Rock Tumbler

Gone a bit further, redesign:

Same basic design, but now pulleys instead of gears with Oogoo belt drive.

The gears were loud, pulleys virtually silent.

Also now using 1 mm thick rubber sheeting.

Rollers much thicker, no oogoo covering, it wore out too easily, instead they have bands of rubber sheet.

Drum has rubber sheet inside ends for sealing, rubber covering inside main drum to deaden rock sound, rubber bands on outside of ends to mate with bands on rollers.

Rubber sheet under base.

Now have 2 of them. Don't really need silencer box anymore.

I've gone through 1 round of rolling with Grand Daughters rocks, usually 4 stages:

• 1 Coarse
• 2 Medium
• 3 Fine
• 4 Polish

Did stage 1 to 3, 1 weeks rolling for each stage. Results ok, but not sure.

So, now doing full test with known good gemstone mix from National Geographic.

Rolled for 1 week on coarse, wanted round pebbles, didn't get that, but I don't think it works that way, so ran it for another week:

Original rocks

After 2 weeks coarse rolling

I'll take them through full sequence, currently been on 2 Medium since Friday 8th December 2017.

But what do you do with results? Get nice shiny pebbles, what then?

I thought I could cut rocks into smaller nice shaped pieces using dremel, no chance. But I could break them with a hammer, so I now have a second set of much smaller rocks:

These are in the second rock roller, been on 1 Coarse since Friday 8th December 2017.

Maybe once polished I can drill them and thread them as beads?

I've actually bought 3 sets of rocks from National Geographic, 1 polishing as supplied, 1 broke up the 2nd for smaller sizes, final set is to pass with rock rollers to Grand Daughter (once I'm happy with them).

Leave off publishing on Thingyverse for now, no point publishing until I'm convinced.

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Rocks 1 progress:

Original (out of box)

After 2 weeks Coarse Rolling

After 1 week Medium Rolling (still wet)

25/12/2017 After 1 week fine

Rocks 2 Progress:

Original, rocks broken into small pieces

After 1 week of Coarse Rolling (still wet)

25/12/2017 after 1 week of medium

27/01/2018 after 1 week of fine

EBike

This is a project for my Father.

My Dad is 82 years young, he's way fitter than I ever was or ever will be, he gets upset if he doesn't do 100 miles each week on his bicycle, he did Lands End to John O'Groats solo in his 70th year.
When he was young, he used to to do bicycle road racing with a cycle club in Manchester, it's where he met my mother. During that time he had a bicycle built especially for him. That bicycle is now 66 years old, still his favourite, but he's losing feeling in his feet and legs and can no longer ride his favourite bike.

So, see here:
https://www.thingiverse.com/thing:2191603
I'm planning on re-creating this attached to his bike.
Costing a fortune (relative to my usual projects), lots of power, dangerous enough to take off fingers.
We don't really need the speed and a pure Ebike as such, what we would like is a system that will give him a bit of a boost only when needed, or take him home if he bites off more than he can chew.
Ok, so I'm playing it by ear really as usual....

I've bought all the parts, got some, awaiting others, soon I'll be able to start putting it together.
Spent £360, that might be the total.

Motor, battery, VESC board (with spllied capacitors and connectors).

Drive pinion and belt coming from Ebay.

10 AWG and 12 AWG wires and connectors ordered from Ebay. 

Most VESC components ordered from Mouser, rest from Farnell.

Saddle bag and thumb throttle ordered from Banggood.

Rock Tumbler

My Granddaughter is now 8 years old, during walks she has always collected pretty stones.
So, I thought about getting her a stone polisher, was a bit shocked at the price, talking £80 for a cheap one, £115 for a good one, but they go up to thousands!
So, I've created a very simple stone polisher of my own design. It's still very much a work in progress.

