The Bucket Foundry

[WilDun]

I saw a post on the first pages, to make the molding cores using 'bondi fill'. Is it some sort of gypsum? is there a more general terms about bondi fill?

Thank you!

It is just ordinary car body filler or "bog" - as we usually call it here.

(Sorry i see that Yow ling has already answered that question!).

[Flettner]

Don't worry Will, things are still happening in the pattern shop. I've sort of got a water jacket shape made but I wasn't sure how I was going to hold it in place ie where the core prints were going to be placed. This all depends on how the sand mold is taken apart and re assembled (without the pattern inside). When I remember how this new cellphone thing works I'll post more pictures.

[WilDun]

Don't worry Will, things are still happening in the pattern shop. I've sort of got a water jacket shape made but I wasn't sure how I was going to hold it in place ie where the core prints were going to be placed. This all depends on how the sand mold is taken apart and re assembled (without the pattern inside). When I remember how this new cellphone thing works I'll post more pictures.

Look forward to hearing and seeing what is happening at your workshop.

I'm also trying to get my head around the Ryger thing on ESE now and I am beginning to form my own opinions on it - beginning to favour something based on the working two stroke by that guy in Oz, which is running with a seperate crankcase (this one I think I mentioned in "Oddball" way back). - come to think of it, he has a Dutch name too! ....... I wonder?

I'm pleased you mentioned over there (in ESE) about this foundry thread - also not forgetting the "Oddball" thread for other stuff (like the Ryger maybe? - too late there! ) - maybe some people could mention there that they have posted something on foundry work here, or some innovative ideas on the "Oddball" thread so keeping everything seperated and prevent a "hodge podge" of good ideas being swept away and swallowed up by the giant, fast moving ESE thread. this could allow the ordinary tuners to have a say on their standard stuff.
It might take a little effort to organise of course and I don't really have a voice over there - just an "also ran" I'm afraid.

Anyway, that was my idea from way back but I'm sure it would take some changing - I hope it hasn't turned into a thread where the record number of postings has become the most important target! (this statement inspired by the recent comment made by Frits).
The ESE thread reminds me on my workshop, ie full of good stuff, but can I find it?! clutter, clutter and more clutter

[Peiter]

I'm gathering all kinds of pictures / info on the 3d scanning / CAD / 3d printing and PLA investment casting of my cylinder, I'll try to post it this evening (Dutch time )

[WilDun]

I'm gathering all kinds of pictures / info on the 3d scanning / CAD / 3d printing and PLA investment casting of my cylinder, I'll try to post it this evening (Dutch time )

Peiter, - That sounds good to me!

[Arifidyan]

Hello Arifdyan, Bondi is the filler used to repair dents in cars before they are repainted , it comes in a tin with a small tube of hardener. When it is set it is like a hard plastic that can be sanded , some people call it Bog, just google automotive body filler

It is just ordinary car body filler or "bog" - as we usually call it here.

(Sorry i see that Yow ling has already answered that question!).

Big thanks to answer.

My 135cc project :
(photos attached)

[WilDun]

My 135cc project :
(photos attached)

I'm not really understanding that core you have made (in the pic) - especially the 'indents' you have in the porting area, but maybe someone can explain (I seem to have missed the plot somewhere !)

[husaberg]

I'm not really understanding that core you have made (in the pic) - especially the 'indents' you have made in the porting area, but maybe someone can explain (I seem to have missed the plot somewhere !)

They are core prints that the transfers attach to. They allow the correct position and orientation to be achieved when the sand or resin core is made and assembled. In the picture You are looked at the female indentation for the transfers, in this case the transfers will carry a male protuberance.

[WilDun]

They are core prints that the transfers attach to. They allow the correct position and orientation to be achieved when the sand or resin core is made and assembled. In the picture You are looked at the female indentation for the transfers, in this case the transfers will carry a male protuberance.

I knew that I wouldn't 'get it' even though the obvious answer was staring me right in the face! - there you go, we learn something new every day - that's really what life is all about!

Come to think of it, reminds me what Ronald Reagan said when he knew that his Alzheimer's was starting to set in - he said " you get to meet lots of new people every day"

[Frits Overmars]

.. reminds me what Ronald Reagan said when he knew that his Alzheimer's was starting to set in

Three advantages of Alzheimer: you meet new people every day, you can hide your own easter eggs, and you meet new people every day.

