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Sherman part modification
Posted: Mon Jul 05, 2021 11:00 pm
by Tom Miller
Hi Guys,
If you have access to a lathe, this is an easy modification that will make your life much easier if you ever want to remove the 8 x 70 pins in the main bogie. As the instructions say it is nearly impossible to get the pins out once installed. Simply machine a groove appx. .080 wide and .040 deep and .160 back from the end of the pin so that you can put a small screw driver in the slot near where the M3 x 20 hex bolt goes and jack or tap the pin out.
You could also drill and tap a small hole in the end of the pin so you could install a small bolt and pull the pin out. Of course you would see the hole when you are not using it. Hence the reason I went with the slot.
Enjoy your build.
Tom
Re: Sherman part modification
Posted: Tue Jul 06, 2021 12:55 am
by GlenStenhouse
Nice solution. I drilled a small hole right through the support so I can tap it out from behind if ever needed. It does mean I have to detach the assembly from the hull though.
Re: Sherman part modification
Posted: Tue Jul 06, 2021 1:00 am
by Adrian Harris
Good forward planning
Those pins can be difficult to get out on the older Sherman models as well, especially if there's any corrosion along the length of the pin.
Adrian.
Re: Sherman part modification
Posted: Tue Jul 06, 2021 8:26 am
by jwwirds
When you have a lathe it's easier to modify the parts. I have drilled a hole in the pin with a drill and will tap an M2.5 thread in it. The original parts in the HVVS bogeys have a hole there as well. With the thread I can pull out the pin.
Re: Sherman part modification
Posted: Wed Jul 07, 2021 9:59 pm
by GlenStenhouse
Ignore this. Turns out using a bottoming tap was the way to go rather than the supplied one.
Re: Sherman part modification
Posted: Wed Jul 07, 2021 10:12 pm
by Tom Miller
Hi Glenn,
OMG with 4 grooves per pin that is a lot of grooves!
I just today tried to start tapping the holes in the cleats. With so many to do I thought I would do a few at a time over the next several weeks. The tap provided by Armortek is under size by about .013 compared to a new M3 tap I have of my own. The Armortek tap hardly makes any threads and the grub screws are hard to thread in. I am going to contact Armortek and see it this is by design to make the grub screws a tight fit or did I get a faulty tap.
I have only done one cleat so I have not run into the problem you describe.
Tom
Re: Sherman part modification
Posted: Thu Jul 08, 2021 12:37 am
by GlenStenhouse
Tom Miller wrote: ↑Wed Jul 07, 2021 10:12 pm
Hi Glenn,
OMG with 4 grooves per pin that is a lot of grooves!
I just today tried to start tapping the holes in the cleats. With so many to do I thought I would do a few at a time over the next several weeks. The tap provided by Armortek is under size by about .013 compared to a new M3 tap I have of my own. The Armortek tap hardly makes any threads and the grub screws are hard to thread in. I am going to contact Armortek and see it this is by design to make the grub screws a tight fit or did I get a faulty tap.
I have only done one cleat so I have not run into the problem you describe.
Tom
I've the same tap. It's not a finishing tap and since I'm using blue Loctite on each grub screw I figure I'll try a finishing tap instead. The grub screw hexes strip very easily.
Re: Sherman part modification
Posted: Thu Jul 08, 2021 5:15 am
by Jerry Carducci
I haven't even looked at my E8 kit yet so I'm reading this with interest. Could you guys take photos of the parts involved to show the issue with the track assembly? Am I understanding correctly that there's a set of parts we need to thread as we assemble the tracks?? What type of tap is provided; what does the tap have written on it? I'm curious what the class of thread this tap is designed for....
Just preparing for when I start building....
Jerry
Re: Sherman part modification
Posted: Thu Jul 08, 2021 10:33 am
by GlenStenhouse
Jerry Carducci wrote: ↑Thu Jul 08, 2021 5:15 am
I haven't even looked at my E8 kit yet so I'm reading this with interest. Could you guys take photos of the parts involved to show the issue with the track assembly? Am I understanding correctly that there's a set of parts we need to thread as we assemble the tracks?? What type of tap is provided; what does the tap have written on it? I'm curious what the class of thread this tap is designed for....
Just preparing for when I start building....
Jerry
I’ve just done another 30 links tonight and they were a breeze and look near perfect. Difference this time is I went and bought a bottoming tap (finishing tap) and used that instead of the supplied taper tap.
Re: Sherman part modification
Posted: Thu Jul 08, 2021 5:19 pm
by Armortek
I had missed this thread somehow ....
The tracks require M3 grubs to hold the track pin in place. On the real tank the T66 track had pins holding track pin in place but we found that was not a great solution on a scale model. The grubs just need to pinch the pin to hold it in place, they should not be done up too tight and in our testing we found that having just one in place provided the "lock" needed. Nonetheless, we recommend putting in all 4 per track.
The tap provided is an M3 taper tap - it will have a lead in or 7 to 9 threads before cutting at full diameter. There should not be any need to use a bottoming tap as the holes are not blind. One problem with a bottoming tap is that if you are not used to tapping, it is very easy to strip the first threads.
Kian
Re: Sherman part modification
Posted: Thu Jul 08, 2021 6:30 pm
by Tom Miller
The supplied tap is only .104 dia even at the top of the threads. This makes the grub screws difficult to engage. I will tap my parts in a milling machine using a PLUG tap which is .118 at the top of the threads making the grub screws easy to install. I will use blue locktite to hold the grubs from vibrating out. A reversible power drill will work too but be sure start the tap straight. My arthritis will not allow me to hand tap hundreds of holes and I suspect I am not alone with this condition.
Tom
Re: Sherman part modification
Posted: Thu Jul 08, 2021 9:49 pm
by GlenStenhouse
Armortek wrote: ↑Thu Jul 08, 2021 5:19 pm
I had missed this thread somehow ....
The tracks require M3 grubs to hold the track pin in place. On the real tank the T66 track had pins holding track pin in place but we found that was not a great solution on a scale model. The grubs just need to pinch the pin to hold it in place, they should not be done up too tight and in our testing we found that having just one in place provided the "lock" needed. Nonetheless, we recommend putting in all 4 per track.
The tap provided is an M3 taper tap - it will have a lead in or 7 to 9 threads before cutting at full diameter. There should not be any need to use a bottoming tap as the holes are not blind. One problem with a bottoming tap is that if you are not used to tapping, it is very easy to strip the first threads.
Kian
Thanks for the clarity Kian. The taper tap is easier with the lead in but I did find some of the grub screws would strip on the hex before they were anywhere near home in the track. I get why the bottoming tap could be a risk for those not used to tapping. I've been coming right through from the back of the track (inside edge) to ensure perfect threads at the outer edge. Good to know that one grub screw is enough to hold the pin and the rest are belt and braces.