Stone Polishing is long term, there are usually 4 levels of grit from coarse through to polish. The stones need to be tumbled at approximately 1 turn per second for a complete week for each stage.
So far I have done 1 week of coarse and am currently on day 3 of stage 2, so early stages.
Been no problems so far.....

Basic design:

Photo of final result.

4 off standard Skate Board 608ZZ, I get these from EBay at 10 off for £2.32.

1 off Flextec FRC365SA DC motor, I bought these off EBay some time back:

• Flextec motor
• FRC365SA,Dc Motor,41V,17000RMP,air compressor
• 3-12v NOMINAL 12v
• No Load: 25500 RPM, 0.40 Amp
• Max Efficiency 20930 RPM, 1.83 Amp, Torque 5.36 mN.m 54.6 g.cm 11.7 Watt
• Stall Torque 29.9 mN.m 305 g.cm 8.4 Amp

Motor is directly soldered to a Maplin mains PSU:

https://www.maplin.co.uk/p/6w-multi-voltage-acdc-power-supply-xx09k

Small gear is mounted to motor using 2 off M2 nuts and grub screws. I also had to create flats on motor spindle.

Rollers are printed and threaded internally.

Rollers are coated with Ooogoo rubber, mould printed.

For Oogoo, see here:

http://www.instructables.com/id/How-To-Make-Your-Own-Sugru-Substitute/

I use 1 part Cornflour to 1 part Silicon and I colour it with printer ink to any colour I choose.

In this case rollers are covered with Magenta Oogoo.

Drum is sealed with a layer of red Oogoo inside both caps.

Drum centre is covered in a layer of Oogoo, then covered in a layer of red electricians tape.

Whole base is sealed with red Oogoo.

It's LOUD, gears make a noise, plus exposed gears could be a safety hazzard, so I added a cover over the gears, that made the gears quieter, but still too loud. Originally I ran it without grit or water, imagine stones tumbling once per second!

So, I built a sound box. Simple ply wood, glued together with PVA glue, then used carpet tiles (lying around) to carpet the plywood box on inside AND outside:

See photo of tumbler, it is mounted to base of ply carpeted box, this box goes over like a hood. Granddaughters name signifies side with cable exit.

More photos:

It's running now in bedroom directly upstairs from where I am sitting, I can just hear it rumbling in the background.

After 1 week of coarse tumbling, stones were nicely rounded, it is working as expected so far.

But time will tell.....

Motor died during last day of 1st week, I hoped this was a bad motor, so switched it for a new one.

After 5 days of second week, motor gave out. They seem to still work but have no power.

So, this time I took both motors apart, suspected brushes were worn out.

Brushes look fine, everything looks fine!

I dressed the armature (where the brushes rub) very carefully with a fine needle file.

Put it all back together, back to fully working.

Coarse week complete, medium week complete, fine next, then polish.

Stones looking really good, these are stones collected by my Granddaughter, not specifically stones normally tumbled, dying to see how they end up.

Maybe I'll try drilling some of them.

Mechy

This is a toy I created for my 5 year old Grandson and 8 year old Granddaughter.
Basically it's just pieces with holes plus nuts and bolts for putting them together.
I've been working upon this for a couple of weeks, they took home the unfinished parts I had been working upon and have been happily playing with them ever since, their Mum and Dad are impressed and have been building things with them (I have no idea what).
Grandson is so happy with it that he has taken it to school for 'Show and Tell'.
A lot of pieces:

This is a design for a model that can be built, a hand cranked fan. 3:1 ratio gears mean fan turns at 3 times the speed you crank it:

Works well:

Here's a design slightly expanded with dual gear chain:

Not built it yet, there is also an incomplete design for a model Cessna single engined plane. Not printed all the bits for that yet.

My 3D Printer

I finished building my printer in July 2012 (making it 5 years old now), it looks like this:

It's a Metric Mendel Prusa with LM8UU bearings, build details here:

http://www.reprap.org/wiki/Prusa_Build_Manual

I bought the plastic printed parts off EBay for around £65 and built the rest myself, total cost around £250. 