[WilDun]

Three advantages of Alzheimer: you meet new people every day, you can hide your own easter eggs, and you meet new people every day.

Yes, probably, but how did this discussion start?.....and .......now what were we talking about?

[polinizei]

Hi guys, I want do introduce my longtime project.
60x66 Bore for my old 4 gear shifted scooter.
I will use CAD and my Zortrax 3D printer.
Since my beginning, I spend more than 1000 hours in cad modelling, so it’s a bit virtual for a while.
The next big thing is that Ryger Stuff, that keeps me away finishing what I have begone…

Here are some Pics.

[polinizei]

More Pics (and more text)

[WilDun]

More Pics (and more text)

All looks good
I think, as you said you should finish it first - seeing that you have actually begun this project (instead of becoming one of the crowd trying to be first with a "Ryger"

You have obviously invested heavily in software and printer etc. but will you still need to clean up the PLA pattern by hand before use? and will you be casting the stud holes as well, ie instead of drilling solid metal?
So far it looks ok. but then there's the casting part to be done as well! - Of course, you may already have experience in doing that, I don't know.
If you haven't though, I feel that you should concentrate on learning that first (before the Ryger) as it will be just as important as the pattern work and will take a lot of practice.

I'm slowly learning to do it all the old way with limited equipment, (I will probably never be able to afford new equipment but I only do it for enjoyment). Moulding and casting, whatever equipment you may have, still takes some learning and depends a lot on "touch and feel".
I think it will be a great pastime once I've mastered it all!

Good luck with your endeavours - they seem to be going well so far.

[Peiter]

Polinzei, cool looking stuff!

Below is my first part on the PLA made cylinder and casting it;
At first I wanted to buy a cylinder kit made by Stage6 or a Malossi speed 7T which all perform reasonably well.
However, in december 2014 I stumbled upon a guy on google who was casting an aluminium piece directly from his PLA printed 3D model (http://3dtopo.com/lostPLA/).
This made me interested in the subject and together with a metal foundry nearby where I live, we tried a sample ourselfs. It turned out that PLA will melt away 100%
without residues, so the method was indeed quite good to cast cylinders!

Together with a good friend we then formed the idea to start designing a cylinder ourself where we could work around the following:
- The original stud size is 56x56 with 7mm studs, this pattern is too small for a 47.6 bore cylinder to shape it correctly at the exhaust and b-port.
- Most aftermarket cylinders have the exhaust channel at a straight angle whereas we have tried to obtain the desired 20-25 degrees (if I recall it correctly).
- Cooling of most cylinders for a Derbi engine is asymmetric on one side of the exhaust channel.

First, I started making silicone molds of all sorts of cylinders I could get my hands on, a friend's 22 hp 50cc, an Aprilia RSA, a Honda 2007 a-kit, a KTM 125, etc..
(in the picture below are only a few of the silicones, I have enough to fill my desk )

With these molds, I went to a Fablab where they had a reasonable 3D scanner and I scanned the molds with an accuracy of (If I recall it correctly..) 0.1 mm.
Next, I sat together with my friend and given our appetite and enthusiasm to discover things ourselfs (in some people's eyes stubbornness), we decided to go with the Honda port lay-out as shown in the images.

The Honda cylinder had the A-port its edge nearest to the B-port almost perpendicular to the bore and aimed at the other side. We decided to go with a more common direction of aiming the A-port further towards the C.
The axial angles are set to about 22 deg. for the A-port, 8 deg. for the B port and 50 deg. for the C-port.

After designing the cylinder in CAD, it was time to print it in PLA. As we had to remove / clean the white shell after casting, we decided to remove the "roof" above the exhaust port such that we could thoroughly clean the cylinder.

Inherent to the FDM process used by our Ultimaker 2, overhangs and roofs larger than 50 or 60 degrees require support material to deposite the material during printing. Therefore, we had to design the cylinder in such a way that it was printable and all the support material was removable.

I'll elaborate on making the design printable and the actual casting next time, hopefully you guys like it!

cheers,

Peter