3D Printing Newbie

[sharpiel]

I have a project to update my Meade 12" LX200 Classic fork mount, which requires some 3D printing. Specifically I want to insert 3D printed spacers approximately 30mm thick between the base and the bottom of each fork arm to widen the distance between the fork arms where the OTA would sit. Then with longer bolts tighten the forks back to rigidity.

I don't want to buy a printer and have never looked into or had anything 3D printed. So I know nothing really about it. Local to me is a printing shop which states the following online:

"FDM 3D printers create objects using the “traditional” printing method of heating thermoplastic filament and extruding it in layers on a heated glass bed. FDM is extremely flexible in terms of resolution and the types of materials that can be used. FDM is great for quickly and cheaply producing parts to determine qualities like aesthetic design, ergonomic shape, and for small batches to perform product testing."

I need the spacers to be non compressible and accurate to specified dimensions. Would the product they advertise suit my requirements?

Also can I drill through the plastic once printed rather than have the holes printed in?

Thanks guys.

[AstroViking]

Hi,

By the description you've provided, the service will print the items you require, to the standard you require.

I recommend getting the holes printed in. 3D printed items are usually hollow (well, they have structural in-fill to provide strength) so you can't drill through them.

Can you use a piece of 30mm thick plastic instead of something 3D printed? Or are they a strange shape that can't be easily machined / cut?

Cheers,
V

[JA]

Hello Sharpiel,

Whilst I'd have to see the abutting surfaces you want to space apart, I'd tend towards using Aluminium depending on your tools and talents, or possibly something like solid plastic (polycarbonate or acyrlic) as suggested by AV, but that would depend on the exact joint details.

Best
JA

[sil]

It may not be so simple depending where the stresses are on the printed item as it may split along the printed layers. 3d printing does NOT produce a solid plastic part and you’re way better off with a well designed object with holes included than try to drill them as its likely to split plus also not be perfectly aligned. Why not just use washers like everyone else as spacers? Plastic and wood is compressible and if i understand your description you need metal or concrete solution. You’ve jumped to 3d printing as your solution and i think you’re wrong. Tightening bolts will compress a spacer and one each side means you’ll be uneven.

[drylander]

have you thought to look for nylon cutting boards as found in woolies or coles? I found them to be very useful in the shed for a variety of things. A hole saw of the right side will even put a 1/4" hole in the centre and won't compress either.
Pete

[OzEclipse]

You're going to have the weight of the forks and expensive heavy OTA riding on those spacers. Why risk it on a material of unknown structural integrity? Why not get them machined out of aluminium instead? Much stronger, not at any risk of cracking. Ask Joshua Bunn for a quote. I've never seen anything but high praise for his work from happy customers.

Specialist places can 3D print metal but this seems like an easier job for a conventional lathe or mill.
Joe

[xelasnave]

I am learning "Blender" now so as to be able to at least do a plan that can be printed..this is probably the first step..I dont know but without outside input that is my approach.

I have something that could be 3d printed but that I can make using my "old" technology...anyways I conclude that it is something to treat as a hobby and go in for it with that mentality rather than getting into it so as to build something specific.

AND I believe with Blender you can generate a file that you can email off to someone who will print it out for you..

But learning the software is probably the place to start..I would like to know what folk already printing think on that.

Alex

[sil]

Blender can get you a model just like and 3d software. I still use Lightwave 3d which i started using in the early ‘90s for tv and film modelling/rendering. But as for it able to create manifold (watertight) models I dont know. You need a printer so you can understand the strengths and limitations of the physical process and results and design accordingly to shape and strengthen as needed. Its knowledge and experience you need to struggle with in order to understand the reality of the likely result for real world use. You still show the ignorance and have an unrealistic expectation as a result. 3D printers are not all the same and results differ depending on how well setup and tuned the printer is. Particularly how good layer adhesion is, how the temperature and humidity in the room the printer was used will widely effect overall strength and how the infill is handled will change dimensional accuracy. Its like people seeing a cheap telescope at Aldi and thinking that’ll be awesome but the reality is far from the truth, its more likely an experience that will turn them off getting a suitable telescope and astronomy altogether. You’re in the same “ head buried in the sand” position. Sure you can build a model and send it off to someone to print but it could look ok on your screen but have errors due to the software and how you built the model that makes it unabled to be sliced for printing, even if its works it may not be strong enough to be relied on to support weight. Which is why services like Shapeways are expensive they have proper 3D printers not the poor consumer levels ones that are not very good for anything more serious than a trinket. I’m yet to see an affordable and reliable consumer level 3D printer but we’re getting close. They are still mostly chinese built kits from chinese parts with poor quality control and work well for a bit at least until something goes wrong (usually due to using cheapie filaments or electronics frying). To build an effective model requires experience of printing, not just being able to build a model. Still a short cylinder is easy enough and will work out but prepare for it to fail since you clearly dont comprehend how it can fail due to zero experience. Its not as simple as you think. I won’t offer my prediction beyond it’ll go together and work for one day. I prefer my prints to work forever not just temporarily for a little while.

[JA]

There's ways to talk to others, but THAT ain't it. People may be ignorant of knowledge, but that can be acquired just like experience. Ignorance of manners and disrespect is another thing all together.

