Jump to content




Photo

Set screw and tap size for Pro Track wheels


  • Please log in to reply
15 replies to this topic

#1 Mattb

Mattb

    Checkered Flag in Hand

  • Subscriber
  • PipPipPipPipPipPip
  • 1,609 posts
  • Joined: 13-August 11
  • Gender:Male
  • Location:IN

Posted 09 August 2018 - 08:14 PM

We run Protrack exclusively on our newer cars.   We (I build everything)   have the occaisional wheel that gets stripped.   The usual repair is to epoxy the wheel to the axle.   This works on our low powered cars, but is not the best fix.     Using the stripped hole as a guide it should be pretty easy to drill thru the other side of the hub and tap it and have fresh threads.     

 

My question is what size are the threads.  Are these M2?    I've bought bags of screws, but don't remember the size.    I also wonder if there is a set screw that is slightly larger that would go in a stripped out hole and cut new, slightly larger threads for a slightly larger set screw.

 

Anybody with some info?

 

thanks

mb


Matt Bishop

Vintage Cox Slot Cars




#2 MSwiss

MSwiss

    Grand Champion Poster

  • Advertiser
  • PipPipPipPipPipPipPipPip
  • 20,460 posts
  • Joined: 16-April 06
  • Gender:Male

Posted 09 August 2018 - 08:30 PM

I'm 98% sure this is the container for the correct tap.

20180809_202853.jpg
  • Steve Roope likes this

Mike Swiss
IRRA® Components Committee Chairman
Five-time USRA National Champion (two G7, one G27, two G7 Senior)
Two-time G7 World Champion (1988, 1990), eight G7 main appearances
Eight-time G7 King track single lap world record holder

17B West Ogden Ave Westmont, IL 60559, (708) 203-8003, mikeswiss86@hotmail.com (also my PayPal address)

Note: Send all USPS packages and mail to: 5858 Chase Ave., Downers Grove, IL 60516


#3 Mattb

Mattb

    Checkered Flag in Hand

  • Subscriber
  • PipPipPipPipPipPip
  • 1,609 posts
  • Joined: 13-August 11
  • Gender:Male
  • Location:IN

Posted 09 August 2018 - 09:35 PM

Mike I've seen 4-40 listed, but I thought that was the size of the old machine screws Cox and Monogram used to mount bodies.  Is this 4-40 set screw size different than those old  body mount screws?    


Matt Bishop

Vintage Cox Slot Cars

#4 MSwiss

MSwiss

    Grand Champion Poster

  • Advertiser
  • PipPipPipPipPipPipPipPip
  • 20,460 posts
  • Joined: 16-April 06
  • Gender:Male

Posted 09 August 2018 - 10:13 PM

You sure you aren't thinking of 5-40 on the body mounts?
 
4-40 is definitely what common gear and wheel set screws are.
 
I think you might be visually tricked because one screw has a head, and the other, a hole.
 
Here is a Parma controller bolt, in a regular slot car wheel.

20180809_215644.jpg

Mike Swiss
IRRA® Components Committee Chairman
Five-time USRA National Champion (two G7, one G27, two G7 Senior)
Two-time G7 World Champion (1988, 1990), eight G7 main appearances
Eight-time G7 King track single lap world record holder

17B West Ogden Ave Westmont, IL 60559, (708) 203-8003, mikeswiss86@hotmail.com (also my PayPal address)

Note: Send all USPS packages and mail to: 5858 Chase Ave., Downers Grove, IL 60516


#5 Bill from NH

Bill from NH

    Age scrubs away speed!

  • Full Member
  • PipPipPipPipPipPipPipPip
  • 9,707 posts
  • Joined: 02-August 07
  • Gender:Male
  • Location:New Boston, NH

Posted 09 August 2018 - 10:19 PM

I don't have Cox or Monogram body screws, but I'm sure most hubs & gears sold in US commercial raceways are the 4-40 Mike shows. Any Protrack hubs I've had were 4-40. The next larger size tap is a 5-40 which requires a #38 drill bit. A 5-40 screw is .013" larger than a 4-40 & might be easier to find. Personally, I'd prefer to keep everything 4-40.


Bill Fernald
 
"I'm not short, I'm just down to earth."

#6 Tim Neja

Tim Neja

    Grand Champion Poster

  • Full Member
  • PipPipPipPipPipPipPipPip
  • 5,751 posts
  • Joined: 11-June 07
  • Gender:Male
  • Location:Orange County

Posted 09 August 2018 - 11:09 PM

The set screws are 4-40 and .050 size wrench.  Simple--- you can get everything you need at a decent hardware store --or McMaster Carr.


She's real fine, my 409!!!

#7 Ramcatlarry

Ramcatlarry

    Posting Leader

  • Subscriber
  • PipPipPipPipPipPipPip
  • 2,163 posts
  • Joined: 08-March 06
  • Gender:Male
  • Location:St Charles, IL 60174

Posted 10 August 2018 - 07:46 AM

and many of the euro/plastic cars use a metric 2mm with the .o39 hex. 


Larry D. Kelley, MA
retired raceway owner... (for now)
race directing around Chicago-land

 

Diode/Omni repair specialist
USRA 2017 member #404
USSCA  member

Host 2006 ISRA/USA Nats
Great Lakes Slot Car Club member
60+ year pin Racing rail/slot cars in America


#8 Courtney S

Courtney S

    Mid-Pack Racer

  • Full Member
  • PipPipPip
  • 102 posts
  • Joined: 07-July 08
  • Gender:Male
  • Location:Chatt, TN

Posted 10 August 2018 - 07:51 AM

I have done this a few times due to my ham hands...

