Drilling a straight hole by hand

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Hi all,

I am in the process of building a simple case for my gainclone amp. I have actually been "in the process of building it" for many months, but I am absolutely useless when it comes to this kind of thing, so it sort of hasn't really progressed....

I need to drill some reasonably straight holes in to the base of the heatsinks, on the top and bottom part, to allow the top and bottom perspex panels to be screwed to the heatsinks. Then it's just a case of attaching a front and back panel, which is also drilling some more holes attaching them to the side of the heatsinks (one heatsink on either side of the case. Hopefully that makes sense.

The problem? I have zero power tools, other than a powered hand drill and dremel clone type tool. I have tried on scrap stuff and have found many times that I am absolutely hopeless at drilling straight holes by hand, just by using the eyes! I can't really afford a drill press / pillar drill / whatever-you-call-them at this time, and know nobody with one to "borrow".

I was just wondering if anybody had used one of these, or knows of something like it which would work? http://cgi.ebay.co.uk/TREND-SNAPPY-...yZ148467QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


Depth doesn't really matter too much in this application. I don't require any accurate depth setting abilities!


If that thing actually works like it says it does, I think that would solve all of my problems, allow me to finish this darned case and get one project completely out of the way!! I think it would also be quite useful for drilling holes in to the heatsink for mounting TO220 style chips / chips with the same size mounting hole (ala lm3886) too. This is something which I am also not very good at because, again, I find they need to be drilled reasonably straight too.

Thoughts? Ideas? Help! :(

Regards,
Mark
 
Hi markiemrboo

I think you are misunderstanding the function of the drill bit shown in your link. It is designed to ensure that you drill in the centre of an existing hole (for example, a hole in a hinge); NOT to help you drill straight.

One way to help drill straight is to hold a couple of squares near the hole location and sight against their edges to see if the drill bit is parallel - the eye is much better at detecting parallelism than whether something is at right angles.

If you don't have any machinist's or carpenter's squares, you could make a couple out of cardboard that would work for this application.

Hope this helps; good luck with it.

Aengus
 
I have (and use) a drill guide similar to that of the last post... works as advertised. For just a few holes, i would probably just buy "jobber" length drill bits and use an adjacent square. Jobber length bits are a tad longer than standard and the extra length is a benefit when it comes to sighting along a square or guide. HTH


7/10
 
You should at least entertain the idea of buying a small made in China 5 speed drill press long enough to hit the home improvement store to see if one is on sale.

By the time you'd purchased a jig to use with your power drill you'd probably be half way there in cost anyway. And the control you have with a press is sooooo much greater for small work than with a power drill.

I paid 39 USD for nice little one with suprisingly good castings, sturdy little pillar, and JT33 chuck (should be about the same in the UK no?). After a few small adjustments it does a very good job on occasional projects.

The motor is usually a bit weak on these but I just keep the belt on the slowest pulleys and take my time. Just for the sake of semiprecision occasional work like you've described it's well worth the small investment.

Here's a picture of one
http://www.tool-usa.com/5spbetopdrpr.html

These all come out of similar shops in China and are of wide ranging quality but essentially the same dimensions. To find one as cheap as twenty GBP where you are may mean you have to take what you get, but take a pal along who knows his tools and if it looks functional then grab it.

Get a cheap little benchtop grinder on your way out the door and two weeks later you'll wonder why you ever hesitated to have these tools.

If you're determined to use your dremel, I heard one guy claim some success with a length of sturdy string attached to the hasp on the back of the dremel. The string is attached to the ceiling above your bench with a strong spring. Using the dremel as a plumb you situate your work (strike a good center punch exactly where you want to drill first) below the dremel and now you should be able to bear down to make a workably good straight hole. Too bad the dremel isn't a bit more powerful at low speed tho.

Good luck!
 
Aengus said:
Hi markiemrboo

I think you are misunderstanding the function of the drill bit shown in your link. It is designed to ensure that you drill in the centre of an existing hole (for example, a hole in a hinge); NOT to help you drill straight.

One way to help drill straight is to hold a couple of squares near the hole location and sight against their edges to see if the drill bit is parallel - the eye is much better at detecting parallelism than whether something is at right angles.

If you don't have any machinist's or carpenter's squares, you could make a couple out of cardboard that would work for this application.

Hope this helps; good luck with it.

Aengus

Whoops, you're right. Nay mind! I'm not sure I trust my eye to do this very well without some sort of supporting object. I'll look in to the square thing though ta.


pinkmouse said:


theAnonymous1 said:
Here are a couple different models. I purchased the one in the first link from a local hardware shop a few months ago. It works OK, although the one in the second link looks to be of better quality and it's also a few dollars cheaper.

http://www.amazon.com/General-Tool-H3487-Drill-Guide/dp/B0000E6TM6

http://www.amazon.com/gp/product/B0..._m=ATVPDKIKX0DER&pf_rd_r=1CSWD8HFXS493Y3DDGRH


seventenths said:
I have (and use) a drill guide similar to that of the last post... works as advertised. For just a few holes, i would probably just buy "jobber" length drill bits and use an adjacent square. Jobber length bits are a tad longer than standard and the extra length is a benefit when it comes to sighting along a square or guide. HTH


7/10


Above three posts, I was just looking at these sorts of things but couldn't find much in terms of reviews / how well they work. The first one of the three links is nicely cheap-ish too!

