Kickstarter Progress Update #1

Hi everyone, here’s our first progress update.

This post has been cross posted from Kickstarter (
https://www.kickstarter.com/projects/sienci/longmill-benchtop-cnc-router/posts/2494923 )

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Manufacturing updates

We’re going to cover some updates around the manufacturing here on this update. 

Just so everyone knows, we’re still waiting on the Kickstarter funding to come in. We talked with the lending company to spot us some cash between the end of the Kickstarter and when the funding comes in, but it seems that the process took a little longer than expected, the fees for the loan are quite high, and it might be better to wait for the funding to arrive first for some of the larger purchases.

Luckily some of the manufacturers we work with have net 30 days or don’t require us to pay for everything up front so the timing should work out for this.

We’ve also been using the money already in our accounts to start off with some of the smaller purchases, but some of the bigger ticket stuff may need to wait a little bit.

3D printing

As you might have saw, we’ve been 3D printing parts on our two Prusa i3s and at a lesser degree on our two Cetus printers. Due to the volume of all of the printing we need to do, it will be hard to keep up with all the printing. We have ordered 8 new 3D printers to add to our farm to let us produce more parts per day.

Just for the record, the 3D printers that we ordered are the Anycubic Mega-S. One of the reasons we got this printer is because of the Ultrabase print surface, a dimpled glass surface that releases prints right off the surface once they are done with very little or no force. In a print farm scenario, this is really important because from our experience, the most force that a printer experiences in its lifetime comes from removing prints, and by minimizing that, the printers can be more reliable and last longer.

I have been testing and printing on one of the Anycubic Mega printers in the office over the last week or so, since I wanted to order one off Amazon to test quickly before making a bulk purchase, and the print quality and reliability have been good.

I expect the printers to arrive at the middle of next week and we will start putting them together!

Aluminum router mounts

On the last update we were talking about the potential to use aluminum mounts versus plastic printed mounts. We received several samples of the mount last week and have been testing them.

Basically what we did to test was to use a dial indicator to measure deflection at the tooltip by applying a force. The Z height for the gantry was kept the same, and the router was moved to be at the same height for both tests. Pulling 10kg (about 22lbs) from the router collet in the Y direction for both types of mounts resulted in approximately 0.014″ of deflection. Since both mounts have approximately the same deflection, we can conclude that the performance for both mounts are approximately the same.

Here are some other things to consider.

  • We tested the aluminum mount on an aluminum plate. Aluminum is slightly less stiff than steel, so performance may be slightly better when the plate is made from steel.
  • The height of the router and gantry, and the placement of the mount on the Z axis has an impact on rigidity as well. The aluminum mount may have better performance depending on where the mount is located on the gantry.

Since the performance of both mount are approximately the same (with more potential for the aluminum to be better), we’ll be working on using these mounts over the plastic ones, but we will have the mounting points available to have printed mounts for the non-standard router sizes.

Aluminum rails

We are just finishing up tallying the amount of rails that we need to manufacture and finalizing the design. We’ve reached out to our manufacturer to get the quotes and process finalized as well as the material supplier as well. 

I am also working on finalizing the drag chain mounting points and size which the rails will need.

Gantries

We are planning to pick up a couple samples of the Z axis gantry on Thursday to test with the aluminum router mount, and once that is all looking good, make about 400 of them. As mentioned before, the steel should be more rigid that the aluminum.

We’ve made some small changes to the Z axis that will let us get a bit more Z axis travel which is pretty exciting!

Next step is to have the X and Y axis gantries finalized and sent in for manufacturing as well.