Question Brian May Red Special Guitar

Regular users will undoubtedly have seen the progress I have made on making a replica Brian May Red Special electric guitar because I have posted several YouTube videos on this thread:

Industrial Quality Small HF Spindle from StoneyCNC
https://www.stepcraft-systems.com/en/forum/accessories/4125-industrial-quality-small-hf-spindle-from-stoneycnc

I thought I would just post up another thread in the correct place to report successes on this build.

The main point that I want to get across is that well tuned Stepcraft CNC machines are perfectly capable of running for several hours at a time and milling complex 3D toolpaths such as a guitar neck. After two previous unsuccessful attempts due to operator inexperience, not machine capabilities or faults, I managed to cut the long tenon neck from a section of reclaimed Cuban mahogany fireplace mantelpiece just as Brian May himself did (but by hand)!

The upper side took around 1.5 hours to mill split about 35 mins roughing and 1 hour finishing. The lower side took nearly 3 hours split 1h 45m roughing and 1h 15m finishing. This is by far the most complicated/longest cut of the project. The parameters were relatively conservative: 2,500 mm/min horizontal (XY) feed rate, 120 mm/min vertical (Z) feed rate. Spindle speed 18,000 rpm.

You can also follow my build thread on specific Red Special forums. This one is publicly accessible without logging in but you can't see the photos unless you log in:

http://www.redspecialforum.com/viewtopic.php?f=25&t=1405

Doug

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Hi Doug.
Thanks for posting this. I am seriously considering the stoney industrial spindle over the hf 500 if I do buy a stepcraft.
Glad to see the stepcraft can do larger stuff as I was a bit concerned it might be a bit weak and not stiff enough.
Do you think the industrial spindle is definitely worth the extra money?
Does the machine last well and maintain accuracy?
Thanks

Ollie

Hi Ollie,

If your budget will cope with it, the Industrial spindle is well worth the extra. I bought one some 4 months ago and am delighted with its performance.

Unlike the HF350 I had originally, it's interface to the Stepcraft is totally reliable and accurate - speeds are well within 1% of the gcode demand over a working range of less than 1000rpm up to it's maximum of 24000rpm, and starting is totally reliable and well controlled. The control box is well made and constructed with high quality parts - wiring is to a high standard too, so expect total reliability there too.

The only negatives I can highlight are that it is quite noisy at 24000rpm, and the Stepcraft vacuum fitting cannot be used as it stands - it masks the collet nut and spindle flats. The noise can be cured by running at a lower speed - 18000rpm. ~I think Doug has designed a vacuum system that works, and I modified my Stepcraft one to be retained by magnets so it can be removed for tool changes - not ideal but I have ideas for a better solution, yet to be made.

Temperature wise, mine has hardly broken sweat even during an hour long session cutting parts for my wooden clock. At a guess I would say the spindle ran to 40 degrees C maximum during this session. I did a long test at 24000rpm with an dummy load attached (a small paint stirrer fan!!) and with a measured input power of around 90VA, neither the spindle case or any of the control box components was more than pleasantly warm. The HF350 was hot enough to fry eggs on in similar long milling sessions!!

Peter

Thanks Peter, good to know. I am still unsure about getting a Stepcraft. This forum has been both positive and negative in equal measure with some great success stories and also frustrating problems.
Thanks.

Hi Ollie.

All is well. I have been busy building so haven’t been on here much.

My machine is holding up well and I recently cut a small, intricate tufnol sheet part for a replica vintage parallel slide switch with it using a 0.8 mm diameter end mill. It cut this very accurately.

Doug

For those of you on Facebook, check out a detailed build thread for my Brian May Red Special guitar and my first build, a 3/4 scale Red Special replica. I met Brian on 3rd December 2017 before the Glagow concert on the current Queen + Adam Lambert tour and he signed the little guitar. Pictures are included on my blog.

www.facebook.com/DougShortGuitarBlog/

In this video I demonstrate how to make a fully radiused and slotted fretboard (for a replica Brian May Red Special guitar) using CNC (Computer Numerical Cutting). There are seven stages in total; only six are shown in this video:

1. Thicknessing the 11.5 mm spruce stock to 7.00 mm using a 6.00 diameter solid carbide two flute flat nose end mill with 18,000 mm spindle speed and 2,500 mm/min XY feed rate in 1.5 mm depths per pass. Actual cut time 14 minutes. [Not shown]

2. Drilling 2 mm deep holes for 1/4" (6.35 mm) diameter mother-of-pearl fret marker dots using a 6.00 mm diameter solid carbide two flute flat nose end mill with 10,000 mm spindle speed and 750 mm/min XY feed rate in 0.5 mm depths per pass. Actual cut time 1m 51s.

3. Cutting the outline using a 6.00 diameter solid carbide two flute flat nose end mill with 18,000 mm spindle speed and 2,500 mm/min XY feed rate. The outline toolpath was generated in MeshCAM using the 'pencil cleanup' finishing toolpath option and then the output G Code copied and pasted for each pass (seven passes at 1.00 mm depth per pass). Actual cut time 3m 28s.

4. Initial (rough) radiusing to 6.50 mm thick at the crown using a 6.00 diameter solid carbide two flute ball nose end mill with 18,000 mm spindle speed and 2,000 mm/min XY feed rate. Stepover is 1.5 mm. Actual cut time is 10m 05s. [This section is speeded up x2]

5. Inserting the 1/4" (6.35 mm diameter), 1.3 mm thick mother-of-pearl fret marker dots manually. Actual time 3 minutes. [This section is speeded up x4]

6. Final radiusing to 1/4" (6.35 mm) using a 6.00 mm diameter solid carbide ball nose end mill at 18,000 rpm spindle speed, 2,000 mm/min XY feed rate. Stepover is 0.5 mm. Actual cut time 28m 20s. [This section is speeded up x4.]

7. Cutting the fret slots with a 0.6 mm diameter solid carbide flat nose end mill, 10,000 rpm spindle speed, 600 mm/min XY feed rate. Actual cut time 14m 49s. [This section is speeded up x2]

For the marker dot drilling toolpath, the initial and final radiusing toolpaths and the fret slotting toolpath, I wrote the G Code myself (instead of using MeshCAM software to generate it) using the G18 command to generate arcs in the XZ plane and G02 and G03 commands for clockwise and counterclockwise arcs.

The wood is spruce tonewood left over from the blockboard assembly. This is another test cut; the final fretboard will be cut from oak. The video will also be on my YouTube channel and my guitar blog. The total time to execute this job was 1h 15m.

Doug

Hi everybody.

I forgot to update this thread. I completed my guitar in June 2020. I set up a new website to present my projects:

dsgb.net

I am still building content but there are some arty pictures of the finished guitar on the home page.

Doug