 

Use the original hole as a guide and drill through it to the other side then tap, it is simple.


Courtney Smith

#9 Pablo

Pablo

    Builder

  • Subscriber
  • PipPipPipPipPipPipPipPip
  • 13,951 posts
  • Joined: 20-February 06
  • Gender:Male
  • Location:Johnson Bayou, Mississippi Gulf Coast

Posted 10 August 2018 - 08:12 AM

Concur with drilling through existing hole to make new one with #43 drill bit, tap with 4-40, use standard set screw.

I used to do it all the time with Slot-It gears, it's easy.


  • Tim Neja likes this
Paul Wolcott

#10 Mattb

Mattb

    Checkered Flag in Hand

  • Subscriber
  • PipPipPipPipPipPip
  • 1,609 posts
  • Joined: 13-August 11
  • Gender:Male
  • Location:IN

Posted 10 August 2018 - 08:29 AM

Thanks so much guys.     Quick and easy answer, I knew it would be.    I guess the visual difference between a set screw and a pan head screw (4-40) is enough for me to not realize they are the same threads.    It should be an easy process to fix the old wheels properly.    I'll order  a tap todayl     

 

I do have a 5-40 tap for old wheels.  I also have used it on tapered hub Cox wheels.    

 

Thanks to all


Matt Bishop

Vintage Cox Slot Cars

#11 Bill from NH

Bill from NH

    Age scrubs away speed!

  • Full Member
  • PipPipPipPipPipPipPipPip
  • 9,707 posts
  • Joined: 02-August 07
  • Gender:Male
  • Location:New Boston, NH

Posted 10 August 2018 - 08:58 AM

Aren't threaded axles also 5-40?


Bill Fernald
 
"I'm not short, I'm just down to earth."

#12 Mike Patterson

Mike Patterson

    Village Luddite™

  • Subscriber
  • PipPipPipPipPipPipPip
  • 2,166 posts
  • Joined: 14-October 07
  • Gender:Male
  • Location:Zanesville, OH

Posted 10 August 2018 - 09:30 AM

I would suggest filling the old threads with JB Weld, and retapping the existing hole. I have never done this on slot car wheels, but in every application I have tried it on, it has worked well. YMMV.


My neighbors listen to heavy metal... whether they want to or not!!!


#13 MSwiss

MSwiss

    Grand Champion Poster

  • Advertiser
  • PipPipPipPipPipPipPipPip
  • 20,460 posts
  • Joined: 16-April 06
  • Gender:Male

Posted 10 August 2018 - 10:24 AM

Aren't threaded axles also 5-40?

Yes.

That's why Matt is modifying taper-loc to 5-40.

That was a common thing at my local raceway, where Charlie Vrba, a retired machinist, would modify taper-loc(which local racers hated) Cox Sil Sliks, he had in stock, to the preferred 5-40.

Mike Swiss
IRRA® Components Committee Chairman
Five-time USRA National Champion (two G7, one G27, two G7 Senior)
Two-time G7 World Champion (1988, 1990), eight G7 main appearances
Eight-time G7 King track single lap world record holder

17B West Ogden Ave Westmont, IL 60559, (708) 203-8003, mikeswiss86@hotmail.com (also my PayPal address)

Note: Send all USPS packages and mail to: 5858 Chase Ave., Downers Grove, IL 60516


#14 Bill from NH

Bill from NH

    Age scrubs away speed!

  • Full Member
  • PipPipPipPipPipPipPipPip
  • 9,707 posts
  • Joined: 02-August 07
  • Gender:Male
  • Location:New Boston, NH

Posted 10 August 2018 - 02:20 PM

Thanks, I missed that in Matt's post. The Cuc I bought in 1967 had the Cox tapered hubs. The first thing I did to it was install a French arm & change the rear tires to Cox silicones. I ran Champion taper-loc hubs a lot in 1967-68 & liked them. They even had taper-loc pinions.


Bill Fernald
 
"I'm not short, I'm just down to earth."

#15 Mattb

Mattb

    Checkered Flag in Hand

  • Subscriber
  • PipPipPipPipPipPip
  • 1,609 posts
  • Joined: 13-August 11
  • Gender:Male
  • Location:IN

Posted 10 August 2018 - 04:33 PM

Mike, I am going to stay with the 4-40 threads, I just was't sure  what size  they are.  To change to 5-40 would be no issue, but it would require having two different sizes of set screws on hand.  I do have a 5-40 tap, but it only for  old threaded wheels  or for Cox tapered hub wheels that I want to use with threaded axles.   

 

 I have 50 or so 4-40 set screws, so I'll just stay with that size.    I figured it would be pretty easy to use the stripped hole for the pilot hole to drill the other side.     I see that is how most  guys have "fixed" stripped wheels successfully.

 

I do appreciate the quick answers.   Always  easy to get answers here.


Matt Bishop

Vintage Cox Slot Cars

#16 Dan Miller

Dan Miller

    Backmarker

  • Full Member
  • PipPip
  • 85 posts
  • Joined: 07-March 09

Posted 12 August 2018 - 12:23 PM

Matt,

 

Do what Mike did and buy a quality HSS tap. The Cleveland brand is just fine for your use. Try for US or Japan made.







Electric Dreams Online Shop