Pre-tapping Holes In Db01 Chassis Question - I'm A Bit Confused By It All

[WW-nut]

Chaps,

Re. building a Baldre/ Durga chassis

I was pondering whether to buy a hex-head screw set or to buy a metric tap and have decided on tapping the DB01 chassis and suspension blocks as per Tamiya's article on the DB01 http://www.tamiyausa.com/articles/feature.php?article-id=414 Though before I do I would like to make sure that I get the right type and size of tap. On searching the TC forum I came across this shop: http://www.modelfixings.co.uk/metric_taps.htm

I think I just need a couple of M3 taps (does this mean 3mm?), though haven't a clue which thread form - I am completely baffled by all the types though guess it might be 'metric course'?????? And I assume I would only need the 'taper' and 'second' tap so there is some resistance when screwing the kit screw into the hole. Here's a link to the DB01 instructions if you need to refer to them: http://www.tamiyausa.com/pdf/manuals/58395ml.pdf

Hope someone can translate this into something that I will be able to understand....thank you Nige

[94eg!]

Don't make it so hard on yourself. Just get yourself one 3mm hex-head screw (borrow from a friend or hobby store), and the matching 2mm hex driver (borrow from a friend or hobby store) and screw it in with a tiny a dab of grease. Then remove the hex-head screw and your done. That's all the pre-tapping you need.

If you actually cut threads with a real tap, it will remove material. In doing so, it will make the for looser fitting screw which is bad in this sort of application...

[HunterZero]

I bought the RC Screwz DB01 hex head screw set, makes it sooo much easier if you run the car often and have to take it apart regularly. The motor screws they give you weren't quite the right length, but you can just use the kit screws or those.

- James

[lucasan]

I found that the easiest thing to do was to just get the aluminum suspension mounts. I had no problems whatsoever. However, I was using the titanium screws from Tamiya. -I do not recommend these though. I had one stripped on my center drive train cover and had to remove it with a dremel. Then I had to get a new center cover. The aluminum makes the screwing in much less laborious though.

[HunterZero]

I found that the easiest thing to do was to just get the aluminum suspension mounts.

Yeah, those small plastic suspension mounts that screw into the chassis suck to put together with the kit screws. Alu suspension mounts are the first thing I picked up, with the slipper.

- James

[dimblum]

I bought the RC Screwz DB01 hex head screw set, makes it sooo much easier if you run the car often and have to take it apart regularly. The motor screws they give you weren't quite the right length, but you can just use the kit screws or those.

- James

I second that. I also used the RC Screws set when I built my Durga. They are excellent stainless steel hex head screws. An M3 screw does mean '3mm'. 94eg! is right, just tap the holes using one of the screws you get with the kit. Add a dab of diff grease to the threads before tapping the hole.

[WW-nut]

Cheers guys for your replies.

There seems to be two good suppliers of hex screw sets (i) RCScrewz and (ii) Tony's screws, both based in the US. Why no UK supplier?

http://www.rcscrewz.com/product_info.php/s...roducts_id/2767

http://www.tonysscrews.com/searchquick-sub...?keywords=durga

Seems most people buy from RCScrewz.

Also I've had a bit more of a search over the forum and found this - read last post: http://www.tamiyaclub.com/forum/index.php?...;hl=screw++sets Although I am no materials scientist I can understand his point of view. So would it be best to tap and use the hex screw sets, if so what type of thread are Tamiya screws, metric fine?

Nige

[peetbee]

Both screwsets are good. Before you start building, take a little time to read the review on oOple:

http://www.oople.com/rc/photos/reviewtamiyadurga/

Enjoy!

[igbandy]

I too would use an M3 Tap to thread the holes.

The thread you require is M3x0.50 aka M3 Course. M3 fine is M3x0.40

[WW-nut]

Thanks Igbandy, on looking at the instructions it doesn't say what pitch (??) the thread is, think that's what you mean by 0.40 and 0.50, but guess it must be the M3 fine. I just need to tap the holes in the chassis. The instructions are here http://www.tamiyausa.com/pdf/manuals/58395ml.pdf though you need to copy and paste the web address into your browser. The list of screws is on page 23, the ones I would need to tap are BA2, BA4, BC1.

Cheers Peetbee - I've seen the Oople review and will read it again whilst building mine, thanks.

