Todays Project - What did you do today?

[TomG]

We used to joke in school about using micrometers for C clamps Greg, but I never thought of using one as a stop.

I guess it would depend on how much force you intend to put on it. The threads are a fine pitch, but they are hardened so they should be able to take more abuse.

Tom

[f350ca]

It will get loaded if the cutting tool pulls the backlash out of the feed screw. Not sure if I'll need positive rake on the cutter when I'm cutting the rack, if it will cut with the same geometry as a threading tool on the lathe there should be minimal loading. Guess we'll see.

[sasquatch]

Good interesting postings guys!!

[ETC57]

I sure learn a lot around here.
so anyway finally got a lathe project pics later,
I was asked if I could make a stepped shaft to replace one that had been broken and welded several times already.
the shaft holds a idler gear that runs between a bull gear on a cutter shaft and the drive gear, this is on a paper shear.
so I scrounged through there shop and found an old pin that would fit the bill took all the measurements on the shaft the mounting hole and the gear went home and got the pin made only to discover that on that day my ability to read a set of calipers and write what I read on to paper was greatly impaired. OOPS do over to come.
Jerry

[TomG]

It's not just you Jerry. Every now and then, just when you are feeling confident, all of the calipers all get together and decide to ruin your day by providing bad information. I'm pretty sure there is some subversive plan out there involving all calipers, so beware.

Looking forward to the pics of the final shaft.

Tom

[f350ca]

Jerry,
Been there done that more often than I'd like to remember.

[PixMan]

Today's project got me into the shop for about 1/2 an hour, first time I've had anything to do in there for weeks. I was fitting the Triumph factory accessory "top box" to my Tiger 800, and that require drilling four 25mm holes through the rear top "parcel shelf" that the bike come fitted with. The hole locations are spotted on the underside as it's molded. The problem in drilling a 2.5mm (.098") thick piece of plastic like that it two-fold.

First, being somewhat thin and soft, the twist drills just want to grab and pull the part up the flutes. I did OK with an 8mm (.315") drill as a starter hole. The problems came with the 15/16" Silver & Deming drill I had to use, closest to 25mm I had that would fit in the Bridgeport. Two of the four holes end up being on an irregular surface, and nothing about the part is truly flat. I tried "freehanding" it, using the Bridgeport as a drill press. Since I had a little trouble with the starter holes, I quickly realized I'd have to strap it down for the big holes.

A very convoluted setup of wood underneath and the usual stepped block clamps and straps got the job done. It all went together as hoped, and I truly hope I never have to do that to another bike again! ;)

[EdK]

(04-06-2013, 08:49 PM)PixMan Wrote: Today's project got me into the shop for about 1/2 an hour, first time I've had anything to do in there for weeks. I was fitting the Triumph factory accessory "top box" to my Tiger 800, and that require drilling four 25mm holes through the rear top "parcel shelf" that the bike come fitted with. The hole locations are spotted on the underside as it's molded. The problem in drilling a 2.5mm (.098") thick piece of plastic like that it two-fold.

First, being somewhat thin and soft, the twist drills just want to grab and pull the part up the flutes. I did OK with an 8mm (.315") drill as a starter hole. The problems came with the 15/16" Silver & Deming drill I had to use, closest to 25mm I had that would fit in the Bridgeport. Two of the four holes end up being on an irregular surface, and nothing about the part is truly flat. I tried "freehanding" it, using the Bridgeport as a drill press. Since I had a little trouble with the starter holes, I quickly realized I'd have to strap it down for the big holes.

A very convoluted setup of wood underneath and the usual stepped block clamps and straps got the job done. It all went together as hoped, and I truly hope I never have to do that to another bike again! ;)

Ken,

Sometimes you've just got to do the best you can and hope for the best.

Ed

[arvidj]

(04-06-2013, 08:49 PM)PixMan Wrote: ... First, being somewhat thin and soft, the twist drills just want to grab and pull the part up the flutes. ...

I will suggest that I have had very good luck on thin sheet metal with step drills. They still grab but not nearly like a regular fluted drill bit.

http://www.harborfreight.com/catalogsear...ult?q=step

Arvid

[TomG]

Brad or spur point drills also work well on thin material, plastic or metal. The center keeps the bit from wobbling and grabbing while the outside of the cutting edges cut cleanly through. They are pretty easy to grind as well. I keep a drill index for these "sheet metal" drills and whenever I grind a new size, I add it to the collection.

Tom