I wish I had your problem when I attempted the same operation on that same engine (Sherline).Yes, holding drill bits is one thing collets are good at.
Here's an ER-11 collet on an extension shaft held by an Albrecht 1/2" chuck. This setup was purchased for drilling in tight spaces as shown.
I used to drill quite a few small holes while still restoring clocks and watches. Fortunately most of the time it was in the end of a shaft / arbor, so the work was spinning in the lathe and the drill bit was hand held in a pin vise and allowed to advance into the work. When I had to do a small hole in a mill and no sufficiently concentric tool holding was at hand, a blank faced piece of rod was held in the lathe and drilled to make a larger shank. Once a shank of 1/8 or larger was loctited to the drill, existing tool holding options could be used. Having the work spinning tends to deliver a nice straight hole.
In the lathe, straight flute solid carbide drills gave the best results, while in a mill the chip extraction provided by a twist drill is beneficial. Frequent removal of the drill to clear chips is a must, particularly when drilling to 4X the drill diameter or greater. Typically when repivotting a clock arbor the depth is 5X the drill diameter or more.
Naturally the official answer would be to purchase an Albrecht 15J0 and a matching arbor, or a nice clean Cameron precision drill press, but those options will leave at least a moderately sized smoking crater in your wallet or credit card...
Yeah. Pretty miserable
Well, it's not my fault. That was a pretty miserable yard sale.
I use sometimes extra nuts, that spare me to take the collets and tool apart. (Provided you do not buy "a Cameron Micro drill with Albrecht chuck" ) One you could give it a try to get some extra nuts to make change more easy.I guess I'm just wondering if there are any downsides to to this method - other than needing to change collets to handle different sizes. Yes, I was looking for the convenience of a keyless chuck but I am retired and could manage to find the few minutes needed to change collets. In my dream world (where I do most of my planning) I was even thinking of attempting to design a spring loaded sliding device with a collet chuck like the "sensitive drill feeds" use.
Thank you,Greetings folks!
Timo's nicely made miniature drill press reminded me that Jerry Howell designed several gadgets that might be of interest. A miniature drill press, a micro drill press, and a high(er) speed mill spindle accessory. I know Jerry used to drill the 0.006 inch orifice in his propane jets with the micro drill press. He and I were talking about small hole drilling and I bought quite a few of his plan sets way back at an early Cabin Fever.
I imagine there are numerous build threads around related to Jerry's engines, but he did some other interesting things too.
Sadly Jerry is gone, but his family continues to sell his plans and for a number of the plan sets the special and odd parts needed (bearings, graphite slugs, the stuff you don't find at the corner shop).
Sorry to take a bit of time to get back, needed to go read over the plans and see. For the micro drill press Jerry suggested the chuck be chosen based on smallest diameter to be drilled. If using numbered bits up to 60 or similarly huge drills the smallest Jacobs chucks could be a good choice as they will usually only have a few thou (0.001 inch, not microns) runout. If going to smaller sizes, the next step was to fabricate a spindle to use a small high quality pin vise selected for minimal run out. Naturally, the final choice and most expensive was the Albrecht 15J0 I'd mentioned before, if drilling smaller than 0.010 inch holes is a regular thing. I imagine that Rohm or other EU and continental makers offer chucks of similar quality, just other than Rohm I'm not familiar with them.Thank you,
on older photos everything looks newer, incl. myself. (drill press is getting rusty, maybe I have to paint the thing)
Under the link you posted in the "Attachment and Tool" section I found plans. Mini Drill press and Micro drill press.
Resulting Question are:
- What kind of chuck is suggested in the plans? (tempted to have a look!)
- Do I really need another small drill press?
- Did anybody built one?
I have a Dumore that is outfitted with x-y table, light, magnifying glass, speed control, depth controlled table that has balance weights so it moves only if dial is turned. It has a magnetic chuck that allows you to center a bit for zero runnout. Smallest it goes down to is a #71 (.026). I made a special insert that let me go down to a #80 (.013). I normally just use the jacobs chuck that is on it, sometimes switch to an albrecht.
Modifying the existing drill device is also not a bad idea.This is my solution, the Dremel has so little runout that I have drilled 0.5mm holes in 3mm brass without a problem. The table lifts with the workpiece held in a small vice . The stand is made from one of the horrible cheap drill press thing and the post is shimmed vertical to the baseplate in both axis.
I really like that way of limiting the feed, with a counterbalance. I wouldn't have thought of that. And making something useful out of plastic crap is very satisfying!View attachment 144308 This is my solution, the Dremel has so little runout that I have drilled 0.5mm holes in 3mm brass without a problem. The table lifts with the workpiece held in a small vice . The stand is made from one of the horrible cheap drill press thing and the post is shimmed vertical to the baseplate in both axis.
View attachment 144307 View attachment 144309
I don't use a speed controller (Variac or Triac) with the Dumore so it's always running full speed: 17000 RPM. If you look on the speed & feeds chart, this is actually on the slow side.Hey Krypto, that looks a really neat set-up. I drill 0.3, 0.25. and 0.2mm drills, using the carbide drills with 3mm shank. But have always used the lathe approach of rotating work and stationary drill bit.
What speed do you use with your smallest size bit?
Wow, that's a little jewel! Do you know the history behind the x-y table setup for the Dumore? I never have seen one like that before. Your Dumore looks similar to mine so it's around 50 years old according to the factory.