Novamill Column Raising Block

[madebymccoy]

Hi

Won't comment on using aluminium, but getting it made from steel shouldn't be a massive task (cast might be a bigger challenge). Either find a local machine shop or consider machining it on the Novamill yourself...

I plan to fit one shortly, and will likely use mild steel, but if I can find grey cast iron at a good price will get it machined for me.

Jon

[flyingmike]

An aluminium block of this size would compromise the stiffness of your machine. However, it depends on what you plan to do with it, if it's light machining of plastics and Ali you might get away with it but I wouldn't recommend it.
Are people refusing to quote? That would be strange as normally people just quote a ridiculous amount if they don't want the job.
Trouble with the design is that there is a lot of waste material.

[Ben L]

Ive tried 5 companies, 4 have said they wont do it at all, one of which is the company i use for water jet cutting, my thought was they could rough cut with the WJC and mill the faces to tolerance, If I had the machines thats what I would do.
One company came back to me this week with a quote for £600 + vat with no mention of whether that was in cast iron or not I took that as "we dont want it".

Its easy to say find a local machine shop, I have tried both Hampshire and west Sussex with the outcome above, Local machine shops are few and far between local to me.

Mike, would you educate me as to why and how it would compromise the stiffness of the machine? Ally is obviously a softer material, my perhaps desperate thought was that thro bolted under compression I might get away with it, but from both your reactions its a no go and I will take that advice on the chin!
I clearly dont understand the forces involved and I would sincerely appreciate you explaining it to me in more detail if you would.



I looked at cast iron today from Loco stockists, small pieces I can handle and make it up from 4 parts, which I think i can do everything except the final facing off due to the bed size of the Nova, it may well be the way to go.

Thank you for both your replies, I thought it would be a fairly easy task tbh, with a little commitment of time and money from me, but it is proving more than a little difficult for me to actually realise this part :/

[TDIPower]

I've been following this for a while now and was wondering if the reason for not doing it might be them having to code for it, but that just seems crazy because even with my limited CAD experience I could produce a 3D model of this in about 20mins, I could then load it into a post processor and produce the G code to machine it, or even do it as a 2D and produce 2.5D code myself. I wouldn't have a clue on feeds and speeds but don't see why it would be that hard.
It could be that the time spent on doing this as a 1 off would interrupt say longer term/bigger runs. If you said you weren't in a rush or say give them a dead line of a month or two then they could slot it in on the end of a run.

I've never dealt with machine shops but am just trying to apply some logic to the problem.

Pete

[Ben L]

If anyone else wants this done, Ive a quote back from a foundry, but it would only be viable really if I were to have a couple done 3 would make it pretty cheap.

Cast iron spacer casting - £143 each

Pattern to make the above casting - £415 lump sum

both prices are ex works so + vat

If there were a couple of people interested we could then split the cost of the pattern making which would bring the price per piece down considerably.

I'm just checking if this includes the facing off of the mating surfaces.

[flyingmike]

A casting is a nice idea but probably not enough interest to cover the tooling costs.
I think making it from pieces and bolting it together would be a good compromise.

The structure of cast iron will suppress vibrations being transmitted through the structure of the machine but there is plenty of cast iron in the pillar to do this so maybe a decent steel would suffice.
Aluminium is relatively soft so will deform more under load, a decent grade may be OK depending on application of machine? Thermal expansion is a big problem with aluminium with a noticeable difference between warm and cold days.

If I did it again I would go for pieces bolted together....

[madebymccoy]

Mike, what orientation/along what lines did you split it into pieces?

Suspect cost of a suitable block of cast iron will be too great, so will maybe machine myself from pieces or from mild.

Jon

[Ben L]

using Mikes drawing ive split it this way, Ive also got the dwg if you want it. I dunno if this is the best way to split it but it seemed like the most logical, although 70mm stock is is harder to buy in small quantities tahn 35mm so maybe split through centre would be better still.

[flyingmike]

Sorry to be a pain, but I would split the raising block 'the other way' so you have two lengths that run front to back, each containing 3 mounting holes. This way you will have one continuous surface to mount each side of the column too.
These 2 blocks would suffice but for completeness and to keep all the debris out you can 'fill' the gaps with additional blocks and bolt it together.

Once together you could skim the assembled raising block to ensure both top and bottom surfaces are flat and parallel but this may be beyond the capabilities of the Novamill.

[Ben L]

Sorry to be a pain, but I would split the raising block 'the other way' so you have two lengths that run front to back, each containing 3 mounting holes. This way you will have one continuous surface to mount each side of the column too.
These 2 blocks would suffice but for completeness and to keep all the debris out you can 'fill' the gaps with additional blocks and bolt it together.

