5-40 x 1" socket head bolts

Those are 3/4" long (too short) but I get the idea. Would nice to find some button heads that fit the Cox spinner too. I will search the google for a local supplier here.

Cheers

warrenlead wrote:Those are 3/4" long (too short) but I get the idea. Would nice to find some button heads that fit the Cox spinner too. I will search the google for a local supplier here.

Cheers

Ok so you need about 1" i will try and find some.

How about this set?
http://motorcycleproducts.co.uk/catalogue/screws-allen-5mm-160pc-kit-stainless-button-p-230898.html

I use these folks for all kinds of hardware needs at work, shipping is very reasonable.

McMaster-Carr

Choose the size of socket head you want from the sizing chart on the left. They have both stainless and black oxide, 1", $3.82/50.

My preference is to buy in bulk in the sizes I need, but in the maximum length I might use; I then use a Dremel cutoff wheel to cut to desired length.

I would be happier if Bernie and Matt stocked them... HINT!

Not sure how I would go with Mcmaster Carr being that I'm in Australia and all.

Anyway I got a bag of 15 from a RC Car supplier for $2.00 so I should be right for now.

Cheers

I use socket head screws on reedy backplates with good results.
They give better torque feedback than a slot head. They do seat flush.
Don't mean to gloat, but those are KustomKraftmanship backplates.
Fine thread collet needles.

dckrsn wrote:I use socket head screws on reedy backplates with good results.
They give better torque feedback than a slot head. They do seat flush.
Don't mean to gloat, but those are KustomKraftmanship backplates.
Fine thread collet needles.

Very nice! What thread size and length are they?

warrenlead wrote:
Very nice! What thread size and length are they?

The .049 (8cc tank) is 2-56 x 1". The .049 (5cc tank) is 2-56 x 3/4".
The .020 should be about 2-56 x 1/2".

I measured a BW with metal backplate and the threaded portion was just under an inch. Since most screws are sold by thread length, you may have to shorten them to get a good tank seal. Usually, I check the depth of the threaded hole in the crankcase and use that to judge how much I may need to cut off.

Gday

I just had a look at some of my engines and checked the length of the screws. I think it's fairly important to get the length spot on because, as you mentioned, the tank will not seal properly if the screws are too long. (As mentioned and shown in Paul Gibeault's Mouse Race Program document, 1" tank screws are usually too long.)

So with that in mind, here are some revised specs and just in case anyone else is considering doing this, Socket Head Bolts are measured from below the socket head to the end of the thread.

BABE BEE 049 (5cc Tank)
Prop Screw = 5-40 x 1/2"
Tank Screw = 2-56 x 11/16"

BLACK WIDOW 049 (8cc Tank)
Prop Screw = 5-40 x 1"
Tank Screw = 2-56 x 15/16"

TEE DEE 049/051
Prop Screw = 5-40 x 1"
Tank Screw = N/A

PEE WEE 020
Prop Screw = 3-48 x 1/2"
Tank Screw = 2-56 x 1/2"

TEE DEE 020
Prop Screw = 3-48 x 3/4"
Tank Screw = 2-56 x 1/4"

Cheers

warrenlead wrote:Gday

I just had a look at some of my engines and checked the length of the screws. I think it's fairly important to get the length spot on because, as you mentioned, the tank will not seal properly if the screws are too long. (As mentioned and shown in Paul Gibeault's Mouse Race Program document, 1" tank screws are usually too long.)

So with that in mind, here are some revised specs and just in case anyone else is considering doing this, Socket Head Bolts are measured from below the socket head to the end of the thread.

BABE BEE 049 (5cc Tank)
Prop Screw = 5-40 x 1/2"
Tank Screw = 2-56 x 11/16"

BLACK WIDOW 049 (8cc Tank)
Prop Screw = 5-40 x 1"
Tank Screw = 2-56 x 15/16"

TEE DEE 049/051
Prop Screw = 5-40 x 1"
Tank Screw = N/A

PEE WEE 020
Prop Screw = 3-48 x 1/2"
Tank Screw = 2-56 x 1/2"

TEE DEE 020
Prop Screw = 3-48 x 3/4"
Tank Screw = 2-56 x 1/4"

Cheers

Hey Warren,

Thanks for this post..handy to copy and paste for quick reference!

http://www.tonysscrews.com/
Just recieved a order from Tony for 5-40x1" button heads (spinner screws), 2-56, 4-40 and 2.5 mm backplate engine mounting screws. Some 10-32 and 6-32 also. Been purchasing Tonys HD standard and metric black oxides for years. Extra deep tool sockets on each screw,,good stuff.

I have found that many of the Surestarts have crankcase holes tapped to various depths. Consequently, out of 4 screws, 3 may seat properly and one will bottom out before tightening up. When cleaning the engine before running, I check the thread depth and trim the screws if necessary. Secondly, I've also noticed that almost all of the cases have tap burrs raised around the screw holes --- a little quick buffing on oiled 400 grit on a piece of glass knocks these off and trues up any low spots on the case back.

andrew wrote:I have found that many of the Surestarts have crankcase holes tapped to various depths. Consequently, out of 4 screws, 3 may seat properly and one will bottom out before tightening up. When cleaning the engine before running, I check the thread depth and trim the screws if necessary. Secondly, I've also noticed that almost all of the cases have tap burrs raised around the screw holes --- a little quick buffing on oiled 400 grit on a piece of glass knocks these off and trues up any low spots on the case back.

Whenever I'm "doing up" an engine, I usually run a 2-56 bottoming tap into the case threads.
Sometimes I find the threads haven't been cut all the way in. Also removes any crud
that may have acumulated at the bottom.
The mating surface almost always needs dressing. Surestarts always need it.
Bob

dckrsn wrote:
Whenever I'm "doing up" an engine, I usually run a 2-56 bottoming tap into the case threads.
Sometimes I find the threads haven't been cut all the way in. Also removes any crud
that may have acumulated at the bottom.

I've got to get me one of those -- it really is the best approach.

andrew wrote:

dckrsn wrote:
Whenever I'm "doing up" an engine, I usually run a 2-56 bottoming tap into the case threads.
Sometimes I find the threads haven't been cut all the way in. Also removes any crud
that may have acumulated at the bottom.

I've got to get me one of those -- it really is the best approach.

Andrew,
I bought a couple from McMaster-Carr with the heavy handed shipping cost , but
Dubro packages them with the appropriate drill included.
From Tower for less $ total.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXE213&P=7
A mini tap handle is almost a must with one this small. Don't forget
to use lube. Tap Magic for aluminum works well but $$$. 3 in 1 works.
Bob

I ordered two each of those dubro sets,,and got two taps per package but no drill bits. Dont know how dubro missed that screwup. Gave a couple to my buddy. A very steady hand required when starting those in the hole.