CNC machining assistance requested

[John HinkleyParticipant @johnhinkley26699]

As reported elsewhere on the forum (Workshop progress thread), I have just about completed all the metal machining involved in the construction of my gearbox design. I am now at the stage where I want to make a display for the mechanism. This involves the provision of four vertical "walls" to support the internals, mounted on a wooden base. I have purchased 10mm thick perspex sheets of the appropriate size and originally intended to make a template from MDF and use this to cut the outlines on my engraving machine at 1:1, of course. I have made the template, but would prefer if possible, to have the perspex cnc cut to more exact dimensions, A Yellow pages search this morning indicates that there are no companies within 200 miles of me that can provide this service. (I am located near to Doncaster.) Unless anyone knows differently. So this is my plea: Has anyone used such a service that would be willing to take on this task? I would provide the material and computer files in dxf or other format to suit their requirements. Maximum size is 125mm x 120mm overall.

Thanks,

John

[John HinkleyParticipant @johnhinkley26699]

[Andrew FirmanParticipant @andrewfirman12129]

Sometimes local universities or technical collages have the equipment and are willing to undertake such tasks for a reasonable fee. Swansea University undertook such work for some art work for my sister.

[Ex contributorParticipant @mgnbuk]

Would waterjet cutting be accurate enough ?

Yorkshire Waterjet

are in Sheffield. I have used them for work projects, just supplying a .dxf file of the shapes required. Their machines didn't hade inclinable heads when I used them last, so the cut isn't exactly square though the cut due to the jet diverging from the nozzle, but that shouldn't be too severe on a 10mm thickness. Nice clean edges with waterjet cutting.

Otherwise maybe check out sign makers or trophy engravers – at my previous employment we used a trophy engraver to supply switchplates cut to size, holes cut for the switches & engraved to drawings. A new sign at the current employer was made up of individual parts cut from different colours of some form of plastic stuck together.

Nigel B

[Involute CurveParticipant @involutecurve]

PM me I'm in Durham if thats close enough and can probably help.

Shaun

[John HinkleyParticipant @johnhinkley26699]

Thanks, all, for the replies. Nigel – that link to waterjet cutting looks interesting. I'll email them in the first instance and see what they say. They are not that far away.

Andrew – I'll bear that in mind, but I suspect the local colleges won't be equipped for this type of work.

Shaun – Thanks for the offer. If I have no luck with Yorkshire Waterjet, I'll be in touch

Regards to all,

John

[Adam MaraParticipant @adammara]

I'm retired, but have access to a commercial Trotec Speedy 400 laser cutter (capacity 1000mm x 600mm and 300mm in height, which I have used to cut up to 16mm Perspex. South Lincs if that helps, please PM if interested.

[CirclipParticipant @circlip]

+ another for water jet, cold and accurate.

Regards Ian.

[John HinkleyParticipant @johnhinkley26699]

Adam – That's a very generous offer and if I have no luck with the Yorkshire Waterjet link, I will most certainly be in touch.

Ian – I must say, if waterjet will do the job, I'll go with that. Apart from the aesthetics, I'm not overly worried about the outside profile as I will be drilling all the holes etc on the mill using the DRO.

John

[Ian PParticipant @ianp]

A waterjet company I used recently have a machine that can alter the angle of the cut and I'm sure they could cut thick perspex more than good enough for your project.

Purely out of interest, since you have machined all these gears and other beautiful, what motivated you to have these plastic parts made by A N Other?

Ian P

[John HinkleyParticipant @johnhinkley26699]

Ian P – in a word – terminal laziness! Having faffed around for a couple of hours making one template, I thought my time could be better spent. Some would say "cheque book engineering" and I won't disagree with that.

John

[John HinkleyParticipant @johnhinkley26699]

Searching for a firm to do the cutting for me, I read in MEW 291, the article by Mark Noel on various cutting techniques. He recommended a company in Nantwich that had done some work for him with good results. I went to the web site referenced at the end of the article, only to find that it is a similarly named company but in Lyme Regis, Dorset. A Google search soon found the correct address:

Precision Waterjet Ltd

I have emailed them with my request and await their reply. Incidentally, I approached a local(ish) firm in Sheffield, but they weren't interested, preferring, quite reasonably, to concentrate on industrial size orders.

I still have in my arsenal, the kind offers of assistance from Adam and Shaun above, of course. I'll wait to see the response from Precision Waterjet.

As an aside, I've also ordered a piece of A4-size clear acrylic to use as a base instead of wood, intending to place a mirror underneath that to further enhance the view of the workings. At least, that's the idea. I'll see what it looks like when (if) it's ever finished.

John

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