Drill Bit Sizes Appropriate for Ship Modeling?

[Mike40]

I would appreciate any tips on drill bit sizes for ship modeling. My first model will be a 1:48 scale. I have seen mentions of drill bit sizes given as numbers like #1, #3, etc. here on the forum, but here in Norway we use the metric scale and not the number system. If anyone can tell me the sizes I need in inches I can convert that to metric, or if you can tell me in millimeters even better.

 

I don't have a pin drill yet so I will probably be using the bits in my Dremel. I can't get the thick shaft small bits here so I am hoping my Dremel will be able to grip the small diameter bits well enough. I can order small bits from out the country, but it's easier if I can buy them here and they are a lot cheaper.

 

 

[Jack12477]

Mike, Dremel offers interchangeable collets for its drill. They will take anything from the micro drills (pin vise type) up to almost a "regular" drill - the supplied Dremel bits (sanding, routing, drilling, etc) are all 1/8 inch shafts, that's their default size.  I have the extra collets and changing them over is easy. If I can find the conversion chart to convert the numbered drills, e.g. #68, #74 etc. to metric I will post a link here. The collet set includes 1 Collet and nuts for 1/8, 3/32, 1/16, and 1 32" bits.

Edited October 8, 2016 by Jack12477

[CDW]

I think you are going to find the metric sizes graduate on a .05 mm interval. The imperial number sized bits fall in between the metric sizes, so there is no direct correlation between the two. Here is a link with a chart:

 

http://www.csgnetwork.com/drillsizeconvert.html

[amateur]

I don' t know which dremel you have, but the smaller sizes: .3-.9 mm tend to break quite easily, especially when used by hand in a powerfull drill.

Especcially the smaller sizes should be bought in multiples (unless you can cope with the frustration of not being able to continue as you last drillbit in the correct size snapped))

 

Jan

[Jack12477]

Yes, the smaller/smallest sizes do tend to break easily.  But I generally use them in the WeCheer micro drill which accepts all of the Dremel collets and I use a lower RPM with these and very light hand pressure.

 

[wefalck]

I found this question - which seems to pop up from time to time, a rather odd. Divide the real size of the hole you want/need to make by the scale - in your case 48, and you will get the diameter you need. Normal CV or HSS bits come in 0.1 mm graduation, but can be also obtained from watchmaking suppliers and other speciality suppliers at 0.05 mm intervals. In practice the 0.1 mm step should be sufficient. Sizes below 0.3 mm are not so easily obtained and are rather fragile.

 

Watchmakers suppliers also have drills with straight flutes that are much more rigid, but rather expensive.

 

Another option are surplus carbide drills that are available on the Internet at reasonable prices down to 0.1 mm diameter. Beware these are even more fragile than HSS drills and may not be suitable for hand-held drills.

[Mike40]

Thanks much for the help guys, this will give me info enough to proceed. I bought a chuck for my Dremel some years ago. It tightens by hand to any size so I don't use the collets anymore. Still not sure how it will work on the smaller bits, but I still have the different sized collets in case and I suppose I can get even smaller ones if needed. I am planning to attach a bracket to my drill press that can hold my Dremel to avoid hand holding it and breaking bits. Not sure how well it will work until I try it out. I'm not too keen on buying a micro drill press until I find that I can't live without one. In fact I am hoping to get by without any micro machines at all if I can help it. My shop is already overcrowded enough!    ​ 

[dgbot]

Pin drills is what I have almost always used.  #1-#80as for their sizes in inch I had a chart that was lost during my move.  II made up the chart by measuring each bit with a digital caliper.  This can also convert to metric as well.  

David B

[Mike40]

Thanks David. I am in fact planning to buy a pin drill, but I'm not sure it will be best for holes that have to be at a precise angle, but probably great otherwise.

[mtaylor]

The chuck is all I ever use with the dremel and it works very well down to the pretty much the smallest size.

[Mike40]

Thanks  Mark. Good to hear that my tool free chuck will work. I would not like going back to using collets. I still can't imagine drill bits under 1mm. I have broken quite a few 1-1/2mm bits and even larger in the past.

[wefalck]

Breaking 2 mm drills ? Sounds like brute force ... OK, done this as well, but it was in steel ...

 

Personally, I prefer collets. Don't know the Dremel products, but the Proxxon ones are pretty good concerning run-out. The tightening nut is smaller than the chuck and, therefore, you can see better what you are doing.

[dgbot]

Some like collets and others prefer a chuck.  It depends on personal preference.

David B

[Jaager]

If you are interested in staying near scale, 1:48 = a 1 inch trunnel would  be 0.0208" in diameter.. that is a # 75 or 76 wire gauge dowel - close enough in metric is 0.52 mm- 0.55 mm.  I would probably find that a # 75  bamboo dowel would need a # 72-# 73  hole to get a push fit that would not grab and snap the dowel.   A 2 inch  would be #58  or 1 mm  @ 1:48.  This is pretty much the practical range.  For hidden dowels - a # 50 dowel  is pretty strong and does not displace too much of the wood - that is 1.8 mm.  So, if you stick with metric,  the practical limit at the lower end is # 80  and these are difficult to mount - that is 0.35 mm   - so as wide a variety of sizes between 0.35 mm and 2 mm  should stand you in good stead.  The lower end is more important.

 

It is difficult not to have an occasional "Parkinson twitch" when hand drilling - and snapping a bit - I think you would get longer use and more accurate placement if you pre-drill using a drill press where possible.  A Eurotool DRL-300 - sold under a variety local company names - has worked for me- and

if you pay more than $80 US equivalent - you are paying too much.  A helpful addition is a momentary foot switch - which should not be more than $20 US for a good enough unit -  fix it to a board.

Edited October 10, 2016 by Jaager

[Mike40]

Thanks Jaager.  Great answer, Thank you.  As for the drill press, I have just finished making a mount for my Dremel to my big drill press. An idea I got from someone's log on the site here, but darned if I can remember who it was, so I don't know who to thank. I will be testing it after lunch to see how accurate it drills. I really don't want to invest a lot in modeling machines, much as I would like to have them. I already have a shop full of full size woodworking equipment so I find it hard to justify the expenditure for the very few models I will be able to complete at my age. 

[WackoWolf]

For drill bits check out     https://www.drillbitcity.com/

They also have charts that you can download. You can buy new, used and resharpen in all sizes.

[Ulises Victoria]

I buy mine here.

http://www.cmlsupply.com/drill-bits-individual/?search_query=&page=4&limit=20&sort=featured&category=530&is_category_page=1

[jay913]

Will you consider using PCB drill bit.

 

size from 0.1 - 3.0 mm

 

I purchase 2 set from ebay

Edited November 7, 2016 by jay913

[Mike40]

Thanks Joe and Ulises.

 

Jay:  Sounds like a good range of sizes. I will check it out.