Controller is an Arduino ATMega 2560 with RAMPS 1.3 driver board. I bought the RAMPS PCB and loaded it myself including POLULU driver modules.

Currently running Marlin 1.0.2+ firmware.

It's a standard MK2 PCB based heated bed with Pyrex glass. The bed is still mounted on 3 off LM8UU bearings (original design, not the one shown in RepRap Wiki).

The cold end is a slightly modified Wade Extruder, hobbed bolt made by me.

The hot end is old style:

M6 steel bolt modified in old pillar drill, filed off threads at business end, centre drilled with 3 mm drill to as close to end as possible, centre drilled 0.5 mm. 16 mm diameter PEEK insulator with PTFE sleeve. PEEK is tapped to take M6 steel end. M6 steel end screwed into PEEK. Kapton tape used for electrical insulation of steel hot end, thermister, thermister wires, Nichrome heater wire. Nichrome wire is covered in kapton tape, then wound around M6 hot end. Finally fibre glass strand is wrapped around assembly to keep heat in and final layer of kapton tape added.

It works, I think it's fast enough and accurate enough for my use, but you can judge for yourself (see shortly).

I use OpenSCAD (currently version 2015.03-2) for design, producing .stl files, Slic3r (currently Version 1.2.9) for slicing to .GCODE, Pronterface (Printrun 2014.03.10) to control printer over USB serial running at 250,000 baud.

On Thingyverse, I am TrevM, see:

https://www.thingiverse.com/TrevM/designs

All designs have been done by me in OpenSCAD, printed by me on this printer and all designs include photographs. You can use the photos to decide on the output quality of my printer for yourself.

Old and new projects

Buggy was not so good, it works, but when motor warms up it heats the plastic worm gear so much that it loses traction with motor spindle.

Monster buggy is still on-going, steering is really good, motor would not drive it, tyres were not balanced enough. Now using inner mould so tyres are uniform wall thickness of 2 mm, that works well. I've figured a better way of mounting gears to rods. Expect to get it fully working soon.

New project: Rock tumbler / polisher. My grand daughter collects small rocks on all walks, she would like to polish them, but rock polishers are very expensive, a cheap one costs £75, a decent one costs £115. So I've 3D printed 1:

It's been a learning experience. No fancy electronics, Maplin £12 power supply straight onto motor.

It makes a racket, so I created a plywood box, covered inside and out with carpet tiles. That deadens it enough.Photo shown is an old design, it was a smaller motor running at 3 Volts, it got too hot and spindle lost traction on gear (same as models!), so it now has a bigger motor running at 9 Volts. So far been continuously running for 3 hours.

But it needs run solidly for a week for each stage of the polishing, so it might work, it might not, time will tell. Once it's fully running then my grand daughter gets to take it home and I'll publish.

New project: My Dad wants me to put an electric motor on his old favourite 66 year old bicycle. It's a bit high geared for him these days, so he uses a different bike to do his standard 100 miles a week. But then he is 82, so adding a motor to give him a hand is perfectly acceptable.

Radio Control 9

Long saga, buggies done:







State the obvious, 4 sequences of 4 aspects.
1st aspect front right, 2nd aspect front left, 3rd aspect rear right, 4th aspect rear left.
Each sequence shows original real car then photos of 2 models underneath.
The engine has separated from body on the model with standard Fly Sky receiver / transmitter controlled model. I'll have to re-glue that.
I'm a bit disappointed in the model quality, but they will have to do.

I'll publish the monster buggy when it's complete.
But that will have to wait as my printer is out of action, every 2 years the Arduino 2560 fails, this has happened twice and in the same very weird way, the ADCs seem to lose accuracy, the hot end appears ok at room temperature but up at temperatures needed (250 degrees C) it is actually much lower temperature. I've ordered a couple of replacements, awaiting arrival from China.