I can imagine it would be pretty easy where there is a fairly large surface in which to rest the base on, like for chip screw holes on a large heatsink base, drilling holes in the sides of the heatsink for the back and front panel also.... but resting it on just the 10mm thick base + fins of the heatsink for the top and bottom panels seems like it would be a bit awkward, as there wouldn't be much for the base of the tool to rest on.

Hope you get what I mean? Do you think it would be OK for doing that?

bluebeard said:
You should at least entertain the idea of buying a small made in China 5 speed drill press long enough to hit the home improvement store to see if one is on sale.

By the time you'd purchased a jig to use with your power drill you'd probably be half way there in cost anyway. And the control you have with a press is sooooo much greater for small work than with a power drill.

I paid 39 USD for nice little one with suprisingly good castings, sturdy little pillar, and JT33 chuck (should be about the same in the UK no?). After a few small adjustments it does a very good job on occasional projects.

The motor is usually a bit weak on these but I just keep the belt on the slowest pulleys and take my time. Just for the sake of semiprecision occasional work like you've described it's well worth the small investment.

Here's a picture of one
http://www.tool-usa.com/5spbetopdrpr.html

These all come out of similar shops in China and are of wide ranging quality but essentially the same dimensions. To find one as cheap as twenty GBP where you are may mean you have to take what you get, but take a pal along who knows his tools and if it looks functional then grab it.

Get a cheap little benchtop grinder on your way out the door and two weeks later you'll wonder why you ever hesitated to have these tools.

If you're determined to use your dremel, I heard one guy claim some success with a length of sturdy string attached to the hasp on the back of the dremel. The string is attached to the ceiling above your bench with a strong spring. Using the dremel as a plumb you situate your work (strike a good center punch exactly where you want to drill first) below the dremel and now you should be able to bear down to make a workably good straight hole. Too bad the dremel isn't a bit more powerful at low speed tho.

Good luck!


I think I would quite love even a cheapo proper benchtop drill press. Unfortunately I am not sure where I would put such a thing. I have no workshop space / garage space (VERY tiny garage) to put such things in. What sort of options do I have with such things in terms of storing and mounting / using really? I guess they really need to be permanently attached, and I wouldn't really be able to just store it in the garage and drag it in to the garden on the rare occasions I need to use it?


How about one of those hand drill "drill stand" thingers? I am doubtful of the quality, especially being ebay, but as an example something like one of these http://cgi.ebay.co.uk/MEJIX-SP125-D...ryZ64812QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

I'd be able to mount that to something in the garden, and they're probably small enough to store (rather than mount) in the garage...?


Thanks a lot for all the replies so far though! I have at least got a few options to mull over at the minute! Off to bed, so I will read anything further in the morning. Night...
 
U should go for a DIY zig.
I don't mean any hi cost device by that.
It needs imagination.

Your power drill should be made to slide on a table top, so that the drill bit stays parallel to the table, by making a support.
Now take the wall as a right angle(check), hold your work piece against it and drill by sliding the drill m/c.
Don't drill the wall, put some wood between the workpiece and the wall.

Improvise the above as per the conditions at your workplace.

Enjoy

Gajanan phadte

Edit: Try 'Money Generator', maybe u could get some useful tool at cheap price.
I bought my drill there.
 
I can imagine it would be pretty easy where there is a fairly large surface in which to rest the base on, like for chip screw holes on a large heatsink base, drilling holes in the sides of the heatsink for the back and front panel also.... but resting it on just the 10mm thick base + fins of the heatsink for the top and bottom panels seems like it would be a bit awkward, as there wouldn't be much for the base of the tool to rest on.

Clamp it to a tabletop, or a largish chunk of wood to increase the surface area for the base to rest on.

But I still recommend practicing aligning the drill bit by eye - it's easier than you think.

Regards.

Aengus
 

nemestra

Member
2002-07-23 4:26 pm
UK
markiemrboo said:

I can imagine it would be pretty easy where there is a fairly large surface in which to rest the base on, like for chip screw holes on a large heatsink base, drilling holes in the sides of the heatsink for the back and front panel also.... but resting it on just the 10mm thick base + fins of the heatsink for the top and bottom panels seems like it would be a bit awkward, as there wouldn't be much for the base of the tool to rest on.

For holes where there is not a lot of surface area see Peter Daniel's tips on tapping (and if you are tapping, read the whole thread)

http://www.diyaudio.com/forums/showthread.php?postid=69419#post69419


James
 
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