Which 3D printer is best for home use

[peterwaller]

I had one attempt at a new chassis for Defiant yesterday but I tried it without a raft an it started to curl so I stopped it.
I had already virtually redrawn it as it had several anomilies and although the UP software accepted it I could see from the raft it generated with a large triangular hole the file was flawed.
Today I had more luck and the chassis came out fairly well.
Here it is printing you can see where it puts in the support structure for the motor mounts and front and rear scoops.

Here is the final chassis which is quite accurate althougth the scoop on the left is not joined to the base, I need to fix the drawing for that.

I need to make the basic structure a little thicker (all 1mm at the moment) to give it more strength and hopfully reduce the not too bad curl of 1mm at each end.

Here are a couple of shots showing one of the motor gearboxes in place.


All in all not a bad start but I recon I can make signifcant improvements.

[Roboteernat]

To reduce warping, see if yu can invest in a heated build plate (heat to 70 for PLA and 110 for ABS)
otherwise add 'ears' to the corner for additional surface area sticking around corners to stop warping (as warping occurs in the ears which are cut off)

http://www.makerbot.com/blog/2011/02/25 ... g-monster/ Shows u examples of ears.

Also heated bed means no more rafting, and therefore easier cleaner surfaces! Esp good for slopes and lifters

Nice prints btw!

[marto]

This is an UP it already has a heated build plate. You also really can't tweak many of the settings at all.

You are pretty much locked in. Good news is that their software is amazing and you really don't need to tweak anything at all. Compared to a reprap it is in a different league.

Steve

[peterwaller]

I must admit I assumed the any warping would be due to the model not bonding correctly to the table or in this case the perforated sheet.
But it appears that it is stresses built up in the structure that are causing the problem.
I have just built a second chassis with 2mm sides and 1.5mm base and ends and it has come out much stronger.
I checked it on the table when it was cooling and it was quite flat.
I then removed the clips holding the perforated sheet to the bed and the chassis and the sheet exibited the 1mm lifting of each end.
Once the model was removed the perforated sheet returned to be flat.

[peterwaller]

Just had a try at a Acetone vapour tratment and I must admit it seemed to work well.
I didn't want to cart the printer out to the garage to use the heated build plate to warm the acetone so I did it with boiling water.
I hung the wheel I was going to treat from a hole in the lid of a jamjar on a piece of wire so to it was about an 25 mm from the bottom.
I then put about a 5mm of acetone in the jar and fitted the lid.
I then stood the jar in a larger metal container into which I poured boiling water.
After about 8 minutes I replaced the water to keep the temperature up.
After a total of 15 minutes I removed the wheel and let it set for a futher 15 minutes.
As you can see from the pictures below the build lines around the rim are still visible although reduced but the main gain beside the gloss finish is the way any slight imperfections and gaps have been filled improving the strength.

[marto]

The acetone treatment is a trade off between smoothness and size constraints most of the time. The more you smooth it the more melty it gets and may change shape. I prefer the rice cooker, as you just throw in 2 cap fulls of acetone. Wait until you can see the vapour condensing on the lid. Turn off rice cooker. Wait 2min then remove part. This is the fast and dirty way of doing it.

I also make sure to stand the part on a platform which I can remove without touching the part.

Steve

[peterwaller]

Thanks for all the infomation and advice and keep it coming.
I have just bought some of the Gekko Table Plates from ebay and they look rather good.
I have read several good reports and they are supposed to stick when hot but detatch easily once cooled.
I just tested it printing another wheel and this time I did it without a raft.
The wheel printed without lifting and even without removing the Gekko sheet from the table after about 3 minutes it came off with a gentle tug.
In the picture you can see where the wheel had been.

The perforated sheets worked well but it takes ages to remove the ABS from all the holes and printing a raft just about doubles the time and material used.

[peterwaller]

It looks as though you still need the raft when printing something that needs supports.
This very small version of Enterprise (5cm) supports were so fine they wouldn't stick so I had to print with a raft.

[earthwormjim]

You are so cool,Peter.
When I grow up,I want to be just like you!
Those wheels are very swish,They look like the wheels from the A-Team van! (which are one of my favorite wheel designs,like ever.)
Amazing stuff,as ever.Well done. ( I want one. 8) )

[peterwaller]

You can't grow up and be like me, they are mutually exclusive as I never have grown up.