Designs for automotive use.

[ajlelectronics]

Gone back to PETg for size checking. Looks like a bit more fettling to do!

 

[DSR]

First attempt a dismal failure. I used Kapton tape with 3DLAC and despite a brim, it detached halfway through the print. Layer bonding looks good though.

I use glue stick (e.g. pritt stick) to cover the bed (where the print is going to be), it washes off with water OK afterwards. I also put a cardboard screen round the printer to stop any draughts. It's not perfect but it decreases my fail rate

 

[ajlelectronics]

I use glue stick (e.g. pritt stick)

Just been over to Tesco for one.. HOWWWW MUCCCHHH? £2.36 for a little Pratt stick! I should have gone to the Pound shop earlier!

 

[ajlelectronics]

First attempt of nylon with Magigoo on Kapton...

 

[ajlelectronics]

Dimensions have altered too. The outer diameter should be 19.75mm and the inner should be 16.3mm. I have 19.1 and 15.6mm respectively.

 

[ukracer]

Hmmm... you've got me thinking, now I don't have a 3D printer or a clue where to start doing this, however... how simple/complicated would it be to copy a connector housing? presumably I'd have to CAD it up and couldn't just scan it somehow? Then there is the accuracy, most connector housings appear to be injection moulded complete with sharp corners and moulded spring latches. Am I right in thinking this wouldn't be possible with current 3D printing tech unless I was going to spend lots?

What type and size connector housing?

 

[ukracer]

Dimensions have altered too. The outer diameter should be 19.75mm and the inner should be 16.3mm. I have 19.1 and 15.6mm respectively.

Now that does not surprise me...

 

[DSR]

That doesn't look to bad TBH. Probably now's the time to start altering the extruder settings. This could get addictive BTW. I spend more time farting about with tweaks than is healthy - raise the nozzle temperature, lower it a bit, alter the layer height, alter the bed temperature, move it to a different area on the bed, recalibrate the machine... etc.

The last job I did was black nylon rollers for a Mam's stairlift, it took me several attempts to get them just right and I still ended up reaming the bore out on a couple of them. PETG & PLA are a dream in comparison.

 

[ajlelectronics]

I am printing the other style of bush now. The last hour has been spent setting the printer up again after the BL Touch probe didn't retract and then got dragged and bent along the bed. Bending it back achieved litte, it was still in alarm mode. Eventually I removed it and fettled the pin until it was happier and then levelled the bed too. Rather than Kapton tape, I have applied to Magigoo to the smooth glass surface, to see how that performs. It looks reasonable so far, the print temperature has been reduced by 5 degrees.

 

[ajlelectronics]

Had to abort the print after it detached.

 

[DSR]

Ball cocks.

That looks like it was a bit too cool and the filament hasn't flowed enough to create a good bond.

If you post the STL I'll have a go on my printer and see how well it works on the basic setting.

I'm always amazed at the quality of some of the prints I see and wonder how they get such good results. I think a lot of it is down to post print processing but nobody ever mentions it in any detail.

 

[ajlelectronics]

Here you are:

 

[DSR]

My slicer only had one easily identifiable Nylon setting so I chose that and printed one part, glued spread on the bed and cardboard screen round it.



It didn't warp bit it was leaning a bit drunkenly to the right. The black specks are from the previous PLA that I was using, it looks as if the nozzle wasn't 100% clean.

I tried a couple of tweaks, found an alternative Nylon setting and tried again, the main change was to go to 100% fill and to throw away my cardboard screen - if it's doing a Tower of Pisa impression, then the cardboard isn't doing much shielding. I also tried using a skirt but that just seemed to blend into the part and I ended up with a bit of a mess. I did find that a rim was better than the skirt though.

I also decided to print both parts close together, the thinking being that it will slow the printing down and allow each layer to set as the part is built up and this was quite successful :-


but this part was a bit peculiar. There's a bit of delamination and I think it needs to have its base increased a bit - one thing else to look at, there. I think it needs to be made a bit thicker, the dimensions are way off as well so it will probably need a bit of tweaking to get them close to what is needed.

While I was playing, I discovered (in the advanced skirt settings) a Draft Shield which basically prints a high brim around the objects so I enable that and fired the printer off. It's a bit wasteful doing the draft shield but if it saves a couple of prints, its going to be worth using. I'm certainly going to make more use of it because it does seem to have made the print more stable.


And these were the results after I took them off the bed. It didn't take much to remove them either.

