-missy-

Hello.

This is a bit of a plea for help! I have been building a machine to cut my own gears. It uses 2 stepper motors to drive the 2 axis I need.

The idea was to use an arduino to drive the 2 motors. They need to drive one motor at a set ratio to the other which is defined by the number of required teeth of the gear.

The thing is, I have been working on trying to work out the arduino drive of the machine for a few months now and to be honest, I have got nowhere after trying out several different types of drive etc. I have limited knowledge of coding and this is stressing me out!

Is there anyone able and willing to help me out or point me in the right direction?

Thanks

Missy.

The only thing about that resin is it states this on the manufacturers website...

http://www.esun3d.net/products/242.html

Anyone have any ideas? My oven doest go that low.

Julia.

43 minutes ago, Crosland said:

 

The 3DP wheels in the kits from "2mm Locomotives" were very fragile. I replaced them with association wheels but still haven't gone back to finishing a kit.

 

Andrew

Hi Andrew.

I think a large part of that was down to the material used for the printing. I am pretty sure he used shapeways for his supply at the time, an awful lot has moved on since then.

Julia.

Hi.

I have been having a bit of success using that eSun resin too.

On the left are some 8mm diameter J94 wheels, on the right are some 6mm diameter class 04 wheels. All need steel rims fitting (once they arrive in the post).

Thank you David for highlighting its potential.

Missy.

12 minutes ago, richbrummitt said:

Thanks Julia, 

 

I would love to see how you arrange the plastic stub axles into the frames. 
 

What is your concern with the larger wheels?

Hi Rich.

In this instance, the stub axle is there purely as a workholding feature so I can put it in the lathe and machine all the features of the wheel in a single setup. The 04 has metal axles so the wheels will be drilled to suit.

The only thing I have experienced with larger diameter wheels in the past was the strength of the rim in relation to the axle, especially with near to scale spokes. I would be much more confident trying something larger using this resin though. I think it would be well suited for smaller items like axleboxes, buffers, etc too.

Thanks to David for doing the R&D with it!

Julia.

1 minute ago, richbrummitt said:

Are these for casting or do you have a cunning plan to use them as is?

Hi Rich.

The class 04 wheels will certainly be used as is, not quite so sure about the J94 wheels yet.

Julia.

Hi.

Very happy with these. 8.5mm Austerity wheels now done too. The resin really suits this particular application. Dimensionally they seem to be within 0.05mm too (but I add material on for a machining allowance anyway).

Julia.

3DP Class 04 wheels fresh off the printer.

Thanks to @2mm Andy for the resin supply

Julia.

Well that was fun to do!

(Its a 0.5mm drill, managed to do 14 of them)

Julia.

11 hours ago, richbrummitt said:

What I have found is it’s important to get the models dry before curing, at least on any visible surfaces because liquid on the surfaces can cure in place and spoil what should be flat or detailed surface.

 

I am working on a wash and cure 'station' that cures the resin whilst submerged in water. So far, the results are very promising.

Julia

Hi.

I have been working on making a gear cutting machine. It uses a slightly different approach in that it uses a gear hob instead on a series of involute cutters. The mechanics are done, I just need to work out the arduino control for it now.

Missy

That wagon has solid wheels!

Merry Christmas Jerry.

Julia ;P

Thank you very much for the replies guys, its really appreciated.

8 hours ago, bécasse said:

A real wall built with semi-finished stones like that wouldn't be bent round a corner. Rather the cuboid stones would be laid in such a way that the result encompassed the corner with stones at the corner laid at angle to those either side. To replicate it you would need to cut individual stones from the sheet and refix them.

It isn't dissimilar to how a brick wall would cope with a rounded corner but the effect is more dramatic because the stones are significantly larger than bricks. In practice most stone walls would be laid with either a sharp corner or a rather gentler bend - or much smaller stones.

I can see where you are comming from. Studying pictures though, to me it looks like there might be a certain amount of final fitting once the blocks are in position. No doubt the inner faces of the blocks would be square but wouldn't the square blocks be 'rounded off' on the outer faces to a degree so they fit? Its hard to tell...

