So for the one who are wondering the Math challenge is called : The cutting stock problem. And nowadays there is a app for everything (Cutter - Cutting Optimizer) “I should warn you the ads in that app are so annoying”
Cost of linear rail is around £120 in total with delivery and making it about £13.5 for each printer. I’ll communicate all this to Peter shortly.
I’m assuming you are using stainless steel ground bearing shafts (not case hardened) for the 3D printer slide ways. If this is the case, then RobertL gave you the best answer. This would be very easy and give you a nice square end.
In-terms of the tools at the maker space, you could hacksaw the bar in the vice and file the ends. This would be functional, take some time and may not be very pretty. 8mm dia bar should not be cut on the metal band saw.
It’s not obvious that you have chosen the best approach. 1.5 or 3m length of 8mm bar with likely arrive bent like a banana! You can buy these from eBay cut to length and delivered in a strong plastic tube that prevents and distortion.
It’s important these are dead straight otherwise the accumulative error with impact the printed parts.
Material: Cf35 h6 (hardened & ground linear shaft)
£33 per set (pretty much ebay price but quality guaranteed so this is the high end upgrade options ) www.euro-bearings.com
Delivery £12
I’ve closed the “Prusa Upgrade Options” topic and protected the google sheets who allowed editing of the upgrades options (small padlock is visible on the sheet tab). This is just to avoid any confusion as all order have been made.
The spreadsheets is now up to date as far as I know for the one who have asked me to print part and cut there frame I’ve added the details to the order list and I will be calculating the balance when we place the finale orders.
Next week I will forward the details for the final orders (fixing, threaded rod, dupont connectors, zip ties, cable wrap) Some of those might be available from the electronic area in the space already but I just had not time to follow up the rest is UK based so will be here within a week.
I’m considering Saturday 18th and some evening session during the week for the first preparation session. Like this all of us will be able to do that important part of the process.
What do we need to prepare you’ll ask.
Soldering wire extension to the stepper motor and crimping dupont connector, motor testing
Testing Electronic, flashing firmware
Testing stepper driver
Cutting threaded rod
Preparing each set with all their parts to make sure I didn’t forget anything
I’m realist knowing that we won’t be able to do all this in one session but the more of us participating who can join the smoother the build would become.
I think 2 sessions of prep we should be able to assemble the printer in 1 session and final calibration on an other one.
The preparation mean that when we seat down to assemble the printer no one will face weird troubleshooting and ultimately allow all of us to move faster
Doesn’t look like 18th is a Saturday. Unfortunately I didn’t heard back from either @peter_hellyer or @electrotechs on the last message so for now we are still waiting on material sorry. I’ll let you know if I can do Saturday 15th otherwise you can still join me next Tuesday evening.
There is separate thread about ordering stuff for that group build in there I’ve listed some requirement and it was mentioned that those items might be available or they could be ordered. Details below
Cable wrap
@electrotechs mentioned they could help provide the items below if they can confirm if it’s possible otherwise will order some. Many thanks
Dupont connector (d@electrotechs mentioned they could help provide the items below if they can confirm if it’s possible otherwise will order some. Many thanks
Dupont connector (details below) and some electrical wires to do extension those are on the electronic workbench usual (red, black, blue , green)