling the head on my main youtube channel.

Hi Barry

Looks good!

What was your reason for mounting on the right hand side vs the normal left hand side?

I've sourced a cylinder, but no brackets, so need to fab some. I've not had chance to get the new plate made, was holding off so I could get the cylinder mounting holes cut at the same time. But, I'm thinking an adjustable shaft is the way to go, otherwise it'll take forever to figure out the hole positions.

Though, the real reason I'm dragging my heels is drilling the holes in the head. I really don't want to take the head off, as it'll probably screw the belt and shaft alignments for the Z axis. How did you get the belt off?

Looking forward to videos of the drilling!

Jon

madebymccoy wrote:Hi Barry

Looks good!

What was your reason for mounting on the right hand side vs the normal left hand side?

I've sourced a cylinder, but no brackets, so need to fab some. I've not had chance to get the new plate made, was holding off so I could get the cylinder mounting holes cut at the same time. But, I'm thinking an adjustable shaft is the way to go, otherwise it'll take forever to figure out the hole positions.

Though, the real reason I'm dragging my heels is drilling the holes in the head. I really don't want to take the head off, as it'll probably screw the belt and shaft alignments for the Z axis. How did you get the belt off?

Looking forward to videos of the drilling!

Jon

Hi Jon,
Link to my first video in the series on doing this is https://youtu.be/gQBkhOaV_hU?t=163, the link is directly to the bit about drilling the head. I didn't take it off for the same reasons you quote...

I mounted it on the right because I got the details of my modified drawings incorrect so the guy doing the welding put it on the wrong side of the plate (dashed line for location which is a sketch construction line in fusion 360). At the time I was also thinking that it would be good to have all of the air on one side of the machine, so given the option of waiting for another part or using the one I had I went for mounting it on the right hand side. I was a little worried that it'd get in the way of the carousel, but it doesn't seem to, phew...

I just hacked the brackets out of some 5mm aluminium L section I had laying about. The main plate definitely needs to be steel as there is a noticeable fraction of a mm of movement at the top when the draw-bar is actuated.

If you want to subscribe to my Youtube channel I'll be posting more about assembling it all, how the air valve works etc.

I have a prototype of my carousel working (there will be videos). It's 3D printed and hence the accuracy of the geometry due to plastic flexing ins't good enough to rely on it doing a good change every time. I may re-print with carbon fibre re-enforced filament, or just mill the parts from aluminium, not sure which way to go, perhaps a mixture of the two.

Hope this helps,
Cheers
BPM

Hi

Genius idea... I was eyeing up magnetic drill presses online, but thought I was just over doing it. I might print something similar and drill it in situ.

Notice you drilled just two holes?

I started making a new cable loom this evening, so getting back into working on the mill. Replacing the electronics with a MESA board and using LinuxCNC. Will be interlocking the spindle release with the spindle "Go" relay... thinking about a foot pedal for the release switch too.

Anyway, decided to fit the slightly short plate I have now and use it as a template to test position the cylinder. Once happy will get a new one laser cut.

Nice job!

Jon

Thanks Jon,
I've stalled for a while but will get back to it.Hopefully your build will go well too.
Cheers
BPM

For anyone interested in BT30 taper storage I have created some 30 taper storage pockets for installing into DIY racks.

https://www.youtube.com/watch?v=MhhaS4C6YMw

I've also listed some for sale on Ebay, and will give anyone contacting me via a Forum PM a heavy discount on the listed prices.

Hi all,

I have been busy with many other things the last while, but finally got som time to Work on my Novamill.

I never liked to have the drawbar design on the side, so I designed a new one that is able to have the original top on if you just make a cutout in the original spindle cover and make a small cover - I will make a new one soon.

Here is a short video https://www.youtube.com/watch?v=pf7msmJDxZ8

Some Pictures of my drawbar and drilling template...

Hope you like it.

Regards Morten

Wow That looks great!

Nice work!

Hi all,

Just got finished with the head:-)

Here are a few more Pictures of it + a Picture of my carrosel design, but I will properly only start working on it later this year...

/Morten