6 hours ago, Nick Mitchell said:

 On a similar theme - because it is a curve not a sharp bend, how about using a skrawker to cut a series of closely spaced parallel grooves on the reverse?

I forgot to mention to complicate things a little, I have added a 3 degree (ish) taper towards the top of the wall (as in the picture above). I know it makes it harder because I am having to gain or loose material somewhere but I was hoping if I could get the plastic flexible enough, there would be just enough compliance to take up the relief.

Julia.

3 minutes ago, John Brenchley said:

Hi Julia

How thick is Kibri embossed plastic?

Best wishes

John

Thanks John.

I haven't tried the boiling water thing yet. Thank you for the advice.

The plastic is 1mm thick (40thou)

Julia.

Hi.

I am trying to form some Kibri embossed plastic stone sheet. So far I havent had much luck...

Gentle? Heat using a hot air gun.

Put in the oven on a low heat and left until soft.

As you can see, I am not having much luck. Has anyone got any help and advice on how it could be possible to form this plastic sheet without getting as much distortion? The plastic is injection moulded so I dont know if that means it acts differently to regular plasticard.

Thank you.

Julia.

Hi.

I really think more people should choose a manufacturing process that fits the model. Not get a model to fit a manufacturing process.

M.

Hi.

According to my friend (who closely inspects these wagons on a daily basis) you have to do a fire damaged version. Its not that uncommon apparently!

M.

10 hours ago, TomE said:

I’ll defer to Julia ( @missy ) on that one as she made the modification to the CAD for this experiment! 

Tom.

Thanks Tom!

I generated the pattern in AutoCAD (Attached just in case anyone would like to use it).

A section of the pattern was then copied then pasted into a sketch on the required surface (in this case, towards the bottom of the wagon), then trimmed to suit the aperture.

This was then extruded to the underside of the roof profile.

OK, this pattern is different from Toms original but I had to regenerate it for the pics.

Simple really!

Julia

honeycombe fill template.dwg

14 minutes ago, Valentin said:

Julia, will this spindle mod take 0.5mm HSS drill bits with the same size shank?

Hi Valentin.

The spindle mod upgrades the milling machine to accept ER11 collets. It will therefore give you the ability to take a wider range of tools.

https://www.arceurotrade.co.uk/Catalogue/Collets/ER-Collets/ER11-Collets/ER11-Collets---Metric

Plenty of suppliers of ER11 collets as they are pretty standard, ranging from cheap Chinese to high quality precision manufactured types.

Julia.

The mechanicals for the gear cutting machine are now close to completion. Working out how to run it is next....

Julia.

Excellent idea!

I would love to see details on what bits are required to complete the kit too. I.E. what chassis, wheels, etc....

Julia

3 minutes ago, Valentin said:

Julia,

 

It is not clear from your picture if there is some protection under the plastic sheet, to protect the milling bed and the milling bit. If not, is it not necessary? I always use a scrap piece of ply but I would happily not use it as it doesn't help much when I try to align the part I want to mill.

 

Valentin

Hi Valentin.

Yes, I always make sure I am not cutting the bed of the milling machine. I think in that picture I am using an off-cut of MDF from an old TV cabinet! As I am profiling only, the flatness is not critical. One thing I have fund is really useful when cutting thin sheet material is 3M re-positional spray mount. Its great at holding material down while cutting.

The adhesive can be easily dissolved using IPA when finished.

Julia

18 minutes ago, Sithlord75 said:

And what are you cutting?

Plastic!

(0.5mm thick plasticard sheet)

J.

9 hours ago, D869 said:

Did you also know there are single flute cutters?.... and reasons why they work better for some jobs... but again, to get started with an MF70 it really doesn't matter.

They are very good at cutting plastic.....

Julia

Hello.

In the fantastic article by Trevor Hughes on Talyllyn Wagons he mentions using a form tool from a company called carbide solutions. I have searched for the company online but sadly havent found anything listing form tools. Can anyone point me in the right direction to the company?

Thanks

M.