Another aluminium extrusion router

[RicknBeachcrest]

I received an offer from Hiwin for ballscrews which was much higher than I expected. It showed up they charge 120 EUR for end machining a single ballscrew...

I read many topics here and it does not look like a rocket science. Btw I did turn ACME rods myself using angle grinder (see my first build).
If the ballscrew is not hardened completly, once you grind the hardened threads you can continue processing using HSS tools on a mini lathe. Wishing I had one...
Chinese eBay sellers like 365bestseller offer end machining for 8 USD. A local workshop does end machining for 30 EUR.

Isn´t 120 a bit unreasonable?

Check out what Misumi wants. That is where I got my ball screws from. I'm real happy with them.

[qwertysimo]

Check out what Misumi wants. That is where I got my ball screws from. I'm real happy with them.

I looked at your build thread again. You got BSST - rolled C7 ballscrew. Misumi price is almost the same as Hiwin for the same specs. Both with ends machined.

[RicknBeachcrest]

I looked at your build thread again. You got BSST - rolled C7 ballscrew. Misumi price is almost the same as Hiwin for the same specs. Both with ends machined.

Well they had two things going for them that I didn't. They had the tools to do the job and they had done it many times before, successfully. If you don't have the tools or the machining knowledge, you can take your changes and do it yourself or pay some one to do it for you.

One thing to keep in mind in this whole process, is that the precision and repeatability of your machine will only be as good as it's weakest link.

Sometimes, you just gotta pay the Man.

[qwertysimo]

Hi again, back on my project...

Looking at Misumi options for connecting extrusions (link) I wonder which type of connection provides stronger joint - bracket or blind joint?

Blind joints shown in this video (youtu.be/7KkePUD1WrI?t=7s) look perfectly elegant compared to 90-degree brackets. I could not find joint strength comparision in Misumi materials. They just recommend blind joints for scenarios when you need "clean corners" and to "avoid interference"...

On picture that Lee posted, would it be huge difference to use four brackets in the middle of his base table compared to blind-joined pieces? In terms of rigidity...

Thanks.

[LeeWay]

I did use 4 brackets and should have used 8, however the extrusions were a good tight fit and stayed in place without brackets. 8 brackets would most certainly be stronger than blind joints, but may actually cost more. However you have extra cost for machining blind joints too.
This machine had a few blind joint connections in the gantry. They work, but I am not really impressed with them.

[qwertysimo]

Thanks. Using brackets...

[qwertysimo]

A progress made... Steel welded base table is finished. There was minor heat distortion so I decided to pour the top of the frame using West System 105 epoxy resin and 209 extra long hardener. The top is self leveled and flat now. After a week from pouring I want to continue with build - to place aluminium extrusion frame on it - and I wonder: wouldn´t be reasonable to place something between the epoxy resin and aluminium extrusion? E.g. bicycle tube to act like an micro damper or gasket?

[qwertysimo]

Welded steel base with rubber legs (hockey pucks) and casters. I modified original design to make the base a two part to be able to adjust height as neccessary, not to rely on legs only. Top part is pushed into the bottom part and fixed by screws through legs.


Decking on top of the frame made of 8 mm MDF, with tape for easier final disassembly. MDF is attached using a waterproof glue, everything sealed to prevent resine leakage.


Epoxy resin poured.


Decking removal and edges grinded.


I am about to mount the extrusion base.

[1Jumper10]

Probably wouldnt want to undo all your effort in pouring a perfectly flat surface to support your rails by adding in spongy rubber or gasket between your epoxy and your rails. I modified my router awhile back and i added sand for extra weight resonance damping. Sand does a good job at killing resonance and on mine it made a noticeable improvement.

Sent from my VS980 4G using Tapatalk

[qwertysimo]

Thanks Jumper, I have placed the extrusion base directly on epoxy layer.

[1Jumper10]

Wow! Nice job on the Epoxy. I've never poured epoxy to get a flat surface before but it looks like its in my future.
Looks like you spent a fortune on Extrusion I priced out mine last night. Seems any time I do that it is always shocking!

[qwertysimo]

Looks like you spent a fortune on Extrusion

The reason I opted for steel table...

[qwertysimo]

Hi,

I cut my first aluminium parts to replace temporary MDF parts on my router. What looked like a success first to me (no broken cutter, nice chips, cold cutter after machining), turned into a problem - machined parts do not have square cuts, but trapezoidal instead.

If the result is like this:

 /-----------------/
/-----------------/

it would indicate I need to tram the spindle.

But what I got is this:

 /-----------------\
/-------------------\

on all four sides on all parts and I do not know what does it mean! I cut three parts from a panel and all have the same problem. I checked all sides against machinist square to confirm this scenario.

It was 6061 T651, faced to 14 mm thickness. Profiling was done using new 6 mm single flute spiral up-cut carbide cutter, DOC 1 mm, chipload 0.06 mm (12.000 rpm, 720 mm/min), 14 mm flute lenght (20 mm sticking out of the collet). Chips were continuously extracted with shop vac. Roughing pass was done by conventional cutting with 0.2 mm left, finishing pass (DOC 6mm) done by climb cutting. WD40 used only during finishing pass.

The part in left bottom corner was supposed to be 60 x 60 mm, but the bottom face is 60.14 x 60.14 and top face is 59.83 x 59.83 mm (at least I am getting equal diagonals).



Climb cut during finishing 0.2 mm pass could not impact dimensions that much. (Or could?)

Can you tell what is wrong?

[jajohnsen]

Hi nice build, did you figure out what caused the trapezoidal cuts? Also do you have any pictures of your build? I'm thinking of building something simular as you