[igbandy]

Thanks Igbandy, on looking at the instructions it doesn't say what pitch (??) the thread is, think that's what you mean by 0.40 and 0.50, but guess it must be the M3 fine. I just need to tap the holes in the chassis. The instructions are here http://www.tamiyausa.com/pdf/manuals/58395ml.pdf though you need to copy and paste the web address into your browser. The list of screws is on page 23, the ones I would need to tap are BA2, BA4, BC1.

Cheers Peetbee - I've seen the Oople review and will read it again whilst building mine, thanks.

Do not buy an M3x0.40 Fine Tap, you wont have any use for it.

As I said in my previous post, get yourself a couple of M3x0.50 Course Taps and job`s a good un

[terry.sc]

Why no UK supplier?

If you want screws in the UK, just buy them individually from Model Fixings or JE Spares.

Metric thread sizes are pretty simple.

M is for metric, the number is the thread diameter in millimetres, so the thread on a 3mm bolt is M3. You will want M3 taper and second taps, and a tap wrench to use them.

Unless specified all metric threads are metric coarse, which is the standard thread size. Metric fine is only used in high precision engineering and I would be surprised if you found M3 fine taps readily available.

[WW-nut]

Ah thanks Terry, the fog in my brain has lifted and I can understand it now.

Think I'll be able to buy the taps and just the few screws I need for the same cost as buying a complete set of hex screws, with the benefit that I can reuse the taps. Quids in, brill.

[tpsolid]

so the screws that tamiya uses are M3 .5 correct?

[igbandy]

so the screws that tamiya uses are M3 .5 correct?

Thats right, also known as M3 course. But as Terry said M3x0.40 fine is very rare and in all my time working with threads etc I have never come across them being used.

[WW-nut]

Hi chaps,

Thanks for you help on this; just wanted to let you know that I've now finished building the car: http://www.tamiyaclub.com/showroom_model.a...78&id=19158

I bought the taps and hex screws from www.modelfixings.co.uk who provided a really good quick service - so I do recommend them.

Now if I remember correctly, I got:

TAPS --> http://www.modelfixings.co.uk/metric_taps.htm [just need the M3 taper tap, M3 second tap and a tap wrench.]

SCREWS --> http://www.modelfixings.co.uk/button_heads.htm [just need to buy replacement screws that fit into the chassis and suspension blocks: M3-10 and M3-12]

Since the responses above were mixed, on a few holes I tapped the hole and others I just used a hex screw (both with a dab of ball diff grease as suggested in the review by Oople.com). I can honestly say that tapping the hole makes things a lot easier and by just using the first two taps there is still enough resistance in the hole to keep the screw in nice and tight.

I really did enjoy building this; it was a nice change to the usual restoration money pits I buy

Ta,

[94eg!]

Yes the belt tensioner works by not allowing room for the belt to skip. This allows the belts to run more freely and not tug on the chassis when it flexes. As for the motor, I would think the EZRun 60amp 5.5 or 8.5 would be a good inexpensive setup. You'll really love how smooth this thing is. Just be sure to check & retighten the diffs after a break-in period. They always loosen a bit. A slipper is another wise investment (if you don't already have one). You need the more expensive dual slipper either...

The car looks great BTW. I really like your choice of colors & decals. The red windows look like 80's style bad-guy cartoon eyes. Kinda reminds me of Saw-Boss from Jayce and the Wheeled Warriors...

[WW-nut]

94eg, nice photo

The one thing I still don't like on the car is the red windows. I would have preferred them clear/black, but with my limited polycarbonate painting experience I took the easy option. The Baldre comes with two separate decals sheets; the horrible blue shiny ones, and some mildly bearable ones which include the red windows. I guess I could have used the window decals as a mask, but was really unsure how to make a good looking edge around the window in black. I know some people use a black paint pen for this, but wasn't sure what this would look like when I did it. The Baldre shells are relatively cheap, so maybe I could give it a go in the future. :-)

[sosidge]

A bit late for my suggestion - but nevertheless...

If you are tapping the holes, there is no need to replace the screws. The Tamiya screws are probably of equal or better quality than any of these (soft) stainless sets that you find.

The one thing that makes the biggest difference to building the Tamiya kits is a proper JIS screwdriver. The Phillips tip, although superficially similar to the JIS, has one crucial difference - it is designed to jump out of the screw head if too much torque is applied. This is what ruins the Tamiya screws. Get a JIS screwdriver (Tamiya's own should be correct, I have one made by TOP) and assembly and re-assembly is much improved.

I covered the issue in my blog... http://www.sosidge.com/2008/11/20/first-th...d-about-screws/