Peace out.
JA

[xelasnave]

Thanks Steve for taking your time to try and help I do appreciate your input.

Perhaps my style which is to always play down my knowledge has given you a somewhat false impression and so I feel guilty that I may have mislead you in my effort not to throw my weight around.

I am totally aware of the various issues and I have been following the game for many years and it is perhaps my unexpressed understanding that has you maybe putting me in the wrong box and moreover it is indeed my understanding of the realities of cheap printers that has seen me not rushing in and buying a cheap two grand printer...indeed same for the reality of expensive printers for me as a prospective buyer..I don't buy media hype you see..if I buy one it would be functional at a level that would offer genuine benefit and as you well know we are talking big bucks.again but it is not the money it is the learning and Expeience I know that must be gained that has me still not getting into the game...it is that understanding that caused me to suggest it is best seen as a hobby ...

The only reason I came back to thinking about printing was for the RASA scopes one needs a cable management system as the cables pass in front of the light path..it seems standard practice with RASA owners to print a unit to manage the cables..now having spent a whole day making one out of plastic from the bottom of a Woolies shopping bag I came up with a better design that would be printable and then I saw this post and as I often do popped in to offer my views ... anyways like I said the best way to build my "better" unit would be to make it up in cardboard then saturate the cardboard with resin ...I have made many parts over the years this way and the more I think about it and particularly with your timely reminder and given how my head hurts learning Blender cardboard plastic is the way to go...a major benefit of this system is you, most times, can do your plans on lite cardboard then cut it out and turn it into a plastic finished model.

AND the only reason I make something these days is if I can't buy something ready made..the only reason I cast in alluminium my pier to mount fitting was I did not think anything on the market was half decent...and yes many molds that did not cut it and failures but guess what my mount now sits upon.

I was going to build a fantastic mount that I designed to be built out of cardboard and resin..but with a overlay of carbon fibre..would it work?...of course but it would probably take several builds to develop such a revolutionary approach...and I would but I have now my EQ 8R which takes away the need to build something...

The thing I was thinking of is in effect a circle or in Blender speak a cylinder approx 11.5 inches in diameter, u section to carry cable with a semi circle "half cylinder" 5.5 inches in diameter attactched to bring the cables over the light path..a further section carrying the cable up the side of the camera would be sensible...can you make me one please..money is no object..spend what you like on it but I am prepared to pay $50.

Have a great day..nice hearing from you.

Alex

[xelasnave]

I take no offence and I am sure Steve was not trying to be offencive...however I percieve your action of standing up for decent behaviour and saying something most honorable and I thank you for looking out for a poor old man like myself.

Alex

[sharpiel]

Hey all. Thanks for all the responses. I think for this application I’ll get an aluminium block machined. Every point you all raised was an excellent one not to use plastic this time.

Glad I asked. And I can think of a different part of the project that now sounds perfect for 3D printing instead.

[sil]

No i didn’t mean Alex any offence but to point out to the people who clearly make assumptions so often when simple google search will answer their question. How some questions are worded want me to use a hammer to drum in some truth to some people, especially when others with clearly no experience are giving definitive answers that are wrong spreading further ignorance. I’m not ignorant of manners just there are times they are ignored and wont do any good. When it comes to 3D modelling I have over 30 years experience and a decade with home 3d printers for which their is heaps of misinformation out there still being spread as fact.

Money is not object and i’m willing to pay as much as $50 I fully understand. I may have offered to design and print the part for nothing, done that plenty of times for people but publically saying it i got toms of PMs from others wanting freebies printed.Theres a LOT of that in the DIY arena. The original poster didnt include photos so I had to image what the item would be but with having to do up a bolt you get compression forces and plastic likely to deform, scopes are heavy and require precise alignment so deformation of a part not something You’d want and again without seeing then its hard to know if part failure can cause the equipment to fall and be broken . So without specifics I could only advise in generalities anyway. I think its good for people to design and print their own parts as the process is iterative and you find other useful ideas of features you can incorporate to add functionality and strength etc, like as you mentioned bits to run or secure cabling, or maybe ledge ends for you to put in a board shelf to hold equipment. Due to being physically disabled I am forced to create my own solutions to dailly difficulties the world has no answer to.

[xelasnave]

I have my carers looking for some plastic channel tomorrow which if found will be perfect for my job.

Anyways Steve if it is any comfort I never underestimate your capabilities as I pick up on various things you mention in your, to me , always interesting posts that give away many of your skills.

Take care

Alex

[AstroJunk]

I used a bent coat-hanger for many years with my 14" with hyperstar!

I have a 3d printed version now which looks more 'professional' but adds no improvement over my 10 minute bodge :rofl:

On the original topic, Marine ply is a superb spacer material. Easy to work, super strong and awesome damping characteristics.

[sharpiel]

How are your local wildlife at your place these days Alex? I know you'll have befriended several species by now.

[RB]

Might be best to take this topic to PMs, so we can stay on topic.

RB

[sharpiel]

Moderators this thread can now be closed. I received an answer to my OP and as has been pointed out this thread went off topic a way back.

Thanks guys