"Speed for the Need" - a mod-package increasing print-accuracy on the Cetus

@techsalad Awesome thanks for the update.

@skezo Finally received a call from the machine-shop this morning. They’ll be working overtime on the weekend and are promising my price quote by Sunday Sept. 22.

With any product in it’s early stages, the question arises, how many to produce? To-date, there has been little indication of demand for this mod-package. To be honest, until you @skezo expressed interest, I had moved-on to other projects…there has been only one other Cetus owner having expressed interest.

I’m extremely happy with my Cetus printer with the modifications I’ve made to enhance the print-quality and enjoying the insane speeds I’m able to achieve when printing prototypes and proof-of-concept with very little loss-of-quality. Basically, it boils done to … I have a small-footprint(truly desktop) 3D printer that prints like a champ. Every print is just like the last one, no blobs, no surface artifacts, no strings, no nozzle clogs, every layer is right where it should be… and I’m still using stock electronics and stock nozzles…lol. Even though I have an extra Azteeg X5, better steppers, a beta first generation Bondtech extruder assembly, what’s the point of installing those goodies??. Ok, there are reasons why I will eventually upgrade the electronics and extruder assembly… but those reasons aren’t based on print-quality! If I was still running a 3D Hubs print-service(in 2013 there were only 8 hubs in Western Canada), I’d purchase 50 of these printers, install my mods and run-circles around the competition… I’d provide a better quality 3D-print quicker than those with $2500+ 3D FDM printers. Meanwhile, I have a $3500 SLA printer sitting-idle collecting dust…why? …post-processing…it really sux… heck, I can run a print on the Cetus, twist the print off the bed with my fingers and use the printed model. Well, not every print is ready to use, I sometimes have to snip off the tiny string of filament from where the print finished… and infrequently the print is welded to the green painters tape on the glass print-bed.

Ok, enough rambling, @skezo , the original point I was trying to make is …if there are only two Cetus owners interested, and I order two sets of mods to be machined, the cost from the machine shop will be too expensive. We’ll see what the machine-shop quote is this weekend. I may have to machine the parts myself, not something I’m looking forward to, it’s incredibly repetitious and it’s boring work. It’s the “boring work” part that gets in my way… as I suffer extreme pain daily and “boring work” is too little to distract from the pain and mistakes are easily introduced.

So there you have it…full transparency… that is where these mods currently exist.

Cheers,
Brent

The weekend came and went, no quotes arrived. It seems the normal these days is cherry-picking potential orders for the greatest revenue, and those that don’t hit the top 10 stay at the bottom of the list until there’s a lull in the incoming projects, not to be confused with… a temporary lack of manpower to meet the demand. The other thing I see happening is long-time customers automatically slotted into the top-ten projects to concentrate on, this is one of those areas where capitalism kinda fails, especially when attempting to support local business. Well, this is strike three, and that’s one too many for me… so it’s time to cut the tether-of- forgiveness and move on. Sorry for the delay @skezo , let me know if this is strike three for me and you have lost interest.

Best regards,
Brent

@techsalad no worries, thanks for looking into it. Would you be open to open sourcing your work on something like github? This way people can use their local machine-shop to get the mods created.

@skezo , I have considered the many ways of making the mods available to folks. Even though the machining processes required to make these mods might look inexpensive to produce, there are a couple of features requiring less than .001" (.03mm) tolerance. When a tolerance dips below .001" the machining cost increases. The angle of the longer bar must have a very low tolerance otherwise it will not comfortably fit in the very-narrow safe-zone where it is close to the print-bed and the z-axis stepper motor. And then there is also the face of the aluminum bars that meet the extrusions, they are milled flat, also requiring a low tolerance over the lengths. The other thing going on is… these extrusions, by design from all the manufacturers, are not flat over the widths of the extrusions. When I hold a Certified-Flat Laboratory-Grade bar across the widths of the extrusions, they are not flat-and-square, some areas might be but not all areas. I was as surprised as you might be. This is no fault of Tiertime, the extrusion quality used by all the printer manufacturers are low to keep the costs lower. So I will likely have to include brass shims.

The short answer is, from your local machine-shop, the cost of making one set will easily be $100+. If you don’t care about dimensionally accurate prints, and only want to get rid of the z-axis wobble on tall prints, then I guess you could relax the tolerances and get the cost below $100, but it won’t be by much. Their setup fee will be $40+ …probably closer to the standard $65.

I’m looking to get the selling price of the three aluminum stabilizer bars well below $100, closer to the $50 mark if possible. If we get 50 Cetus owners committed then we are probably around the $70 mark, 100 sets will be closer to the $50-60 mark.

