[FW] Wedge Spinner in time for Robo Challenge champs!

[Giles]

Talking of which, any advice on drilling hardox? does it need anything special? I've every so slightly fucked up the CAD and misaligned a set of holes by around 3mm, so need to drill em out a bit. I knew I'd fuck up something rushing it like I did :P

[Rapidrory]

Filing isn't really an option with hardox unless you have a power tool to do it for you; it's not called a ware resistant steel for nothing! Paint scrapers are used quite a lot and have been shown to get underneath most things with a lot less effort than filing hardox (something like this would probably do: http://www.ebay.co.uk/itm/EXTRA-WIDE...0AAOxy~ilSPeiz)

For drilling hardox, a fresh cobalt drill or similar and plenty of cutting fluid will do the job nicely.

[Eventorizon]

Just don't let the Hardox or the dill bit overheat. If it does you will work harden the Hardox further and make it impossible to drill. We've had this issue with countersinking and drilling Hardox in the past. Just take it slow and it should be fine.

[Rapidrory]

Yeah, don't go easy on the cutting fluid; I normally drill about 1mm deep at a time, then apply a load more.

[Giles]

I have a second option, which is to put a 3mm strip of metal between the frame and the 12mm threaded rod, thus aligning it with the holes in the hardox..... sounds like it might be the easier choice. The hardox has other points of attachment that don't have any issues, so I think this would be an ok fix :x
Good advice though, I have plenty of cutting oil, might need a higher quality drillbit though if I do try to drill it!

[Rapidrory]

I got a suitable one from screw fix for about £3 for a single drill... If you only need one size it's well worth it for Hardox!

[overkill]

As well as using cutting oil, use slow speed and lots of pressure. I find hardened steel drills much easier if you start a pilot hole with a small drill around 2 to 3mm. The pressure per sq. inch is huge with a small bit, allowing it to punch through quickly with less heating. Try to find a cobalt drill bit with a split point and a 135 degree angle, they will last longer and cut faster in hardened steel.

[GlenR]

https://www.youtube.com/watch?v=UUIj9ut5y1E

see if you can dig up the bosch blue style masonry bits, they will drill a hole in any hardness material but it isn't accurate (6mm hole will be 6.3 etc etc).

[Ellis]

I just got some 5mm "Bosch blue" bits from Screwfix, like the above. I need to drill quite a few holes in hardox so fingers crossed they do the job!

[PJ-27]

Make sure you pilot, cobalt bits go through Hardox like butter, lots of pressure, slow speed lots of cutting fluid (I just use WD40, works fine).

[typhoon_driver]

Ellis, they will but make sure that your setup is rigid. In other words that your work isn't going to vibrate and I would recommend only using them with a pillar drill or mill on the slowest speed you can.

A few things I found with them,

- They weren't great at hole cleaning and I to manually remove material after the hole got deeper than the diameter of the drill bit.
- The white coolant you would use with a lathe or mill worked best for keeping things cool. I also tried drilling / tapping paste but this didn't work as well. I think the coolant assisted in removing material.
- I was drilling 10mm hole and they actually seemed to prefer no pilot hole. I was initially drilling a pilot hole with a 5mm before opening it to 10mm but 10mm straight seemed to work best.
- Once the diamond head has gone then bin them, they are useless at that point.
- I had a 5mm bit snap off in the hardox (was drilling 20mm thick hardox 400). Couldn't remove it with pliers etc but the 10mm bit just went straight through the broken bit in the hole no bother.
- I quickly nackered my first 10mm bit but the second one got 80mm of hardox drilling done before it was junk.
- They are good but at the same time, not being able to sharpen them means that they have less of a life than a cobalt bit which can be sharpened on a bench grinder.

[Ellis]

Cheers for the tips Gary, all noted. I only have to drill the 5mm holes into 3.2mm hardox so hopefully chip clearance and the small size of the drill (relative to the fairly chunky drill press I have) should be okay. I bought 3, expecting to burn through them, for £8 all in, so not going to cry if it goes badly.

[Giles]

Good tips indeed! Will see how it goes

Harry, parts from you arrived this morning, they look amazing! Will see how well they fit tonight. I've bought a pair of TZ85's as backup ESC's just incase we don't finish our custom ones this weekend to an acceptable level. I'll be converting them to brushed drive this weekend. I only have one receiver at the moment, should I assume it will break and bring backups? Any recommendations on cheap receivers that do the job?

[Gabe01]

We put the mill into the slowest possible speed and then keep applying pressure if you let the tip rub it will heat up and loose its edge. plus keep that white sauce flowing.

[Giles]

So much to do arghhhhh!!!



Firstly... the ebay seller for all the bolts sent me cap heads when I ordered a mix of counter sunk flats and button heads.... I've re-ordered another load from a different seller, but for now cap heads will do. New ones come on Wednesday. Side/back will be counter sunks with buttons everywhere else.

Secondly, my belts don't fit! Had to order the next size up from belting online, but fear they wont come in time. Will probably search for another shop to buy from just in case.

NONE of the electronics are done yet! Hopefully this won't be the case by tomorrow night :P