New Pilots for MTH C40-8

[up148]

Excellent results Jim and a good tip on drilling holes to distribute whatever bonding agent you're using. Question on the razor saw blades. Is there a holder or is it a "just be careful" situation?

The GP9 tank modification is coming along pretty good and I trimmed one sideframe to match the prototype. It dawned on my that this is the 1st time since I was a kid building model cars, that I worked this much with plastic. It's been a lot of fun, but I also understand your comments on alignement and needing more than 2 hands.

[Rufus T. Firefly]

Question on the razor saw blades. Is there a holder or is it a "just be careful" situation?

Yes. Those are interesting - holder or what to use them and where do you get them?

[Norton]

For those that have a MTH engine with a swinging pilot and don’t have a 3D printer, know that if your engine has a PS3 version there is a good chance it was done in two rail and a fixed pilot may be available from MTH. Unfortunately their parts section is still under construction with Diesels being the last to be entered so you might have leave a request to be notified when that particular engine is included in the database. Searching on Dash 8 gives zero results at this time.
This PS3 SD70 was purchased in three rail with a swinging pilot. The two rail pilot was available and installed.



4141 was purchased in two rail, 1943 with its two rail pilot.



Pete

[big bad jim]

Question on the razor saw blades. Is there a holder or is it a "just be careful" situation?

Yes. Those are interesting - holder or what to use them and where do you get them?

These razor saws are common in plastic kit and military modeling circles. The CMK brand is available, at a minimum, from Sprue Brothers (https://spruebrothers.com/search-results-page?q=cmk%20saw). The JLC saws are available from UMM-USA (https://umm-usa.com/onlinestore/advanced_search_result.php?keywords=jlc+saw). The blades themselves are essentially identical to each other, so there's no advantage in one versus the other. However, there is a big difference in handles. CMK offers a plastic handle, while JLC offers a wood handle. In my opinion, the plastic handle is too flexible and doesn't really feel that comfortable in my hand. The wood handle is much better, and that would be my recommendation.

Editing to add that Micromark used to carry a knockoff version, but I'm not finding it on their website. It comes up in the Google search results, but it doesn't appear to be available from them currently.

If I remember correctly, the form factor and hole spacing on each brand's blades match each other, so 99% sure you can buy the wood handle and use either brand of blade. Most of my stuff is currently packed up, but I might be able to find some blades to verify. I know where they should be, but that doesn't mean a whole lot in my basement.

Yes, you can use them by hand rather than with the handle, but of course some care needs to be taken. You can also snap them into smaller pieces if you need to saw in tight areas. Same caveat applies, don't end up with a piece in your eye. The blades are very thin at about .005" thickness, so kerfs are very fine. And you can make surprisingly straight cuts with them.

All in all, a great add to the tool box. I would use one of these over a traditional X-Acto or Zona razor saw every time if I had the choice.

I will check for the blades and report back if I find them.
Jim R.

[big bad jim]

Excellent results Jim and a good tip on drilling holes to distribute whatever bonding agent you're using. Question on the razor saw blades. Is there a holder or is it a "just be careful" situation?

The GP9 tank modification is coming along pretty good and I trimmed one sideframe to match the prototype. It dawned on my that this is the 1st time since I was a kid building model cars, that I worked this much with plastic. It's been a lot of fun, but I also understand your comments on alignement and needing more than 2 hands.

The holes are part of the 3d print. I think the original plan might have been to use epoxy to attach the pilots to the shell (wicking CA from the back side might have applied to attaching the steps), so I added the holes so that excess epoxy could squish through. The holes are tapered, narrower at the face that mates with the shell, and opening out slightly as they pass through the part. The goal was to have the excess epoxy fill the holes and form mechanical keys to reinforce the adhesive bond. They would essentially function as conical dovetails

That being said, the holes can also be used as JIm mentions, to flow CA into the joint between shell and printed part. I do feel more comfortable with CA applied both from the outside edge and from the center. Using CA might also allow for a tighter fit between mating surfaces. I haven't used epoxy in this application, so I don't know if it would effectively force a gap between parts due to viscosity.

Jim R.

[big bad jim]

No joy on the saw blades here. However, I did a quick search on Google and at least one non-AI result says the blades and handles are interchangeable.

Everybody should be careful if they go to the sites I linked. There are a lot of neat things to buy besides mini-saws, whether that was the original intention or not.

Jim

[Rufus T. Firefly]

Everybody should be careful if they go to the sites I linked. There are a lot of neat things to buy besides mini-saws, whether that was the original intention or not.

Indeed.