If I can be so bold to say…ok I will …
These stabilizer mods are awesome, not because I’m biased, they really do the job… all the way…very little room for improvement if at all. There is no other way to effectively apply a completely bolt-on(exoskeleton type) solution that ties into the print-bed axis with the minimum amount of materials and zero interference as inexpensively as this mod-package provides. I know, that’s a tall order for sure.

I have installed 11 mods on my Cetus printer, they all work together. Whenever I print something, I have to say I’m just amazed at the quality… from a sub-$1000 printer! …and a cantilever style!, not the most popular of 3D printers for sure.

If folks do just one thing… just one mod…stabilize the nozzle…your print accuracy will increase by a very large amount… guaranteed. That mod combined with stabilizing the z-axis will make you smile.

Cheers,
Brent

Just finished building a storage/dispensing box for 6 reels of filament. To reduce the friction of the filament delivery I designed a ball-swivel that attaches to the box minimizing the friction as the filament moves from the moisture controlled environment through to the extruder. As the amount of filament on a reel declines, the friction through whatever you use to deliver the filament to the extruder increases…and by a fair amount I might add. When the amount of filament on the reel gets to less than 50%, the amount of friction within a moisture proof delivery system triples… more depending on the type of filament.

I found a manufacturer of PTFE tubing that reduces those amounts of friction. It’s the Capricorn XS brand. They have a 4mmOD x 1.90mmID PTFE tubing… I highly recommend the Capricorn XS tubing, it’s pure PTFE and is very slippery. The 1.90mmID versus 2.00mmID also reduces friction by some amount, especially flexible filament. The XS type is rated at 340deg Celsius. They also have the XS type in 3.00mmOD x 2.00mmID, this is the size in the upper neck of your nozzle. I believe the tubing that comes with a standard nozzle is only rated to 200deg Celsius, so if you are printing at above 200deg Celsius, then the tubing is degrading at an advanced rate and over-time will contaminate the filament as the tubing burns, so frequent cleaning is required, by removing the tubing and wiping clean the black grunge of burnt filament and burnt tubing. The other thing happening before the burning is deformation, so it will no longer line-up with the surface of the lower brass part of the nozzle as engineered by Tiertime. There is very little room for error here, if the nozzle ptfe tubing is not perfectly square at the bottom end, there will be filament delivery issues. If the nozzle tubing is too long it will flare and choke the filament creating filament delivery issues. The problems created when using a standard PTFE tubing above the rated 200deg Celsius are numerous…basically most of the problems reported by Cetus owners when filament is not delivered to the print-bed as expected.

OK, done with today’s ramblings…as usual…assume the position…happy printing that is!
Cheers,
Brent

@skezo , looks like I will be machining the first couple sets on my cnc mill. I’m not geared for production runs of machined parts, I’m an idea prototyper and product developer…so mostly one-of machined parts.

This first production run of the z-axis stabilizer mod will be priced at $65.00USD to get the ball rolling. I’ll machine 5 sets this time. This initial price will include stainless-steel fasteners, lockwashers and shims. This first production-run price will change if there is a second batch produced at a machine-shop.

This morning I met with 2 machine-shops with the mods I use on my Cetus printer and asked for a ball-park cost. Their verbal cost(not guaranteed) estimate is roughly $80.00 each when producing quantities of 25 sets per batch. This ball-park cost is only for the machining and does not include any post-processing such as a nice-looking surface finish.

If any other Cetus owners are interested please let me know soon, as the price will likely be much higher if batch quantities produced at a machine-shop are less than 25 sets per batch.

@skezo , let me know if you want to order a set and we can set-up payment via private message.

Cheers,
Brent

@skezo, There is a way to reduce the cost for folks wanting to have a local machine-shop in their area produce the parts for the z-axis stabilizer mod I’ve designed.

The idea I have in mind will substantially reduce the setup charge ($45 - $65USD) that all machine-shops build into the overall cost.

This idea would involve a little work from folks to get the aluminum bars to the point where the machine-shop would simply perform the machining operations without much setup, effectively reducing that huge setup charge.

I’m thinking of creating a thin sheet-metal template etched and cut with a laser. The drilling locations would have a tiny laser-cut hole where folks could simply center-punch the location, near the hole would be laser-etched dimensions and specific instructions.

The template would be cut to the size the aluminum bar needs to be with any angles included, near the angle would be laser-etched instructions. To reduce the material costs(shops usually profit by providing the materials), folks could take the templates to a local metal supplier to have the aluminum-bar lengths precision-cut.

The other cost effectively reduced is shipping from my shop.

Any thoughts?

Is this still an active project? I would be interested in buying this if it fits the MK3 standard.