Once together you could skim the assembled raising block to ensure both top and bottom surfaces are flat and parallel but this may be beyond the capabilities of the Novamill.

Happy new year!
Not a pain at all Mike, and since ive now woken up a bit from having some R&R it seems like the obvious thing to do.
So i'm in the middle of making a simplified version drawing, are there any reasons to have the walls and back the thicknesses they are the height is set for good reason, but could the walls be 40mm thick and the back the same for example?

Also Ive noticed my base has only 2 holes rather than the 3 yours has, told you I was asleep! :/

[Ben L]

Well that took a bit longer than i expected! but its here i'm so pleased its happened, now ive got to try and work out how to fit the bugger!
Turns out my machine only has 4 mounting bolts, as opposed to 6 and the hole centers arent the same either anyone getting this done be aware of what you have,

I found a really good machine shop in the process too, really nice company and decent prices



Mike if you've any good tips for removing the column and fitting this beastie i would be forever grateful.

Really looking forward to that extra z height

[DavidJ]

When I removed column from my Novamill (to cut weight for transit to new location) I disconnected all cables that go into the side of column from the multi-way connector on the side of the cabinet. This was to avoid chopping wires - I bought the proper Harting terminal removal tool (from RS) which made life much simpler, I could then remove column complete with all wires. Making a note of what wires go where is important!

IIRC I had to unscrew the bracket for the Y axis stepper from the rear of the column, then removed the column to base capscrews after removing the little plastic fillers from the screw heads. After that it required a sharp knock to separate the column from the base.

Be warned, the column/head combination is heavy but manageable with care. If you have an engine crane or similar available, use that.

[fgc]

Ben

fantastic job in getting it made! cant wait for your next update with it fitted and running!

[Ben L]

When I removed column from my Novamill (to cut weight for transit to new location) I disconnected all cables that go into the side of column from the multi-way connector on the side of the cabinet. This was to avoid chopping wires - I bought the proper Harting terminal removal tool (from RS) which made life much simpler, I could then remove column complete with all wires. Making a note of what wires go where is important!

IIRC I had to unscrew the bracket for the Y axis stepper from the rear of the column, then removed the column to base capscrews after removing the little plastic fillers from the screw heads. After that it required a sharp knock to separate the column from the base.

Be warned, the column/head combination is heavy but manageable with care. If you have an engine crane or similar available, use that.

Thanks for all the tips David, Ive just injured my hand, so wont even be looking at it for a while which is a little frustrating to say the least.
Great idea to remove the wires from the "umbilical" end rather than each individual component within the head which is what i would have tried :/
Is this the tool you mean ?
https://uk.rs-online.com/web/p/extraction-tools/1147728/

Cheers
Ben

[DavidJ]

Ben - yes that is the RS part number I purchased. Expensive for what it is, but made that part of the job pretty effortless. Do remember to note which wire/terminal goes in which hole!

Don't attempt it with a dodgy hand - I was concerned about possibly scarring mating surfaces when replacing the column single handed. I managed OK in the end, but was glad it wasn't any heavier...

[Ben L]

Ben - yes that is the RS part number I purchased. Expensive for what it is, but made that part of the job pretty effortless. Do remember to note which wire/terminal goes in which hole!

Don't attempt it with a dodgy hand - I was concerned about possibly scarring mating surfaces when replacing the column single handed. I managed OK in the end, but was glad it wasn't any heavier...

Thanks for that, i dont mind spending a tenner on the right tool, ive struggled too many times with the wrong one to know when its necessary!
I wont, frustrating as it is , i'll have to wait

[Ben L]

Ok here we go! I started the procedure tonight, all seems well, only 2 cables to disconnect and the rest seem ok for enough slack to raise the head.

[madebymccoy]

Hi

What's the plan for shimming/aligning the head?

Jon

[Ben L]

Hi

What's the plan for shimming/aligning the head?

Jon

A combination of finger DTI and a dial gauge, lots of different gauge shim a 200mm round piece of plate glass and about 4 hours!

It took much much longer than i thought it would but i'm happy with it at about 30 microns (0.03) i'm sure for some that's still way out but for me i cant believe it was any better before i did it. Maybe i'm kidding myself though

I havent taken any pics yet as the machine was down for a few days so ive been catching up with work, but safe to say i'm well chuffed with 150mm of Z under the chuck

i'll take some pics in the next couple of days after ive fitted the new chip guard.

[Ben L]

Well here it is, Thank you all for the help, but especially Mike to get me here, its been a journey. Worth it!