 

[DSR]

I'll add, Prusa I3 Mk3S+, 100% infill, Filamentum Nylon FX256 profile, 90°C bed, 250°C nozzle with Draft Shield seems to be getting close on my printer.

 

[ajlelectronics]

Thankyou for going to all that trouble for me.

My slicer only had one easily identifiable Nylon setting so I chose that and printed one part, glued spread on the bed and cardboard screen round it.

What glue did you use? Is it a glass bed or something else?

It didn't warp bit it was leaning a bit drunkenly to the right. The black specks are from the previous PLA that I was using, it looks as if the nozzle wasn't 100% clean.

That looks to my inexperienced eye like damp filament?

I tried a couple of tweaks, found an alternative Nylon setting and tried again, the main change was to go to 100% fill and to throw away my cardboard screen - if it's doing a Tower of Pisa impression, then the cardboard isn't doing much shielding. I also tried using a skirt but that just seemed to blend into the part and I ended up with a bit of a mess. I did find that a rim was better than the skirt though.

It needs to be 100% infill as it is a bearing surface, but apparently that is one reason why warping is a factor. I went straight to a brim, but it didn't seem to help on the D shaped bush.

I also decided to print both parts close together, the thinking being that it will slow the printing down and allow each layer to set as the part is built up and this was quite successful :-

Yes, I tried a full set. Two small ones and a larger one in the middle, so that the brim was merged. It still came off!

but this part was a bit peculiar. There's a bit of delamination and I think it needs to have its base increased a bit - one thing else to look at, there. I think it needs to be made a bit thicker, the dimensions are way off as well so it will probably need a bit of tweaking to get them close to what is needed.

I can't make it thicker as it is a "bearing shim". The selector shaft runs through it and the selector levers bear against it. Once we have a good quality print, I suspect that the size will not need much tweaking.

While I was playing, I discovered (in the advanced skirt settings) a Draft Shield which basically prints a high brim around the objects so I enable that and fired the printer off. It's a bit wasteful doing the draft shield but if it saves a couple of prints, its going to be worth using. I'm certainly going to make more use of it because it does seem to have made the print more stable.

Yes I have tried that in the past, but as I have a full enclosure now, with a nice 34-40C fug up, I didn't deem it necessary. Perhaps I ought to try it again.

And these were the results after I took them off the bed. It didn't take much to remove them either.

They are looking reasonable. I will have another go this evening, given time or certainly over the weekend.

 

[carbon]

Would the production of this be suitable for casting in polyurethane resin? If it is you could print the part in PLA and make sure the dimensions are correct. Then make a silicone mould from that, than cast it in resin.

 

[DSR]

Thankyou for going to all that trouble for me.

It was for me as well - I learnt some stuff that will make my life easier in the future when I do Nylon

What glue did you use? Is it a glass bed or something else ?

I just used a cheap and cheerful glue stick - just checked and it's Pritt, I think I pinched it off my grand-daughter - Thank's Amélie The bed is a steel sheet with a plastic coating on it, it's the standard bed supplied with the printer, smooth double sided with PEI coating. It is a heated bed.

Prusa Printer Detail Page

That looks to my inexperienced eye like damp filament?

Could be but I have no way of testing if the filament is damp and Mrs R won't be very happy if I taint her Yorkshire Puddings with the smell of Nylon...

I do keep all my filaments in vacuum sealed bags when not in use to minimise the risk of absorption - though they do tend to be left hanging on the printer for a few days when I'm using them. I did look at building warm boxes etc. to try and keep them dry when on the printer but it's too much hassle for the type of printing and use I do.

They are looking reasonable. I will have another go this evening, given time or certainly over the weekend.

Good luck.

 

[ajlelectronics]

I think that as bearing surfaces, that nylon is the only game in town? The originals are I suspect carbon loaded nylon.

 

[ajlelectronics]

I do keep all my filaments in vacuum sealed bags when not in use to minimise the risk of absorption

Apparently nylon has to be dried before every use, even if correctly stored. I read that it will absorb 10% of its weight in water in a week, a little less when bagged. I'm running mine from a dryer (Sunlu clone) which runs flat out at 55C and feeds into the extruder by blue Bowden hose I had left over.

 

[ajlelectronics]

Looking better. 250/100 no fan. Kapton tape and then Magigoo Pro PA. It seemed not to stick on the glass but the tape worked with internal and external brim. I am about to try a triple print.