@incrediblej1 , sorry for the late response. I’ve been battling with a sophisticated attack on my business server. An incredulous story for sure… the attack completely crippled my online business activities, long story short… we caught the hacker…a tenant in the apartment building…my neighbor!

Yes, this project is re-activated now that I have regained control of my business services.

It is my understanding the structural backbone of the MK3 has not changed from the MK1/MK2.

Are you interested in purchasing the sheet-metal template or the finished ready to bolt-on stabilizer mod?

Best regards,
Brent
Technology Salad

Hi Brent!
I just stumbled upon your mods today! I would love to buy your mod kit ready made for my MK3!
Awesome work!

@dar303 , Thanks for the interest! I’ve experienced a few setbacks getting mod kits ready for sale. Looks like there will be a few kits ready by Jan 30th. I’ll contact you when I have a kit ready for you.

Cheers,
Brent
Technology Salad

@techsalad

Any luck on those kits?

Hi guys,

I increased the first batch quantity twice last week and again yesterday. The quantity was based on those that strongly confirmed they would like a kit.

@skezo I got the feeling you had lost interest because I did not receive a reply from you. I currently have 4 extra kits available in this first batch. If you let me know before they are gone I will put your name on one.

@incrediblej1 are you still interested in committing to a mod-kit?

This first batch will be ready within the next week.

Best regards,
Brent
Technology Salad

@techsalad

Yes still interested.

Thank-you for the confirmation @skezo , you are definitely in on the first batch!

Also thank-you for your patience, it’s been painfully slow to get this mod-kit ready for folks. I had hoped to have a machine-shop make the stabilizer parts because I suffer severe pain from a car accident and don’t have many good hours in a day to machine the parts myself. If demand becomes unmanageable I will have to contract a machine-shop to make the parts and the cost will likely double.

Cheers,
Brent

Hi,

Sorry for the late reply. I’m just curious about the price and was wondering if it will work on a MK3 with the extension board installed

Hi @incrediblej1 , I’m trying to keep the cost as low as possible. A typical machine shop is over $100. I’m almost done machining 18 sets and thinking the price will be around the $65 mark. If folks would like to use their own fasteners, lockwashers, brass-shims and tnuts, the price would be lower by $8-10. The expansion board is easily re-located on the stabilizer mod or the z-axis extrusion.

I’ll design a printable mount to relocate the expansion board, I’m thinking of many different solutions. I see the relocation of the expansion board as a minor inconvenience compared to the performance upgrade of the z-axis stabilizer mod.

Cheers,
Brent

Brent I just wanted to say thanks for the heater block bolts tip. My bolts were not loose but also not very rigid and I could see some artifacts.

Worrying about overtightening and stripping the heater block threads, I bent up a 1mm stainless steel wire hanger. It loops around the top notch of the cold end while the other wire end secures to the extruder printed drive gear assembly which is now printed in ABS. I repaired my original MK2 extruder.

Another simple mod is moving the extruder printed belt attachment part to the top side of the belt. I mirrored the Cetus STL file and printed it in ABS. You need to reverse the polarity of one stepper phase to make the software happy. The motivation was that I built a heated ultrabase glass bed and found the original Cetus PLA part got very soft when using ABS bed printing temperatures which for my setup is 115 to 150C. I believe all the Cetus printed motion parts need to be printed out of polycarbonate, PEI or machined out of metal if printing on a heated build surface.

Another lower mainland guy.
-Peter

@peter101 , tks for the comments and the tip about the belt attachment, I believe that attachment should be a thin stainless-steel part…your solution works for sure tho!

Even though you have comfortably tightened the heater block bolts the problem still exists. The bolts inside those stainless steel tubes are too small for the forces being applied and the threads will easily strip and become damaged. I installed a larger bolt size, but even a larger bolt size only gets you part-way to a rigid filament extrusion system. If you browse earlier posts in this thread you will find a picture of my modified extrusion delivery system. I added an aluminum post that anchors the nozzle…this aluminum post solves soooo many problems and allows the extrusion-motor to do its job precisely. If the nozzle is rigid then retraction works properly…precisely… and exactly when retraction is needed.

If the nozzle-height is rigid throughout the entire print process you will no longer experience a nozzle collision with previously printed areas/layers of the part being printed. Although, if the z-axis is not rigid then the nozzle-height will fluctuate throughout the print job, I guarantee you would be surprised at how much!

A rigid nozzle-height solves many other issues, too numerous to list here at this time. I’ve been struggling with some pain flare-ups which keep me from being in my shop and getting those stabilizer-mods finished for the folks patiently waiting.

I should have you over to my shop Peter, you could see the mods and the quality of prints they allow!

Cheers,
Brent